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  • Effect of dynamic storage temperatures on the microstructure of frozen carrot imaged using X-ray micro-CT
    J. Food Eng. (IF 3.197) Pub Date : 2018-11-17
    Victor Vicent, Fatou-Toutie Ndoye, Pieter Verboven, Bart Nicolaï, Graciela Alvarez

    Frozen vegetables are often exposed to dynamic temperature conditions during cold storage and distribution chain. The resulting ice recrystallization leads to microstructural changes, which is directly linked to the final vegetable quality. To this end, X-ray μCT was applied to visualize and quantify 3D ice crystal changes in carrot over a period of two months of frozen storage with dynamically changing temperature. The studied conditions revealed a significant increase in ice crystal size during the storage period. The equivalent diameter of the ice crystals increased from 246 ± 15.9 μm, to 342 ± 13.2 μm, 394 ± 18.5 μm, 525 ± 28.0 μm and 578 ± 27.6 μm at 0 d, 7 d, 14 d, 30 d and 60 d of storage, respectively, while the number of ice crystals decreased. The 3D data on the ice crystals and image analysis presented within this paper provide an insight making it possible to describe microstructure evolution, and for better control cold storage sector of frozen vegetables.

    更新日期:2018-11-17
  • Effect of high cooling and shear rate on the microstructural development of hybrid systems containing diacylglycerols and triacylglycerols of palm origin
    J. Food Eng. (IF 3.197) Pub Date : 2018-11-15
    Iris Tavernier, Ian T. Norton, Tom Rimaux, Aris Lazidis, Koen Dewettinck

    This research explores the potential of diacylglycerol (DAG) and triacylglycerol (TAG) combinations in shortenings. An alternative formulation of a fat blend alters the crystallization behavior, which was investigated with differential scanning calorimetry (DSC) and synchrotron X-ray diffraction. DSC experiments demonstrated that by replacing TAGs with DAGs, crystallization had an earlier onset. However, the lower concentrations of TAGs require more undercooling to fully crystallize, which resulted in more crystallization events during the isothermal step for samples with a higher DAG and lower TAG concentration. A higher DAG concentration also resulted in a more dominant presence of the β polymorphic form. As both DAG and TAG structuring are based on crystal network formation, processing conditions (cooling and shear) will play an important role. Considering processing is essential to understand the behavior of newly formulated fats on an industrial processing line. Samples were prepared both statically, without shear or rapid cooling, and dynamically, under high shear and fast cooling using a bench-top scraped surface heat exchanger. Dynamically crystallized samples containing DAGs were more brittle than samples without DAGs, which can be related to the slower crystallization kinetics of lower TAG concentrations at higher DAG concentrations. The final textural properties of the statically crystallized samples could not predict the properties of the dynamic values. As such, it was demonstrated that preparing crystalline samples using processing conditions similar to those used in an industrial setting is essential to assess applicability of alternatively structured crystalline fat phases.

    更新日期:2018-11-15
  • The influence of food composition and tag orientation on UHF RF IDentification
    J. Food Eng. (IF 3.197) Pub Date : 2018-11-15
    Paolo Barge, Alessandro Biglia, Lorenzo Comba, Paolo Gay, Davide Ricauda Aimonino, Cristina Tortia

    Ultra-high frequency (UHF) radio frequency (RF) labelling is considered to be one of the most promising techniques for automatic identification through all food supply chain phases. However, the efficacy of RF IDentification (RFID) systems has proven critical for some food products. In this paper the role of the composition and the temperature of the food product and of the mutual label-reader orientation on identification performances is investigated. For this purpose, basic food constituents, prepared as solutions (salts, sugars, organic acids and ethanol) at different concentrations and temperatures, were considered and then the identification results were compared to those obtained from whole food products. The results show how the reading performances of UHF RFID systems are influenced by the considered parameters. The reading ranges for the identification of critical food products by UHF RFID systems can be estimated and then improved by considering the composition of the food product directly from the design phase.

    更新日期:2018-11-15
  • Nanoencapsulation of caffeic acid phenethyl ester in sucrose fatty acid esters to improve activities against cancer cells
    J. Food Eng. (IF 3.197) Pub Date : 2018-11-13
    Yongguang Guan, Huaiqiong Chen, Qixin Zhong

    Caffeic acid phenethyl ester (CAPE) is a natural compound with anticancer activities but has low water solubility. In this work, sucrose fatty acid ester (SFAE) was used to nanoencapsulate CAPE in aqueous propylene glycol (PG) with a temperature-cycle method by heating at 90 °C for 20 min and cooling to 21 °C, followed by additional heating at 90 °C for 5 min and cooling to 21 °C. A higher amount of PG facilitated encapsulation with up to 0.1%w/w CAPE in 1.0% w/w SFAE. Additional 0.3%w/w thymol further improved the CAPE loading capability to 0.15%w/w to form nanoparticles smaller than 100 nm and stable in 30 days at 21 °C. Nanoencapsulation enhanced cytotoxicity of CAPE against colon cancer HCT-116 and breast cancer MCF-7 cells, and thymol additionally enhanced the cytotoxicity of CAPE dispersions. This work provides a new approach to nanoencapsulate CAPE in stable aqueous dispersions with improved cytotoxicity.

    更新日期:2018-11-13
  • Fouling and in-situ cleaning of ion-exchange membranes during the electrodialysis of fresh acid and sweet whey
    J. Food Eng. (IF 3.197) Pub Date : 2018-11-13
    Sahar Talebi, George Q. Chen, Benny Freeman, Francisco Suarez, Adrian Freckleton, Karren Bathurst, Sandra E. Kentish

    This work investigated the fouling of ion-exchange membranes during the electrodialysis of sweet and acid dairy whey. Fresh whey was used, rather than solutions made up in the laboratory, giving a unique perspective. While membrane fouling occurred in all experiments, the effects on system performance were limited. Reductions in the current during pure NaCl circulation fell to a minimum of 80% of the original value after 5 h of whey processing. The use of an alkaline concentrate resulted in the strongest increase in system resistance, but the mineral deposits formed appeared to detach readily, thereby reducing these effects. The use of an acidic concentrate gave significantly greater rates of lactic acid removal, which is important in industrial applications. A solution of HCl with a pH of 1.0 ± 0.15 was effective for in-situ cleaning of the mineral deposits. However, protein deposits were not readily removed using the recommended base cleaning formula of 3% NaCl at a pH of 9.2 ± 0.2.

    更新日期:2018-11-13
  • Ultrasound-assisted vacuum drying of nectarine
    J. Food Eng. (IF 3.197) Pub Date : 2018-11-13
    Edilene Souza da Silva, Shirley Clyde Rupert Brandão, Amanda Lopes da Silva, João Henrique Fernandes da Silva, Antônio Carlos Duarte Coêlho, Patrícia Moreira Azoubel

    Convective drying is a widely used conservation process, and in an attempt to improve it, the use of ultrasound and/or vacuum can be an alternative. The objective of this work was to evaluate the influence of ultrasonic waves and vacuum, combined or not, on the drying kinetics at 60 °C and the impact in terms of fruit quality, through the following techniques: ultrasonic assisted drying (USD), vacuum drying (VD), ultrasonic assisted vacuum drying (USVD) and control drying (CD). Six different semi-theoretical drying mathematical models were compared based on their coefficient of determination and mean square error to characterize the drying curves. The application of the USVC technique resulted in a higher rate drying kinetics and a reduction of the process time above 50%. The dehydrated kinetics was successfully described by the Two-terms Exponential model. Effective moisture diffusivities were in the range of 10−9 m2/s and the higher value was obtained for USVD. It was verified that the use of ultrasound (USD and USVD) had a strong influence in obtaining the highest retention of polyphenols, while the use of vacuum (VD and USVD) resulted in lower color differences of processed samples in relation to fresh fruit and lower energy consumption. Thus, the combined use of ultrasound and vacuum can provide satisfactory results.

    更新日期:2018-11-13
  • WHEAT HYDRATION PROCESS INTENSIFICATION BY PERIODIC OPERATION
    J. Food Eng. (IF 3.197) Pub Date : 2018-11-12
    Fernanda Mattioda, Luiz Mario de Matos Jorge, Regina Maria Matos Jorge

    Periodic operation has emerged to increase process performance focused on imposing a transient operating regime, however, it has not been employed in industrial grain hydration yet. Thus, periodic operation for wheat grains hydration process with temperature oscillation as a single manipulated variable was investigated. Periodic hydration experiments were performed considering the temperatures of isothermal hydration, with 10°C and 20°C amplitude. In order to compare the performance of periodic with isothermal operation, hydration experiments were carried out at three mean temperatures: 22ºC, 30ºC and 40ºC. Kinetic models were studied, among them the generalized diffusion model presented the best fit with a maximum deviation of 7%. The hydration at 30º C and 40ºC with 20ºC amplitude intensified the process, with increase in rate mass transfer leading to a 40% reduction in process time. This study proves that periodic operation with temperature oscillation is a highly promising strategy for hydration process intensification.

    更新日期:2018-11-12
  • Determination of properties of black pepper to use in discrete element modeling
    J. Food Eng. (IF 3.197) Pub Date : 2018-11-12
    K. Charithkumar, T.K. Goswami

    Discrete element method (DEM) is widely used to model different granular materials. Knowledge of the input parameters such as material properties and interaction properties that are necessary for modeling is important for getting accurate results. In this study, DEM properties needed to model the black pepper were investigated. Rotating drum apparatus was used to analyze the angle of repose and flow characteristics of black pepper. Experimental and simulated dynamic angle of repose results were compared to select the accurate input parameters. Coefficient of static friction for particle to particle contact and coefficient of rolling friction for particle to wall contact have highest impact on the results. The simulations which best suited the experimental results have values of coefficient of static friction for both particle to particle and particle to wall contact as 0.4 and coefficient of rolling friction between particle to wall contact of 0.03.

    更新日期:2018-11-12
  • New prospects for immersed hollow-fiber membranes in fruit juices microfiltration: Case of grapefruit juice
    J. Food Eng. (IF 3.197) Pub Date : 2018-11-10
    Camille Rouquié, Layal Dahdouh, Michèle Delalonde, Christelle Wisniewski

    Side-stream tubular membranes are largely used to perform cross-flow microfiltration of fruit juices. However, this configuration presents well-known drawbacks (e.g. energy consumption). Immersed membranes configurations have been developed in many fields to overcome these disadvantages. This paper investigates for the first time the possibility of using immersed configuration for fruit juices microfiltration. Firstly, a lab-scale methodology was adopted to characterize the fouling propensity of the juice, while studying the impact of transmembrane pressure, membrane material and the role of large particles on the juice fouling behavior. Secondly, pilot-scale experiments were performed to identify the optimal operating conditions for both configurations. Both lab-scale and pilot-scale experiments suggested that the operating conditions of immersed configuration (no removal of large particles, low pressure and organic membranes) could be suitable to perform juice microfiltration. The optimal permeate flux of immersed configuration was in accordance with the ones reported in other fields. A productivity similar to the one related to side-stream configuration might be obtained through an increase of the filtration surface, made possible by the great packing density and low membrane cost related to immersed configuration. These findings offer new application for immersed membrane configuration in the microfiltration of delicate fruit juices.

    更新日期:2018-11-10
  • Validation and use for product optimization of a phenomenological model of starch foods expansion by extrusion
    J. Food Eng. (IF 3.197) Pub Date : 2018-11-09
    M. Kristiawan, G. Della Valle, K. Kansou, A. Ndiaye, B. Vergnes

    A phenomenological model is proposed for calculating the volumetric (VEI) and radial (SEI) expansion indices, and the anisotropy factor of extruded starch from the melt shear viscosity (η). The model parameters depend on the moisture content (MC), the specific mechanical energy (SME), the melt temperature (T) and the melt storage modulus (E′). The latter represents the contribution of the elongational viscosity. The model is developed using a large data-set covering a wide range of thermomechanical conditions and rheological properties. The cellular structure is also predicted by linking the anisotropy factor to the cellular fineness (F). The model is validated using both a specific validation data-set and data taken from the literature. The simulation results show that η, MC and T influence positively VEI and negatively F, while E’ positively affects both properties. These trends make it possible to adjust the structure of the extruded starches by selecting appropriate processing conditions. Finally, an optimization method based on overlaid contour plots is applied to determine the range of input variables leading to a targeted cellular structure.

    更新日期:2018-11-09
  • Increased stability of alcohol oxidase under high hydrostatic pressure
    J. Food Eng. (IF 3.197) Pub Date : 2018-11-08
    Martina Buchholz, Ali Halalipour, Daoyuan Yang, José I. Reyes-De-Corcuera

    Alcohol oxidase (AOX), in the presence of oxygen, catalyzes the bioconversion of short-chained alcohols into their corresponding aldehydes and ketones. Alcohol oxidase can be used in the production of aldehydes that can serve as precursors of flavor compounds and fine chemicals. However due to AOX's poor stability, its practical industrial or analytical application is limited. Two kinetic inactivation regions suggest that one of AOX's isozymes is more resistant to thermal inactivation at atmospheric or high pressures. The resistant fraction was 4–34 times more stable than the labile fraction. High hydrostatic pressure (HHP) stabilized AOX against thermal inactivation. A 14-fold stabilization was observed at 49.4 °C for the labile fraction at 200 MPa relative to atmospheric pressure. The activation energy of inactivation at 40–160 MPa ranged from 95 to 184 kJ mol−1 for the resistant fraction and from 232 to 402 kJ mol−1 for the labile fraction. The activation volume of inactivation was independent of temperature and of approximately 20 cm3 mol−1.

    更新日期:2018-11-08
  • Tomato Peeling Performance under Pilot Scale Catalytic Infrared Heating
    J. Food Eng. (IF 3.197) Pub Date : 2018-11-08
    Sriram Vidyarthi, Hamed M. El- Mashad, Ragab Khir, Ruihong Zhang, Tara H. McHugh, Zhongli Pan

    Steam and lye peeling methods have been the most commercialized methods in tomatoes industry. However, they are water and energy intensive and have adverse effects on the environment. The infrared (IR) dry-peeling was studied as a sustainable tomato peeling method because it does not require water nor chemicals. An IR peeling system equipped with catalytic IR emitters was designed and constructed. The peeling performance of the system, in terms of peelability, peeling loss, and product quality, was examined under different loading rates using the tomatoes cultivars, Hz 5608, Seminis DRI 319, and Seminis HP 849. Peeling performance was significantly (α = 0.05) affected by surface temperature of tomatoes during IR heating. A tomato surface temperature range of 109 - 115°C (±2°C) during IR heating was found to be optimum for achieving a good peeling performance. Compared to conventional lye peeling, IR dry-peeling produced up to 38.2% firmer peeled tomatoes and up to 12.2% lower peeling loss with a similar or better peeling easiness and more desirable color of the peeled tomatoes.

    更新日期:2018-11-08
  • Comparison of ultra high temperature (UHT) stability of high protein milk dispersions prepared from milk protein concentrate (MPC) and conventional low heat skimmed milk powder (SMP)
    J. Food Eng. (IF 3.197) Pub Date : 2018-11-08
    Jaspal Singh, Sangeeta Prakash, Bhesh Bhandari, Nidhi Bansal

    This study compared the UHT (145 °C for 5 s) stability and fouling behavior of high protein milk dispersions prepared from reconstituted low heat skimmed milk powder (RSMP) and milk protein concentrate powder (RMPC). It was found that RMPC at 10 and 14% protein content was more UHT stable as compared to lower protein content RSMP (3.25, 6.5, 7, 7.5, 8%). Matching the total solids and mineral composition of 7.5-RMPC with 7.5-RSMP by addition of minerals and lactose markedly reduced its UHT stability (UHT run-time reduced to 66 min from >120 min). The RP-HPLC analysis showed increased casein dissociation but similar whey protein aggregation in 7.5-RSMP as compared to 14-RMPC. UHT processing lead to formation of larger particles in case of 7.5-RSMP (1.84 μm D(0.9)) as compared to 14-RMPC (0.23 μm D(0.9)). It was observed that mineral environment affected protein interactions leading to the differences in UHT behavior of RSMP and RMPC.

    更新日期:2018-11-08
  • Pressure-driven infiltration of water and bacteria into plant leaves during vacuum cooling: A mechanistic model
    J. Food Eng. (IF 3.197) Pub Date : 2018-11-07
    Mohsen Ranjbaran, Ashim K. Datta

    Vacuum cooling of leafy greens can quickly lower their temperature, thus efficiently extending their shelf-life. However, passive bacterial infiltration into the leaf through openings such as stomata or wounds during this process presents a risk. This study develops a mechanistic model of stomatal infiltration and elaborates controlling parameters. Water and vapor phases transport in the leaf tissue as a porous medium, with convective flow driven by pressure changes outside the leaf, capillary diffusion of water and molecular diffusion of vapor. Water exchange between symplast and apoplast in the leaf is driven by pressure changes. Bacteria are convected with intercellular water, along with their motility. Heat transfer includes evaporation that varies with pressure. Increased water and bacterial infiltration are primarily caused by longer re-pressurization time, lower initial moisture content of the leaf and larger stomatal pores, and less so by increased vacuum level. Findings should help making vacuum cooling processes microbiologically safer.

    更新日期:2018-11-07
  • Modelling the changes in viscosity during thermal treatment of milk protein concentrate using kinetic data
    J. Food Eng. (IF 3.197) Pub Date : 2018-11-01
    Quang Tri Ho, Kevin M. Murphy, Kamil P. Drapala, Mark A. Fenelon, James A. O'Mahony, John T. Tobin, Noel A. McCarthy

    This work aimed to model the effect of heat treatment on viscosity of milk protein concentrate (MPC) using kinetic data. MPC obtained after ultrafiltration was subjected to different heat treatments with time-temperature. Heat treatment at high temperature and short time (i.e., 100 or 120 °C×30 s) led to a significant increase in viscosity in MPC systems. Second-order reaction kinetic models proved a better fit than zero- or first-order models when fitted for viscosity response to heat treatment. A distinct deviation in the slope of the Arrhenius plot at 77.9 °C correlated to a significant increase in the rate of viscosity development at temperatures above this, confirming the transition of protein denaturation from the unfolding to the aggregation stage. This study demonstrated that heat-induced viscosity of MPC as a result of protein denaturation/aggregation can be successfully modelled in response to thermal treatment, providing useful new information in predicting the effect of thermal treatment on viscosity of MPC.

    更新日期:2018-11-02
  • Comparing the viscoelastic properties of gelatin and different concentrations of kappa-carrageenan mixtures for additive manufacturing applications
    J. Food Eng. (IF 3.197) Pub Date : 2018-11-01
    E.L. Warner, I.T. Norton, T.B. Mills

    Recent interest in personalisation of food through additive manufacturing has identified a need for more information on the formulation and printability of potential ingredients. The printability of mixtures of gelatin and kappa-carrageenan were investigated, design rules were established to determine whether the materials fit the requirements of the process. The gelling temperatures of the systems (24-42°C) and the rheological characteristics including: flow profiles, evolution of elastically dominated structures and frequency dependent behavior, were established. The mixtures were subsequently printed at two temperatures, just above and much greater than, their gelling temperatures. Analysis showed rheological behaviour accompanying the coil-helix transition were key to printing the product in a well-defined manner. The printing fidelity was related to the magnitude of the storage modulus, which needed to be greater than 23 kPa, as well as the rapid formation of an elastic network, recovering at least 73% of the maximum storage modulus within 200s.

    更新日期:2018-11-02
  • Microfluidic fabrication of wrinkled protein microcapsules and their nanomechanical properties affected by protein secondary structure
    J. Food Eng. (IF 3.197) Pub Date : 2018-10-30
    Yiming Feng, Youngsoo Lee

    Wrinkled microcapsules have attracted great interest due to their distinguished features, including enhanced adhesion propensity and release profiles. These features could be beneficial for food-related applications and improve the bioavailability of encapsulated compounds by promoting their attachment to epithelium. However, the fabrication of such microcapsules with food-grade materials has been met with limited success. In this study, a facile approach to produce wrinkled microcapsules using a food-grade protein, zein, is proposed. Internal phase separation was used to form zein microcapsules and three acids (phytic acid, citric acid, and succinic acid) were incorporated at two concentration levels (10 mM and 20 mM) to modify the secondary structure of zein in the microcapsules. The results showed that the mechanical properties of the microcapsules, which were characterized by nanoindentation, were greatly dependent on the protein secondary structure, particularly the α-helix structure. The morphology of the microcapsules was evaluated by image analysis. An extensive wrinkle was observed on the surfaces of the microcapsules with high viscoplasticity. Among the three acids used in this study, phytic acid significantly increased the degree of wrinkling and viscoplasticity of the microcapsules. Further characterization with circular dichroism and wide-angle X-ray scattering suggested that a less ordered zein secondary structure was formed in the samples prepared using phytic acid than in those prepared using other acids or without acid, which further supports the hypothesis that the nanomechanical properties and degree of wrinkling are associated with the protein secondary structures.

    更新日期:2018-10-31
  • Formation and characterization of spray dried coated and uncoated liposomes with encapsulated black carrot extract
    J. Food Eng. (IF 3.197) Pub Date : 2018-10-29
    Burcu Guldiken, Annika Linke, Esra Capanoglu, Dilek Boyacioglu, Reinhard Kohlus, Jochen Weiss, Monika Gibis

    The degradation of black carrot anthocyanins (BCE) under stress conditions as under the effect of a spray drying process was evaluated in different encapsulation systems (extract, chitosan-coated and uncoated liposomes and chitosan-extract-mixture). The encapsulation efficiencies of liposomes prepared by high-pressure homogenization containing 2% lecithin with 0.1%, 0.2%, and 0.4% extract were found as 86.6% ± 16.1%, 82.2% ± 9.7%, and 46.9% ± 6.3%, respectively. The extract-loaded liposomes (0.2% extract) were chosen for liposomes considering further dilutions. The chitosan-coated liposomes were generated with 0.1% chitosan according to their particle size (82.7 ± 1.5 nm) and zeta potential of 51.4 ± 0.6 mV. All samples were found to be physically stable after the spray drying process. In addition, SEM images of the liposomal powder particles showed a uniformly wrinkled surface that would indicate stability of liposomal systems against spray drying. However, the liposomal samples showed lower stability compared to the BCE and BCE-chitosan mixtures according to the biochemical analysis of the reconstituted powders.

    更新日期:2018-10-30
  • Effects of Liquid Smoke Infusion on Osmotic Dehydration Kinetics and Microstructural Characteristics of Apples Cubes
    J. Food Eng. (IF 3.197) Pub Date : 2018-10-29
    Felix Akharume, Kaushlendra Singh, Litha Sivanandan

    The influence of the addition of Refined Liquid Smoke (RLS) (1% w/w) to a sugar-based Osmotic Solution (OS) (42 °Brix) on the osmotic dehydration (OD) kinetics and microstructure of apple cubes was evaluated. Cubes of 10 mm were cut from peeled apples and subjected to OD at the incubation temperature of 50 °C and over a range of OD duration (5 – 240 min.). Influence of addition of RLS was evaluated for selected OD kinetic variables: solid gain (SG), water loss (WL), dry matter (DM), soluble solid content (SSC), and moisture content. Results showed that addition of RLS significantly increased SG, DM, and SSC in apple cubes compared to pure sugar solution-based OD. As a result of RLS addition, the sugar concentration in apple cubes increased from 9.90 °Brix to 33.8 °Brix whereas it was 31.02 °Brix for the pure sugar solution-based OD. Further kinetic analysis showed that the effective diffusion coefficient for SG was same (4.40 x 10-10 m2/s) irrespective of the addition of RLS; however, the effective diffusion coefficients for WL were different (2.94 x 10-10 m2/s for pure sugar-based OD and 4.40 x 10-10 m2/s for RLS-added OD). Microstructural visualization of the dried apples revealed that the addition of the RLS might have prevented the collapsed of cell wall up to the first hour of OD.

    更新日期:2018-10-30
  • Interpretation and rapid detection of secondary structure modification of actomyosin during frozen storage by near-infrared hyperspectral imaging
    J. Food Eng. (IF 3.197) Pub Date : 2018-10-29
    Weiwei Cheng, Da-Wen Sun, Hongbin Pu, Qingyi Wei

    Secondary structure of proteins is closely related to the overall quality of meat. The sequence of the changes in chemical bonds caused by secondary structure modification and rapid detection method of secondary structure fractions was investigated by near-infrared hyperspectral imaging combined with generalized (G2D-CS) and heterospectral (H2D-CS) two-dimensional correlation analysis in this study. Synchronous and asynchronous spectral results from G2D-CS analysis indicated that, as α-helix fraction decreasing, the spectral intensity of N-H stretching changed before that of the C-H and O-H, and the spectral fluctuation of O-H stretching occurred after the carbonyl related C-H band and before those aliphatic and aromatic C-H band. Feature wavebands identified by H2D-CS analysis obtained good results with R2CV of 0.836 in predicting α-helix fractions. The results of this study are useful for interpreting the secondary structure modification process of proteins during frozen storage and monitoring the secondary structure fraction in a rapid way.

    更新日期:2018-10-30
  • High moisture extrusion of wheat gluten: Modeling the polymerization behavior of wheat gluten in the screw section of the extrusion process
    J. Food Eng. (IF 3.197) Pub Date : 2018-10-29
    Valerie L. Pietsch, Frederic Schöffel, M. Rädle, Heike P. Karbstein, M. Azad Emin

    Thermomechanical treatment in the screw section of the extrusion process has a major impact on wheat gluten polymerization and subsequent structuring mechanisms leading to the formation of anisotropic product textures. Therefore, this study presents a modeling approach that allows to predict wheat gluten polymerization considering non-isothermal conditions by measuring material temperatures and temperature variations along the screws section. Since no study exists considering modeling of the reaction behavior of plant proteins during extrusion processing, the predictive accuracy of the non-isothermal approach was compared to another approach assuming isothermal conditions by measuring material temperature at die exit and mean residence time. Results show that the approach considering non-isothermal conditions significantly improved the predictive accuracy of wheat gluten polymerization as compared to the results from isothermal modeling.

    更新日期:2018-10-30
  • Improving heat and fat bloom stabilities of “dark chocolates” by addition of mango kernel fat-based chocolate fats
    J. Food Eng. (IF 3.197) Pub Date : 2018-10-25
    Jun Jin, Qingzhe Jin, Xingguo Wang, Casimir C. Akoh

    Mango kernel fat (MKF)-based fats characterized as high levels of 1,3-distearoyl-2-oleoyl-glycerol (StOSt), including physical blend (PB), interesterified blend (IB) and its counterpart non-interesterified blend (Non-IB), were used to prepare “dark chocolates” by optimizing tempering process. High melting StOSt promoted thermal properties in PB-, IB- and Non-IB-chocolates compared to traditional cocoa butter (CB)-chocolate. The three MKF-based chocolates were solid at 32 °C and became runny at 37 °C and may avoid leaving waxiness in the mouth, whereas CB-chocolate completely lost its shape at 32 °C. Further bloom tests showed that CB-chocolate was covered with white-greyish haze within 15 days, Non-IB chocolate exhibited white-round-shaped stripe around 45 days, while only slight bloom was observed in PB and IB-chocolates after 60 day-storage. The significant improvements on heat and fat bloom stabilities of PB- and IB-chocolates were attributed to their optimal triacylglycerol compositions (StOSt = 55.7–60.9%, 1-palmitoyl-2-oleoyl-3-stearoylglycerol = 21.1–23.8%, and 1,3-dipalmitoyl-2-oleoylglycerol = 8.2–11.1%) and plate-like growth at 20 °C. The plate-like growth-crystals could prevent bloom from fat recrystallization and further transformation into β1 polymorph.

    更新日期:2018-10-26
  • Application of nozzleless electrostatic atomization to encapsulate soybean oil with solid substances
    J. Food Eng. (IF 3.197) Pub Date : 2018-10-24
    Chinatsu Mori, Kazunori Kadota, Yuichi Tozuka, Atsuko Shimosaka, Mikio Yoshida, Yoshiyuki Shirakawa

    Many oil-encapsulation techniques, in which particles are used to improve the stability of polyunsaturated fatty acids (PUFAs) against oxidation and the handling of oils, have been reported. We developed techniques for encapsulating oil within powders with a liquid–liquid interfacial crystallization by using nozzleless electrostatic atomization. This process was used to prepare fine spherical encapsulated soybean oil particles with a microscale single process. An inexpensive soybean oil containing PUFAs was chosen as the oil phase. W/O emulsion systems were synthesized via the electrostatic atomization process. After the W/O emulsions were prepared, glycine and taurine well provided in supplements were used as the wall material for encapsulation. The soybean oil content of the encapsulated particles and their stability at high temperatures were evaluated. The oxidative stability of the soybean oil during high-temperature storage was improved for the encapsulation.

    更新日期:2018-10-24
  • Effect of egg yolk on the textural, rheology and structural properties of egg gels
    J. Food Eng. (IF 3.197) Pub Date : 2018-10-22
    Mengqi Zhang, Junhua Li, Cuihua Chang, Chenying Wang, Xin Li, Yujie Su, Yanjun Yang

    Egg gel is the combined gelation of egg white (EW) and egg yolk (EY); its properties depend on the fixed ratio of EW and EY in shell egg. This study investigated the gelation properties of egg mixtures in artificial blends to explore innovative egg solutions catering to the market demands and provide guidance for the production of creative egg products. Results showed that solubility of samples decreased with the increase of EY proportion while solid content increased. More surface hydrophobicity and total SH group increases were observed with higher EY proportion. Rheological tests suggested that adding EY decreased samples’ initial G’ values. Egg gel containing 20% EY presented the largest hardness value, which seems to be related to the fine gel network microstructure. Besides, the springiness and water-holding capacity of gels gradually increased with EY addition, which may be the result of dense microstructure and high solid content of EY.

    更新日期:2018-10-22
  • A review of magnetic separation of whey proteins and potential application to whey proteins recovery, isolation and utilization.
    J. Food Eng. (IF 3.197) Pub Date : 2018-10-19
    Paula Nicolás, María Luján Ferreira, Verónica Lassalle

    Cheese whey (CW) is a voluminous effluent generatin environmental and economic impact in milk producing countries. Proteins from CW are useful for biotechnological applications. Available procedures to purify CW are complex and expensive. Magnetic nanotechnology emerges as an alternative to attain this goal. Magnetic nanoparticles are easily and economically prepared and can be formulated to selectively bind proteins in whey. Magnetic decantation allows simple and fast protein isolation by means of a magnet. The extra advantage is the possibility to regenerate and reuse the magnetic material in successive cycles. In this contribution, competitiveness of magnetic nanodevices is reviewed as a potential tool for the valorization and remediation of milk industry wastes. A critical analysis of recompiled data is included comparing magnetic nanomaterials with the current technologies intended for CW treatments. The purpose is to determine the most important factors that carry towards an effective recovery of proteins for diverse applications.

    更新日期:2018-10-22
  • Evaluation of Vis-NIR hyperspectral imaging as a process analytical tool to classify brined pork samples and predict brining salt concentration
    J. Food Eng. (IF 3.197) Pub Date : 2018-10-20
    Achata EM, Inguglia ES, Esquerre CA, Tiwari BK, O’Donnell CP

    Hyperspectral imaging in the visible and near infrared spectral range (450-1664 nm) coupled with chemometrics was investigated for classification of brined and non-brined pork loins and prediction of brining salt concentration employed. Hyperspectral images of control, water immersed and brined (5, 10 or 15% salt (w/v)) raw and cooked pork loins from 16 animals were acquired. Partial least squares (PLS) discriminative analysis models were developed to classify brined pork samples and PLS regression models were developed for prediction of brining salt concentration employed. The ensemble Monte Carlo variable selection method (EMCVS) was used to improve the performance of the models developed. Partial least squares (PLS) discriminative analysis models developed correctly classified brined and non-brined samples, the best classification model for raw samples (Sen = 100%, Spec = 100%, G = 1.00) used the 957–1664 nm spectral range, and the best classification model for cooked samples (Sen = 100%, Spec = 100%, G = 1.00) used the 450-960 nm spectral range. The best brining salt concentration prediction models developed for raw (RMSEp 1.9%, R2p 0.92) and cooked (RMSEp 2.6%, R2p 0.83) samples used the 957-1664 nm spectral range. This study demonstrates the high potential of hyperspectral imaging as a process analytical tool to classify brined and non-brined pork loins and predict brining salt concentration employed.

    更新日期:2018-10-22
  • Pectin-whey protein complexes vs. small molecule surfactants for stabilization of double nano-emulsions as novel bioactive delivery systems
    J. Food Eng. (IF 3.197) Pub Date : 2018-10-18
    Pouria Gharehbeglou, Seid Mahdi Jafari, Hamed Hamishekar, Aziz Homayouni, Habibollah Mirzaei

    Water-in-oil-in-water (W1/O/W2) double emulsions are one of the most efficient nutraceutical delivery systems. Our main objective was to compare some emulsion properties of double nano-emulsions loaded with gallic acid in W1 phase. Polyglycerol polyricinoleate (PGPR), and pectin-WPC or/Tween 80 were applied as emulsifiers in W1-O and O-W2 interfaces, respectively. Our results revealed that complex of pectin-WPC had the same resistance against sedimentation and creaming as Tween 80. The particle size of double emulsions produced by Tween 80 and pectin-WPC were in the range of 98–577 and 100–1520 nm, respectively. Z-potential of double emulsions prepared with pectin-WPC were more negative than −30 mV; so they were more stable during the long term storage. The optimum conditions for preparing WPC-pectin stabilized delivery systems were determined as 5, 75 and 20 (wt. %) PGPR, soybean oil and deionized water, respectively for internal W1/O nano-emulsion; and 1, 4, 79 and 16 (wt. %) pectin, WPC, deionized water, and internal nano-emulsion, respectively for the W1/O/W2 emulsions. Student's t-test analysis revealed that except for z-potential, there were no significant differences between emulsifiers (pectin-WPC and Tween 80). The present study demonstrates that pectin-WPC complex can be used as an appropriate emulsifier comparable with Tween 80 for stabilizing double emulsions.

    更新日期:2018-10-19
  • Analysing the dynamics of quality loss during precooling and ambient storage of pomegranate fruit
    J. Food Eng. (IF 3.197) Pub Date : 2018-10-18
    Matia Mukama, Alemayehu Ambaw, Tarl Michael Berry, Umezuruike Linus Opara

    In this paper the spatiotemporal profile of quality loss of pomegranate fruit (cv. Wonderful) was investigated during precooling and simulated shelf conditions. The effects of relative humidity (RH) inside the cold room, polyliner inside the packaging and stack orientation on fruit quality loss were studied. Weight loss during the precooling operation ranged from 0.01 to 0.06% h-1 of the initial fruit weight and was highest in stack without liner and inside non-humidified room (0.06% h-1). It was observed that fruit weight loss during precooling was minimised best in liner-based packaging. Results of the shelf life study demonstrated the importance of room humidification to preserve fruit quality. Storing fruit in a room at 95% RH minimised weight loss and best maintained fruit colour, firmness, size and chemical quality attributes of pomegranates. On the other hand, fruit stored at ambient condition (65% RH) up to 30 days had excessive weight loss (up that 29.13 ± 1.49%), which led to shrivelling, deformed appearance and considerably reduced overall visual quality.

    更新日期:2018-10-18
  • Combined industrial olive oil extraction plant using ultrasounds, microwave, and heat exchange: Impact on olive oil quality and yield
    J. Food Eng. (IF 3.197) Pub Date : 2018-10-15
    Tamborrino Antonia, Romaniello Roberto, Caponio Francesco, Giacomo Squeo, Leone Alessandro

    In this study, an industrial combined plant (ICP) constructed from a low-frequency ultrasound device, microwave apparatus and heat exchanger is employed to investigate the real possibility of introducing these innovative technologies to the olive oil extraction process and evaluating their influence on olive oil quality and yield. The novelty of this study lies in the simultaneous use of these three technologies to condition the olive paste in a real olive oil extraction plant. Different olive paste treatments were compared in order to define the effects on the olive oil quality and yield. The use of a spiral heat exchanger in addition to the malaxer reduced the malaxation time to 20 min, and with the microwave apparatus it was possible to obtain an entirely continuous process, without interruptions, from the milling phase to the solid-liquid separation phase. The internal spiral aids in moving the paste from the input to output section, resulting in limited operating pressure. Using the ICP device led to an average increase in extractability ranging from 2.30 to 3.85% with respect to the control thesis, for the Arbosana and Arbequina varieties, respectively, but this difference was not statistically significant. Regarding the virgin olive oil (VOO) quality, the use of the ICP did not affect the marketable parameters and total phenol content, while in terms of the process efficiency, the ICP obtained a higher value than the conventional process and improved the extraction yield.

    更新日期:2018-10-16
  • Multi-objective optimization based on the utopian point method applied to a case study of osmotic dehydration of plums and its storage
    J. Food Eng. (IF 3.197) Pub Date : 2018-10-16
    Agnieszka Szaparaga, Marta Stachnik, Ewa Czerwiсska, Sіawomir Kocira, Maria Dymkowska-Malesa, Marek Jakubowski

    In this study, authors present the results of multi-objective optimization of parameters of osmotic dehydration of plum and its storage conditions. Multi-objective optimization is a method of multiple criteria decision making involving more than one objective function to be optimized simultaneously. The objective functions are conflicting and an infinite number of Pareto optimal solutions are possible. A solution is Pareto optimal if none of the objective functions can be improved in value without degrading some of the other objective values. All Pareto optimal solutions are considered equally good, the choice is subjective. To limit subjectivism the Utopian point method and Multidimensional Euclidean metrics was applied. The idea is to minimize the distance between the non-existing Utopian solution and Pareto-optimal solutions. This approach is offered in relation to the cost of osmotic solution, time of dehydration process, and duration of storage by considering the following factors: content of dry mass, reducing sugars, and extract, as well as the amount leak after thawing. Authors made the choice of minimizing cost with simultaneous maximization of quality of the product. Pareto-optimal solutions were obtained with the use of MATLAB program. Furthermore, the method of multidimensional Euclidean preferences was applied to find the set of best parameters for the production process. Two sets of results were obtained. First is the set of optimal process parameters is in relation to cost minimizing: concentration of an osmotic solution: 0.55%; time of osmotic draining:, 1 h 42 min; time of the cold storage: 6 months; and the method of thawing: microwave. Second set is focused on quality and process parameters are: the concentration of an osmotic solution: 0.65%; time of osmotic draining:3 h; time of the cold storage: 5 months and 21 days; method of thawing: microwave.

    更新日期:2018-10-16
  • The application of dehumidified air in rapeseed and honeydew honey spray drying - process performance and powders properties considerations
    J. Food Eng. (IF 3.197) Pub Date : 2018-10-13
    Aleksandra Jedlińska, Katarzyna Samborska, Agata Wieczorek, Artur Wiktor, Ewa Ostrowska-Ligęza, Wojciech Jamróz, Krystyna Skwarczyńska-Maj, Dariusz Kiełczewski, Łukasz Błażowski, Marcin Tułodziecki, Dorota Witrowa-Rajchert

    Rapeseed and honeydew honey were spray dried by dehumidified air, with NUTRIOSE® as a drying carrier, to create a product with prebiotic properties, in line with current "clean label" trend. Because of the low inlet air humidity, drying temperature was decreased (inlet/outlet: 75/50°C). Such an approach gave the possibility to reduce the amount of added carrier. Thus, honey powders containing 80% of honey solids were produced and characterized. Drying was performed with very high powder recovery (84.4-93.9%), especially in the variants containing 80% of honey solids. Although there were some differences in the physical properties between powders produced by the application of dehumidified air and by the traditional spray drying (but containing the same ratio of honey to carrier), the overall properties were comparable: low water content (below 2.5%) and low water activity (below 0.2), medium or high cohesiveness, high hygroscopicity (above 20%), bed porosity between 50 and 70%.

    更新日期:2018-10-14
  • In-line rheological and microstroctural characterization of high moisture content protein vegetable mixtures in single screw extrusion
    J. Food Eng. (IF 3.197) Pub Date : 2018-10-13
    Yogesh L.N. Thadavathi, Sophia Wassén, Roland Kádár

    To increase the utilization of side-streams from the food industry more investigation of multiple protein systems could be beneficial, complementary to the available extensive studies on single sourced protein isolates. Here, high moisture content protein-rich side streams were investigated in single screw extrusion. Vegetable protein mixtures comprising of potato protein, oat protein and wheat bran were considered. Potato starch and potato fibers were used as structuring agents. Microstructurally, all compositions were dominated by protein aggregates. The structural agents enhanced the interconnected starch phase and/or additionally introduced fiber aggregates, with little apparent influence on the protein aggregates size and distribution. The moisture content was found to exert a dominant influence on the shear viscosity of the compositions. In addition, a saturation behavior of the power law parameters over 44% moisture content was apparent in the presence of the structural agents. A better knowledge of industrial side-streams processability could increase their use in novel food products and exploited to create products with improved nutritional profiles.

    更新日期:2018-10-14
  • Soft Lubrication Characteristics of Microparticulated Whey Proteins used as Fat Replacers in Dairy Systems
    J. Food Eng. (IF 3.197) Pub Date : 2018-10-13
    M.L. Olivares, K. Shahrivar, J. de Vicente

    In this work the fat mimicking mechanism of microparticulated whey proteins (MWP) in milk-based systems was studied using rheological and tribological techniques. Flow curves and friction measurements in a soft contact of skim milk-MPW dispersions (SM-MPW) and skim milk-dairy fat emulsions (SM-DF) at different concentrations (3, 6, 9, 12, 15, 18 and 20% w/w) and temperatures (25°C and 37°C) were carried out and compared. Friction coefficient curves of SM-MPW dispersions as a function of the product of entrainment speed and viscosity collapsed into a single master curve in the mixed and elastohydrodynamic (EHL) regimes when the high shear viscosity values as obtained through Carreau-Yasuda model were used. This suggests that the dispersions as a whole entrained in the contact. However, in the case of SM-DF emulsions, a very good collapse is obtained if only SM is assumed to pass through the contact. Simulations of friction coefficient within the EHL region showed a reasonably good continuity of the experimental data for SM-MPW dispersions and SM-DF emulsions. Finally, it was observed that friction levels attained with MPW proteins and DF at typical speeds involved in oral processing were comparable, hence demonstrating the capability of SM-MPW proteins dispersions to imitate DF in milk-based systems from a lubrication point of view.

    更新日期:2018-10-14
  • Effect of porous structure and spreading pressure on the storage stability of red onion microcapsules produced by spray freezing into liquid cryogenic and spray drying
    J. Food Eng. (IF 3.197) Pub Date : 2018-10-13
    L.A. Pascual-Pineda, M.P. Rascón, M.X. Quintanilla-Carvajal, M. Castillo-Morales, U.R. Marín, E. Flores-Andrade

    Red onion microcapsules were produced by spray freezing into liquid cryogenic (SFLC) and spray drying (SD) and their anthocyanin contents were evaluated kinetically at different water activities ( a w ) at 35 °C. The spreading pressure-area isotherms were determined at 35 °C. These isotherms provide important information about the different phases of adsorbed water present in SD and SFLC capsules, which can be related to minimal integral entropy and to chemical stability during storage. The porosity of the microcapsules was examined using low-temperature adsorption of nitrogen. The maximum anthocyanin stability occurred at a w from 0.108 to 0.318, and 0.108 to 0.515, for SD and SFLC, respectively. SD products were nonporous whereas SFLC were mesoporous. The tendency to contraction of the adsorbed water film was compared with the minimum integral entropy and was proposed as a new stability criterion to predict suitable storage conditions of dehydrated foods.

    更新日期:2018-10-14
  • Effect of inlet air drying temperatures on the physicochemical properties and antioxidant activity of whey protein isolate-kale leaves chlorophyll (WPI-CH) microcapsules
    J. Food Eng. (IF 3.197) Pub Date : 2018-10-12
    Zhi-Hong Zhang, Huadong Peng, Haile Ma, Xin-An Zeng

    The whey protein isolate-kale leaves chlorophyll (WPI-CH) microcapsules were prepared by spray drying in this work. Results from Fourier transform infrared spectra (FT-IR) showed that WPI-CH microcapsules were successfully obtained by forming the hydrogen bonds between WPI and chlorophyll, which resulted in shifting of the absorption band at 1074 cm−1 to 1078 cm−1 with a new absorption band revealed in 1049 cm−1. Effect of inlet air drying temperatures on the physicochemical properties and antioxidant activity of WPI-CH microcapsules were investigated. The result revealed that the moisture content of WPI-CH (20% addition) microcapsule was decreased by 21.1% with the inlet air drying temperature increased from 120 to 180 °C. Moreover, the encapsulation efficiency and solubility of chlorophyll were enhanced by 3.78% and 7.79%, respectively. Furthermore, DPPH scavenging capacity of WPI-CH microcapsules under different addition of chlorophyll were increased from 42.9% to 74.3%, 52.7%–82.7% and 71.8%–85.3%, respectively.

    更新日期:2018-10-12
  • Thermal transitions and enthalpic relaxations as related to the stability of microencapsulated paprika powders
    J. Food Eng. (IF 3.197) Pub Date : 2018-10-09
    Josefina Porras-Saavedra, Leonardo Cristian Favre, Liliana Alamilla-Beltrán, María Florencia Mazzobre, Gustavo Fidel Gutiérrez-López, María del Pilar Buera

    Present work investigates the effect of thermal transitions and enthalpy relaxation phenomenon on the physico-chemical stability of paprika microencapsulated powders. Wall materials were combinations of soy protein isolates, maltodextrin and gum arabic. Powders stability was evaluated through the solid-water interactions, determined by sorption kinetics, calorimetry and color changes. The water sorption isotherms were well described by the GAB model. Below the critical condition, aw 0.6 and water content 11 % (d. b.) the systems were in amorphous state at 25 °C, and enthalpy relaxations were detectable as endothermal events in the stored samples. The magnitude of the enthalpy relaxations increased with storage temperature below Tg and with time of storage. In the amorphous microencapsulates, luminosity changes measured as (Lo*-L*) values decreased as a function of time and aw, indicating pigment decoloration. The kinetics of the enthalpy relaxations changes, instead of the punctual values of the variables under study, were related to the dynamics of deteriorative changes. It can be concluded that enthalpy relaxation phenomenon can be established as a criterion for defining storage conditions or predict changes in microencapsulated and other systems that have to be stored in the glassy state.

    更新日期:2018-10-10
  • Solubility of functional compounds in supercritical CO2: Data evaluation and modelling
    J. Food Eng. (IF 3.197) Pub Date : 2018-10-08
    Paul Antonie, Camila G. Pereira

    The solubility data of functional compounds in supercritical carbon dioxide were compiled and discussed. The investigation included essential oils, phenolic compounds, carotenoids, tocopherols, carboxylic acids, alkaloids and vitamins. The data were correlated with four mathematical models. The parameters of each model were adjusted for each compound using the experimental data from literature. From the evaluation of the compiled data, it was possible to observe that the essential oils are the most soluble compounds and the phenolic compounds are the least soluble compounds in supercritical CO2, in the range of temperatures and pressures that were evaluated. In relation to the models, it was observed that the prediction of the solubilities of the biocompounds in supercritical fluids was acceptable for all the models, with the Jiang et al. equation being the model that presented the best results to predict the solubility for all functional groups.

    更新日期:2018-10-09
  • Application of electrical impedance spectroscopy and rheology to monitor changes in olive (Olea europaea L.) pulp during cold-pressed oil extraction
    J. Food Eng. (IF 3.197) Pub Date : 2018-10-09
    Shuo Yang, Ian Hallett, H. Eustina Oh, Allan B. Woolf, Marie Wong

    Cellular changes during cold-pressed extraction of ‘J5’ olives (Olea europaea L.) were investigated to better understand factors that affect oil release and recovery. Electrical impedance, electrical conductivity, rheological flow properties and light microscopy were used to monitor flesh or pulp structure at defined steps during the extraction process (grinding, malaxing and decanting). Light microscopy revealed most parenchyma cells in the flesh were ruptured in the grinding step. A significant reduction in electrical impedance concurrent with an increase in conductivity of tissue that occurred when cells were ruptured during the grinding process. Malaxing assisted aggregation of oil into larger droplets, observed by microscopy. Increasing malaxing time resulted in a decrease in the storage modulus (G’) of olive pulp, which correlated with the oil droplets in the olive paste coalescing together and becoming larger. The extraction process can be monitored with different techniques to assist with improved extraction yields.

    更新日期:2018-10-09
  • Stochastic modeling of expansion of starchy melts during extrusion
    J. Food Eng. (IF 3.197) Pub Date : 2018-10-05
    Pavan Harshit Manepalli, John M. Mathew, Sajid Alavi

    The objective of this study was to develop a stochastic model for flow behavior of starchy melts inside extruder barrel and bubble growth dynamics after exiting the extruder and obtain the variability of the end product characteristics, using the variability of operating conditions (screw speed, water injection) and material properties (consistency coefficient). The model was written in Visual Basic and experimentally validated using pilot-scale twin screw extrusion of corn meal. Process and product data was measured at different in-barrel moisture contents (19–28 g/100g dry basis) and screw speeds (250–330 rpm). The variability in input parameters was characterized using a Data Acquisition System and Monte Carlo Simulation was used to incorporate this variability into the model. The coefficient of variation (CV) of output parameter i.e. expansion ratio obtained from the model (0.24–3.11%) compared well with the CV of the experimental expansion ratio (2.54–4.89%). This model was also used to conduct sensitivity analysis for understanding which raw material and process characteristics contribute most to product variability. Sensitivity analysis showed that the relative increase in CV in expansion ratio was greatly affected by the CV increase in water added in extruder (1.605) compared to screw speed (0.0325) and consistency index coefficient (0.25).

    更新日期:2018-10-06
  • Manothermosonication: Inactivation of Escherichia coli and Staphylococcus aureus
    J. Food Eng. (IF 3.197) Pub Date : 2018-10-05
    Thunthacha Chantapakul, Ruiling Lv, Wenjun Wang, Watcharapong Chummalee, Tian Ding, Donghong Liu

    Manothermosonication (MTS) has been one of the key alternatives to current pasteurization techniques. This study evaluates the effectiveness of the MTS system in the inactivation of two opposite gram-stained bacteria: E. coli ATCC 25922 and S. aureus ATCC 25923. Samples were treated with different conditions, including mild heat (T, 50 °C, 100 kPa), sonication (US, 30 °C, 100 kPa), thermosonication (TS, 50 °C, 100 kPa), manosonication (MS, 30 °C, 400 kPa), and manothermosonication (MTS, 50 °C, 400 kPa) in pulse mode for precise temperature control. After 5 min, the viability of E. coli and S. aureus treated with MTS decreased by 6.25 and 4.55 log CFU/mL, and the maximum decrease in non-linear Biphasic decimal reduction (D-value) of the sensitive population was 91.35% and 94.24%, respectively. Since pressurized ultrasound generated excess heat of up to 0.88 °C/sec, an inactivation experiment employing such heat resulted in minimal linear D-values of 0.17 (E. coli) min and 0.18 min (S. aureus) with power intensity of 3.69 Watt/mL thermally or 14.29 Watt/mL electrically. All experiments indicated that gram-positive S. aureus was more resistant to sonication than gram-negative E. coli, but the lethality rate became more comparable with more violent cavitation.

    更新日期:2018-10-06
  • Identification of complex glass transition phenomena by DSC in expanded cereal-based food extrudates: Impact of plasticization by water and sucrose
    J. Food Eng. (IF 3.197) Pub Date : 2018-10-06
    Supuksorn Masavang, Gaëlle Roudaut, Dominique Champion

    The physical state and mechanical properties of extruded cereal based products were studied as a function of sucrose content and relative humidity (RH) to evaluate how the presence of sucrose affects glass transition temperature ( T g ), sorption isotherm, and texture parameters. Extrudates were prepared with different sucrose content (0–20 %wt). Sorption isotherm showed the water content of extrudates decreased when product contains high sucrose at low aw range and the inverse effect was observed at high aw. T g s were determined using differential scanning calorimetry (DSC) and two transitions were detected on the heat flow first derivative curve. Addition of sucrose or water decreased both T g s in extrudates. Young's modulus showed water acts as anti-plasticizer at low aw, while shows plasticizing effect at high aw. A stability map can explain the brittle-ductile transition occurred while it was below T g .

    更新日期:2018-10-06
  • Shear and Extensional Rheological Characterization of Thickened Fluid for Dysphagia Management
    J. Food Eng. (IF 3.197) Pub Date : 2018-10-05
    E.K. Hadde, J. Chen

    Thickened fluids are used in the medical management of individuals who suffer from swallowing difficulties (known as dysphagia). Recent studies show that understanding the rheological properties of thickened fluids is advantageous in designing better-controlled fluids. Whilst the rheological behavior of thickened fluids in shear deformation has been studied by several authors, studies on their extensional behavior are limited, despite their critical importance in influencing bolus flow and swallowing. Our aim in this work was to rheologically characterize extensional deformation of dysphagia fluids thickened with different types of commercial thickeners at varying concentrations using a filament stretching and break-up device. It was observed that the extensional viscosity increased and became more cohesive as the thickener concentration was increased. Additionally, it was observed that for similar shear viscosity at 50 s-1, the extensional viscosity of the fluid was dependent on the type of thickener. This study confirms that by thickening fluid with different types of thickeners, the cohesiveness of the fluid may be very different even at the same shear viscosity. Therefore, both shear and extensional rheology of thickened fluids should be considered for the management of dysphagia.

    更新日期:2018-10-05
  • Effect of LAPONITE® Addition on the Mechanical, Barrier and Surface Properties of Novel Biodegradable Kafirin Nanocomposite Films
    J. Food Eng. (IF 3.197) Pub Date : 2018-10-03
    Nathalia Olivera, Tahrima B. Rouf, Jose Bonilla, José G. Carriazo, Nathania Dianda, Jozef L. Kokini

    The objective of this research was to evaluate the effect of LAPONITE® addition on mechanical, surface and barrier properties of kafirin films. Kafirin was extracted using 70% ethanol, sodium metabisulphite and glacial acetic acid at 70 °C, which gave it a less hydrophobic character compared to earlier studies as determined using water contact angle (WCA) and secondary structure analysis through FTIR. Kafirin was then plasticized with equal concentration of lactic acid, glycerol and poly ethylene glycol and then loaded with different concentrations of LAPONITE® (1, 3, 5 and 10 % by weight). Kafirin nanocomposite films were characterized using FTIR, water vapor permeability (WVP), water contact angle (WCA), mechanical properties, optical microscopy and transmission electron microscopy (TEM). Collectively these measurements helped understand the interaction of LAPONITE® with kafirin in the film matrix. The α-helix and β-sheet content correlated with the relative hydrophilicity. Addition of LAPONITE® into kafirin films made the films stronger and less ductile while the WVP did not show any significant change. The new information obtained from this study can help in fabricating improved biodegradable films that can be used in various packaging, coating, biomedical and other functional film applications.

    更新日期:2018-10-03
  • Physiochemical properties of modified starch under yogurt manufacturing conditions and its relation to the properties of yogurt
    J. Food Eng. (IF 3.197) Pub Date : 2018-10-03
    Zhihua Pang, Ruolin Xu, Tianqi Luo, Xianing Che, Nidhi Bansal, Xinqi Liu

    The characteristics of three acetylated distarch phosphates with different degree of cross linking (ADP-L < ADP-M < ADP-H) and acetylation were studied under yogurt manufacture conditions, and the properties of yogurts made with these starches were evaluated. The modified starch showed lower solubility and viscosity than native starch (NS), but better resistance to acid and shear force was obtained. The acid milk gels containing modified starches exhibited well-organized and homogenized microstructure, while much denser structure with large aggregates were observed in control and NS samples. The modified starch improved the properties of yogurt more effectively than NS at 0.5% concentration, in terms of yield stress, consistency, apparent viscosity, thixotropy, pseudoplasticity. By increasing the concentration, ADP-M showed increasing positive effect on apparent viscosity, thixotropy, pseudoplasticity, firmness, adhesiveness of yogurt; while no significant difference or adverse effect was seen with ADP-L or ADP-H.

    更新日期:2018-10-03
  • Investigation of radio frequency heating as a dry-blanching method for carrot cubes
    J. Food Eng. (IF 3.197) Pub Date : 2018-10-03
    Chuting Gong, Yanyun Zhao, Hangjin Zhang, Jin Yue, Yubin Miao, Shunshan Jiao

    Radio frequency (RF) heating was investigated as a novel dry-blanching method for carrot cubes in this study. RF heating uniformity and effectiveness for inactivating peroxidase (POD) in carrot cubes were evaluated along with carrot quality (texture, color and vitamin C (Vc) content) after blanching. Results showed that RF heating uniformity increased with increasing RF electrode gap, and was affected by container shape and size, in which carrot cubes filled in cylinder shape container had better RF heating uniformity than that in rectangle container. Besides, POD activity of carrot cubes was reduced by 90-95% after RF blanching for 3.0-7.0 min at different electrode gaps (8.0-8.6 cm). RF dry-blanching maintained hardness, redness and Vc content of carrots cubes much better than hot water blanching. This study indicated that RF heating is an effective dry-blanching method for carrot cubes.

    更新日期:2018-10-03
  • On the feasibility of metal oxide gas sensor based electronic nose software modification to characterize rice ageing during storage
    J. Food Eng. (IF 3.197) Pub Date : 2018-10-02
    Hassan Rahimzadeh, Morteza Sadeghi, Mahdi Ghasemi-Varnamkhasti, Seyed Ahmad Mireei, Mojtaba Tohidi
    更新日期:2018-10-02
  • A moving boundary model for food isothermal drying and shrinkage: A shortcut numerical method for estimating the shrinkage factor
    J. Food Eng. (IF 3.197) Pub Date : 2018-09-28
    A. Adrover, A. Brasiello, G. Ponso

    We exploit prediction capabilities of the moving-boundary model for food isothermal drying proposed in Adrover et al. (2018). We apply the model to two different sets of literature experimental data resulting from the air-drying process of eggplant cylinders (two-dimensional problem) and potatoes slices (three-dimensional problem). These two food materials, both exhibiting non-ideal shrinkage, are characterized by very different “calibration curves“, i.e. different behaviours of volume reduction V / V 0 as a function of the rescaled moisture content X / X 0 . The purpose is twofold: to validate the model for different food materials and different sample geometries and to propose a simpler numerical approach for estimating the shrinkage factor, thus bypassing too lengthy analytical calculations and developing a general method that can be easily applied to any sample geometry and any food material characterized by a non-linear calibration curve.

    更新日期:2018-09-28
  • External factors and nanoparticles effect on water vapor permeability of pectin-based films
    J. Food Eng. (IF 3.197) Pub Date : 2018-09-26
    Aldo Stefano Spatafora Salazar, Paola Alejandra Sáenz Cavazos, Hugo Mújica Paz, Aurora Valdez Fragoso

    Permeation of water vapor through hydrophilic films is a rather complicated phenomenon. Water vapor permeability (WVP) of pectin films containing silicon dioxide nanoparticles was investigated under different temperature and relative humidity (RH) conditions, using orange and mango peel as pectin sources. No significant effect of the pectin source on WVP was observed. It was found that WVP increased with increasing RH and RH gradients created by different water vapor pressures in either sides of the films. Permeation tests showed that silicon dioxide nanoparticles in the films significantly reduced WVP (30–60%), compared to films without nanoparticles. Changes of WVP with temperature followed an Arrhenius type behavior and the activation energy of permeation decreased as RH increased. The opposite effect of temperature on diffusivity and solubility was observed.

    更新日期:2018-09-27
  • Fat powders stabilized with soy protein used to prepare oil-in-fat dispersions
    J. Food Eng. (IF 3.197) Pub Date : 2018-09-22
    Iris Tavernier, Bart Heyman, Paul Van der Meeren, Tony Ruyssen, Koen Dewettinck

    We report on the use of a soy protein stabilized, spray-dried oil powder as a vehicle for the introduction of unsaturated liquid oil in a continuous fat matrix. The spray dried oil powder was mixed with the molten continuous fat phase in concentrations of 30, 40, 50 and 60% of powder. The static crystallization of the continuous fat phase resulted in the formation of oil-in-fat dispersions, as was visualized with light microscopy and cryo-SEM. The isolation of the liquid oil in the internal oil droplets ensured that the continuous fat phase dominated the structuring of these newly developed oil-in-fat dispersions, which was rheologically demonstrated with amplitude sweeps. The elastic modulus of a 40% oil-in-fat dispersion (G’LVR = 3.54 ± 0.731 *105 Pa) was not significantly different from that of the undiluted fat phase (G’LVR = 4.55 ± 1.87 *105 Pa), even though the dispersion contained 40% more unsaturated oil. However, thixotropic tests revealed that the oil-in-fat dispersions are shear sensitive which can limit their applicability. The recovery percentage after shear of the undiluted fat was 39%, while the 30 and 40% oil-in-fat dispersion had a maximal recovery percentage of 19%. These findings provide a potential approach to reduce the saturated fat content of fat-based food products using only food-grade ingredients and traditional food processing techniques. Nevertheless, further optimization of the emulsion formulation and preparation and of the spray drying process is essential to improve the shear stability of these oil-in-fat dispersions.

    更新日期:2018-09-25
  • Accurate methodology to determine slip velocity, yield stress and the constitutive relation for molten chocolate
    J. Food Eng. (IF 3.197) Pub Date : 2018-09-24
    Emeline Talansier, Audrey Bacconnier, François Caton, Carine Chastel, Lucy Costa, Deniz Z. Gunes, Denis C.D. Roux

    Concentrated soft materials like molten chocolate often has the ambiguity of behaving like a solid or a liquid depending on the external constraints. Determination of the constitutive relation is often unreliable and consequently the yield stress value too. This difficulty of determining yield stress, particularly when using a standards protocol such as the IOCCC for chocolate, is a consequence of the presence of wall slip. Assessment of slip velocity using Yoshimura and Prud’homme’s method most often leads to erroneous results. We propose to tackle this problem by using an easy and reliable methodology applied to a commercial chocolate in a melted state with, as equipment, a plate-plate rotational rheometer. This method allows precise determination of the yield stress value, the constitutive relation and the slip velocity law. Furthermore, it provides an explanation to the apparent Newtonian plateau and thickening behavior of the raw flow curve.

    更新日期:2018-09-25
  • A moving boundary model for food isothermal drying and shrinkage: General setting
    J. Food Eng. (IF 3.197) Pub Date : 2018-09-20
    A. Adrover, A. Brasiello, G. Ponso

    A moving-boundary model is proposed for describing food isothermal drying. The model takes into account volume reduction of food materials and it is capable to predict sample shrinkage and surface deformation during the drying process. It can be applied to any sample geometry (discoid, cylindrical, cubic, parallelepiped) and to any food material since it can take into account that sample volume can decrease of a quantity that can be smaller, equal or larger than the corresponding volume of removed water. The core of the present model is the adoption of a pointwise shrinkage velocity equal (and opposite in sign) to the water diffusive flux times a shrinkage factor α ( ϕ ) depending on the pointwise water volume fraction ϕ ( x ) . The shrinkage factor α ( ϕ ) can be assumed a priori or directly derived from experimental data of the rescaled volume V / V 0 vs the rescaled moisture content X / X 0 . For ideal shrinkage α ( ϕ ) = 1 . The model provides good results in terms of prediction of volume reduction, surface deformation and effective water diffusivity for potato strips air-drying.

    更新日期:2018-09-21
  • Effects of prefreezing on the drying characteristics, structural formation and mechanical properties of microwave-vacuum dried apple
    J. Food Eng. (IF 3.197) Pub Date : 2018-09-19
    Yasumasa Ando, Shoji Hagiwara, Hiroshi Nabetani, Itaru Sotome, Tomoya Okunishi, Hiroshi Okadome, Takahiro Orikasa, Akio Tagawa

    The effects of prefreezing on the drying rate, internal structure and mechanical properties of apple fruit processed by microwave-vacuum drying (MVD) were evaluated. The drying rate of the prefrozen sample was approximately 1.2–1.3 times higher than that of the nontreated sample. In the frozen-thawed tissue, damage to the cell wall structure and cell membrane due to ice crystal formation during freezing was confirmed; thus, improvement in the drying rate was suggested to be the result of accelerated water transfer in the tissue. Structural observation using X-ray computed tomography showed that the prefrozen MVD sample had a porous internal structure with larger voids than air dried or nonpretreated samples. Alterations in the mechanical properties, such as higher maximum stress and number of peaks during the puncture test, indicating a softer and crisper texture, were observed in the prefrozen MVD sample.

    更新日期:2018-09-20
  • Applicability of different brewhouse technologies and gluten-minimization treatments for the production of gluten-free (barley) malt beers: Pilot-to industrial-scale
    J. Food Eng. (IF 3.197) Pub Date : 2018-09-19
    H.G. Watson, D. Vanderputten, A. Van Landschoot, A.I. Decloedt

    The fate of gluten proteins and (poly)peptides throughout the brewing process of reference and gluten-minimized all-malt beers was monitored on both pilot-scale and industrial-scale. Common process steps such as wort separation, cooking, wort and beer clarification already significantly reduce the mass of gluten proteins (72–99%). Nevertheless, gluten derived (poly)peptides remained present at high concentrations in the final reference beers (58–397 ppm). A lauter tun, with course husk material as filter bed, showed to be more effective in reducing the mass of gluten proteins than a mash filter (33% vs. 18%). The mass of gluten proteins and (poly)peptides could be further significantly reduced (16–89% and 33–81% respectively) depending on the use of tannins, AN-PEP (Prolyl-endopeptidase from Aspergillus niger) and silica gel. To render all-barley malt beers gluten-free (≤20 ppm) (EC No 41/2009, 2009) gluten-minimization treatments with AN-PEP and silica gel were combined successfully; these beers contained <5 ppm gluten proteins and <10 ppm gluten (poly)peptides.

    更新日期:2018-09-20
  • Experimental and theoretical study of polypropylene: Antioxidant migration with different food simulants and temperatures
    J. Food Eng. (IF 3.197) Pub Date : 2018-09-19
    Yoonjee Chang, Kyungmo Kang, Se-Jong Park, Jae Chun Choi, MeeKyung Kim, Jaejoon Han

    Polypropylene is a synthetic plastic widely used in industry due to its low price and convenience. Although its wide applications, serious safety issues have been raised about toxic chemicals such as butylated hydroxytoluene (BHT) and pentaerythritol tetrakismethylene-(3,5-di-tert-butyl-4-hydroxyhydrocinnamate) (Irganox 1010) which may migrate from polypropylene packaging into foods. Here, the effects of severe processing conditions [autoclave heating (121°C), microwave radiation (700 W), and freezer storage (−30°C)] on migration behavior were confirmed. Mathematical models were used to estimate the migration behavior of these compounds, and the results were compared with data from real experimental analyses which were performed by high-performance liquid chromatography. Overall, the estimated values from the mathematical model were 1.5–2 times larger than the experimental values for all conditions, suggesting that the mathematical migration models provide reliable predictions of migration. Taken together, computational assessment of migration behavior may be an effective way to decrease the time and expense of food safety evaluations.

    更新日期:2018-09-19
  • A novel critical point for isotropic gel in rheological-fractal model
    J. Food Eng. (IF 3.197) Pub Date : 2018-09-19
    Chong-hao Bi, Meng Zhang, Dong-yu Sun, Zhe Hua, Ying-dan Zhu, Yi Liu, Zhi-gang Huang, Fei Gao

    The determination of critical point in rheological-fractal models for most of the food gel systems and polymer viscoelastic systems are based on the point of 95% or 90% value of the storage modulus in linear viscoelastic region. It is not a precise method because the modulus during linear-nonlinear viscoelastic transition region are not always monotonous decreasing. Therefore, there is an urgent need for a more stable and precise approach to determine the critical point, making the scaling behavior calculation closer to the physical truth. This research studied on a typical food system, acid-induced peanut protein isolate (PPI) gel, trying to put forward a new critical point for isotropy food gel and non-newton polymer systems. Result shows that when the increasing higher harmonic reaches a certain value, the corresponding strain could be regarded as a new critical strain point. The image of the microstructure captured by confocal laser scanning microscope (CLSM) was used to calculate the actual fractal dimension, which was 2.3517. It was demonstrated that the fractal dimension calculated from rheological fractal model using the new critical strain obtained from the Fourier transform analysis is closer to its actual value (2.3517).

    更新日期:2018-09-19
  • Analysis and model-based optimization of a pectin extraction process
    J. Food Eng. (IF 3.197) Pub Date : 2018-09-18
    Ricardo F. Caroço, Boeun Kim, Paloma A. Santacoloma, Jens Abildskov, Jay H. Lee, Jakob K. Huusom

    Raw material quality disparity is an unavoidable and systemic variability in the solid-liquid extraction process of pectin manufacturing. A mathematical model is considered for a robust optimization of the process, taking into the account raw material quality uncertainty, for two different scenarios of pectin product quality profiles. Before application, the model is evaluated through local sensitivity analysis. Raw material-specific parameters and non-significant parameters are removed from the parameter set targeted for identification. Furthermore, it is shown that the model outputs are highly sensitive to the peel specific parameters, which inherently vary from peel-to-peel. This impact was further assessed through an uncertainty analysis, which quantified the variability of model predictions due to the raw material parameter uncertainty for three different types of fruit. The model exhibits a good general depiction of the extraction phenomena. Major operating variables, i.e., temperature, pH and batch time, are optimized in a deterministic manner for each fruit to maximize the final pectin concentration while satisfying given requirements. Based on this, a robust optimization strategy is examined to design an optimal operation strategy in consideration of the inherent uncertainty of feedstock and the desired product quality.

    更新日期:2018-09-18
  • Changes in structural integrity of sodium caseinate films by the addition of nanoliposomes encapsulating an active shrimp peptide fraction
    J. Food Eng. (IF 3.197) Pub Date : 2018-09-17
    Pilar Montero, Mauricio Mosquera, Daniel Marín-Peñalver, Ailén Alemán, Óscar Martínez-Álvarez, M. Carmen Gómez-Guillén

    A shrimp peptide fraction (ST1) with biological activity (ABTS radical scavenging capacity, angiotensin-converting enzyme and dipeptidyl-peptidase-IV inhibitory activities), was encapsulated in partially purified soy phosphatidylcholine nanoliposomes (L-ST1) using glycerol to preserve the bilayer during the film-forming dehydration step. The z-average, zeta potential and encapsulation efficiency of L-ST1 were, respectively, 99.98 nm, -53.87 mV and 52.37 %. Transmisssion Electron Microscopy images showed that the liposomes incorporated in sodium caseinate films caused film matrix disruption, but vesicle structure was well preserved and uniformly distributed along the film matrix. The films with liposomes became more water soluble, adhesive and mucoadhesive, with no changes in thickness or transparency. The film showed a very favourable taste perception, regardless the presence or type of liposomes, while the buccal dissolution was faster with the films carrying the liposomes. The film could be used in different food designs without distorting the sensory acceptance of the final product.

    更新日期:2018-09-18
  • Unusual drying behaviour of droplets containing organic and inorganic solutes in superheated steam
    J. Food Eng. (IF 3.197) Pub Date : 2018-09-17
    Amanda Lum, Nicholas Cardamone, Ron Beliavski, Shahnaz Mansouri, Karen Hapgood, Meng Wai Woo

    There are currently limited studies on the effect of superheated steam (SHS) on the solidification behaviour of droplets with dissolved solids which is a core phenomenon in spray drying. In this work, the single droplet drying technique was used to investigate how SHS affects the particle formation process of organic sugar droplets (lactose and mannitol), protein droplets (whey protein isolate) and droplets containing inorganic solute (sodium chloride). Unexpected droplet drying phenomenon was observed differing from drying behaviour typically assumed in the literature. While SHS is well known to result in slower drying rates below the inversion temperature, it also exhibits a lower potential to remove moisture at the end point ‘pseudo-equilibrium’ stage of drying. This led to lactose and mannitol droplets encountering incomplete moisture removal challenges in its drying process. The higher constant rate drying temperature experienced by droplet in SHS led to the precipitation of ultrafine protein particles. This higher constant rate drying temperature also led to the production of inverted pyramidal shaped salt crystals highlighting the potential of SHS as a useful medium for spray drying crystallization control.

    更新日期:2018-09-18
  • Experimental analysis of heat transfer and airflow in a closed refrigerated display cabinet
    J. Food Eng. (IF 3.197) Pub Date : 2018-09-17
    Nattawut Chaomuang, Denis Flick, Alain Denis, Onrawee Laguerre

    This study presents the experimental investigations on heat transfer and airflow in a closed refrigerated display cabinet. Air and product temperatures and air velocity were measured with thermocouples and a hot-wire anemometer, respectively. Temperature variation in the cabinet depends on the positions. The front areas contributed to higher temperature, whereas the rear areas were at a lower temperature. Benefits of doors were also examined by comparing the results of air and product temperatures with the case without doors. The cabinet with doors provided less temperature heterogeneity ( = 2.1°C) compared to the case without door ( = 4.9°C). The maximum air velocity in the air curtain of 0.6 m·s-1 was observed at the discharge grille. The horizontal air velocity from the perforated plate was low (< 0.2 m·s-1) for all shelves. The loading percentage in the cabinet did not significantly affect the airflow rate through the perforated plate.

    更新日期:2018-09-18
  • Effect of homogenization on binding-affinity of bacteriophage A511 in bovine milk fractions
    J. Food Eng. (IF 3.197) Pub Date : 2018-09-18
    Mayra C. García-Anaya, David R. Sepúlveda-Ahumada, Claudio Ríos-Velasco, Paul B. Zamudio-Flores, Carlos H. Acosta-Muñiz

    The effect of milk homogenization conditions, including speed (17,400 rpm; 20,600 rpm; and 24,000 rpm) and time (5 to 25 min) on phage affinity in milk fractions was investigated. A broad host-range Listeria phage (A511) was inoculated. Milk fractions separation was carried out and phage enumeration was expressed as percentage of added phages. A maximum quantifiable phage of 42.6 % was obtained in unhomogenized milk. Homogenization (5 min, at any speed) further reduced quantifiable phages (15.9 to 20.6 %), but this percentage increased as homogenization time increased. Phage distribution in unhomogenized milk showed preference for fat followed by caseins. Milk homogenization caused milk fat to lose its ability to bind phages, inducing phages to bind to caseins preferentially. Whey was the milk fraction with the lowest affinity for phage. The effect of homogenization speed and time on phage affinity was only observed in caseins. A correlation between phages bound to caseins, fat surface area and fraction Φ was observed.

    更新日期:2018-09-18
Some contents have been Reproduced with permission of the American Chemical Society.
Some contents have been Reproduced by permission of The Royal Society of Chemistry.
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