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  • Physicochemical and rheological properties of rice-based gluten-free blends containing differently treated chickpea flours
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-08-21
    Gokcen Kahraman, Sebnem Harsa, Mara Lucisano, Carola Cappa

    This study focused on the evaluation of the physicochemical and rheological properties of chickpea flours and blends obtained by partially substituting rice flour (25 g/100 g) with raw, roasted and dehulled chickpea flour. The characteristics of the resultant doughs were evaluated. In comparison with rice flour, blends containing chickpea flours exhibited high protein and fat content, a reduced retrogradation tendency (setback values of 404–415 vs. 479 BU) and a higher foaming capacity and stability, which can be beneficial for their use in baked food formulations. However, roasting decreased foaming capacity and stability. Even if the rheofermentographic test evidenced a slight reduction in dough development, high CO2 retention capacity (≥98%) and similar-to-lower leavening times were observed for doughs containing chickpea flours. Incorporating chickpea flours also caused an increase in the viscous and elastic moduli of rice-based doughs, resulting in a good structuring of the dough. The results of this study indicated that chickpea flours could be used as a healthy ingredient in gluten-free rice-based formulations.

    更新日期:2018-08-21
  • Extraction of anthocyanins from haskap berry pulp using supercritical carbon dioxide: Influence of co-solvent composition and pretreatment
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-08-21
    Guangling Jiao, Azadeh Kermanshahi pour

    Extracts rich in anthocyanin compounds were obtained from haskap berry pulp paste using supercritical carbon dioxide (scCO2) and water as co-solvent. The extraction conditions including pressure, temperature, and amount of water were further optimized by Box-Behnken design. The highest total anthocyanins (TA) yield of 52.7% was achieved at 45 MPa, 65 °C, 5.4 g water to 3.2 g berry pulp paste, 15 min static and 20 min dynamic time. Different combinations of water and ethanol as co-solvent did not significantly affect the TA yield. Furthermore, similar anthocyanin extraction yields were obtained in the case of the pulp paste and rehydrated freeze-dried berry pulp powder, which indicates that freeze dryings pretreatment is not required prior to scCO2 extraction. Compared with conventional extraction, the use of scCO2 and water as co-solvent offered higher anthocyanin extraction efficiency (52.7% versus 38.3%) with improved antioxidant activity (89.8% versus 72.2%).

    更新日期:2018-08-21
  • Effect of ozone or carbon dioxide pre-treatment during long-term storage of organic table grapes with modified atmosphere packaging
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-08-20
    Naouel Admane, Francesco Genovese, Giuseppe Altieri, Antonella Tauriello, Antonio Trani, Giuseppe Gambacorta, Vincenzo Verrastro, Giovanni Carlo Di Renzo

    The aim of this study was to maintain the quality of organic table grapes extending its shelf-life during long-term storage by using organic approved methods. The effectiveness of pre-treatments with different concentrations of O3 (5, 10, 20 μL L−1) or CO2 (50%, 70%) followed by storage under modified atmosphere packaging (2%O25%CO2) were evaluated on late-season organic Scarlotta table grapes as alternatives to the usual commercial SO2 application. The main quality attributes as mass loss, decay incidence, rachis chlorophyll content, antioxidant activity, phenolic compounds and acetaldehyde content, were measured at harvest and after 15, 30, 45 days of cold storage (0 °C) under simulated shipping conditions and one week of shelf-life (15 °C). The O3 at 20 μL L−1 controlled the concentration of acetaldehyde, preserved rachis chlorophyll content and skin colour; in addition, the cumulative decay incidence was reduced compared to untreated samples, however, CO2 caused organoleptic quality loss with strong stem browning and perceived off-flavours; moreover, it was effective to preserve the initial sensory quality and to control the decay. The results encourage the use of this alternative approach treatment in other cultivars and under commercial conditions.

    更新日期:2018-08-20
  • The effect of organic acid and sodium chloride dips on the shelf-life of refrigerated Irish brown crab (Cancer pagurus) meat
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-08-18
    A. McDermott, P. Whyte, N. Brunton, J. Lyng, J. Fagan, D.J. Bolton

    Crab (Cancer pagurus) meat (white and brown) has a short shelf-life. Chemical treatments may inhibit microbial spoilage and extend shelf-life. The effect of 5% organic acids (lactic acid (LA), acetic acid (AA) and citric acid (CA) and 5% sodium chloride (NaCl) on TVC (mesophiles and psychrophiles), Enterobacteriaceae, Pseudomonas spp. and lactic acid bacteria (LAB) were investigated during storage (2 °C for 12 days). AA was the most effective treatment for white meat, reducing the initial TVCm and TVCp by 1.6 and 1.8 log10 cfu/g, respectively, and extended the shelf life to 8–11.5 days, compared to 5 days for untreated control samples. LA treatment also significantly (P < 0.05) reduced the initial TVC, but the shelf life was only increased by 3 days. CA and NaCl treatments had no significant effect (P > 0.05). A similar pattern was observed for brown meat samples, although the shelf life was increased by a maximum of 1–3 days. The growth of Enterobacteriaceae, Pseudomonas spp. and LAB was significantly (P < 0.05) reduced on AA treated samples only. It was concluded that the shelf-life of crab meat may be extended by up to 3 days using lactic acid and more than doubled using acetic acid.

    更新日期:2018-08-18
  • Formula optimization approach for an alternative Ready-to-Use Therapeutic Food
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-08-18
    Vincenzo Armini, Nicoletta A. Miele, Matteo Albero, Raffaele Sacchi, Silvana Cavella

    Ready-to-Use Therapeutic Food (RUTF) is an energy-dense, micronutrient-enriched paste used for the Community-based Management of Acute Malnutrition (CMAM) in under-five children of low-income countries. Alternative recipes have to reach a decrease of production costs and the use of local staple ingredients, enforcing quality and acceptability of the product. This work consisted on an alternative RUTF formula optimization, with the aim to have a set of optimized creams suitable for child feeding, based on local and cheap ingredients. A response surface D-optimal design was carried out, adopting United Nations Children's Fund (UNICEF) constraints for RUTF formula. The creams showed a time-independent pseudoplastic behavior with n and K in the range 0.38–0.45 and 35–110 Pa∙sn, respectively. The Particle Size Distribution (PSD) curves, as determined by laser diffractometry, were mainly unimodal, with 90% percentiles (D90) varying from 40 to 140 μm. Response variables better explained through chosen models were D90 and K parameter. Thanks to formula optimization approach it has been verified that the consistency and the particle size are strongly affected by the ingredient formulation. The best formulation of model RUTF was found, through the desirability function, imposing as constraints the minimization of both D90 and K index.

    更新日期:2018-08-18
  • Production, physicochemical stability of quercetin-loaded nanoemulsions and evaluation of antioxidant activity in spreadable chicken pâtés
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-08-17
    Cynthia de Carli, Marília Moraes-Lovison, Samantha C. Pinho

    Quercetin is recognized by its high antioxidant activity, but its incorporation in food products can be challenging due to its hydrophobicity. This disadvantage can be overcome by encapsulation in lipid-based matrices like nanoemulsions. In the present study nanoemulsions encapsulating quercetin were produced, using a low-energy method - emulsion inversion point - and using two surfactants (Tween 80 and Brij 30). The average droplet diameters of the nanoemulsions were in the range 180–200 nm, and the nanoemulsions containing 0.30 g quercetin/100 g were capable of preserving around 70% of the flavonoid after 90 d of storage. Conductivity curves indicated the stabilization of nanoemulsions by Brij 30 required a longer time to occur. Both quercetin-loaded nanoemulsions incorporated in chicken paté were capable of protecting it against lipid oxidation, but not against protein oxidation The inhibition of secondary lipid oxidation by the quercetin-loaded nanoemulsions was highly expressive (about 60% after 24 wk of storage, against 8.4% of inhibition in pâtés added with butylated hydroxytoluene – BHT - and sodium nitrite). Sensory data indicated the panelists approved the chicken pâtés incorporated with quercetin-loaded nanoemulsions in terms of odor, taste and color, and that encapsulation of the flavonoid was required to avoid undesirable sensory effects due to its addition.

    更新日期:2018-08-17
  • Potentiality of the use of starter culture in PDO Strachitunt production on chemical-physical and microbiological features: A pilot study
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-08-17
    E. Tirloni, M. Vasconi, P. Cattaneo, A. Ravasio, E. Pesenti, V.M. Moretti, F. Bellagamba, S. Stella, C. Bernardi

    In the present study, Strachitunt, an Italian PDO cheese (PDO), traditionally produced starting from raw milk without addition of starter culture (SC) was compared for chemical, physical and microbiological characteristics to an experimental cheese (EC), produced from the same raw milk but with the addition of commercial SC. EC resulted in significantly lower in bacterial counts during the whole period considered (115 days of ripening), for Enterobacteriaceae, Coliforms, Enterococci and Staphylococcus aureus. Strachitunt fatty acids profile was not influenced by the cheese and it was dominated by saturated fatty acid. Volatile compounds analysis revealed that PDO and EC presented the typical aroma of blue veined cheese, where ketones as 2-pentanone, 2-heptanone and 2-nonanone were the most abundant compounds. Considering sensorial analysis, significantly higher scores were obtained for EC if compared to PDO.

    更新日期:2018-08-17
  • Novel autochthonous lactobacilli with probiotic aptitudes as a main starter culture for probiotic fermented milk
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-08-17
    Yousef Nami, Babak Haghshenas, Reza Vaseghi, Hossein Mohammadzadeh Jalaly, Hajie Lotfi, Solat Eslami, Mohammad Amin Hejazi

    This study focused on the selection of probiotic lactobacilli as main starter culture for production of probiotic fermented milk without application of any commercial ones. Forty-four Lactobacillus strains were examined in-vitro for potential probiotic properties and their application in functional food formulations. Susceptibility was observed in strains to 13 antibiotics, but none of the isolates were sensitive to ciprofloxacin. The tolerance of the strains Lactobacillus plantarum DP3, Lactobacillus casei DP21 and DP25, and Lactobacillus brevis DP30 and DP31 to bile salts and low pH was more than 68.0 ± 0.5 and 69.3 ± 0.3%, respectively and they adhered to Caco-2 cells with values ranged from 15.5 to 33.2%. These strains showed remarkable auto-aggregation capacity with values ranging more than 74%. They showed the highest cholesterol removal capability without any hemolytic activity. Strain DP3 showed the inhibitory activity against all tested pathogens. These five strains, especially DP3 and DP21, demonstrated remarkable probiotic properties and were suitable for application in functional food formulations. The results were promising as the use of the isolates DP3 and DP21 reduced the fermentation time to 10 h. The microbial count of the final products (CFU > 108) ensured their probiotic activity after 24 days of storage.

    更新日期:2018-08-17
  • Comparison of rheological properties of wet gluten: Shear and biaxial compression strain analyses
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-08-17
    Pavalee Chompoorat, Zorba Josué Hernández-Estrada, Steven Mulvaney, Mark E. Payton, Barry K. Lavine, Ayuba Fasasi, Patricia Rayas-Duarte

    The objective of this study is to examine the fundamental rheological properties of gluten extracted from six commercial wheat flours and four gluten products (GA, GB, GC and GD) at two substitution levels (3 and 6 g/100 g). Experimental data from creep-recovery (shear deformation, 100 Pa) and compression-recovery (biaxial deformation, 8 N) tests were fitted into a Burgers model. GA and GC were associated with variation in elastic recovery (strength) while CB and GD with variation in softening effect that would result in improved extensibility. Differences in composition based on mass-to-charge ratio suggested that GA and GC can form longer polymer chains and has higher LMW-GS ratio and LMW-GS/HMW-GS ratio compared to GB and GD, which form shorter polymer chains. Redundancy analysis clearly separated the effect of gluten substitutions and levels across the six flours in terms of strength and deformability of the structure.

    更新日期:2018-08-17
  • Characterization of functional properties of proteins from Ganxet beans (Phaseolus vulgaris L. var. Ganxet) isolated using an ultrasound-assisted methodology
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-08-17
    Tomás Lafarga, Carlos Álvarez, Gloria Bobo, Ingrid Aguiló-Aguayo

    This study investigated different methods of extraction of protein from Ganxet beans (Phaseolus vulgaris L. var. Ganxet) and evaluated the functional properties of these valuable proteins. Overall, ultrasound processing (40 kHz, 250 W) resulted in higher yields and increased percentages of material solubilized and proteins recovered. The highest percentage of recovered protein was obtained after extraction using 0.4 M NaOH followed by ultrasound processing for 60 min and was calculated as 78.73 ± 4.88% (p < 0.05). Extraction using 0.4 M NaOH followed by sonication for 60 min resulted in the highest yield and percentage of solubilized material calculated as 37.98 ± 0.02 and 54.58 ± 0.19%, respectively (p < 0.05). The water- and oil-holding capacities of the Ganxet protein concentrate were calculated as 2.33 ± 0.12 and 2.69 ± 0.32 g of water or oil per g of protein concentrate, respectively. The highest emulsifying capacity was observed at pH 8.0 and was calculated as 69.4 ± 0.8%.

    更新日期:2018-08-17
  • Intercalation technique can turn pomegranate industrial waste into a valuable by-product
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-08-16
    Mohammadreza Balooch, Hossein Sabahi, Heshmatolah Aminian, Morteza Hosseini

    The development of nanotechnology has led to the production of new valuable by-products in the food industry. In this way, we synthesized a new green fungicide using the impure montmorillonite (Mt) and extract of pomegranate fruit waste. In addition, we compared the Mt/pomegranate fruit peel extract (Mt/PFPE) with the Mt/clove leaf extract (Mt/CLE) and Mt/Gallic acid (Mt/GA) composites. The mentioned composites were prepared through the simple and low-cost intercalation technique. The antifungal activity of these composites on postharvest gray mold (Botrytis cinerea) in apple fruit were tested in vitro and in vivo. XRD pattern confirmed the highly intercalation of plant extracts between interlayers of Mt nanoparticles. HPLC analysis and FTIR spectra showed that Mt nanoparticles absorbed the phenolic compounds from extract selectively. TGA analysis indicated high loading yield up to 70%. The Mt/PFPE, Mt/CLE and Mt/GA nanocomposites had 102%, 84% and 75% higher antifungal activity than single Mt nanoparticles. These findings suggest the Mt/PFPE nanocomposite as a low-cost but valuable by-product in the pomegranate juice industry.

    更新日期:2018-08-17
  • Osmotic dehydration of mango: Effect of vacuum impregnation, high pressure, pectin methylesterase and ripeness on quality
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-08-15
    Ita Sulistyawati, Matthijs Dekker, Vincenzo Fogliano, Ruud Verkerk

    The effects of pretreatment with vacuum impregnation (VI) and high pressure (HP) and adding pectin methylesterase (PME) with calcium on the quality of osmotic dehydrated mango of different ripeness were investigated. Unripe and ripe ‘Kent’ mango cubes were osmotic dehydrated (OD at 50 °C in 60 °Brix sucrose solution containing 2 g calcium lactate/100 g and 0 or 0.48 mL PME/100 g), preceded either by VI (OD-VI) or HP (OD-HP). Use of unripe mango in OD showed two to five-fold higher soluble solid gain (SSG) compared to ripe mango for all treatments. Unripe mango pretreated with OD-VI showed the lowest water loss (WL) and the highest SSG. OD-HP had a similar but less pronounced effect as OD-VI on WL and SSG. Hue (h*) were generally preserved and color intensity (C*) were maintained or only slightly increased in both ripeness in all treatments. Lightness (L*) was greatly reduced in unripe mango but stable in ripe mango. In general, firmness and work of shear slightly increased when adding PME.

    更新日期:2018-08-15
  • Starch edible films loaded with donut-shaped starch microparticles
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-08-15
    Yousof Farrag, Sara Malmir, Belén Montero, Maite Rico, Saddys Rodríguez-Llamazares, Luis Barral, Rebeca Bouza

    This paper describes the preparation of thermoplastic starch edible films (TPS) loaded with donut-shaped starch microparticles from two different botanical origins. The microparticles were produced by a simple thermal aqueous-alcoholic treatment. The average size was 14.01 ± 2.65 μm and 28.61 ± 6.84 μm for the microparticles from corn and pea starch, respectively. The double helical A-type and C-type crystallinity of corn and pea starch granules, respectively were converted to single helix V-type crystalline structure during the donut-shaped microparticles preparation. This crystalline distortion was revealed by X-ray diffraction, differential scanning calorimetry (DSC) and the enhanced swelling properties of the microparticles. The starch films were produced using the solution casting method with glycerol as plasticizer. The X-ray diffraction patterns showed both residual and processing induced crystallinity of the TPS films. The starch films were found to be more thermally stable by increasing the donut-shaped microparticles percentage as confirmed by the thermogravimetric analysis (TGA). The water vapour and the oxygen transmission rates through the TPS films can be modified by changing the microparticle content. The TPS films are intended mainly for food packaging applications.

    更新日期:2018-08-15
  • 更新日期:2018-08-14
  • Physicochemical and nutritional composition, volatile profile and antioxidant activity differences in Spanish jujube fruits
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-08-14
    J. Reche, F. Hernández, M.S. Almansa, Á.A. Carbonell-Barrachina, P. Legua, A. Amorós

    In Spain, jujube can be considered a minor crop; thus, its cultivars have not yet been investigated in depth. The objective of this study was to evaluate the composition, nutritional profile, and volatile composition of three cultivars of Spanish jujube fruits. The total antioxidant activity and phenolic compounds in peel and pulp of the fruits were studied. The obtained results proved that 'Isidro' cultivar presented the largest fruits, had the highest ascorbic acid content, with a good color intensity, total soluble solid content, and glucose and fructose. In addition, fruits of the ‘Isidro’ cultivar presented together with the 'Phoenix' ones, the highest protein content and juiciness. The cultivar ‘Phoenix’ behaved differently than the other two cultivars studied; its fruits had significantly lower contents of total phenols, flavonoids and flavonols and these compounds were mainly accumulated in the pulp. In the other two cultivars, bioactive compounds reached higher values and were mainly accumulated in their peels. 'Isidro' was the cultivar that presented maximum amounts of phenols and total flavonoids. Thus, both cultivars 'Isidro' and 'Phoenix' could be promising cultivars to be used in future breeding programs, to obtain fruit with high content of bioactive compounds as well as interesting organoleptic properties.

    更新日期:2018-08-14
  • Addition of buttermilk improves the flavor and volatile compound profiles of low-fat yogurt
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-08-14
    Lili Zhao, Ran Feng, Fazheng Ren, Xueying Mao

    We investigated the sensory properties and volatile compounds of full-fat yogurt, low-fat yogurt, and low-fat yogurt with addition of buttermilk at different concentrations. Full-fat yogurt exhibited higher sensory scores than the others. Addition of buttermilk improved the sensory of low-fat yogurt, but an excessive addition (>4%) decreased its acceptability with respect to flavor. Low-fat yogurt with addition of 1% buttermilk (1% LF-BMY) exhibited similar flavor as full-fat yogurt by the analysis of sensory and electronic nose. Low-fat yogurt produced a lower concentration of volatile compounds, and addition of 1% buttermilk increased the content of key volatile compounds of esters, aldehydes, alcohols, and acids. Some unique acids, aldehydes, ketones, aromatics, esters, alcohols, and sulfides were also found in 1% LF-BMY. Overall, addition of buttermilk at appropriate concentration can improve the acceptability of low-fat yogurt.

    更新日期:2018-08-14
  • Effect of electrospun thymol-loaded nanofiber coating on vitamin B profile of gilthead sea bream fillets (Sparus aurata)
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-08-14
    Zafer Ceylan, Mustafa Yaman, Osman Sağdıç, Ercan Karabulut, Mustafa Tahsin Yilmaz

    The effect of electrospun chitosan-based nanofibers (CH) and thymol-loaded electrospun chitosan-based nanofibers (TCH) were investigated in terms of stability of unstable B vitamin complex during cold storage period. Scanning Electron Microscopy revealed that the average fiber diameters were determined to range between 98.12 nm and 135.94 nm. CH and TCH were both effective against loss and rapid changes of unstable B vitamin complex. 7% average change in thiamin value was observed for samples coated with TCH, but it increased up to 39% in uncoated samples. In terms of thiamin content, the positive effect of nanofiber coating for the samples coated with TCH was observed on the 11th day of storage. Average change in riboflavin for CH and TCH was found to be lower. Particularly, sharply changes in nicotinamide acid, pyridoxal, pyridoxine and pyridoxamine contents were determined for uncoated samples, as compared to slightly changes in CH and TCH. The objective of this work was to obtain nanofibers. In this sense, potential effect of nanofibers on vitamin B profiles of fish fillets was to investigate. The results revealed that coating of the fish fillets with the nanofibers could be a promising technique to keep the stability of unstable B vitamin complex.

    更新日期:2018-08-14
  • Camel whey protein hydrolysates displayed enhanced cholesteryl esterase and lipase inhibitory, anti-hypertensive and anti-haemolytic properties
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-08-14
    Sabika Jafar, Hina Kamal, Priti Mudgil, Hassan Mohamed Hassan, Sajid Maqsood

    Camel whey protein hydrolysates were generated using gastric (pepsin) and pancreatic (trypsin and chymotrypsin) enzymes for 3 and 6 h. Hydrolysates were characterized using degree of hydrolysis (DH) and reverse phase-high performance liquid chromatography (RP-HPLC). Camel whey protein hydrolysates (CWPHs) showed DH ranging from 11 to 47.5%, with chymotrypsin (6 h) and trypsin (3 h) exhibiting highest and lowest DH, respectively. HPLC analysis revealed that α-lactalbumin underwent complete degradation and newer shorter peptides were generated. Inhibition of cholesteryl esterase, (CE) pancreatic lipase and anti-hypertensive properties via angiotensin converting enzyme (ACE) inhibition were found to be higher in pepsin (6 h) and (3 h) generated CWPHs, respectively. Pepsin (P3 and P6) and trypsin (T6) generated hydrolysates exhibited highest anti-hemolytic activity followed by chymotrypsin generated CWPHs. Whereas, trypsin (T3) generated hydrolysate showed minimum anti-hemolytic activity (8.02% ± 1.40). Overall, CWPHs displayed enhanced inhibition of CE, lipase, ACE and anti-hemolytic properties upon hydrolysis, providing a strong scientific base for their potential to be considered as functional and nutraceutical ingredients. This study provides a strong indication of biologically active peptides responsible for such health related bioactive properties. Future work must include identification of the peptides in the most potent camel whey protein hydrolysates.

    更新日期:2018-08-14
  • Variability of free and glycosylated volatiles from strawberries destined for the fresh market and for processing, assessed using direct enzymatic hydrolysis
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-08-14
    Stephane Gaborieau, Aurelie Cendres, David Page, Christian Ginies, Catherine M.G.C. Renard

    Free- and glycosylated-volatile profiles of 14 strawberry varieties, 9 for industrial processing (‘Darselect’, ‘Clery’, ‘Honey’, ‘Honeoye’, ‘Siabel’, ‘FCMO060’, ‘Fraise19’, 2 ‘Senga Sangana’) and 5 for fresh market (‘Gariguette’, ‘Charlotte’, ‘CIR121’, 2 ‘Clery’ (full-field and hydroponic)), were compared. All volatiles were analysed by GC-MS. Volatiles from glycosides were first released by direct enzymatic hydrolysis. The extraction method was optimised for furaneol, a key component of strawberry aroma. More than 60 volatile compounds were identified, the most abundant being butyl acetate (average: 17 mg/kg), furaneol (average: 2 mg/kg) and free hexanoic acid (average: 3 mg/kg). Free-volatile profiles showed a split between fresh market strawberries, distinguished by esters and carbonyl molecules like isobutyl acetate or hexanal, and strawberries for processing, distinguished by molecule like 3-penten-2-one and 1-butanol. The three ‘Clery’ profiles were different notably in their hexanal, 4-vinylguaiacol and 3-penten-2-one concentrations. The glycosylated volatile profiles were similar among most strawberry varieties with, as major glycosylated volatiles, hexanoic acid (average: 1.7 mg/kg), benzyl alcohol (average: 0.5 mg/kg), gamma-decalactone (average: 0.5 mg/kg) and coumaran (average: 2.5 mg/kg). The potential for volatile enhancement by deconjugation was different. Potentially fresh market strawberries had a volatile increase of 6% against 50% for strawberries for processing.

    更新日期:2018-08-14
  • Effect of heat treatment on physicochemical and emulsifying properties of polymerized whey protein concentrate and polymerized whey protein isolate
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-08-14
    Shanshan Jiang, Muhammad Altaf hussain, Jianjun Cheng, Zhanmei Jiang, Hao Geng, Ying Sun, Changbao Sun, Juncai Hou

    Whey proteins (WP) have many nutritional and beneficial therapeutic properties. Whey proteins isolate (WPI) and whey protein concentrate (WPC) are the two major forms of WP, which are indispensable for the functional and nutritional properties of foods. The core aim of this research work was to study the effect of heat treatment on physicochemical and emulsifying properties of polymerized whey protein concentrate and polymerized whey protein isolate. Whey protein solutions (8, 10, 12 w/v %) were heated at temperatures (80, 85, 90 °C) for 30 min, and the physicochemical, emulsification and stability indices properties of WPC and WPI thermal polymers were scrutinized. Results revealed that the content of free sulfhydryl groups, zeta potential and the EAI of polymerized whey protein (PWP) were lower than those of native whey protein (WP) under the same conditions. Meanwhile, the viscosity of PWP was increased with increase in temperature and protein concentration. Additionally, both EAI and ESI of polymerized whey protein isolate (PWPI) were higher than those of polymerized whey protein concentrate (PWPC). TEM and SDS-PAGE results clearly demonstrated that heating induced the formation of large protein aggregates. Conclusively, PWPI network was more homogeneous, stable and denser than that of PWPC.

    更新日期:2018-08-14
  • The effect of glazing based on saponin-free quinoa (Chenopodium quinoa) extract on the lipid quality of frozen fatty fish
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-08-14
    Marcos Trigo, Alicia Rodríguez, Gretel Dovale, Alexis Pastén, Antonio Vega-Gálvez, Santiago P. Aubourg

    This study focussed on the rancidity stability of frozen fatty fish. Its basic objective was to investigate the effect of a glazing system including a saponin-free quinoa (Chenopodium quinoa) extract during the frozen storage of Atlantic mackerel (Scomber scombrus). For it, two different concentrations of 80% aq. (v/v) ethanol quinoa extracts (0.45 and 1.36 g lyophilised quinoa L−1 solution, respectively) were tested and compared with two control treatments (water glazing and non-glazing conditions). Chemical and sensory changes were monitored for a 8-month frozen storage. An inhibitory effect (p < 0.05) of the glazing system including the most concentrated saponin-free quinoa extract was observed on the lipid hydrolysis (free fatty acid formation) evolution and on the formation of secondary (thiobarbituric acid reactive substances) and tertiary (fluorescent compounds) lipid oxidation compounds. A sensory quality enhancement and shelf life increase was obtained in fish submitted to glazing conditions including the most concentrated quinoa extract in agreement to raw (gills and muscle odour) and cooked (muscle odour) descriptors. A novel quinoa-glazing system is proposed, this avoiding the inconveniences of the saponin compounds presence.

    更新日期:2018-08-14
  • Comparison of dextran molecular weight on wheat bread quality and their performance in dough rheology and starch retrogradation
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-08-13
    Yao Zhang, Dandan Li, Na Yang, Zhengyu Jin, Xueming Xu

    The aim of this study was to compare effects of linear dextrans (backbones of α-(1 → 6) linkages) varying with weight-average molecular weights (Mw: T10, T70, T250, T750, T2000) on the quality of wheat breads. The firmness of fresh bread crumb was decreased with increasing dextran Mw and the highest Mw dextran (T2000) lowered the staling rate of stored breads. Dough rheology clarified that only the specific dextran (T70) apparently changed dough viscoelastic, strengthening the viscous behavior. Significant decreases in breakdown and setback viscosity of starch slurry were observed by addition of dextrans, especially dextran T2000. Analyses in the long-term retrdgradation of starch and starch-gluten systems indicated that the promising antistaling influence of dextran T2000 was caused by either inhibitions of amylopectin retrogradation or beneficial variations induced by gluten. Positive effects of starch-gluten and dextran-gluten associations on amylopectin retrogradation were revealed. These results suggested that the highest Mw dextran (T2000) possessed the potential for increasing consumer acceptance of bread products.

    更新日期:2018-08-13
  • Effect of pre-treatment conditions and freeze-drying temperature on the process kinetics and physicochemical properties of pepper
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-08-12
    Andrzej Krzykowski, Dariusz Dziki, Stanisław Rudy, Urszula Gawlik-Dziki, Renata Polak, Beata Biernacka

    This study shows the effects of blanching, citric acid addition, and drying temperature on the freeze-drying kinetics, l-ascorbic acid content, colour, and antioxidant activity of freeze-dried pepper. The process was performed at 20 °C, 40 °C, and 60 °C and with a constant pressure in a drying chamber at 63 Pa. The samples of pepper were pulped before drying. Blanching of pepper reduced the drying time to approximately 30%. The shortest drying time (about 290 min) was found for blanched pepper that was freeze-dried at 60 °C, whereas the samples of pepper freeze-dried at 20 °C and without blanching required the longest drying time (about 900 min). The kinetics of freeze-drying of pepper pulp are best described by using the Page model. The addition of citric acid increased the redness and yellowness of dried pepper, whereas an increase in drying temperature caused a decrease in the total phenolics content, antioxidant activity, and colour coordinates of all samples. The highest l-ascorbic acid content was found in unblanched pepper and when the temperature of drying did not exceed 40 °C. Water blanching pretreatment had the most negative effect on total phenolics content and antioxidant activity of dried pepper.

    更新日期:2018-08-13
  • Gelling properties of hake muscle with addition of freeze-thawed and freeze-dried soy phosphatidylcholine liposomes protected with trehalose
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-08-09
    D. Marín-Peñalver, A. Alemán, P. Montero, M.C. Gómez-Guillén

    Soy phosphatidylcholine liposomes made with addition of trehalose as cryoprotectant were subjected to freeze-thawing and freeze-drying treatments, and subsequently incorporated in salt-ground hake (M. merluccius) muscle to study their effects on protein aggregation, water binding and thermal gelation. Both liposomal preparations presented similar particle size (≈215 nm, expressed as z-average) and strong electronegative zeta potential (−46 mV). The addition of both types of liposomal preparations led to more water trapped within the myofibrillar protein in the salt-ground muscle, as observed by water holding capacity (WHC) and low field nuclear magnetic resonance (LF-NMR). However, the liposomes interfered strongly with the thermal gelation ability of the muscle protein. Differential scanning calorimetry (DSC) analysis of the salt-ground muscle showed that the liposomes caused an increase in the main transition temperature associated with the actin molecule, with a concomitant reduction in total enthalpy change. The hydration state of the trehalose-containing liposomes did not play a significant role in textural properties of the resulting gels. The detrimental role of liposomes in the texture of fish gels should be considered in the design of functional fish products.

    更新日期:2018-08-10
  • Effect of barrel temperature and moisture content on the composition and oxidative stability of extruded palm oil in an oil-starch model system
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-08-09
    Liting Wan, Lin Li, Wenjuan Jiao, Linlu Mao, Bing Li, Xia Zhang

    This study aimed to evaluate changes in the fatty acid composition, oxidative stability and contents of some functional groups of palm oil (PO) during extrusion with corn starch or potato starch under two different extrusion conditions. The contents of saturated fatty acids in extracted PO ranged from 48.5 to 53.06 g/100 g of total fatty acids and were higher than that in unprocessed PO, while the proportions of unsaturated fatty acids were reduced after extrusion. Compared with extrusion at 100 °C with 22 g/100 g moisture content, extrusion at 160 °C with 16 g/100 g moisture content yielded peroxide values, conjugated diene values and p-anisidine values that were greater for extruded PO by ∼1-fold, ∼1-fold and ∼5-fold, respectively, regardless of the type of starch. Moreover, PO extruded with potato starch showed a better oxidative stability than PO extruded with corn starch. Alterations in the O-H, cis C=C, trans C=C and C=O content in extruded PO were measured by the FTIR-based method. These results showed that extrusion conditions and the type of starch affect the quality of extruded lipids and can be used to choose a formula, determine the extrusion processing parameters and devise the package of oil-containing extruded food products.

    更新日期:2018-08-10
  • Sensory evaluation of a prebiotic sheep milk strawberry beverage
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-08-09
    Celso F. Balthazar, Antonella Santillo, Lucia Figliola, Hugo L.A. Silva, Erick A. Esmerino, Mônica Q. Freitas, Adriano G. Cruz, Marzia Albenzio

    The sensorial evaluation of a prebiotic sheep milk juice beverage considering a consumer's perception was performed. Four beverages with different concentration of skimmed sheep milk, strawberry pulp and sugar, added with a fixed inulin level (3 g/100 g) were manufactured and submitted to hedonic and preference ranking test with 60 consumers. Beverages containing decreased sugar levels and higher content of strawberry pulp were most preferred and presented the higher scores in the acceptance test. According the Principal Component Analysis, sample B3 was characterized by strawberry flavor and aroma, acid taste, strawberry seeds presence, sheep aroma, fatty flavor, and pinkish color; while sample B4 was associated with reddish color, astringent flavor, bitter taste, brightness, viscous, sweet, acid and rancid aromas attributes. Finally, sample B2 presented salt and sweet taste, and thinner texture, while samples B1 presented sheep flavor, cooked aroma, cooked flavor and residual flavor. Our findings suggest that formulation should contain 550/370/50 g/L of skimmed sheep milk, strawberry pulp and sugar in beverage.

    更新日期:2018-08-10
  • Electrospun thyme essential oil/gelatin nanofibers for active packaging against Campylobacter jejuni in chicken
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-08-07
    Lin Lin, Yulin Zhu, Haiying Cui

    Campylobacter jejuni (C. jejuni) contamination on poultry surface posed great threats to meat industry and human health. In order to control the propagation of C. jejuni, the gelatin nanofibers containing thyme essential oil/β-cyclodextrin ε-polylysine nanoparticles (TCPNs) were engineered. Firstly, TCPNs were successfully fabricated via ionic gelation. The prepared TCPNs showed excellent antimicrobial activity against C. jejuni, which caused membranolysis and protein leakage of C. jejuni. Subsequently, TCPNs were incorporated into gelatin nanofibrous matrix via electrospinning to produce antimicrobial nanofibers. Uniformly disordered fibrous structure with good continuity and fine diameter distribution was observed. Finally, the aerobic bacterial count, thiobarbituric acid, total volatile basic nitrogen, pH, color and texture of meat samples packaged with the nanofibers were detected. The results implied the TCPNs embedded gelatin nanofibers had a promising prospect in meat preservation without impact on sensory evaluation.

    更新日期:2018-08-07
  • Effect of chia seed on glycemic response, texture, and sensory properties of Chinese steamed bread
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-08-07
    Fan Zhu, Coline Chan

    Chia (Salvia hispanica) seed is a source of diverse bioactive components with various potential health effects. Chinese steamed bread (CSB) is a traditional staple among Asian population. In this report, intact white chia seeds replaced wheat flour for northern-style CSB formulation at various levels up to 300 g/kg. The impact of seed replacement on in vitro starch digestion, expected glycemic index (eGI), expected glycemic load (eGL), volumetric properties, colour, texture, and sensory quality of the CSB were studied. Chia seed addition reduced the eGI and eGL of CSB by up to 25% and 48%, respectively. Chia seeds increased the hardness of CSB and reduced the specific volume of CSB by up to 211% and 27%, respectively. Sensory analysis showed that the overall acceptance of CSB was not affected by chia seed addition. It may be concluded that intact chia seed addition up to 300 g/kg can nutritionally enhance CSB without compromising the eating quality.

    更新日期:2018-08-07
  • Insights into a century of breeding of durum wheat in Tunisia: The properties of flours and starches isolated from landraces, old and modern genotypes
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-08-06
    Fatma Boukid, Elena Vittadini, Barbara Prandi, Monica Mattarozzi, Mia Marchini, Stefano Sforza, Rhouma Sayar, Yong Weon Seo, Ines Yacoubi, Mondher Mejri

    The present work had a dual objective: to assess if the evolution of durum wheat from landraces to modern genotypes as function of breeding programs impacted proteins and starch fractions, as well as starch properties. Flours and starches isolated from Tunisian durum wheat landraces, old and modern lines were thoroughly characterized for their compositional, morphological, and gel properties. Statistical results showed significant (p ≤ 0.05) differences among the studied set. Protein and starch fractions assessment revealed that modern genotypes had the highest total starch and albumin contents, old genotypes had the highest amylose and glutenin contents, and landraces had the highest protein and gliadin contents. Starch properties screening allowed several findings: no significant (p > 0.05) differences were found among starch granules morphology, significant (p ≤ 0.05) differences were recorded in terms of technological properties, and old genotypes had the highest starch gel hardness. Overall, these results indicated that the influence of genotype on flour and starch properties was more relevant than breeding history.

    更新日期:2018-08-06
  • Incorporation of natural colorants obtained from edible flowers in yogurts
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-08-06
    Tânia C.S.P. Pires, Maria Inês Dias, Lillian Barros, João C.M. Barreira, Celestino Santos-Buelga, Isabel C.F.R. Ferreira

    The substitution of artificial dyes by natural colouring agents is among the top concerns of food industry to fulfil current consuming trends, justifying the prospection of novel natural sources of these compounds. Herein, the hydrophilic extracts from rose, cornflower and dahlia were tested as potential substitutes to E163 (anthocyanin extract). Besides comparing the colouring capacity, the potential occurrence of changes in the chemical composition of yogurts (nutritional parameters, free sugars and fatty acids) was also assessed throughout storage (up to 7 days) and compared with a “blank” (free of any additive) yogurt formulation. In general, yogurts prepared with flower extracts, presented similar nutritional value and free sugars profile to those prepared with E163 and to the “blank” yogurt. Nevertheless, rose extract turned out to be the most suitable alternative to E163 as these two groups of yogurts had similar nutritional composition, free sugars and fatty acids composition, besides presenting close scores in colour parameters.

    更新日期:2018-08-06
  • Proximal composition, sensorial properties and effect of ascorbic acid and α - ocopherol on oxidative stability of bread made with whole flours and vegetable oils
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-08-06
    Mariana B. Osuna, Cecilia A. Romero, Ana M. Romero, María A. Judis, Nora C. Bertola

    Proximal composition, shelf-life, sensory properties and effects of ascorbic acid and α-tocopherol on the oxidative stability of bread made with whole flours and vegetable oils were evaluated. Such effects were analyzed in two formulations: one with wheat flour + flaxseed flour + soybean flour + canola oil (F1), and the other with wheat flour + flaxseed flour + wheat bran + olive oil (F2). The proximal composition showed significant differences in moisture, fibre and carbohydrates due to the presence of wheat bran in one formulation. Omega 3 content in F1 was twice as high as that in F2, due to the contribution of flax meal and canola oil. Furthermore, both formulations presented good scores in the evaluated sensory attributes and a shelf-life of 2 days. The ascorbic acid in F1 produced a 40% reduction in primary lipid oxidation, while α-tocopherol as antioxidant for F2 produced a 50% reduction in thiobarbituric acid-reactive substances and exerted a greater inhibiting effect than butylhydroxyanisole. Therefore, the fortification of wheat bread with whole flour and vegetable oils is an effective tool that allows to obtain functional food and the addition of antioxidants would be a good option to prolong the stability of multigrain bread studied.

    更新日期:2018-08-06
  • The use of soft fresh cheese manufactured from freeze concentrated milk as a novelty protective matrix on Bifidobacterium BB-12 survival under in vitro simulated gastrointestinal conditions
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-08-04
    Isabella de Bona Muñoz, Silvani Verruck, Maria Helena Machado Canella, Carolinne Odebrecht Dias, Renata Dias de Mello Castanho Amboni, Elane Schwinden Prudencio

    Bifidobacterium BB-12 intended for use in functional dairy products are selected traditionally by taking into account a proper technological performance. Therefore, in vitro simulated gastrointestinal conditions should be studied to obtain essential information about the potential probiotic properties of bifidobacteria since there is a lack of this study. Our study aimed to evaluate the protective effects of probiotic and symbiotic soft fresh cheeses matrices, both manufactured from the concentrated milk from the second stage of block freeze concentration process, on Bifidobacterium BB-12 survival under in vitro simulated gastrointestinal conditions. These simulated assays were done consecutively including all gastrointestinal tract compartments, such as the mouth, esophagus-stomach, duodenum, and ileum. After the simulated gastrointestinal conditions, it was possible to verify a positive effect on the viable cells count and survival rate of Bifidobacterium BB-12 in probiotic cheese followed by symbiotic cheese, this last one also with inulin addition. Finally, both novelty kinds of cheese can be considered a protective matrix on Bifidobacterium BB-12 survival.

    更新日期:2018-08-05
  • Guava, orange and passion fruit by-products: Characterization and its impacts on kinetics of acidification and properties of probiotic fermented products
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-08-04
    Sabrina N. Casarotti, Tais F. Borgonovi, Carolina L.F.M. Batista, Ana Lúcia B. Penna

    This study aimed at characterizing guava, orange, and passion fruit by-products and investigating the effect of adding these fruit by-products to probiotic fermented goat milk and cereal-based fermented products. Fruit by-products showed total fiber content, phenolic compounds and antioxidant activity varying from, respectively, 58.20–89.80%, 253.14–420.89 mg GAE/100 g, and 8.31–13.82 μmol TE/g. Most carotenoids were represented by β-carotene, which ranged from 7.91 to 56.07 μg/g. The presence of fruit by-products did not affect the fermentation time of fermented oat beverage and fermented goat milk; however, a significant increase (ranging from 0.28 to 0.91 h) in fermentation time of fermented rice beverages was observed after the addition of by-products. Fruit by-products also resulted in an increase in acidification throughout storage; however, they did not affect the counts of probiotic bacteria. A decrease in probiotic survival during in vitro gastrointestinal simulation was observed in all treatments. Nonetheless, the presence of orange and passion fruit by-products enhanced the resistance of the probiotics to simulated gastrointestinal conditions and resulted in population 2 log CFU/mL higher than the control treatment. Fruit by-products can be considered relevant sources of bioactive compounds useful in raising the functional attributes of probiotic fermented products.

    更新日期:2018-08-05
  • Anti quorum sensing and anti biofilm efficacy of cinnamaldehyde encapsulated chitosan nanoparticles against Pseudomonas aeruginosa PAO1
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-08-04
    Pattnaik Subhaswaraj, Subhashree Barik, Chandrasekhar Macha, Potu Venkata Chiranjeevi, Busi Siddhardha
    更新日期:2018-08-05
  • Characterization of sacha inchi protein hydrolysates produced by crude papain and Calotropis proteases
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-08-04
    Saroat Rawdkuen, Nurdalila Rodzi, Suttiporn Pinijsuwan

    Sacha inchi is widely used as a raw material in the edible oil industry. The de-oiled pressed cake has high amounts of proteins, which makes it highly desirable for industrial use due to their value-added products. The objectives of this study were to produce and characterize protein concentrate (PC) and its hydrolysates (PH) hydrolyzed by crude papain and Calotropis proteases. The proximate compositions of sacha inchi used in this study included protein 459, carbohydrate 361, fat 67, ash 59, crude fiber 58, and moisture 53 g/kg (wb). PC hydrolyzed by crude papain (PH-P) and Calotropis proteases (PH-C) had a degree of hydrolysis (DH) of 2.7% and 11.2%, respectively. PH-P contained a higher amount of essential amino acids (474 g/kg) than PH-C (410 g/kg). The protein pattern of PC and PHs were determined by SDS-PAGE, and the molecular weights were clearly observable between <8 and 57 kDa. The antioxidant properties, such as DPPH scavenging and FRAP showed a rising PH when increasing the DH. Sacha inchi protein hydrolysates can be produced in a cost-effective way by using crude enzyme extracts.

    更新日期:2018-08-05
  • Chemical compositions of Pu'er tea fermented by Eurotium Cristatum and their lipid-lowering activity
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-08-03
    Chenkai Jiang, Zhen Zeng, Yahui Huang, Xu Zhang

    In order to reveal the effect of microorganisms on the chemical composition of tea and their lipid-lowering function, Pu'er raw tea (PR) made from sun-dried leaves of Yunnan large-leaf tea cultivars was processed through a period of flowering fermentation mainly facilitated by Eurotium cristatum, and thus converted into flowering Pu'er tea (FP) in the present study. Tea aqueous extracts were successively extracted by chloroform, ethyl acetate and n-butyl alcohol. Afterwards, non-volatile and volatile compounds of PR and FP were identified and compared through high performance liquid chromatography (HPLC) and gas chromatography-mass spectrometer (GC-MS), respectively. Furthermore, high lipid HepG2 cells induced by OA were treated by those extracts of different polar to explore their impact on lipid-lowering. It can be observed that the contents of tea polyphenols (TPs) and amino acids of FP significantly decreased whereas the total amount of flavonoids significantly increased, compared to those of PR. Besides, the ethyl acetate fraction of FP (EAF-FP) was of the most prominent effect on lipid-lowering, and its optium effective concentration was 80 μg/mL.

    更新日期:2018-08-03
  • Storage stability of sorghum phenolic extracts' flavones luteolin and apigenin
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-08-03
    Jordan Bradwell, Mason Hurd, Philipus Pangloli, Angela McClure, Vermont P. Dia

    Sorghum is an important crop with reported health-promoting properties. The objectives were to determine the stability of two major flavones in sorghum phenolic extract as affected by pH and temperature. Luteolin and apigenin were quantified every two weeks in the extracts stored at 4, 22 and 32 °C. Their degradation followed first-order reaction kinetics and stability was dependent on temperature and pH. Flavones were more stable in pH 2 as shown by lower energy of activation, lower reaction rate constants and longer half-lives. This study reported for the first time the storage stability of luteolin and apigenin from sorghum which may help in the design of functional food and beverage utilizing sorghum bioactive components.

    更新日期:2018-08-03
  • Effect of grape (Vitis labrusca L.) pomace dried by different methods on physicochemical, microbiological and bioactive properties of yoghurt
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-08-02
    Melike Demirkol, Zekai Tarakci

    In this study, the effect of grape (Vitis labrusca L.) pomace dried by different methods on the functional properties of yoghurt was examined. Oven- and freeze-dried pomaces were added to the yoghurts at the ratios of 1, 3 and 5%. The freeze-dried pomace had the highest levels of bioactive components, with 34.959 mg GAE/g of total phenolics and 12.586 mg/L DPPH of radical scavenging activity, followed by the pomace oven dried at 80 °C (p < 0.001). At the beginning of the storage period, the yoghurt that contained oven dried, powdered pomace had higher levels of antiradical activity and total phenolics than the yoghurt containing lyophilized pomace (p < 0.05). The total phenolic content, radical scavenging activity, pH, acidity and whey separation decreased, and viscosity increased, during storage for 21 days at 4 °C. Microbiological analysis showed that the amount of lactic acid bacteria did not change significantly (p > 0.05) in yoghurt samples during storage. The sensory analysis done at the end of the storage revealed that the yoghurt samples containing pomace dried in the forced air oven were mostly liked by consumers. This study showed that Isabella grape (V. labrusca L.) pomace can be used as a functional food ingredient in yoghurt production.

    更新日期:2018-08-02
  • Sensory metabolites profiling in Myristica fragrans (Nutmeg) organs and in response to roasting as analyzed via chemometric tools
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-08-02
    Mohamed A. Farag, Engy Mohsen, Abd El Nasser G. El-Gendy

    Nutmeg is a plant grown in tropical region for its seeds distinct flavor, nutritive value and health benefits. Despite extensive studies on nutmeg seed metabolites composition, much less is known regarding volatiles composition in the seed outgrowth mace and fruit and or roasting impact on its flavor. Avolatile extraction method was applied for the first time to reveal for nutmeg distinct aroma using headspace solid-phase microextraction (SPME) coupled to mass spectrometry. A total of 53 volatiles were identified belonging to various classes viz., aromatic ethers, monoterpenes and sesquiterpenes. Compared to seeds and mace tissue, fruit was found more enriched in the key flavor “myristicin” 40%. In contrast, monoterpene hydrocarbons amounted as major volatile forms in seeds. Compared to nutmeg fruit, roasted seeds showed a distinct aroma composed of (E)-isoeugenol 16% and methoxyeugenol 11% not detected in fresh seed concurrent with lower anti-nutrient alkaloid levels. GC–MS was further utilized to localize primary metabolites (i.e., sugars and organic acids) and revealing for free sugarsabundance in seeds at 47% versus enrichment of organic acids 58% viz. malic acid in fruit, and accounting for the later less palatable taste. This study provides the most comprehensive map for sensory metabolites distribution in nutmeg.

    更新日期:2018-08-02
  • Functional properties of protein isolates from bell pepper (Capsicum annuum L. var. annuum) seeds
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-08-02
    Mo Li, Xin Wen, Yu Peng, Yuxiao Wang, Kunli Wang, Yuanying Ni

    Bell pepper seeds comprise the bulk of solid waste from bell pepper processing. Aiming to utilize rather than waste these seeds, we investigated the functional properties of bell pepper seed protein isolates extracted using two methods. Ultrasound-assisted extraction of bell pepper protein isolates (BPPIU) achieved a higher yield (6.05 g/100 g), protein content (83.93 g/100 g), and oil absorption (5.63 g/g), while the solubility and water absorption were lower, and emulsifying and foaming properties diminished, compared with those of bell pepper protein isolates from alkaline dissolving and acid precipitating (BPPI). We also evaluated effects of pH and NaCl concentration on BPPI and BPPIU because they were significantly correlated with the functional properties. The antioxidant properties of bell pepper protein hydrolysates were studied in vitro by measuring the radical scavenging capacity (DPPH, O2·ˉ, ABTS·) and Fe2+ chelating capacity. Flavourzyme protease hydrolysates (FH) showed better DPPH and ABTS radical scavenging, while alkaline protease hydrolysates (AH) exhibited higher O2·ˉ scavenging and Fe2+ chelating activities.

    更新日期:2018-08-02
  • Physicochemical and antimicrobial properties of kefiran /waterborne polyurethane film incorporated with essential oils on refrigerated ostrich meat
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-08-02
    Fatemeh Hedayati Rad, Anousheh Sharifan, Gholamhassan Asadi

    The evaluation of the physicochemical and antimicrobial properties of kefiran/waterborne polyurethane blend (K/WPU) film incorporated with Zataria multiflora (ZM) and Rosmarinus officinalis essential oils (RO) with concentration 5, 10, 15 and 20% (v/v) for ostrich meat packaging were the goals of this study. The band shift of the Fourier transform infrared spectra implied that intermolecular hydrogen bonding between the EOs and K/WPU film. By increasing the EOs concentration on the films thickness, elongation at break and yellowness index were increased while water vapor permeability, tensile strength, lightness and whiteness index significantly decreased (P < 0.05). Both of the EOs has significant antibacterial activity against Lactobacillus plantarum, Escherichia coli and Staphylococcus aureus; this was proved by the agar diffusion method (P < 0.05). The total viable counts similar to all the tested bacteria were significantly inhibited by the K/WPU film containing 20% ZM and RO on ostrich meat during 12 days of storage in the refrigerator at 4 °C. ZM shows higher antimicrobial activity in comparison to RO due to the presence of terpenoid phenol compounds. Overall, these active films, especially in combination with ZM, exhibited desirable properties thus can be protected the safety and extended the shelf-life of food products.

    更新日期:2018-08-02
  • Investigation of inhibition of lipid oxidation by L-carnosine using an oxidized-myoglobin-mediated washed fish muscle system
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-08-02
    Shulan Xiao, Hong Zhuang, Guanghong Zhou, Jianhao Zhang

    The objective of the present study was to understand mechanisms of inhibitory effect of l-carnosine on lipid oxidation using an oxidized myoglobin (metMb)-mediated washed cod muscle system. Experiments were conducted to compare l-carnosine with commercial antioxidants, tert-Butylhydroquinone (TBHQ) and α-tocopherol, and metal chelating reagent EDTA for inhibition of lipid oxidation, to compare l-carnosine with TBHQ for scavenging free radicals and to evaluate the effect of l-carnosine on structure of pro-oxidant metMb with spectral methods. Results showed that the inhibitory effect of l-carnosine on lipid oxidation was comparable with TBHQ and better than α-tocopherol. However, 1,1-diphenyl-2-picrylhydrazyl assay showed that TBHQ was much more effective in scavenging free radicals than l-carnosine. Comparing with 1.5% EDTA, 1.5% l-carnosine was much more effective against lipid oxidation. Incubation of l-carnosine with metMb resulted in spectral changes of metMb in wavelengths between 370 nm and 450 nm, Soret band shifted from 409 nm to 420 nm, and reduced molar ellepticity values. These results indicate that the high inhibitory effects of l-carnosine on meat lipid oxidation may result from not only its scavenging and chelating functions but also its effect on pro-oxidant metMb structure.

    更新日期:2018-08-02
  • Quality changes in fat-reduced sausages by partial replacing sodium chloride with other chloride salts during five weeks of refrigeration
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-08-02
    Jin-won Hwang, Sang-Keun Jin, Sun Jin Hur, Gap-Don Kim

    This study was conducted to estimate the effect of partially replacing NaCl by blends of CaCl2, MgCl2 and KCl on quality changes in fat-reduced emulsified pork sausages. All blends of salts increased redness (P < 0.001) and decreased yellowness (P < 0.001) over storage time. MgCl2 at 15% replacement of NaCl strongly affected texture and chewiness, however negatively affected lipid oxidation at five weeks of refrigeration. Sausages partially replaced NaCl with 5% CaCl2 did not reveal improved quality despite having the highest ionic strength. Sausages formulated with a blend of all chloride salts (replacing 70% NaCl: 5% CaCl2, 15% MgCl2 and 50% KCl) were not acceptable for sensory properties at initial refrigeration (P < 0.01) and were worse at three weeks of storage (P < 0.05). Except for this formulation, blends with one or two other NaCl substitutes (CaCl2, MgCl2, and KCl) are acceptable for partial replacement of NaCl for processing fat-reduced emulsified sausages without impairing quality property.

    更新日期:2018-08-02
  • Use of talc in oil mills: Influence on the quality and content of minor compounds in olive oils
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-08-02
    Alfonso M. Vidal, Sonia Alcalá, Antonia de Torres, Manuel Moya, Francisco Espínola

    In oil milling, in order to obtain high-quality oils without reducing the industrial yield, to the use of coadjuvants with a physical action and adequate operating conditions is necessary. The aim of this study was to evaluate the influence of talc addition during the malaxation stage in an oil mill on the resulting oil. Moreover, the oil obtained by talc treatment can be classified as extra virgin olive oil as this coadjuvant has a physical action. Talc increases the extraction efficacy by up to 2.35%, but retains 26.2% of its weight in oil; therefore, it is disadvantageous to use a dose higher than 0.75%. The volatile compound contents were increased in trials using lower doses of talc. In contrast, the quantity of the phenolic compounds was increased in trials using higher talc doses. In low doses, talc does not influence the content of antioxidants and volatile compounds.

    更新日期:2018-08-02
  • Effects of water extractable and unextractable pentosans on dough and bread properties of hard wheat cultivars
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-08-02
    Saqib Arif, Mubarik Ahmed, Qasim Chaudhry, Abid Hasnain

    The impact of pentosans on dough and bread properties of wheat flour considering its type (based on water extractability) and the wheat genotypic variation has been explored in this study. Water extractable pentosan (WEP) exhibited a more pronounced effect (P < 0.001) in terms of water absorption (59.5–68.8%), dough stability (3.8–18.1 min), mixing tolerance index (9–56 BU), and bread crumb firmness (820–922 g). Water unextractable pentosan (WUP) largely influenced dough development, physical and sensory attributes of the breads. Both the fractions imparted positive influence on dough properties by increasing the water absorption capacities of flours (3–10%), delaying the development of dough (31–82%), and enhancing the stability (28–71%) and tolerance against dough mixing (24–50%). Baking results, however, revealed a different picture. WEP and WUP exhibited opposite impacts on all physical and sensory attributes of the breads, with the exception of crumb firmness. WUP imparted remarkably negative effects (P < 0.001) whereas WEP showed marginal to significant improvement in bread physical and sensory attributes. The influence of wheat genotype appeared large in the variation of dough properties and crumb firmness. Increase in supplementation level upto 2 g/100 g flour also contributed in magnitude of pentosans' impact on flour quality.

    更新日期:2018-08-02
  • Comparative analysis of chemical composition, antimicrobial and antioxidant activity of citrus essential oils from the main cultivated varieties in China
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-08-01
    Jia-jing Guo, Zhi-peng Gao, Jin-lan Xia, Mark A. Ritenour, Gao-yang Li, Yang Shan

    In this work, the chemical composition, antimicrobial and antioxidant activities of fourteen species of citrus essential oils (EOs) from the main cultivated varieties in China were evaluated and compared. A total of more than 200 components were identified, which are mainly composed of terpenes, alcohols, aldehydes, esters, ketones and acids. Antimicrobial ability of fourteen EOs and seven major components were tested against six bacteria and two yeasts. The susceptibility of Gram-positive bacteria tested was observed to be greater than Gram-negative bacteria, and the yeasts tested were relatively more susceptive than bacteria. Three groups (Strong, Medium and Weak) were divided according to the antimicrobial ability. The EOs of Citrus Changshan huyou B. Chang and Citrus. medica var. sarcodactylis Swin exhibited the strongest antimicrobial activity against all tested strains. Linalool showed the strongest antimicrobial activity against all microorganisms except Pseudomonas aeruginosa. Three characters and tendencies were found out to correlate chemical composition with antimicrobial activity of different citrus essential oils. The EOs of Citrus aurantium L and Citurs medica var. sarcodactylis Swing showed strong ABTS radical scavenging, and the EOs of Citurs medica var. sarcodactylis Swing and Citrus Changshan huyou B. Chang exhibited strong free radical scavenging activity.

    更新日期:2018-08-01
  • Extrusion cooking of cassava-soy flour with 200 g/kg wheat bran promotes slower oral processing during consumption of the instant porridge and higher derived satiety
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-08-01
    Dolapo A. Oladiran, Mohammed N. Emmambux, Henriëtte L. de Kock

    In this study, the descriptive sensory attributes, oral processing characteristics of and subjective satiety responses for extrusion cooked cassava-soy porridge with wheat bran at 0, 100 and 200 g/kg addition levels were determined. Fifteen subjects (23–47 years, mean BMI 22.6 kg/m2) consumed 250 g of each porridge type over 8 breakfast meals while being video recorded. Oral exposure time and number of bites, and eating and bite rates were determined. Subjects rated hunger, fullness and desire to eat before meal, post meal and periodically over 3 h post consumption. A separate panel profiled the descriptive sensory attributes of the porridges. The addition of wheat bran increased visually perceived viscosity and presence of visible particles. The porridge with 200 g/kg wheat bran was eaten with more bites and at a slower rate thus, having longer oro-sensory exposure. Also, the porridge with 200 g/kg wheat bran led to greater reduction in subjective reported hunger compared to the other porridges. Wheat bran as a source of dietary fibre has the potential to be incorporated as a component of extruded starch-rich foods to produce instant products which can promote satiety.

    更新日期:2018-08-01
  • Evaluation of chickpea as alternative to soy in plant-based beverages, fresh and fermented
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-07-31
    Shi Wang, Venkata Chelikani, Luca Serventi

    A novel plant-based beverage made with garbanzo chickpeas was developed. Compared to soymilk, the chickpea beverage contained lower amounts of protein (1.21 vs. 2.09 g/100 g), fat (0.34 vs. 0.74 g/100 g) and sugar (0.24 vs. 0.33 g/100 g), due to a higher starch content (2.08 vs. 0.14 g/100 g). Fermentability of the chickpea beverage was acceptable, with colony forming units (CFU) increasing from about 5 × 104 to 7.4 × 106 after a 16-h fermentation, whereas in soy the final value was 1.7 × 107. Nonetheless, syneresis was significantly higher than that of the soy counterpart: 19.4 vs. 3.8%. This was attributed to the weaker protein network in the fermented chickpea beverage and to the high starch level that may have led to starch retrogradation during storage, hence resulting in whey expulsion. Sensory analysis revealed that the fresh chickpea beverage was as acceptable as the soy one. On the contrary, the fermented chickpea beverage received lower ratings than the soy one for appearance. This study showed that chickpea can be a promising alternative to soy in the development of a fresh plant-based beverage, while optimisation is required to apply it in a fermented beverage.

    更新日期:2018-07-31
  • Fortification of γ-aminobutyric acid and bioactive compounds in Cucurbita moschata by novel two-step fermentation using Bacillus subtilis and Lactobacillus plantarum
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-07-31
    Eun-Jin Park, Coralia V. Garcia, Sun-Joo Youn, Chi-Deok Park, Sam-Pin Lee

    Pumpkin (Cucurbita moschata) was co-fermented using Bacillus subtilis HA and Lactobacillus plantarum EJ2014 for producing a novel food ingredient fortified with γ-aminobutyric acid (GABA) and bioactive compounds. After the first fermentation, the broth showed pH 6.1, 0.26% acidity, 8.9 log CFU/mL viable cell counts of B. subtilis, 2.61% mucilage, and a consistency index of 5.43 Pa·sn. After the second fermentation, the broth indicated pH 5.1 and 0.23% acidity. The viable cell counts of B. subtilis decreased to 7.7 log CFU/mL, while L. plantarum counts increased from 7.4 log CFU/mL to 9.1 log CFU/mL by the end of the co-fermentation. The final mucilage content was 0.58% and consistency index was 0.15 Pa·sn. The co-fermented pumpkin contained 1.47% GABA, indicating that the MSG precursor was successfully utilized by the stepwise fermentation. Therefore, the co-fermented pumpkin paste could potentially be used as a novel ingredient for the food industry.

    更新日期:2018-07-31
  • Fermenting liquid vinegar with higher taste, flavor and healthy value by using discarded Cordyceps militaris solid culture medium
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-07-31
    Lu Liu, Yang Chen, Qing Luo, Ning Xu, Yong Hu, Mengzhou Zhou, Bing Gao, Chao Wang, Dongsheng Li

    Cordyceps militaris has entered a large-scale artificial cultivation, and the solid culture medium of Cordyceps militaris are usually discarded. In this study, two kinds of liquid vinegars were prepared with discarded solid culture medium of Cordyceps militaris and rice, respectively. The contents of tartaric, methanoic, lactic and total organic acids were higher in cordyceps vinegar than in rice vinegar. Cordyceps vinegar showed higher antioxidant activity than rice vinegar. Moreover, cordyceps vinegar contained higher cordycepin and adenosine. The contents of sweet and umami free amino acids in cordyceps vinegar were higher than those in rice vinegar. Meanwhile, flavor groups such as esters and acids in cordyceps vinegar also significantly improved. According to sensory analysis, cordyceps vinegar showed higher intensity for sweet and umami attributes, as well as fruity attributes. Thus, discarded solid culture medium of Cordyceps militaris can be used to ferment liquid vinegar and improve the flavor and quality of vinegar, thereby indicating additional economic benefits of fermentation.

    更新日期:2018-07-31
  • Comparison between the 3M MDS® method and phenotypic methods to detect Salmonella spp. in foods
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-07-30
    Greici Bergamo, Cláudio Dias Timm, Natália Rodrigues Carvalho, Elizabete Helbig, Eliezer Avila Gandra

    The objective of this study was to compare three methods for detection of Salmonella spp., the first recommended by the Brazilian Ministry of Agriculture, Livestock and Supply - known as MAPA -, the second described by Annex D of ISO 6579 - known as MSRV and the third method based on molecular techniques known as 3M MDS®. The assays were performed using samples of artificially contaminated UHT milk (101–103 CFU - Test), and mixed-meat and pork sausages commercialized in southern Brazil. MAPA, MSRV and 3M MDS® methods present a sensitivity of 100%, 100% and 97.6%, respectively. The specificity was 100% for the three methods. The data shows that 3M MDS® and MSRV are reliable methods because they revealed equivalent sensitivity and specificity to the Brazilian official method (MAPA) and that possibly can be used as a viable alternative for the detection of Salmonella spp.

    更新日期:2018-07-31
  • 更新日期:2018-07-31
  • Development and comparison of a porcine gelatin detection system targeting mitochondrial markers for Halal authentication
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-07-30
    Su San Na Kang, Hyeon Gyu Lee, Hyunsook Kim

    This study aimed to compare the sensitivity of porcine-specific primers targeting different mitochondrial DNA for the detection of porcine gelatin in ramen stock powder designated “Halal” using SYBR Green I real-time PCR. Four mitochondrial DNA markers (D-loop, ATP8, ND5, and 12S rRNA) were used to detect the porcine gelatin DNA. Extraction of DNA from porcine gelatin and spiked mixtures was successfully performed using a DNeasy Mericon Food Kit. Each primer had high porcine specificity for D-loop, ATP8, and ND5 genes, but not the 12S rRNA gene. Also, the detection limit for each primer was tested in a serial dilution of porcine gelatin DNA (10, 1, 0.1, 0.05, 0.01, and 0.005 ng) and ramen stock powder spiked with porcine gelatin (1, 0.1, 0.05, and 0.025%). Assays targeting both D-loop and ND5 genes were able to detect a level as low as 0.01 ng, while the detection limit for the ATP8 gene was 0.05 ng in pure porcine gelatin. The detection limits of D-loop, ATP8, and ND5 genes were 0.05%, 0.1%, and 1% (w/w) in ramen stock powder spiked with porcine gelatin, respectively. In conclusion, a novel detection system targeting the mitochondrial D-loop was superior to the others and could be an effective and simple method to authenticate Halal products.

    更新日期:2018-07-31
  • Inoculation strategies to improve persistence and implantation of commercial S. cerevisiae strains in red wines produced with prefermentative cold soak
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-07-30
    Y.P. Maturano, M.C. Lerena, M.V. Mestre, L.F. Casassa, M.E. Toro, F. Vazquez, L. Mercado, M. Combina

    Prefermentative cold soak is a winemaking technique aimed at enhancing aroma and colour extraction in red wines. This study aimed at evaluating implantation and persistence rates of commercial active dry yeast strains (ADY) in wines produced with cold soak using two different inoculation strategies. Cold soak was conducted at 4 ± 1 °C, 8 ± 1 °C and 12 ± 1 °C for 7 days. Two yeast strains (Lalvin ICV D254 and Lalvin Rhône 2056) were inoculated before and after cold soak. Implantation of Lalvin ICV D254 at the end of cold soak was higher when conducted at 8 °C and 4 °C, whereas it was undetectable (<5%) at 12 °C. Lalvin Rhône 2056 showed implantation percentages at the end of cold soak ranging from 40% to 100%, with higher percentages in cold soak conducted at 12 °C. Moderate persistence of ADY at the end of alcoholic fermentation was observed in all treatment inoculated before cold soak. In the treatments inoculated after cold soak, the persistence of Lalvin ICV D254 ranged from 12 to 38% whereas Lalvin Rhône 2056 was less than 5% at the end of alcoholic fermentation. Overall, persistence of both strains improved in inoculation before cold soak relative to inoculation after cold soak.

    更新日期:2018-07-31
  • Edible films and coatings based on mango (var. Ataulfo) by-products to improve gas transfer rate of peach
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-07-28
    Cristian Torres-León, António A. Vicente, María L. Flores-López, Romeo Rojas, Liliana Serna-Cock, Olga B. Alvarez-Pérez, Cristóbal N. Aguilar

    Fruit waste and by-products are economical materials for the development of biodegradable and active packaging. The aims of this study were to develop, characterize and evaluate biodegradable coatings and films by using mango peel and antioxidant extracts of seed kernel. The proximate composition of peel was also determined. Structural, barrier, optical and antioxidant properties were analyzed in the films. Gas transfer rates and the ethylene production in peach were evaluated. Edible films formulated with mango peel showed good barrier properties, with the water vapor permeability varying from 0.88 × 10−10 - 1.00 × 10−10 g m−1 s−1 Pa−1. The addition of antioxidant extract does not show a significant effect (p > 0.05) on optical properties. Furthermore, antioxidant activity and polyphenol content increased by 18% and 60% respectively. Peach coated with a solution of mango peel (1.09%), antioxidant extract of mango seed kernel (0.078 g L−1) and glycerol (0.33%) showed 64% and 29% less ethylene and CO2 production, respectively, and 39% less O2 consumption when compared with peaches without coating. The reduction in gas transfer ensures the greater extension of the shelf life of fruit treated. By-products of mango may thus be suitable for the production of low-cost biodegradable and active packaging.

    更新日期:2018-07-29
  • Reduction of formaldehyde residues induced by the thermal decomposition of trimethylamine oxide during the processing and storage of jumbo squid (Dosidicus gigas)
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-07-28
    Tao Zhang, Xueqian Xin, Yong Xue, Yuanhui Zhao, Changhu Xue

    Thermal decomposition of trimethylamine oxide (TMAO) during the processing and storage of jumbo squid was characterized to find an innovative approach to its safe consumption. A combination of Fe2+ with ascorbic acid (AA) promoted the almost complete degradation of TMAO from 438.89 mg/L to 0.23 mg/L, generating considerable equimolar amounts of dimethylamine (DMA) and formaldehyde (FA). Moreover, the role of “Fe2+ + AA” on the decomposition of TMAO could be significantly altered by varying the pH values. At pH 9, TMAO was degraded through two different pathways to give trimethylamine (TMA) with content of 148 mg/L and DMA of 57 mg/L, while at pH 3, TMAO was mainly transformed into TMA (210 mg/L) but a small amount of DMA (15 mg/L). Water activity (aw) and water mobility were also found to influence the formation of FA, as it obviously dropped from 136.6 μg/g to 100.6 μg/g when aw was reduced from 0.750 to 0.667 with less free water. Interestingly, during accelerated storage experiment, the quantity of FA increased prior to decreasing. This was attributed to its role in crosslinking the squid muscle fibers to give a stable network structure and significantly altering the microstructures observed by scanning electron microscopy.

    更新日期:2018-07-28
  • Industrial production of a balanced virgin olive oil
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-07-26
    Alfonso M. Vidal, Sonia Alcalá, Antonia de Torres, Manuel Moya, Francisco Espínola

    The aim of this work is to obtain a balanced commercial virgin olive oil (VOO) using response surface methodology at an industrial level under continuous working conditions. Thus, a factorial design was developed with three factors: sieve size of the hammer mill, temperature, and malaxing time. Forty different responses were modulated, including extraction efficiency, but with special attention to phenolic and volatile compounds because they are responsible for the taste and aroma of VOO. The conditions for malaxing were 22 and 32 °C for 60 and 120 min using 5 and 6 mm sieve sizes.After modeling the responses, the highest extraction efficiency was obtained at 32 °C and 120 min; similar conditions were necessary to obtain the maximum contents of chlorophyll, carotenoid, and phenolic compounds, but the maximum content of volatile compounds was obtained at 22 °C. Therefore, it has also realized a combined optimization of total phenolics and total volatiles.

    更新日期:2018-07-26
  • Qualitative and quantitative analysis of chlorpyrifos residues in tea by surface-enhanced Raman spectroscopy (SERS) combined with chemometric models
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-07-26
    Jiaji Zhu, Akwasi Akomeah Agyekun, Felix Y.H. Kutsanedzie, Huanhuan Li, Quansheng Chen, Qin Ouyang, Hui Jiang

    Surface-enhanced Raman spectroscopy (SERS) combined with chemometric models were employed to develop a rapid, low-cost, and sensitive method for qualitative and quantitative analysis of chlorpyrifos residues in tea. Au@Ag nanoparticles (NPs) with high enhancement factor were synthesized and coupled with chemometric algorithms for SERS measurements. K-nearest neighbors (KNN) classification models gave the best performance model with high classification rates (90.84–100.00%) achieved. For the quantification models for predicting chlorpyrifos contents, the genetic algorithm-partial least squares (GA-PLS) models and synergy interval partial least squares-genetic algorithm (siPLS-GA) models applied to standard normal variate transformation (SNV) preprocessed training and validation data set showed better prediction performances with excellent regression quality (slope = 0.98–1.00), higher correlation coefficient of determination (r2 = 0.96–0.98), and lower root-mean-square error of prediction (RMSEP = 0.29, 0.31) than other quantification models. Paired sample t test exhibited no statistically significant difference between the reference values determined by GC-MS and the predicted values in most quantification models. The proposed method would be a more effective and powerful tool for classification and determination of chlorpyrifos (CPS) residues in tea samples.

    更新日期:2018-07-26
  • Interaction of salt content and processing conditions drives the quality response in streaky rashers
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-07-26
    Gonzalo Delgado-Pando, Paul Allen, Joe P. Kerry, Maurice G. O'Sullivan, Ruth M. Hamill

    Response surface methodology was utilised to explore the relationship between processing conditions, including cooking temperature and drying time, and ingredients in reduced-salt streaky rasher formulations. The goal of this project was to assess the impact of reducing salt content on physicochemical and sensory properties. Salt levels above 2.44 g/100 g did not affect cooking loss. Cooking temperature (240 °C) was negatively correlated with lightness and redness, n-3 fatty acids, and sensory acceptance, and positively correlated with hardness and monounsaturated fatty acids. Salt content was highly correlated with perceived saltiness and both were identified as negative attributes by the sensory panel. Results indicate that optimised reduced-salt streaky rashers with acceptable technological and sensory performance could be achieved under the following conditions: 2 g/100 g salt, 94 min of drying and grilling at 190 °C.

    更新日期:2018-07-26
  • Effects of enzymatic hydrolysis on the chemical constituents in jujube alcoholic beverage fermented with Torulaspora delbrueckii
    LWT - Food Sci. Technol. (IF 3.129) Pub Date : 2018-07-26
    Jingjing Guo, Yilan Yan, Mei Wang, Yuchen Wu, Shao-Quan Liu, Dai Chen, Yuyun Lu

    This study evaluated the chemical and volatile composition of jujube alcoholic beverage fermented with Torulaspora delbrueckii after enzymatic hydrolysis treatment. The results showed that enzymatic hydrolysis first and then alcoholic fermentation (EHAF) significantly improved the growth of T. delbrueckii with higher amount of final yeast population (9.67 × 107 CFU/mL) than that of alcoholic fermentation control (AFC) treatment (5.02 × 107 CFU/mL). Additionally, the enzymatic hydrolysis significantly improved the contents of total saponins and nitrogen sources (ammonia and amino acids), but decreased the production of acetic acid. Furthermore, EHAF treatment significantly promoted the productions of ethanol, various esters (including methyl esters, ethyl esters and isoamyl esters), which are beneficial for flavor complexity. This study suggested that EHAF treatment could significantly improve the production of aroma compounds and this strategy might be a useful way in fruit alcoholic beverage fermented with T. delbrueckii.

    更新日期:2018-07-26
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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