Copado, Claudia N.Julio, Luciana M.Diehl, Bernd W. K.Ixtaina, Vanesa Y....
12页
查看更多>>摘要：A multilayer microencapsulation process was carried out to protect and deliver chia oil, which presents high nutritional value but also a high susceptibility to lipid oxidation. A high-pressure homogenization was performed with deoiled or hydrolyzed sunflower lecithins (pH 5) to obtain the primary emulsion. The secondary and ter-tiary layers were deposited, applying the layer-by-layer technique with the addition of chitosan and chia mucilage, respectively. After spray-drying these emulsions, the corresponding microcapsules were obtained and the influence of the types of lecithin (deoiled or hydrolyzed) and microcapsule (mono or multilayered) were studied. The zeta-potential evidenced the electrostatic deposition of the layers through the inversion of the electric charge. Microcapsules presented high microencapsulation efficiency (84-99%) and low moisture content and water activity levels. Most microparticles exhibited whitish and light color, spherical shapes, with continuous and slightly rough walls. The powder dispersibility was compatible with instant foods. All the microcapsules presented low oxidation levels after storage, especially the three-layer systems. This information suggests that multilayer systems can contribute by providing high stability against the oxidative deterioration of functional lipid components present in chia oil.
查看更多>>摘要：To valorise meat by-products such as trimmings from the food industry, this study investigated the influence of thermal treatment, cysteine and xylose addition on the modification of volatile compounds in lactic acid bacterium fermented pork hydrolysates on the basis that xylose and cysteine are precursors to aroma compounds formation via the Maillard reaction. In this study, xylose (3.5% w/v) and cysteine (1.0% w/v) were added to Lactobacillus fermentum fermented pork hydrolysates and the mixture was adjusted to pH 5.5 before thermal treatment at 100 degrees C for 60 min. The addition of xylose and cysteine combination produced most of the desired sulfur-containing volatiles such as 2-furfurylthiol (5.21 ppb) and methionol (1.61 ppb) that would impart a savoury and roasted meat note. Lipid derived aldehydes (mainly hexanal) and alcohols (mainly 1-hexanol and 1-octen-3-ol) were significantly decreased after the Maillard reaction, while thermal degradation of amino acids increased the amount of some Strecker aldehydes such as benzaldehyde. In conclusion, the potent sulfur-containing volatiles were formed only when both cysteine and xylose were present, but the variety and amount of these volatile compounds were limited due to the moderate heating temperature and shorter time.
查看更多>>摘要：Shrimp allergy is a critical public health concern worldwide, and is also the most frequent cause of food allergy in Taiwan. Tropomyosin is recognized as the major shrimp allergen. However, information of tropomyosin content in Taiwanese shrimp is unknown. Therefore, it is an urgent need to develop a reliable analytical approach to detect tropomyosin. An absolute quantification method of proteins (AQUA) method was developed to detect tropomyosin in seven Taiwanese shrimps in this study. Both signature peptide, ALSNAEGEVAALNR, and its isotope-labeled peptide were used as standards and internal standards. The determination coefficient (R2) of the calibration curve is 0.9989, and the limit of detection (LOD) and limit of quantification (LOQ) were 0.072 ng/mu l and 0.219 ng/mu l, respectively. The intra-day and inter-day precision of this analytical method are 2.30-12.80% and 2.93-11.97%, respectively. Recovery was measured as 85.53-101.87% by adding signature peptide with 0.5, 1.0, 7.5 ng/mu l into the blank matrix. The method showed no cross-reactivity with squid, tilapia and chicken. Also, the current validated method was successfully applied to shrimps and processed foods. The levels of tropomyosin in seven Taiwanese shrimps ranged from 555.50 to 973.93 mu g/g. The present study demonstrated this analytical approach may be an useful technique to analyze tropomyosin in foods.
查看更多>>摘要：5-Hydroxymethyl-2-furaldehyde (5-HMF) in dairy food products generated via Maillard reaction may bring health risks. Herein, the interaction of 5-HMF with beta-casein (beta-CN) and its influences on the structure and function of beta-CN were investigated. 5-HMF was found to quench the inherent fluorescence of beta-CN by a static mode and the binding constant was in the order of magnitude of 10(4) L mol(-1). Thermodynamic analysis indicated that hydrophobic forces played the major role in the interaction. The results of synchronous and threedimensional fluorescence revealed that 5-HMF changed the microenvironment of tyrosine and tryptophan residues and interfered the stability of the polypeptide backbone structure in beta-CN. Molecular docking revealed that 5-HMF bound to the hydrophobic cavity of beta-CN mainly interacting with the amino acid residues Pro196, Val155, Leu163, Phe157 and Leu192. The binding of 5-HMF with beta-CN caused partial unfolding of beta-CN conformation, resulting in the increase in surface hydrophobicity and emulsifiability, and decrease in emulsification stability of beta-CN, thereby reducing the solubility of beta-CN. The study might facilitate the comprehensive understanding of 5-HMF affecting the structure and functional properties of beta-CN.
查看更多>>摘要：This study investigated the effects of HPP and heat treatment on digestibility and trypsin inhibitor activity in lentil protein concentrate (LPC) and faba bean protein concentrate (FPC). LPC and FPC with 15 g protein/100 g were treated with HPP (600 MPa/5 degrees C/4 min) or heat (95 degrees C/15 min), then subjected to in vitro digestion. Digesta were analyzed by SDS-PAGE for hydrolyzed protein fraction patterns and their concentrations. The concentration of peptides and free amino acids was also determined. The effect of HPP and heat treatment on trypsin inhibitor activity was determined for 5 g protein/100 g LPC and FPC. HPP and heat treatments led to different hydrolyzed peptide patterns after gastric digestion. HPP resulted in comparable or greater gastric digestibility than untreated controls, but higher gastric proteolysis than heat treatment. Neither treatment impacted overall in vitro protein digestibility, for either LPC or FPC. HPP slightly reduced trypsin inhibitor activity (similar to 8% for LPC, similar to 6% for FPC), while heat treatment led to much greater reductions (86% for LPC, similar to 78% for FPC) than untreated controls. Overall, HPP and heat treatment did not negatively impact lentil and faba bean protein quality, which is useful information for developing new food product applications.
查看更多>>摘要：The lipid oxidation of soybean oil or peanut oil under accelerated oxidation was retarded after addition of non-saponification (N-Asta) or saponification astaxanthin (S-Asta) derived from Penaeus sinensis by-products, determined by lower malondialdehyde and peroxide value as compared with the oil controls. S-Asta or N-Asta degradation in soybean oil or peanut oil fit well to first order model. Further, the soybean oil or peanut oil containing S-Asta demonstrated lower lipid oxidation as compared to those with N-Asta addition. The thermal stability of S-Asta was further evaluated under 60-90 degrees C pasteurization. Significant decreases of scavenging hydroxyl radical and superoxide anion, and Asta isomers concentrations were found for S-Asta under 90 degrees C pasteurization; whereas the antioxidant activity of S-Asta was largely restored under 60-70 degrees C pasteurization. The degradation kinetics of all tans, 9-cis and 13-cis Asta, as well as Asta stereoisomers in S-Asta fit to zero order kinetics, and well described by the Arrhenius equation. The highest and lowest activation energy values of 164.83 +/- 14.87 kJ/mol for all trans Asta and 17.63 +/- 0.99 kJ/mol for 3S,3'R Asta suggested their highest and the lowest pasteurization stabilities. By comparison, 13-cis, 3S,3'S, and 3R,3'R showed similar thermal stabilities under pasteurization.
查看更多>>摘要：The positive effect of mannoproteins (MPs) on wine astringency is of great interest during winemaking. Phenolic components with different structural characteristics in wine could elicit different intensities of astringency when combined with salivary proteins. Aiming to use commercial MPs to modulate the unbalanced wine astringency, this work selected three commercial MPs and phenolic fractions (phenolic acids, monomeric/oligomeric procyanidins, polymeric procyanidins) with different mDP extracted from wine. The relationship between the structure and concentration of MPs, phenolic fractions, and astringency was investigated by physicochemical techniques (fluorescence quenching, SDS-PAGE, dynamic light scattering, and isothermal titration calorimetry) and sensory evaluation. Results showed that 0.6 g/L of MPs played a role in reducing wine astringency. MPs were more effective in inhibiting the interaction between monomeric/oligomeric or polymeric procyanidins and proteins than that of phenolic acids, through ternary or competitive mechanisms. Moreover, MPs with high protein portion and high molecular weight exhibited a stronger binding capacity to phenolics or protein, thus showing competing effect with phenolics for binding to protein. This work could provide the wine industry with valuable information for optimizing the application of commercial MPs to modulate wine astringency.
查看更多>>摘要：Microwave processing is a combined treatment of thermal and non-thermal effects on microorganisms and food ingredients. There may exist synergism between these two types of effects. The objective of this study was to explore the synergism of microwave thermal (i.e. temperature) and non-thermal effects on microbial inactivation and on fatty acids quality of pasteurized salmon fillets. Water bath processes with same time-temperature profiles and same microbial inactivation intensity were designed as control. Results showed that the microwave nonthermal effect on microbial inactivation was significantly (P < 0.05) enhanced by increasing temperatures. Compared with the microbial inactivation of thermal effect, the inactivation efficiency of microwave nonthermal effect increased from 22.18% to 35.25% while final temperatures of samples increased from 84 degrees C to 100 degrees C. Furthermore, with the same microbial inactivation intensity of 7.5-log CFU/g, microwave process retained better fatty acids quality in consideration of significantly higher (P < 0.05) PUFAs (especially for ARA, EPA and DHA) than those with water bath treatments. These results demonstrated that high temperatures could bring significant enhancement on microwave non-thermal effect, and microwave processing could provide better bacteria control and meanwhile retain higher product quality due to the synergism of microwave thermal and non-thermal effects.
查看更多>>摘要：This study focused on the correlation between microbial communities and precursor substances of ethyl carbamate (EC) during soy sauce fermentation. High-throughput sequencing showed that there were ten dominant bacterial communities in soy sauce fermentation. The dominant fungal communities were Zygosaccharomyces rouxii, Candida versatilis and Candida tropicalis. Weissella, Pediococcus and Lactococcus were the dominant bacteria which had positive correlation with ethanol accumulation, while Acinetobacter, Pseudomonas and Bacillus were negatively correlated with ethanol accumulation. Fungi with the strongest positive correlation with ethanol accumulation were OTU3 and OTU110, which all belong to Zygosaccharomyces rouxii, while Ascomycotina and Aspergillus had the strongest negative correlation with ethanol accumulation. Three bacteria belong to Halobacterium, Acinetobacter and Halomonas, and two fungi belong to Aspergillus and Saccharomyces cerevisiae had the strongest positive correlation with urea accumulation, while Lactococcus and Leuconostoc, and Zygosaccharomyces rouxii had strongest negative correlation with urea accumulation. The main bacteria with positive correlation with citrulline and arginine content were Leuconostoc, Weisiella and Galactococcus, while the bacteria with negative correlation were mainly Acinetobacter, Halomonas and Halobacterium. The fungi with positive correlation with citrulline and arginine content were all mainly Zygosaccharomyces rouxii, while the fungi with negative correlation were mainly Mortierella and Apiotrichum loubieri.
查看更多>>摘要：Probiotic composite beverage was prepared from underutilized resources, whey-skim milk (60:40, v/v), germinated pearl millet flour (4.5%, w/v), liquid barley malt extract (3.0%, w/v) and fermented with Lactobacillus acidophilus NCDC 13. In vivo feeding trials on mice revealed better weight gain and blood haemoglobin level in the probiotic beverage-fed group (P) than in the control group (casein diet) and unfermented beveragefed group (UF) which indicates that the nutritional quality in terms of protein efficiency ratio and apparent protein digestibility was better for probiotic group than UF and control group. The relative weights of organs of mice fed on the P were not significantly different from the organs of the mice fed on the basal diet, indicating no abnormality induced due to feeding of probiotic beverage. Probiotic beverage can be a cost-effective source of nutrition for wide segments of population in the society specially for underprivileged one.
NSTL
Elsevier