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  • Impact of inclusion of flaxseed oil (pre-emulsified or encapsulated) on the physical characteristics of chicken sausages
    J. Food Eng. (IF 3.099) Pub Date : 2018-02-24
    Zara Bolger, Nigel P. Brunton, Frank J. Monahan

    Functional meat products containing elevated omega-3 (n-3) fatty acids, such as α-linolenic acid (ALA), may be formulated by replacing animal fat with flaxseed oil, but the addition of flaxseed oil to meat products can adversely affect sensory properties, particularly textural properties. The objective of this study was to investigate how different methods of flaxseed oil incorporation into chicken sausages affected their physical characteristics, as assessed by proximate composition, water holding capacity, water and fat binding capacity, cook loss, texture profile analysis (TPA), rheological analysis and nuclear magnetic resonance relaxometry (NMR). Sausages were formulated to contain enough ALA to meet the European Food Safety Authority requirements for nutrient and health claims (0.6 g per 100 g and 100 kcal) and compared with a non-oil containing control (C). Flaxseed oil, as a source of ALA, was incorporated in the following forms: direct addition (O); pre-emulsified (E); encapsulated and freeze-dried (F); encapsulated with cross-linker genipin and freeze-dried (G); encapsulated and spray-dried (S). When compared to the other formulations, the F and G formulations had lower values for storage and loss modulus and for all TPA measurements (p≤0.05). G and S formulations had lower values (p≤0.05) for cook loss than the other formulations. NMR showed that water populations in the G and S formulations behaved differently during heating compared to the other formulations. In summary, the physical characteristics of sausages were affected by flaxseed oil incorporation method, with encapsulation methods having the greatest impact compared to direct or pre-emulsified oil addition.

    更新日期:2018-02-24
  • High-speed cutting of foods: Cutting behavior and initial cutting forces
    J. Food Eng. (IF 3.099) Pub Date : 2018-02-24
    Stefan Schuldt, Yvonne Schneider, Harald Rohm

    The viscoelastic properties of foods determine deformation, fracture and friction during industrial cutting applications and substantially affect the cutting behavior, especially at high cutting velocity. Using a custom-built high-speed test station the cutting behavior of representative foods (either based on a protein network, plant tissues, and sugar based confectionary) and food models on elastomer basis was investigated at a cutting velocity ranging from 10−4 m/s up to 10 m/s. On the basis of cutting force data and dynamic mechanical analysis performed between 1 rad/s and 100 rad/s, the cutting behavior of the systems was investigated. In general, the cutting force profiles depended on cutting velocity and could be related to deformation characteristics that were measured in dynamic mechanical analysis (except for plant tissue whose inherent composite structures seem to contribute to brittle behavior at each cutting velocity). Sugar based confectionary showed a strong rate dependence with brittle fracture and splintering in the high-speed region. For all systems except plant tissues a velocity dependent deformation cutting parameter, derived from the initial cutting forces, coincides with the power law frequency dependence of the complex modulus. This relation was used to build a model approach with which the pre-crack cutting forces at high-speed cutting velocity can be predicted with commercially available standard testing machines.

    更新日期:2018-02-24
  • Corrigendum to “Soy PC liposomes as CLA carriers for food applications: Preparation and physicochemical characterization” [J. Food Eng. 212 (2017) 174-180]
    J. Food Eng. (IF 3.099) Pub Date : 2018-02-24
    María A. Vélez, María C. Perotti, Paula Zanel, Erica R. Hynes, Ana M. Gennaro

    Highlights: • Soy PC liposomes containing up to 33% CLA have been formulated. • CLA encapsulation efficiency is over 80% and does not decrease over 30 days. • Membrane fluidity and liposome size are influenced by CLA content. • We do not use organic solvents, and the method is easily scalable. • Promising results in view of the design of functional foods based on liposomes.

    更新日期:2018-02-24
  • Implementation of osmotic membrane distillation with various hydrophobic porous membranes for concentration of sugars solutions and preservation of the quality of cactus pear juice
    J. Food Eng. (IF 3.099) Pub Date : 2018-02-23
    Lydia Terki, Wojciech Kujawski, Joanna Kujawa, Marzanna Kurzawa, Anna Filipiak-Szok, Ewelina Chrzanowska, Souad Khaled, Khodir Madani

    Hydrophobic polymeric (0.45 and 0.20 μm polytetrafluoroethylene (PTFE) and 0.10 μm polypropylene (PP)) membranes were efficiently applied for cactus pear juice and sugars solutions concentration using Osmotic Membrane Distillation (OMD) process. It is reported that the PTFE membranes gave higher permeate fluxes and higher final juice concentrations. Furthermore, the filtration of raw juice prior to OMD process, the extension of the process time and the increase of processing temperature resulted in the increase of the final juice concentration. Using 0.45 μm PTFE membrane, the final concentration of the filtered juice (FJ) was 16.4 °Brix ± 0.1 (at 20 °C, after 5 h) and 23.4 °Brix ± 0.2 (at 35 °C, after 18 h). The juice quality was assessed by determining the juice viscosity, the total phenolic content, total flavonoids content, antioxidant activity and phenolic acids content. It was revealed that the physicochemical properties were preserved in the concentrated juice.

    更新日期:2018-02-23
  • Online Determination of Heat Transfer Coefficients in Sugar Juice Evaporation Process
    J. Food Eng. (IF 3.099) Pub Date : 2018-02-22
    Somchart Chantasiriwan

    In the sugar juice evaporation process, the temperature of incoming juice is raised to the boiling point, and the water content of the juice is reduced by evaporation. The main process outputs are raw sugar and molasses. Heat transfer coefficients are important parameters in the simulation of this process. Due to scaling, the values of heat transfer coefficients decrease over time, and cleaning must be carried after a certain period of operation. Although correlations of heat transfer coefficients and recommended values of scaling rates are available in the literature, there are uncertainties in their values. Therefore, reliance on these correlations to predict when an evaporator station requires cleaning may be in error. In this paper, a method of online determination of heat transfer coefficients and scaling rates using measured values of process parameters is presented. Testing of this method indicates that it can produce accurate values of heat transfer coefficients and scaling rates despite possible errors in input data.

    更新日期:2018-02-22
  • Shrinkage of cellular food during air drying
    J. Food Eng. (IF 3.099) Pub Date : 2018-02-21
    Thanh Khuong Nguyen, Martin Mondor, Cristina Ratti

    Shrinkage of potato and carrot (cylinders and slabs) was determined during convective drying at air temperature of 25, 55 or 65 °C with air speed of 1.6 or 0.5 m/s. Initial moisture content of slab samples at different positions within the carrot root and potato tuber was determined gravimetrically and by the vacuum method at 60°C. Structure of potato slabs at exterior and center of tuber was analysed by Scanning Electron Microscope (SEM). Glass transition temperature (Tg) was approximately 50 °C for dry potato (0.021 kg/kg dm), and 40 °C for dry carrot (0.005 kg/kg dm) indicating that potato and carrot would be in rubbery state throughout drying at 65 °C. Glass transition of the samples could be observed at the end of the drying process with air temperature of 25 °C. The initial moisture content of carrot at exterior and center of root were identical. However, the center potato layers had initial moisture content higher than the exterior potato layers. SEM images showed that the cells of the exterior potato samples had smaller volume with higher starch content than the center sample, thus indicating a correlation between structure characteristics and initial solids content. For all drying conditions used in this study, shrinkage of carrot samples (cylinders and slabs) had a linear relationship with moisture content during drying. For potato, however, a change in the slope of the shrinkage curve as a function of moisture content during drying was observed for cylinder samples. For potato slabs, only those having initial moisture contents lower than 5.5 ± 0.5 kg water/kg dm showed a similar change in slope, otherwise slabs presented a straight line for the whole water content range. The air temperature and air speed had no effect on the shrinkage behaviour of both carrot and potato samples under the operation conditions used in this study. No significant impact of glass transition on shrinkage of carrot and potato samples has been found, and if any this impact would be considered minor. Differences in starch content, in structure of the cellular material and its relationship with mechanical properties of material may explain the different shrinkage behaviour observed in this work.

    更新日期:2018-02-21
  • Changes in lycopene content and quality of tomato juice during thermal processing by a nanofluid heating medium
    J. Food Eng. (IF 3.099) Pub Date : 2018-02-21
    Seyyed Sajjad Jabari, Seid Mahdi Jafari, Danial Dehnad, Seyyed Ahmad Shahidi
    更新日期:2018-02-21
  • Ohmic heating of beef at 20 kHz and analysis of electrical conductivity at low and high frequencies
    J. Food Eng. (IF 3.099) Pub Date : 2018-02-21
    Yvan Llave, Toshifumi Udo, Mika Fukuoka, Noboru Sakai

    The increase in temperature during ohmic heating (OH) at 20 kHz of conventional beef (CB) and wagyuu beef (WB) was evaluated by analyzing the effects on drip loss due to cooking, shrinkage and microstructure changes. The effects of parallel and series current directions, temperature (5–65 °C), frequency (50 Hz–20 kHz), and chemical composition on the EC values of samples were evaluated. A mathematical explanation of the effect of current direction on EC was provided. A low drip loss due to cooking and shrinkage were found in both beef treated by OH at 20 kHz and 50 V. A good temperature uniformity independent of the current direction was obtained in CB. Increasing the frequency caused a drop in resistance and an increase in heating rate, thereby decreasing the heating time needed for beef muscles, especially for CB, due to its high water and low fat content. A large amount of endogenous fat in WB does not generate heat as quickly as CB muscles due to the poor conductivity of fat; therefore, the presence of fat decreases EC, resulting in uneven heating.

    更新日期:2018-02-21
  • Phospholipids in chocolate: Structural insights and mechanistic explanations of rheological behavior by coarse-grained molecular dynamics simulations
    J. Food Eng. (IF 3.099) Pub Date : 2018-02-19
    Moritz Kindlein, Ekaterina Elts, Heiko Briesen

    The structural properties of phospholipid layers and micelles at sucrose crystal cocoa butter interfaces were investigated by coarse-grained molecular dynamics simulations to understand the molecular mechanisms and structures vital for the chocolate conching process. Influences of the different hydrophilic head groups phosphatidylcholine, phosphatidylethanolamine, phosphatidylinositol, and phosphatidic acid of lecithin phospholipids as well as influences of the degree of saturation of aliphatic chains were investigated. Phospholipid monolayers at sucrose–cocoa butter interfaces were shown to have similar molar composition as soy lecithin, indicating that all phospholipids adsorb with similar probability. Phospholipids with saturated aliphatic chains have smaller areas per lipid in the monolayer on the sucrose cocoa butter interface than unsaturated phospholipids. It was shown that phospholipids that are not adsorbed in the monolayer assemble in spherical, cylindrical, and wormlike micelles in cocoa butter, depending on the phospholipid concentration. Wormlike micelles were shown to be able to build a hydrophilic network in the cocoa butter medium. This is proposed as an explanation for the increasing yield values at higher lecithin concentrations in chocolate manufacturing which have been reported in several studies. The resulting structures of phospholipids on sucrose surfaces were related to experimental measurements from the literature.

    更新日期:2018-02-21
  • Particle swarm optimization as alternative tool to sensory evaluation to produce high-quality low-sodium fish sauce via electrodialysis
    J. Food Eng. (IF 3.099) Pub Date : 2018-02-19
    San Ratanasanya, Nathamol Chindapan, Jumpol Polvichai, Booncharoen Sirinaovakul, Sakamon Devahastin

    Electrodialysis (ED) has been proposed as a means to produce low-sodium fish sauce to serve the need of health-conscious consumers. Artificial neural network in combination with genetic algorithm and experimental sensory results was previously used to optimize the ED process to produce high-quality low-sodium fish sauce. However, a large number of training data and exhaustive computational resource were required in such a case. In this study, particle swarm optimization (PSO) is proposed to optimize the ED process. Changes in the total nitrogen, total amino nitrogen and total aroma compounds concentrations were generated from our previously developed phenomenological model and used for the optimization; no experimental sensory data were needed. PSO indicated that fish sauce should contain 14.4% (w/w) salt if all the quality indicators were to be optimized; this result agreed well with the result of an independent sensory test.

    更新日期:2018-02-21
  • Microalgae protein heating in acid/basic solution for nanofibers production by free surface electrospinning
    J. Food Eng. (IF 3.099) Pub Date : 2018-02-17
    Juliana Botelho Moreira, Loong-Tak Lim, Elessandra da Rosa Zavareze, Alvaro Renato Guerra Dias, Jorge Alberto Vieira Costa, Michele Greque de Morais

    The objective of this work was to evaluate the effect of the biopolymers heating in alkaline and acidic solutions in the formation of nanofibers using protein concentrate from Spirulina sp. LEB 18 for potential application in food packaging field. With the highest protein concentration, the mean diameter of nanofibers was approximately 450 nm. For nanofibers developed with 5% (w.w-1) of protein concentrate, the peaks in FTIR spectra were observed at 1641 cm-1 (amide I) and 1533 cm-1 (amide II). Moreover, the increasing of protein concentration of 5 to 10% (w.w-1) enhanced the initial temperature of degradation of the nanofibers at 34 °C, when the poly (ethylene oxide) (PEO) was added after solution heating. The possibility of formation of uniforms nanofibers using the acidic solution with a low concentration of PEO (0.8%, w.w-1) shows the potential of the protein concentrate from Spirulina sp. LEB for the production of these materials.

    更新日期:2018-02-17
  • An alternative elongational method to study the effect of saliva on thickened fluids for dysphagia nutritional support
    J. Food Eng. (IF 3.099) Pub Date : 2018-02-17
    Mihaela Turcanu, Nadja Siegert, Sébastien Secouard, Edmundo Brito-de la Fuente, Corneliu Balan, Crispulo Gallegos

    Powder thickeners are used to modify liquid consistency in dysphagia management. These thickeners may contain starches, gums or their mixtures. Since the salivary α-amylase enzyme favours starch hydrolysis, this might affect the overall rheology of thickened fluids. This study provides a first insight into the impact of salivary α-amylase on the elongational properties of different types of thickened fluids, differentiating between gum-based and starch-based fluids, when considering the axial force developed during uniaxial elongation. The experimental results obtained in this study showed a dramatic decrease in the axial force as a result of salivary α-amylase addition to a pudding-like starch-based thickened fluid, while no significant change was observed after addition to a pudding-like gum-based thickened fluid. Monitoring axial forces during the stretching phase of CaBER was found to be a quick alternative method to identify structural changes of pudding-like thickened fluids in the presence of saliva, for which the conventional CaBER experiments are technically limited.

    更新日期:2018-02-17
  • Extraction and Modeling of Flaxseed (Linnum usitatissimum) Oil Using Subcritical Propane
    J. Food Eng. (IF 3.099) Pub Date : 2018-02-16
    Guilherme Sabadin Piva, Thiago André Weschenfelder, Elton Franceschi, Rogerio Luis Cansian, Natalia Paroul, Clarice Steffens

    This study aimed at investigating flaxseed (Linnum usitatissimum) oil extraction using subcritical propane. Extractions were performed in a laboratory scale unit at temperature (20−60 oC) and pressure (80−120 bar) experimental conditions. Subcritical extraction process kinetic aspects evaluation was performed using four mathematical models found in the literature. The subcritical propane process successfully extracted Omega 3-6-9 fatty acids presenting good yielding in the experimental conditions studied. Physical characterization for commercial and subcritical propane extraction oils presented 1.477 and 1.473 refractive indexes at 40 ºC, respectively. The oil extracted using subcritical propane presented free fatty acid contents lower than commercial oil (0.95% wt vs 1.37% wt). The adjusted parameters models presented good fitting with the experimental data under the investigated conditions.

    更新日期:2018-02-16
  • Osmotic distillation applying potassium pyrophosphate as brine
    J. Food Eng. (IF 3.099) Pub Date : 2018-02-16
    Ricardo Schmitz Ongaratto, Leonardo Menezes, Cristiano Piacsek Borges, Paulo Laranjeira da Cunha Lage

    Potassium pyrophosphate was applied as stripping solution in osmotic distillation of fruit juices. The permeate ranged between 0.56 and 1.45 kg/m2h, being more sensitive to the variation of the feed temperature. After pre-saturating the experimental apparatus, no significant effect on the degradation of ascorbic acid was found and the losses of volatile compounds were no larger than 62% while 100% of the aroma compounds were lost during thermal concentration. In addition, orange juice was concentrated from 10 to 27 °Brix and the process did not change the physicochemical characteristics of the final juice. In conclusion, potassium pyrophosphate can advantageously substitute calcium chloride as the stripping solution of osmotic distillation in the concentration of fruit juices, allowing brine reconcentration using direct contact evaporation with flue gas.

    更新日期:2018-02-16
  • Influence of stainless steel surface properties on whey protein fouling under industrial processing conditions
    J. Food Eng. (IF 3.099) Pub Date : 2018-02-14
    Sawsen Zouaghi, Thierry Six, Nicolas Nuns, Pardis Simon, Séverine Bellayer, Sona Moradi, Savvas G. Hatzikiriakos, Christophe Andre, Guillaume Delaplace, Maude Jimenez

    Heat-induced fouling is a financial and environmental burden for food and dairy industries and its control is therefore desperately needed. A better understanding of the fouling mechanisms and their relation to stainless steel surface properties is thus of considerable interest. This work aims at studying the impact of stainless steel's surface morphology and surface free energy on fouling by a model dairy solution by a close examination of the deposit's growth and adhesion at the substrate-fluid interface. Pristine model surfaces of controlled roughness and surface energy, i.e. native, mirror polished and biomimetic femtosecond laser textured stainless steel surfaces, fluorosilanized or not, were tested under isothermal conditions in a pilot pasteurization facility fed with a model dairy fluid (whey protein and calcium solution). Multi-scale characterizations of those surfaces before and after fouling, using a wide range of analytical tools (goniometry, SEM, ToF-SIMS, EPMA X-Ray mappings) allowed for a better comprehension of the impact of surface energy and morphology modifications on the fouling behavior while highlighting their complex interactions in fouling governance. Lower surface energy was shown to be an asset against deposit growth, as fluorosilanization of native stainless steel allowed to reduce fouling by 72% (wt.%). The relative sizes of surface relief versus fouling agents has been found crucial, as it impacts interlocking phenomena. Textured surfaces have shown a tremendous increase in fouling (+391% for textured, +86% for fluorosilanized textured). However, interesting fouling performances were obtained on smooth, hydrophobic surfaces, as a reduction by 83% of fouling weight was achieved with fluorosilanized polished samples.

    更新日期:2018-02-14
  • Technology for Processing of Potato Chips Impregnated with Red Rootbeet Phenolic Compounds
    J. Food Eng. (IF 3.099) Pub Date : 2018-02-13
    Rosana G. Moreira, Samar Almohaimed

    The objective of this study was to produce healthy snacks using vacuum impregnation (VI) and vacuum frying (VF) technology. Potato slices were pre-treated with different concentration of beetroot solution (3, 5, and 7% w/w), vacuum pressures (300 mmHg, 450 mmHg, 600 mmHg), and vacuum and restoration times (5, 10, 15 minutes). The optimum VI conditions were 7 w/w red-beet extract concentration solution, 600 mm Hg vacuum pressure for 10 min and 60 min of restoration time. The potato slices were vacuum fried at 110, 120, and 140°C. Moisture loss of potato chips during vacuum frying was faster at higher temperatures and was successfully modeled with a modified equation for moisture diffusion in a flat plate. The diffusion coefficient values varied from 1.65x10-8to 4.99x10-8 for temperaturea ranging from 110°C to140oC, respectively. The influence of the frying oil temperature on the moisture diffusion coefficient during vacuum frying was describe using an Arrhenius equation, where the pre-exponential factor (A) was 3.57×10-2 s-1, and the activation energy (Ea) was 4.61x105 J/mol for the temperature range from 110°C to 140°C. For the oil content, two regions (120oC and 140oC) were defined for the kinetic model considering that each curve presents different behaviors before and after the maximum oil content reached during frying. Chips fried at 110°C and 120°C had a maximum total phenolic content (TPC) of only 11% and 20% higher than the initial TPC values of the VI slices, respectively, while the TPC of slices fried at 140°C was 27% higher. Vacuum impregnated potato slices fried were also fried using different flying methods (vacuum at 140°C, dual stage at 140°C, and traditional frying at 165°C). The VI chips fried by traditional frying (TF) had 9% reduction in TPC after frying, while those fried under vacuum and dual-stage frying (DSF) had a 38% and 23% increase in TPC, respectively. Compared to the impregnated potato slices, the color of the chips fried under TF deteriorated more (higher b* value) than the chips fried under vacuum or in the DSF method. The chips fried by the TF method were harder to break than the chips fried by the other two methods. A consumer test panel found the potato chips fried under vacuum and dual-stage frying more acceptable than the potato chips fried under atmospheric pressure. Vacuum frying at 140°C for 120 s after vacuum impregnation is a potential technology to produce healthier functional snacks with desired quality attributes.

    更新日期:2018-02-14
  • Dielectric properties, heating rate, and heating uniformity of various seasoning spices and their mixtures with radio frequency heating
    J. Food Eng. (IF 3.099) Pub Date : 2018-02-13
    Samet Ozturk, Fanbin Kong, Rakesh K. Singh, Jesse Daniel Kuzy, Changying Li

    Low moisture foods, including seasoning spices, have been associated with a number of multi-state outbreaks of salmonellosis in the past decade. The long-term objective of this study was to develop an effective in-package pasteurization treatment for seasoning mixtures based on radio frequency (RF) heating. Seasoning spices obtained from grocery stores included red, white, and black pepper; cumin; curry powder; and garlic powder with moisture contents ranging from 3.1-12.3% (wet basis). The dielectric properties (DP) of the seasoning mixtures as influenced by frequency, mixing fraction and salt content were determined using a precision LCR meter and liquid test fixture at frequency ranging from 1 to 30 MHz. The RF heating rates of each spice and their mixtures were evaluated using a 27.12-MHz RF system with 105 mm gap between electrodes. To evaluate the effect of mixing on heating uniformity, a sample (50 g) was placed into a polystyrene plastic cylindrical container and heated to 70 °C, and surface images were taken by an infrared camera. The results showed that the relationship among moisture content, temperature and DP of white pepper can be explained by a second-order model at 13.56 and 27.12 MHz. The DP and heating rates of spice mixtures ranged between the highest and lowest values of their respective individual spices. Increase in salt content resulted in a decrease in heating rate and uniformity index. The RF heating rate of samples ranged from 2.97 to 23.61 (°C min-1). The highest heating rate in the samples was in correspondence to the worst heating uniformity and highest average temperature on the sample surface. The best heating uniformity index was obtained for garlic powder as 0.012 at 70 °C. The information obtained from this study is important to develop an effective RF heating strategy for pathogen control in seasoning mixture.

    更新日期:2018-02-13
  • The influence of storage time and temperature on the corrosion and pressure changes within tomato paste cans with different filling rates
    J. Food Eng. (IF 3.099) Pub Date : 2018-02-09
    Seid Mahdi Jafari, Morad Amanjani, Mohammad Ganjeh, Iman Katouzian, Narjes Sharifi
    更新日期:2018-02-09
  • Mass transfer dynamics in soaking of chickpea
    J. Food Eng. (IF 3.099) Pub Date : 2018-02-08
    Rui Costa, Francesca Fusco, João F.M. Gândara

    Chickpea (Cicer arietinum L.) is a widely-used pulse in industrial production of foods and home cooking with soaking being the most used operation in its processing. Insight into its mass transfer behavior enables the design of optimum processing conditions to achieve maximum quality and nutrient content. In this work, water gain and solids loss were modeled assuming ordinary diffusion. Water diffusivities vary between 1.12 × 10−10 m2/s at 25 °C to 3.83 × 10−10 m2/s at 100 °C. Solids diffusivities vary between 9.77 × 10−11 m2/s and 4.07 × 10−10 m2/s at 75 °C and 50 °C, respectively. Activation energies were calculated, assuming an Arrhenius model. Three periods of mass transfer have been identified, with the first characterized by a density increase and a solids loss until 5%. Hydrodynamic flow and diffusion occur simultaneously, both for water and solids transfer. The new insights gained with this work can support the development of more rigorous modelling of chickpea soaking, based on more accurate mass transfer mechanisms.

    更新日期:2018-02-08
  • Modelling of coupled heat and mass transfer for combined infrared and hot-air drying of sweet potato
    J. Food Eng. (IF 3.099) Pub Date : 2018-02-07
    Daniel I. Onwude, Norhashila Hashim, Khalina Abdan, Rimfiel Janius, Guangnan Chen, Chandan Kumar

    This study aims to develop a numerical model to accurately predict moisture content and temperature distribution for sweet potato during combined infrared and hot-air drying (IR-HAD). The coupled heat and mass transfer during drying was simulated considering both temperature and shrinkage dependent diffusivity. The simultaneous heat and mass transfer model were solved using COMSOL Multiphysics, considering 2-D axisymmetric geometry. The IR energy input was determined by the Lambert’s law. The simulations results were further evaluated based on data obtained from experiments conducted, showing that the model could adequately describe the coupled heat and mass transfer process of sweet potato during combined IR-HAD (R2= 0.986-0.996). The IR was also shown to be the most influential factor with regards to the heat transfer rate during the combined IR-HAD. The developed model can serve as a good basis for applications in other agricultural crops under different drying conditions.

    更新日期:2018-02-08
  • Analysis of MRI by fractals for prediction of sensory attributes: a case study in loin
    J. Food Eng. (IF 3.099) Pub Date : 2018-02-07
    Daniel Caballero, Teresa Antequera, Andrés Caro, José Manuel Amigo, Bjarne K. ErsbØll, Anders B. Dahl, Trinidad Pérez-Palacios

    This study investigates the use of fractal algorithms to analyse MRI of meat products, specifically loin, in order to determine sensory parameters of loin. For that, the capability of different fractal algorithms was evaluated (Classical Fractal Algorithm, CFA; Fractal Texture Algorithm, FTA and One Point Fractal Texture Algorithm, OPFTA). Moreover, the influence of the acquisition sequence of MRI (Gradient echo, GE; Spin Echo, SE and Turbo 3D, T3D) and the predictive technique of data mining (Isotonic regression, IR and Multiple Linear regression, MLR) on the accuracy of the prediction was analyzed. Results on this study firstly demonstrate the capability of fractal algorithms to analyse MRI from meat product. Different combinations of the analyzed techniques can be applied for predicting most sensory attributes of loins adequately (R>0.5). However, the combination of SE, OPFTA and MLR offered the most appropriate results. Thus, it could be proposed as an alternative to the traditional food technology methods.

    更新日期:2018-02-07
  • Adhesion of liquid food to packaging surfaces: mechanisms, test methods, influencing factors and anti-adhesion methods
    J. Food Eng. (IF 3.099) Pub Date : 2018-02-07
    Xiaowei Liu, Liqiang Wang, Yanfang Qiao, Xinxing Sun, Shufeng Ma, Xueyu Cheng, Wenfei Qi, Wenqian Huang, Yinghui Li

    The adhesion of liquid food to packaging surfaces is an unsolved problem in the food industry. The theoretical backgrounds that are provided in this article are based on an adequate understanding of the mechanisms of adhesion between liquid food and packaging materials. Various mechanisms of liquid food adhesion are reviewed, such as mechanical interlocking, thermodynamic adsorption, diffusion, and electrostatic adsorption. The available tests and calculation methods are summarized and discussed, but there is no universal test standard. Basing on several available liquid food adhesion cases, it was found that liquid food adhesion results from multiple factors, such as rheological properties, surface tension, philicity, and roughness. Finally, we summarize some of the anti-adhesion methods developed in related fields, including surface coating technologies, surface structure design, and ecologically friendly approaches. It is important to produce re-entrant geometric structures combined with low surface energy compounds in the design of anti-adhesion packaging. In addition, for food applications, more attention should be paid to ecologically friendly materials. Comprehensive and systematic examination of these aspects would be conducive to the development of anti-adhesion materials for food packaging.

    更新日期:2018-02-07
  • Rheological and structural characteristics of whey protein-pectin complex coacervates
    J. Food Eng. (IF 3.099) Pub Date : 2018-02-07
    Masoomeh Raei, Ali Rafe, Fakhri Shahidi

    Complex coacervation of protein/polysaccharide has found much interest for the encapsulation of bioactive materials. The rheological properties of the coacervates of whey protein/high methoxyl pectin (WPI/HMP) at different pH including 3.0, 3.5 and 4.0 were investigated. The complex viscosity (η*) of the coacervate was decreased linearly with frequency, showing the shear-thinning phenomenon of the coacervates. Furthermore, the highest complex modulus (G*) and more compact coacervate were obtained at pH 3.5, revealing less deformability and flow behaviour. All the coacervates showed higher storage modulus (G') than loss modulus (G") indicating the formation of highly interconnected gel-like structure. The maximum fracture stress was obtained at pH 3.5 revealing the highest intermolecular interactions between WPI and HMP. It seems the high fracture stress and gel strength of the complex coacervate would be suitable for encapsulation of bioactives. The high aggregation was also achieved at pH 3.5, as the lower charge density of HMP should make it more readily neutralized by whey protein binding. FTIR results showed the spectrum of the coacervate was different from each individual biopolymer, related to their compatibility and intermolecular interactions between the functional groups of HMP and WPI. Although, to get more insight toward dynamic rheological measurements in surveying the interaction of any biopolymer blends, further work should be carried out for other biopolymers.

    更新日期:2018-02-07
  • Mathematical model for determining thermal properties of whole bananas with peel during the cooling process
    J. Food Eng. (IF 3.099) Pub Date : 2018-02-05
    Wilton Pereira da Silva, Cleide Maria D.P.S. e Silva, Leidjane Matos de Souto, Inacia dos Santos Moreira, Elaine Cristina Oliveira da Silva

    Usually, the thermophysical parameters of bananas available in the literature refer to the flesh of the product. However, to prolong the shelf life avoiding injuries, product cooling should be performed for bananas with peel (from room temperature to 13 oC). Thus, the main objective of this article was to determine thermal properties of banana with peel during its cooling. A solver was developed for the direct problem, using a two-dimensional solution of the diffusion equation to describe heat transfer. For the inverse problem, we used an experimental dataset of the temperature over time at the center of a banana, and a ready-to-use optimizer software. Convective heat transfer coefficient and thermal diffusivity were h = (2.186 ± 0.021)×10-6 m s-1 and α = (1.45 ± 0.06)×10-7 m2 s-1, respectively. Heat transfer coefficient and thermal conductivity were hH = (4.93 ± 0.05) W m-2 K-1 and k = (0.328 ± 0.014) W m-1 K-1, respectively. The chi-square and determination coefficient of the optimization process were 3.5484×10-2 and 0.999955, respectively.

    更新日期:2018-02-06
  • Semi-continuous pressurized hot water extraction of black tea
    J. Food Eng. (IF 3.099) Pub Date : 2018-02-03
    Chunlan He, Hongfei Du, Chunbin Tan, Zhong Chen, Zeliang Chen, Fengjun Yin, Yuanjian Xu, Xiaoling Liu

    The pressurized hot water extraction (PHWE) of six representative compounds from black tea brick was investigated in a semi-continuous extractor under the conditions of various temperatures (120–180°C) and water flow rates (6–18mLmin-1). The extracted solutions were dark brown liquid suspensions, and a significant proportion of the six compounds (70.7–92.0%) was found in the supernatant phase after centrifugation. Theophylline is the most stable compound with respect to increasing temperature and extraction time. Epicatechin gallate (ECG) and epigallocatechin gallate (EGCG) were sensitive to temperature, while the other compounds (caffeine, catechin, and gallocatechin gallate (GCG)) were affected by both temperature and water flow rate. The optimum conditions were found to be 160°C and 12 mL min-1. Compared to the traditional tea brewing (TTB) method, PHWE can achieve significantly higher extraction yields of theophylline, caffeine, catechin, and GCG.

    更新日期:2018-02-04
  • A review on heat and mass transfer coefficients during deep-fat frying: Determination methods and influencing factors
    J. Food Eng. (IF 3.099) Pub Date : 2018-02-03
    Afsaneh Safari, Razieh Salamat, Oon-Doo Baik

    Deep-fat frying is one of the main methods applied to processing food materials, in which heat and mass transfer take place simultaneously. These phenomena, which govern product quality and safety, are strongly controlled by heat and mass transfer coefficients. They are of great importance in modeling and simulation and are now widely paid attention to in order to optimize and control the process. Several researchers have studied determination techniques and numerous factors influencing heat and mass transfer coefficients during frying, and some contradictory results concerning the effect of parameters on these coefficients have been occasionally reported, which are necessary to be more considered. Some of these inconsistencies could originate from inherent difference of approaches. In this paper, we aim to give a detailed insight into all determination procedures and provide a primary focus on all studied parameters having a significant effect on heat and mass transfer coefficients.

    更新日期:2018-02-04
  • Rapid prediction of single green coffee bean moisture and lipid content by hyperspectral imaging
    J. Food Eng. (IF 3.099) Pub Date : 2018-02-03
    Nicola Caporaso, Martin B. Whitworth, Stephen Grebby, Ian D. Fisk
    更新日期:2018-02-04
  • Effects of microwave combined with conduction heating on surimi quality and morphology
    J. Food Eng. (IF 3.099) Pub Date : 2018-02-01
    Hongwei Cao, Daming Fan, Xidong Jiao, Jianlian Huang, Jianxin Zhao, Bowen Yan, Wenguo Zhou, Wenhai Zhang, Hao Zhang

    Past studies have reported that microwave heating (MW) usually leads to higher cooking loss and texture deterioration in surimi processing. The objective of this study was to evaluate the effects of different microwave heating methods on surimi gel properties. Compared to traditional two steps water bath heating method (WB), using microwave heating to replace the first step of water bath heating would lead to the deterioration of surimi quality. By contrast, using microwave heating to replace the second step of water bath heating could significantly improve gel strength and water holding capacity. Microwave heating contributed to gelation and promoted the cross-linking of proteins via disulfide and non-disulfide covalent bonds. From scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM), microwave heating coupled to the traditional water heating method resulted in more compact network structures. Although the favorable gel strength was obtained by both the time-dependent mode and temperature preservation mode, CLSM three-dimensional micrographs revealed that the time-dependent mode contributed to shrinkage and rough surfaces. Therefore, the rapid heating rate of microwave results in the aggregation of proteins with superior texture, and the temperature-preservation mode results in desirable morphology and improved texture.

    更新日期:2018-02-02
  • Influence of nanofiltration membrane features on enrichment of jussara ethanolic extract (Euterpe edulis) in anthocyanins
    J. Food Eng. (IF 3.099) Pub Date : 2018-01-30
    Gláucia S. Vieira, Francys K.V. Moreira, Regiane L.S. Matsumoto, Mariano Michelon, Francisco M. Filho, Miriam D. Hubinger

    Anthocyanins have been concentrated from ethanolic jussara (Euterpe edulis) extract by nanofiltration. Six commercial flat-sheet membranes with nominal molecular weight cut-off ranging from 150 to 1000 g mol−1 (NF270 and NF90 from Filmtec Dow, NP010 and NP030 from Microdyn Nadir and Desal 5-DK and Desal 5-DL from GE Osmonics) were characterized in terms of their textural properties, surface morphology and further evaluated for jussara extract nanofiltration performance. Nanofiltration trials were conducted on a stainless steel stirred dead-end cell, in which permeate fluxes were recorded by keeping operational conditions constant at 25 bar and 25 °C. N2 adsorption isotherms and atomic force microscopy images revealed a nanoporous bulk for all membranes. Changes in roughness and contact angle of membranes were observed to occur after nanofiltration trials. The Desal 5-DK membrane showed the highest efficiency for jussara extract nanofiltration due to its highest flux and smallest flux decline, in addition to the highest anthocyanins retention capacity in relation to the other commercial nanofiltration membranes.

    更新日期:2018-01-30
  • Development of a coaxial extrusion deposition for 3D printing of customizable pectin-based food simulant
    J. Food Eng. (IF 3.099) Pub Date : 2018-01-30
    Valérie Vancauwenberghe, Pieter Verboven, Jeroen Lammertyn, Bart Nicolaï

    A coaxial extrusion printhead was designed for 3D printing of pectin-based food simulants in which the inner flow is the food-ink and the outer a CaCl2 crosslinking solution. A series of cubic-shaped objects was successfully 3D printed by changing the printing parameters including the food-ink composition, the layer height, and the rate and CaCl2 concentration of the outer flow. The printed objects did not necessitate any incubation post-treatment because the gelation of the food-ink occurred during the printing. The mechanical properties of the printed object were correlated to their final Ca2+ concentration which can be controlled by the rate and CaCl2 concentration of the outer flow. A predictive model was established for determining the printing settings to print 3D objects with a priori defined texture. The layer height was recommended to be set in function of the food-ink swelling behavior. Finally, we compared objects printed by coaxial and simple extrusion methods. The compared objects had similar Young's moduli but their other properties including volume and final Ca2+ concentration, were considerably impacted by the printing method.

    更新日期:2018-01-30
  • Implementation of NIR technology for at-line rapid detection of sunflower oil adulterated with mineral oil
    J. Food Eng. (IF 3.099) Pub Date : 2018-01-19
    Pierre A. Picouet, Pere Gou, Risto Hyypiö, Massimo Castellari

    Three experimental setups, based on near infrared technology (NIR), were tested for rapid “at-line” assessment of sunflower oil adulteration by mineral oil. Experimental setups included a commercial portable NIR, coupled to both reflexion (S1) and immersion probes (S2), and a prototype of a multichannel Quasi Imaging Visible NIR spectrometer (QIVN) coupled to an immersion probe (S3). Independent calibration and validation samples sets were prepared with mineral oils (MOs) content up to 10 % (w/w), and calibrations were developed using partial least square (PLS) regressions. Root mean square error of prediction (RMSEP) ranges from 0.23 to 1.26 % (w/w) MOs, depending on the NIR setup. The best performances were obtained with S1, which provides satisfactory calibrations, and low number of false positives starting from levels of mineral oil around 1 %. S3 still provides acceptable calibrations, and could be practically used to detect mineral oil at concentrations higher than 2.5% (w/w) MOs.

    更新日期:2018-01-19
  • Derivation of two layer drying model with shrinkage and analysis of volatile depletion during drying of banana.
    J. Food Eng. (IF 3.099) Pub Date : 2018-01-18
    Bithika Saha, Martin Bucknall, Jayashree Arcot, Robert Driscoll

    An existing two layer evaporation/diffusion model of thin layer drying was modified to incorporate shrinkage. The model was developed and tested for a heat pump test dryer using cylindrical slices of banana, which were dried as a single layer. Shrinkage and drying data were collected over a range of conditions from 28-38°C and 12-30% relative humidity. In addition, models of depletion of key aroma volatiles were developed, to allow prediction of aroma profiles under different drying conditions. It was found that inclusion of shrinkage significantly improved the goodness of fit of the drying model, with shrinkage in the direction of slice thickness found to have a greater effect on drying rates than shrinkage in the radial direction. Aroma profiles were compared at different drying intervals, using four banana flavor compounds as indicators. Volatile depletion during drying was found to approximate a first order kinetic reaction with exponential decay over short periods.

    更新日期:2018-01-18
  • Influence of non-fat particulate network on fat bloom development in a model chocolate
    J. Food Eng. (IF 3.099) Pub Date : 2018-01-12
    Huanhuan Zhao, Gokhan Bingol, Bryony J. James

    Particle size effect on fat bloom formation in chocolate was studied. Model chocolates with 68% (w/w) sand particles of varying particle size distributions (D90 of 18.7, 29.3, 41.4 and 51.1 μm) were produced and stored under cycling temperatures of 20 °C (7 h) and 29 °C (17 h). Fat bloom formation was evaluated by the change of surface whiteness during 60 days’ storage, whilst the associated changes of melting temperatures were determined using Differential Scanning Calorimetry. The melting temperatures increased significantly (P < .05) from 31.5 to 35.7 °C with storage time due to polymorphic transformation of fat; the increase in onset temperature indicated reduced liquid fat content which decreased the rate of bloom formation from 9 days of storage. Image analysis showed that smaller particle sizes had higher particle packing density, decreasing the radius of inter-particle channels for fat movement. Therefore, the samples with smaller particle size were more resistant to fat migration and had less changes of surface whiteness, thus bloom rate was slower.

    更新日期:2018-01-12
  • Simulation of a sugar beet factory using a chemical engineering software (ProSimPlus®) to perform Pinch and exergy analysis
    J. Food Eng. (IF 3.099) Pub Date : 2018-01-11
    Charlène Lambert, Benjamin Laulan, Martine Decloux, Hédi Romdhana, Francis Courtois

    To reduce energy cost and comply with recent European regulations, there is a growing interest for generic computer-aided tools to optimize energy consumption in food factories. There are several chemical engineering software but none dedicated to food processes. Prior to Pinch and exergy analysis, the entire process needs to be modelled, with specific constraints related to exergy analysis and scientific bottlenecks related to the estimation of thermophysical properties of food products and the modelling of unit operations specific to food processes. In this study, a generic methodology to model food processes to in fine allow Pinch and exergy analyses is proposed. The methodology was applied to the sugar beet process. The developed model allowed simulation of a real sugar beet factory, with deviation ranges within the uncertainties on industrial data.

    更新日期:2018-01-12
  • Design of dipalmitoyl lecithin liposomes loaded with quercetin and rutin and their release kinetics from carboxymethyl cellulose edible films
    J. Food Eng. (IF 3.099) Pub Date : 2018-01-04
    A. Silva-Weiss, M. Quilaqueo, O. Venegas, M. Ahumada, W. Silva, F. Osorio, B. Giménez

    Quercetin and rutin were encapsulated in liposomes based on dipalmitoyl lecithin. The effect of liposomal formulation stage for flavonol incorporation and the size-reducing method on encapsulation efficiency (EE) of flavonols and physical properties of liposomes were evaluated. In addition, the release mechanism and kinetics of polyphenols from carboxymethyl cellulose edible films were studied through modeling and simulation equations. When flavonols were incorporated during the phospholipid film formation stage, low polydispersity index (0.32 and 0.20) and high EE (88.9 and 74.1%) of quercetin and rutin, respectively, were obtained. Sonication gave liposomes with higher zeta potential (36.9–42.4 mV) than extrusion (13.3–17.1 mV), and quercetin-loaded liposomes were the most stable during 21 days of storage. In CMC films, diffusion coefficients of flavonols were higher for non-encapsulated flavonols than encapsulated flavonols. The release of non-encapsulated quercetin and rutin from CMC films was 25% and 24% higher than in the case of encapsulated quercetin and rutin at day 21. The released mechanism agreed with Fickian diffusion for encapsulated and non-encapsulated quercetin, whereas the release mechanism of encapsulated and non-encapsulated rutin agreed with non-Fickian diffusion. These results highlight the relevance of using liposomes as encapsulation technology, able to preserve polyphenols and control their release in the design of edible films with antioxidant activity for improving food shelf life.

    更新日期:2018-01-04
  • Study of the cheese salting process by dielectric properties at microwave frequencies
    J. Food Eng. (IF 3.099) Pub Date : 2018-01-03
    J. Velázquez-Varela, M. Castro-Giraldez, L. Cuibus, J.A. Tomas-Egea, C. Socaciu, P.J. Fito

    The salting process involves complex phenomena that affect the overall quality of cheese due to its effect on water activity and induced biochemical changes. The permittivity of cheese was analysed throughout the cheese salting treatment in order to relate it to water and salt transport. The salting treatment was carried out using 25% (w/w) sodium chloride brine at 4 °C. The samples were immersed in a vessel containing the osmotic solution with continuous stirring, for 0, 10, 20, 30, 40, 50, 60, 90, 120, 180, 240, 360, 480, 720, 900 and 1440 min. Samples were subsequently equilibrated in an isothermal chamber at 4 °C for 24 h. Mass, volume, surface water activity, moisture, ion content and permittivity were determined in fresh and salted samples. Permittivity was measured from 500 MHz to 20 GHz, using an open-ended coaxial probe connected to a Vector Network Analyzer. The results showed that measurements at 20 GHz explain the water loss and water flux in the overall product. The state of the electrolytes in cheese can be followed using the ionic conductivity at 500 MHz. A coupled measurement of permittivity at 20 GHz and 500 MHz can predict the chemical species involved in the cheese salting process, and its structural changes. In conclusion, the measurement of permittivity in the microwave range can be used to monitor the salting cheese process.

    更新日期:2018-01-03
  • Progressive stirred freeze-concentration of ethanol-water solutions
    J. Food Eng. (IF 3.099) Pub Date : 2018-01-02
    M. Osorio, F.L. Moreno, M. Raventós, E. Hernández, Y. Ruiz

    Progressive freeze-concentration is a technology to separate water from solutions by freezing. In the present investigation, ethanol-water solutions were freeze-concentrated by the progressive stirred technique. The freezing stage was carried out in a stirring vessel. Solute recovery by the fractionated thawing of ice was also studied. The effects of stirring speed (500, 1000, and 2000 rpm), initial concentration of the solution (3%, 5%, and 8% ethanol), and temperature of the thawing stage (0, 10, and 20 °C) on the solute yield and average distribution coefficient were determined using response surface analysis. The ethanol concentration was found to have increased by 1.3 and 2.1 times at the end of the freeze concentration process. It was found that the initial concentration had a significant effect on the distribution coefficient. In addition, the average yield was increased by 28% by fractionated thawing. Subsequently, a non-dimensional analysis of the distribution coefficient was developed to yield a model to predict the distribution coefficient as a function of the Reynolds number, the relationship between the average ice growth rate and the stirring speed, the agitator diameter, and the liquid fraction. This technique proved to be valid with respect to the concentration of ethanol-water solutions, with better yields being obtained at low initial concentrations. This model is the first of its kind to describe the ethanol-water interaction in agitated freeze-concentration systems.

    更新日期:2018-01-03
  • Microwave absorption capacity of rice flour. Impact of the radiation on rice flour microstructure, thermal and viscometric properties
    J. Food Eng. (IF 3.099) Pub Date : 2018-01-02
    Marina Villanueva, Joanna Harasym, José María Muñoz, Felicidad Ronda

    The microwave radiation thermal treatment of rice flour was studied and its impact on physical and structural characteristic in relation to the initial moisture content (IMC) (20% and 30%) was evaluated. To explain the fundamentals of observed changes the microwave radiation absorption capacity of flour as well as temperature and moisture change during the treatment were evaluated. The flour particle morphological structure as well as crystallinity/amorphous region ratio changed after the treatment. The flour thermal properties also altered revealing IMC significant impact on the gelatinization temperature, that raised up to 3ºC, and the amylopectin retrogradation extent that increased up to a 7% in the most intense microwave-treated flours with respect to the native flour. Lower peak, setback and breakdown viscosities - that decreased with respect to the native flour up to 42%, 34% and 86% respectively-and higher pasting temperatures -that increased up to 10 ºC- were also observed. An exceptional microwave irradiation efficiency resulting in rice flour physical changes in significantly shorter times, 4–8 min, than conventional heat-moisture treatment processes was concluded.

    更新日期:2018-01-02
  • Whey protein concentrate (WPC) production: Environmental impact assessment
    J. Food Eng. (IF 3.099) Pub Date : 2017-12-30
    Jacopo Bacenetti, Luciana Bava, Andrea Schievano, Maddalena Zucali

    Cheese-making is a process that produces multiple coproducts, of which whey is the most abundant in terms of volume. It is often considered a waste product, but whey is rich in lactose, proteins and fats. The aim of the study was to evaluate the environmental impact of the production of whey protein concentrate (WPC) with an ultrafiltration process throughout a life cycle approach. The environmental impacts of three WPCs, characterized by different protein concentrations (WPC35, WPC60, WPC80), were estimated. A scenario analysis was performed to understand the mitigation effect of the pre-concentration process carried out in a pretreatment plant to obtain whey with a dry matter content of 20%. Two sensitivity analyses were performed: the first changing the transport distance of whey, the second using a different allocation method. Transportation of the whey was one of the main hotspots in the life cycle assessment performed (28–70%); electricity use accounted for 18–20% of the impact. The alternative scenario, that involves the pre-concentration of whey, obtained a reduction of the impacts from 0.9% to 14.3%. The pre-concentration of whey in a pretreatment plant closer to the cheese factory reduces the environmental burden of the whole process. This occurs even if the energy consumption for pre-concentration increases due to the use of smaller and less efficient devices.

    更新日期:2017-12-31
  • Temperature-controlled microwave-vacuum drying of lactic acid bacteria: Impact of drying conditions on process and product characteristics
    J. Food Eng. (IF 3.099) Pub Date : 2017-12-30
    S. Ambros, P. Foerst, U. Kulozik

    An efficient drying process for high-value products such as bacterial cultures is characterized by high retention of viability or activity, but low energy demand. Microwave-vacuum drying was tested in this work as a new technique for the preservation of probiotics and starter cultures, which has the potential to fulfill all of these requirements. The impact of chamber pressure (7, 15, 30 mbar), microwave power (1 to 5 W g-1) and maximum product temperature (30 to 50 °C) on drying time, drying rate, efficiency of microwave input and survival rate of the model strain Lactobacillus paracasei ssp. paracasei F19 (L. paracasei F19) was studied. Microwave drying time ranged from 50 to 240 min with microwave power as main influencing factor on drying behavior and efficiency. The maximum product temperature and vacuum pressure did not affect the drying time, absorbed energy and thus microwave efficiency significantly, but both parameters had a great impact on survival rate. The combination of 3 W g-1 microwave power input and 35 °C maximum temperature at a low chamber pressure of 7 mbar resulted in a very short drying time of 64 min, a high level of energy efficiency (27%) and also the best product quality in terms of survival rate (33%). Thus, a microwave-vacuum drying process is a potential alternative to conventional freeze or vacuum drying.

    更新日期:2017-12-31
  • Noncontact evaluation of soluble solids content in apples by Near-infrared hyperspectral imaging
    J. Food Eng. (IF 3.099) Pub Date : 2017-12-30
    Te Ma, Xinze Li, Tetsuya Inagaki, Haoyu Yang, Satoru Tsuchikawa

    Near-infrared (NIR) hyperspectral imaging was used to evaluate soluble solids content (SSC) in ‘Fuji’ apples [Malus sylvestris (L.) Mill. var. domestica (Borkh. Mansf.)]. Eighty ‘Fuji’ apples were analyzed by collecting four small block samples from each one (approximately 2.0 cm×2.0 cm×1.5 cm). Partial least squares (PLS) regression analysis was performed to determine the relation between SSC reference data and NIR spectral data measured from each sample. The cross-validation coefficient of determination (r2) between predicted and measured SSC values is 0.89 with a root mean squared error of cross-validation (RMSECV) of 0.55%. Then, we successfully mapped SSC at a high spatial resolution (375 μm per pixel). In addition, the absorption and reduced scattering coefficients of the measured samples were determined based on a diffusion theory model. The absorption coefficients are positively correlated to the SSC values (chemical information), whereas water cored tissue content (physical information) causes a characteristic change in light scattering coefficients. The fitting results were validated by Monte Carlo simulation, and the light penetration depth in ‘Fuji’ apples was estimated to be around 0.33 cm at 1198 nm and 0.17 cm at 1450 nm, respectively.

    更新日期:2017-12-31
  • Strategies to improve carotene entry into cells of Yarrowia lipolytica in a goal of encapsulation
    J. Food Eng. (IF 3.099) Pub Date : 2017-12-30
    Pham-Hoang Bao Ngoc, Romero-Guido Cynthia, Phan-Thi Hanh, Waché Yves

    Yeasts are good materials for encapsulation of actives, but, as they are preformed capsules, they have to be loaded. Our goal was to load cells with a big and very hydrophobic molecule, β-carotene (LogP ≈15). In classical conditions, the entry of this compound into cells is negligible and we have worked on ways to favor the entry through the cell wall. Carotene was prepared at 0.3-3 g L-1 in solvents to improve solubility and alter the cell wall structure. After a 3 h-incubation of cells with this solution, with the apolar hexane, the entry was increased to 95 µg g-1 cell wet weight but the monopolar chloroform was much more efficient (220 µg g-1 cell wet weight). However, increasing the carotene concentration in chloroform increased the adhesion of carotene on the cell wall (over 900 µg g-1 cell wet weight) but did not increase the amount into the cell. The use of ultrasound (6-min-treatment at 50% and an output control of 4) as a green physical treatment increased significantly the result for β-carotene encapsulation (852 µg g-1 cell wet weight).

    更新日期:2017-12-31
  • Authenticity of freeze-dried açai pulp by near-infrared spectroscopy
    J. Food Eng. (IF 3.099) Pub Date : 2017-12-30
    Kleidson Brito de Sousa Lobato, Priscila Domingues Alamar, Elem Tamirys dos Santos Caramês, Juliana Azevedo Lima Pallone
    更新日期:2017-12-31
  • Kinetic and isotherm studies on the adsorption of tenuazonic acid from fruit juice using inactivated LAB
    J. Food Eng. (IF 3.099) Pub Date : 2017-12-29
    Bei Liu, Na Ge, Bangzhu Peng, Siyi Pan

    Tenuazonic acid is a fungal secondary metabolite that is produced by a number of Alternaria species and is therefore a natural contaminant of food and feed samples. The aim of this study was to investigate the adsorption kinetics and isotherms of tenuazonic acid (TeA) from citrus juice using inactivated lactic acid bacteria (LAB). The results showed that inactivated LAB-20023 could significantly reduce TeA from contaminated fruit juice. The kinetic models indicated that the biosorption process of TeA onto inactivated cells from fruit juice obeys a pseudo-second-order model rather than a pseudo-first-order kinetic model at all studied temperatures and initial concentrations. The equilibrium data were fitted to Langmuir and Freundlich isotherm models, and the results showed that the adsorption equilibrium was best described by the Freundlich isotherm.

    更新日期:2017-12-31
  • Effect of a heat-spray and heat-double spray process using radiofrequency technology and ethanol on inoculated nuts.
    J. Food Eng. (IF 3.099) Pub Date : 2017-12-28
    Fredy Salazar, Sara Garcia, Manuel Lagunas-Solar, Zhongli Pan, James Cullor

    Almonds provide a nutritious source of energy and are known to have led to positive health benefits when consumed. However, outbreaks of Salmonella spp. in raw almonds have led to reduced consumer confidence in the nut industry. Regulatory standards established by the FDA require almonds destined for consumption in the US to undergo a process treatment that reduces Salmonella spp., by 4.0 log10 CFU/g. Four Generally Recognized as Safe (GRAS) surface disinfectants suchs as ethanol, hydrogen peroxide, acetic acid, and peracetic acid were tested on almonds inoculated with Enterococcus faecium NRRL B-2354. It was found that 70% ethanol has the most potential to achieve a high log10 CFU/g reduction, while holding quality. The optimal spray process had the following parameters: (1) a spray quantity of 4.5% w/w (p<0.05), (2) contact time of 1-30 min (3) use of 2 spray phases (p<0.05). The use of radiofrequency (RF) heating and 70% ethanol in the heat-spray process achieved 5.8 log10 CFU/g reductions. In this experimental mode, independent heat and spraying achieved 2.9 and 3.0 log10 CFU/g reduction, which corresponds to a contribution of 50% each to the combined heat-spray process using RF heating. The RF experiments in the heat-double spray process achieved log10 reductions of 6.7, 4.7, 3.8, and 3.5 log10 CFU/g for almonds, pecans, pistachios, and walnuts, respectively. The implications of these findings are that both the heat-spray and heat-double spray process may become alternatives to current nut disinfection process to achieve high log10 reduction.

    更新日期:2017-12-31
  • Ultrasound-assisted bleaching of olive oil: Kinetics, isotherms and thermodynamics
    J. Food Eng. (IF 3.099) Pub Date : 2017-12-28
    Sara Asgari, Mohammad Ali Sahari, Mohsen Barzegar

    Experimental data of the adsorption of carotenoids and chlorophylls were investigated to obtain adsorption kinetic, isotherm and thermodynamic information during ultrasound-assisted bleaching (US bleaching) of olive oil and to compare them with the results from conventional bleaching method. Adsorption of pigments on activated bentonite was rather fast and efficient by applying ultrasound. In both bleaching procedures, the kinetics of carotenoids adsorption followed pseudo-first order model whereas pseudo-second order equation gave a better fit to the adsorption of chlorophylls. It is speculated that adsorption of carotenoids is mainly facilitated by physisorption while chemical reactions are also involved in the removal of chlorophyll pigments under sonication. Equilibrium study shows that the adsorption behavior of the two pigments is different. Freundlich isotherm provided accurate estimates of adsorption equilibrium data of chlorophylls during US bleaching indicating a multilayer adsorption under ultrasound irradiation. According to the thermodynamic analysis, both bleaching methods are endothermic and spontaneous with increased randomness at the solid-liquid interface.

    更新日期:2017-12-31
  • Menthol/cyclodextrin inclusion complex nanofibers: Enhanced water-solubility and high-temperature stability of menthol
    J. Food Eng. (IF 3.099) Pub Date : 2017-12-27
    Zehra Irem Yildiz, Asli Celebioglu, Mehmet Emin Kilic, Engin Durgun, Tamer Uyar
    更新日期:2017-12-27
  • Green coffee extracts rich in diterpenes – Process optimization of pressurized liquid extraction using ethanol as solven
    J. Food Eng. (IF 3.099) Pub Date : 2017-12-26
    Naila Albertina de Oliveira, Heber P. Cornelio-Santiago, Heidge Fukumasu, Alessandra Lopes de Oliveira

    In this study, a pressurized liquid extraction (PLE) was optimized to obtain green coffee extract rich in cafestol and kahweol diterpenes. The effects of temperature (T) and static time (St) (time of contact between the solvent and the matrix during each cycle or batch) on global yield, cafestol and kahweol concentrations and antioxidant activity were studied. The greatest green coffee extract global yield (9.78%) was obtained at 70 °C and 8 min St. PLE at 74 °C and 6 min St presented the highest concentration of cafestol (20.08 g/kg extract) in the green coffee extract, whereas, the highest kahweol concentration (25.16 g/kg extract) was obtained at 60 °C and 6 min St. The extracts showed high DPPH• antioxidant activity, particularly after PLE at 50 °C and 8 min St (EC50 1.56 μg/mL of extract). This extract also presented a high total phenolic content (35.99 mg GAE/g of extract).

    更新日期:2017-12-27
  • Dry heating a freeze-dried whey protein powder: Formation of microparticles at pH 9.5
    J. Food Eng. (IF 3.099) Pub Date : 2017-12-23
    Marie-Hélène Famelart, Elise Schong, Thomas Croguennec

    We investigated the effect of dry heating (DH) a whey protein powder (water activity 0.24) at pH 3.5, 6.5 and 9.5 for up to 36 h at 100 °C on the structural properties of proteins. Powder browning, particle structures in suspensions reconstituted from the dry-heated powders (DHP), residual native protein content and Maillard reaction markers were studied. The browning index of the DHP rapidly increased after 6–10 h of DH and then levelled off at all pH values. β-Lactoglobulin, α-lactalbumin and bovine serum albumin were denatured by DH at all pH values. In contrast to pH 3.5 and 6.5, DH at pH 9.5 led to abundant production of microparticles. The highly heterogeneous size of these particles was related to the initial powder particle size. One g of DHP in suspension led to 20 g of hydrated microparticles made from 0.5 g of dry material. Maillard reactions at pH 9.5 were probably involved in microparticle formation.

    更新日期:2017-12-27
  • Kinetic modeling of ascorbic acid degradation of pineapple juice subjected to combined pressure-thermal treatment
    J. Food Eng. (IF 3.099) Pub Date : 2017-12-22
    Santosh Dhakal, V.M. Balasubramaniam, Huseyin Ayvaz, Luis Rodriguez-Saona

    A study was conducted to investigate and model kinetic degradation of ascorbic acid in freshly prepared pineapple juice subjected to various pressure (0.1, 300,450 and 600 MPa)-thermal (30, 75, 85 and 95 °C) treatment combinations. Experiments were conducted using a semi-custom made high pressure kinetic tester as well as an aluminum thermal kinetic tester. Thermal degradation of ascorbic acid was described with simple first order kinetics. The thermal rate constants (k75 -95 ◦C, 0.1 MPa) and activation energy ( View the MathML source E a ) for ascorbic acid degradation reaction varied in the range of 0.004–0.006 per min and 14.22–29.78 kJ/mol, respectively. Within the experimental conditions of the study (300–600 MPa at 30 °C for holding times up to 15 min) high pressure processing did not alter ascorbic acid content (535.5–564.5 mg/kg). Combined pressure-thermal treatment (300–600 MPa at 75–95 °C) degraded ascorbic acid with increasing thermal intensity and was modeled using first order fractional conversion kinetics model. The lower asymptote value ( View the MathML source [ A ] ∞ [ A ] 0 ), rate constants (k75 -95 ◦C, 600 MPa) and View the MathML source E a were in the range of 77–85%, 0.108 to 0.138 per min and 17.4–43.8 kJ/mol, respectively. Similarly, pressure sensitivity (ΔV≠ Δ V ≠ ) was ∼0 and −2.99 cm3/mol at 30 and 95 °C, respectively. Knowledge gained from the study can be useful for food processors to optimize high pressure treatment conditions for pineapple juice products.

    更新日期:2017-12-22
  • Online reconstruction of oil oxidation kinetics and reaction schemes during deep-frying by deconvolution of ATR-FTIR spectra
    J. Food Eng. (IF 3.099) Pub Date : 2017-12-21
    Maxime Touffet, Anna Patsioura, Aman Mohammad Ziaiifar, Luc Eveleigh, Olivier Vitrac

    Evaluating and improving the thermal stability of frying oil is of major concern for the whole frying industry, including oil producers and manufacturers of deep-fryers. Online measurements of oil degradation rely on coarse indicators such as total polar compounds (TPC) and free-fatty acids. We propose in this study to increase the “chemical resolution” of rapid tests by proposing point ATR-FTIR measurements for the local determinations of oxidation products in batch and continuous deep-fryers. Based on the deconvolution of four main regions of interest in the mid-infrared range and the identification of ten peaks, we describe the reconstruction kinetics of eight compounds or chemical functions. The whole methodology has been validated on the broad range of temperatures (140–180 °C), oxygenation conditions and oil composition described in Ref. [Patsioura et al., Food Bioprod Process Journal, 2017, 101, 84–99]. The study illustrated how the local oil composition can be used to discriminate oil oxidation pathways and to analyze the coupling between mass transport, heat transfer and oxidation reactions in connection with the deep-fryer design. An example of the local reconstruction of reaction schemes is detailed in inhomogeneous oxygenation and temperature conditions.

    更新日期:2017-12-21
  • Encapsulation of food waste compounds in soy phosphatidylcholine liposomes: Effect of freeze-drying, storage stability and functional aptitude
    J. Food Eng. (IF 3.099) Pub Date : 2017-12-20
    D. Marín, A. Alemán, P. Montero, M.C. Gómez-Guillén

    Liposomes made from soy phosphatidylcholine entrapping food waste compounds (collagen hydrolysate, L-HC; pomegranate peel extract, L-PG; and shrimp lipid extract, L-SL) were freeze-dried and stored for seven months. The freeze-drying process increased the particle size and decreased water solubility. The freeze-dried L-HC and L-PG preparations presented large multivesicular vesicles with spherical and unilamellar morphology. Large multilamellar vesicles were observed in L-SL, coinciding with greater structural changes in the membrane bilayer and increased thermal stability, as observed by ATR-FTIR and DSC. Dynamic oscillatory rheology revealed a slight hardening in the dried liposomes, induced by storage time. A sharp rigidifying effect in the temperature range from 40 to 90 °C was observed in L-SL. The loading with antioxidant compounds prevented freeze-drying-induced lipid oxidation. The storage stability of freeze-dried liposomes and their technological aptitude as a food ingredient varied depending on the chemical nature of the entrapped compounds.

    更新日期:2017-12-21
  • Classification of puffed snacks freshness based on crispiness-related mechanical and acoustical properties
    J. Food Eng. (IF 3.099) Pub Date : 2017-12-20
    Solange Sanahuja, Manuel Fédou, Heiko Briesen

    The use of instrumental methods to support sensory panels in the routine quality control of crispiness remains challenging. Texture analysis is often insufficient to accurately classify this complex sensory attribute. Herein, 70 different food properties were combined via machine learning algorithms to mimic multisensory integration. Force and sound were measured during crushing of puffed snacks equilibrated at different humidity levels. Sensory panels then ranked crispiness-related freshness and preference based on the recorded sounds. Selected feature combinations were used to train machine learning models to recognize the freshness levels at different humidity levels. The classification accuracy was improved compared with traditional texture analysis techniques; an accuracy of up to 92% could be achieved with quadratic support vector machine or artificial neural network algorithms. Moreover, third-octave frequency bands, characterizing breakage frequencies and sound pitches, were determined to be main descriptors to be taken into account during the research and development of puffed snacks.

    更新日期:2017-12-20
  • Wheat dough imitating artificial dough system based on hydrocolloids and glass beads
    J. Food Eng. (IF 3.099) Pub Date : 2017-12-20
    Silvia Brandner, Thomas Becker, Mario Jekle

    Viscoelastic wheat dough properties are a function of processing time, raw material fluctuations, (baking-) process conditions and enzyme/yeast activity. Consequently, varying dough properties complicate analysing mechanisms of structure determining reactions. Therefore, the replacement of wheat dough by an artificial dough system offers a simplified and standardized system, allowing better analysis of mechanistic interdependences in dough systems. To imitate wheat dough, natural and synthetic hydrocolloids were combined with filler particles. These systems were analysed in terms of their ability to mimic wheat dough by using fundamental rheological tests. In total, 106 artificial dough systems were tested and their functional properties compared to that of wheat dough. Particularly, a blend of HPC and PVP showed consistent viscoelastic properties. The flow index of the storage module is identical for the artificial system (n' = 0.21 ± 0.01) and wheat dough (n' = 0.21 ± 0.02). Finally, a dough imitating artificial polymer system was developed. It offers the advantages of simplification due to a limitation to the essential network elements and standardization, based on avoided enzyme activity and constant material properties.

    更新日期:2017-12-20
  • Effect of ultrasound on structure and functional properties of laccase-catalyzed α-lactalbumin
    J. Food Eng. (IF 3.099) Pub Date : 2017-12-19
    Xiangying Yuan, Xueyan Li, Xinliu Zhang, Zhishen Mu, Zengli Gao, Lianzhou Jiang, Zhanmei Jiang

    The effects of ultrasound (400 W, for 0, 20, 40, 60, 80, or 100 min) pre-treatment on the physicochemical properties, functionality and structure of laccase-catalyzed α-LA in the presence of ferulic acid (FA), were investigated in this study. Size exclusion chromatography showed that α-LA monomers decreased significantly in the presence of laccase and FA, and its high molecule polymers were formed with increasing ultrasonic time. SDS-PAGE analysis also showed that ultrasound treatment contributed to the formation of oligomers and polymers of α-LA treated with laccase and FA. Surface hydrophobility and gel strength of laccase-catalyzed α-LA-FA conjugates were higher than that of three control systems, and gradually enhanced with the ultrasonic time increased. Moreover, ultrasound-treated α-LA with laccase and FA had greater G′ values than other three control systems according to the rheological measurements. Ultrasound treatment did not significantly changed conformational structure of laccase-catalyzed α-LA-FA conjugates, as demonstrated by CD spectra. Therefore, ultrasound contributed to form greater non-covalent and covalent interactions between α-LA molecules and aggregates, and could remarkably change physicochemical and functional properties of laccase-catalyzed α-LA-FA conjugates.

    更新日期:2017-12-19
  • Effects of metal nanoparticles on the physical and migration properties of low density polyethylene films
    J. Food Eng. (IF 3.099) Pub Date : 2017-12-19
    Süleyman Polat, Hasan Fenercioğlu, Mehmet Güçlü

    This paper reports the impact of the addition of Ag or ZnO nanoparticles on the morphological, mechanical, barrier properties and migration behavior of low-density polyethylene (LDPE) films prepared by melt extrusion. Depending on the nanoparticle concentrations, the color of the films was changed, and the light transparency decreased. The addition of nanoparticles reduced the oxygen and water vapor transmission rates, as well as the mechanical (tensile strength and percent elongation) properties, compared to pure LDPE films. ZnO nanoparticles caused a greater decrease in the tensile strength of the nanocomposite films than the Ag-containing nanoparticles. The migration tests of the majority of the films, in isooctane, ethanol and acetic acid showed that the total migration limit of 10 mg/dm2 was not exceeded. However, the migration tests of LDPE-based films containing 3 and 5% ZnO nanoparticles in 3% acetic acid, representing acidic foods, were determined as 15.93 and 23.29 mg/dm2, respectively.

    更新日期:2017-12-19
  • Assessing the potential of whey protein fibril as emulsifier
    J. Food Eng. (IF 3.099) Pub Date : 2017-12-14
    Raphaela Araujo Mantovani, Guilherme de Figueiredo Furtado, Flavia Maria Netto, Rosiane Lopes Cunha
    更新日期:2017-12-14
  • 3D printing of plant tissue for innovative food manufacturing: Encapsulation of alive plant cells into pectin based bio-ink
    J. Food Eng. (IF 3.099) Pub Date : 2017-12-09
    Valérie Vancauwenberghe, Victor Baiye Mfortaw Mbong, Els Vanstreels, Pieter Verboven, Jeroen Lammertyn, Bart Nicolai

    3D food printing allows creation of foods by depositing food material according to computer aided designs. However, the number of printable materials for food is still low which limits the possibilities of creating specific structures and textures. A novel approach is tested of using food printing materials incorporating plant cells in order to print foods that resemble plant tissues in various ways. A 3D printing method was developed based on the extrusion of bio-inks composed of a low-methoxylated pectin gel and embedded lettuce leaf cells. Bovine serum albumin was added in order to increase the air fraction in the printed gel matrix. Objects containing up to 5 × 106 cells/mL were successfully 3D printed. The mechanical strength increased by the pectin concentration and decreased with the increase of air fraction and concentration of encapsulated cells. The viability of the encapsulated plant cells depended on the pectin concentration and varied from 50 to 60%.

    更新日期:2017-12-14
  • Analysis of the heat transfer characteristics of blackberries during microwave vacuum heating
    J. Food Eng. (IF 3.099) Pub Date : 2017-12-05
    ChunFang Song, Tao Wu, Zhenfeng Li, Jing Li

    Microwave vacuum heating of blackberries was carried out to investigate the effects of microwave power and vacuum degree on the temperature of blackberries during the heating process, and the distribution of the temperature field was observed. Using numerical simulations, a combined electromagnetic and heat transfer model was established. The simulations can be used to observe the locations of hot spots and cold spots during heating. The appropriate microwave power and vacuum could also be selected using the simulation to reduce the temperature difference of the locations of hot spots and ensure uniform heating. The results show that, for blackberries heated for 2 min at a microwave power of 400 W and vacuum degree of −80 kPa, the temperature of the hot spot was maintained at about 60 °C and the temperature difference was about 0.27; thus, the heating was uniform, meeting the industrial drying requirements for blackberries.

    更新日期:2017-12-14
  • Efficacy of decontamination and a reduced risk of cross-contamination during ultrasound-assisted washing of fresh produce
    J. Food Eng. (IF 3.099) Pub Date : 2017-12-01
    Kang Huang, Steven Wrenn, Rohan Tikekar, Nitin Nitin

    Contamination of fresh produce with bacteria can occur during cultivation, harvest and post-harvest processing and the current sanitation approaches for post-harvest processing are not adequate for inactivation of pathogenic or spoilage bacteria that may be attached to the surface of fresh produce. This study evaluated the role of ultrasound with and without surfactants and sanitizers to improve decontamination of fresh produce and the impact of these treatments on the quality of fresh produce. Gram-positive bacterial strain Listeria innocua, and gram-negative bacterial strains Escherichia coli O157:H7 and Pseudomonas fluorescens were tested in this study. The reduction in bacterial concentration from inoculated leaf samples increased with an increase in ultrasound treatment time until 10 minute for all the three strains. When compared to ultrasound treatment alone, combination of ultrasound treatment with surfactants did not significantly increase the removal of E. coli and L. innocua from the lettuce surfaces, however, the removal efficacy of P. fluorescens increased significantly under the same treatment conditions. The results of simultaneous washing of multiple leaves using ultrasound showed the net bacterial reduction from lettuce leaves decreased by approximately 0.5 log CFU/cm2 for all the selected strains compared to treatment of a single leaf. Similarly, combination of ultrasound with surfactants for simultaneous treatment of multiple leaves did not improve removal of E. coli and L. innocua from the surface of lettuce leaves, but improved removal of P. fluorescens by approximately 1 log unit when compared to ultrasound treatment alone. The evaluation of the risk of potential cross-contamination during ultrasound washing suggested ultrasound could significantly reduce the bacterial attachment to the uninoculated lettuce surface. Combination of ultrasound with adequate active free chlorine could prevent the transfer of E. coli and L. innocua cells from the inoculated leaf sample to uninoculated leaves. Evaluation of lettuce quality attributes in our study found that exposure to ultrasound treatment for less than 10 min had no significant effect on the quality of fresh lettuce. Thus, ultrasound treatment has a potential to be an alternative for maintaining the safety and quality of fresh produce during post-harvest processing.

    更新日期:2017-12-14
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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