查看更多>>摘要：Fish oil (FOL) and encapsulated fish oil by tragacanth (TRG) and carrageenan (CGN) were added to chicken nuggets to evaluate the physicochemical, fatty acid profile and oxidative stability of pre-fried nuggets during frozen storage. The panelists preferred fish oil addition as encapsulated (P < 0.05). The percentage of addition microcapsules (4-8%) was effective in acceptance of nuggets. The enriched samples by 4 g/100 g microcapsules were monitored by chemical and oxidative stability during storage. The CDs, TBARS and carbonyl values showed significant differences during time of storage and between treatments (p < 0.05). At TRG and CGN treatments, the EPA and DHA amount of the nuggets was significantly higher than control and FOL pre-fried samples. Encapsulation of fish oil showed a protective effect against lipid and protein oxidation, and improved the oxidative shelf life and the sensory characteristics of the enriched nuggets. The encapsulating of fish oil by tragacanth was more effective in preserving the sensory characteristics.
查看更多>>摘要：The aim of this study was to identify optimal storage conditions able to preserving date palm quality and minimising their loss in the supply chain. Hence, the effect of storage at -18, 0, 2 and 4 degrees C for 3, 6 and 9 months during two harvest seasons (2017 and 2018) on sugars, organic acids, polyphenols and cell wall yields and composition of 'Deglet Nour' Tunisian dates, were studied. Mid Infrared Spectroscopy (MIR) as a non-targeted method allowed to highlight a year effect on chemical composition and to discriminate samples stored at 4 and 2 degrees C regarding to major components (moisture, sugars, organic acids.). Cell wall yields were stable during the time. However, galactose from pectin side chains decreased with time, causing an increase of lignin, cellulosic glucose, fucose and rhamnose. Procyanidins, accounting for 98% of total polyphenols, were not affected by storage. Regarding quality parameters stability, stored fruits at -18 degrees C could be the solution for a long term storage but due to its high energetic costs, 2 degrees C must be the optimal temperature with a lower time.
查看更多>>摘要：Skim milk powders may be used as a convenient alternative to fresh milk in high moisture Mozzarella cheese manufacturing. The effects of a blend of 40 g/100 g of reconstituted low heat skim milk powder and 60 g/100 g fresh milk on processing and quality of Mozzarella cheese (experimental) were evaluated, in comparison with cheeses produced only with fresh milk (control). The ability of experimental curd to retain fat during stretching was lower than control, as showed by the fat content in stretching water (2.85 +/- 0.45 g/100 g and 2.01 +/- 0.31 g/100 g for experimental and control curds, respectively). However, cheeses showed a similar composition. Cheese rheological properties were affected, as experimental Mozzarella showed a more organized casein network with tans and n' values lower than control cheeses. The use of powder milk also increased the fraction of solvation water measured with low field NMR when compared with control cheeses. This study demonstrated the applicability of a blend with 40 g/100 g of reconstituted milk to obtain Mozzarella cheese without major changes in product quality.
查看更多>>摘要：The pit mud microbes are tightly correlated with the quality of Chinese strong aroma-type Baijiu. However, it is still unclear the explicit contributions of pit mud microbes to flavour formation. Through down-scaled fermentation with or without pit mud, we found that 85 genera from pit mud, dominating by Caproiciporducens, Caloramator, Sedimentibacter and Caldicoprobacter, migrated into fermented grains. These microbes increased the microbial diversity in fermented grains and resulted in an improved flavour profiles: 13 volatiles acids, 6 linear-chain alcohols and 37 esters were more abundant in the pit mud group. Most of these compounds were positively correlated with anaerobes derived from pit mud by network correlation analysis. Moreover, a synergistic effect of diverse esters formation was found between pit mud microbes and starter (Daqu). The pit mud microbes contributed to abundant volatile acids and linear-chain alcohols that were selectively esterified by Daqu (starter), and the metabolism of pit mud microbes elevated the pH of fermented grains, which further elevated the esterification capability of Daqu. These findings improve the understanding of the diverse flavour compounds formation during strong aroma-type Baijiu fermentation.
查看更多>>摘要：The aim of this study was to explore whether the state of the formation of interfacial protein film (IPF) could be utilized to increase the emulsion ability modified by high pressure processing (HPP). The meat emulsion was obtained from the meat batters with reduced fat and reduced salt (RFRS). The results revealed the highest stability and activity of meat emulsion were obtained as 68.12% and 76.89% at 200 MPa, respectively, and the minimized diameter of emulsion particles was D-3(,2) 2.29 mu m. Besides, after obtaining the interfacial proteins (IPs) and the fat droplets individually, the diameter of fat droplets and proportion of ionic bonds first decreased then rose along with increasing pressure, and the lowest values were exhibited at 200 MPa. In contrast, the adsorbed IPs content (0.657 mg/m(2)), zeta potential (-0.27), hydrophobic interactions (63.57%), hydrogen bonds (83.29%), and disulfide bonds (75.69%) presented the opposite trends, with the highest value also exhibited at 200 MPa. In conclusion, 200 MPa helped proteins adsorbed at the interface, corresponding with the unfolding conformational rearrangement and reorientation of IPs at the interface with the dispersed fat droplets.
查看更多>>摘要：The gel properties of underutilized plant proteins, such as pea protein isolate (PPI), can be improved by adding inulin (a prebiotic). Herein, the effects of the inulin concentration (10-70 g/L) on the rheological, mechanical, and microstructural properties, as well as the interactions and pH stability of PPI-based emulsion gels, fabricated by combining high-pressure homogenization and Ca2+-induced gelation, were investigated. The highest gel strength (166 +/- 3 N) and water-holding capacity (91.5 +/- 0.9 g/100 g) were reached with an inulin concentration of 50 g/L. Scanning electron microscopy revealed that inulin changed the emulsion gel microstructure from porous with a rough surface to dense with a smooth surface. The enhanced gel strength can be explained by the highly cross-linked gel network. The protein solubility results indicated that hydrogen bonding and hydrophobic interactions play important roles in improving the gel properties, and infrared spectroscopy confirmed the important role of hydrogen bonding during PPI-inulin emulsion gel formation. The PPI-inulin emulsion gels were more stable at pH 2.0. These results reveal a possible method for preparing stable and natural carriers with suitable gel properties to deliver lipid-soluble food bioactives.
查看更多>>摘要：In the present study, the modification of myofibrillar protein (MP) by hydroxyl radicals (center dot OH) and the effects of oxidative modification on the proteolysis of MP by mu-calpain were investigated. Isolated MP was exposed to different oxidation conditions and then incubated with mu-calpain. With increasing H2O2 concentration, the carbonyl and dityrosine contents as well as the surface hydrophobicity of the MP increased, while the total sulfhydryl groups and tryptophan fluorescence intensity gradually decreased. Disulfide bonds and other covalent bonds resulted in the cross-linking and aggregation of proteins. Increasing oxidant concentration resulted in the alpha-helix content decreasing from 19.19% to 17.32% whereas the beta-sheet content increased from 21.59% to 26.47%. Protein oxidation increased the proteolytic susceptibility of actin, but inhibited the proteolysis of myosin heavy chain, troponin T, and desmin. Overall, our data demonstrate that center dot OH can change the structure of MP and its susceptibility to proteolysis by u-calpain, providing mechanistic information that links protein oxidation with proteolysis.
Ferreira, Suzane MartinsCapriles, Vanessa DiasConti-Silva, Ana Carolina
7页
查看更多>>摘要：Inulin is an interesting dietary fiber with potential to improve the technological and nutritional properties of food products. Thus, the objective of this work was to develop breakfast cereals through extrusion of corn grits with added inulin and evaluating the effects of different extrusion conditions on the chemical, physical and technological characteristics. The independent variables of the experimental design were the moisture of the 'corn grits and inulin' mixture (11.5-18.5 g/100 g) and the amount of inulin added (5.1-24.9 g/100 g). The breakfast cereals presented adequate expansion ratio and they maintained their texture after milk addition. Increasing the inulin enhanced the total fructan content and reduced the cutting force after the addition of milk, although increasing together with the moisture of 'corn grits and inulin' mixture resulted in higher losses of the total fructans. Decreasing the amount of inulin and increasing the moisture of the 'corn grits and inulin' mixture enhanced the color parameters (chroma and hue) and the paste properties (final viscosity and setback). Therefore, the production of breakfast cereals through extrusion of corn grits and inulin is feasible, providing products with fructans in their composition and contributing to consumption of breakfast cereals with fibers.
查看更多>>摘要：The influences of bran components and glucose oxidase on the gluten development and water distribution in bread dough were investigated. Two major bran components, such as cellulose and arabinoxylan (AX), were included in the dough formula, and exogenous ferulic acid (FA) was also added together with AX. GOX was included in both straight grade flour (SGF) dough and bran components containing dough. Bran components reduced the dough density and interfered protein polymerization in bread dough. AX caused more deterioration in gluten development than cellulose owing to its higher water competing ability with gluten. Inclusion of free FA induced a weaker gluten network probably because of its accelerating effect of dough breakdown. Moreover, GOX improved dough porosity and increased dough development time and stability. GOX stabilized protein secondary structure by increasing a-helix and (3-sheet conformation and enhanced water availability to gluten by promoting the proportion of less-tightly bound water. Cellulose resulted in smaller enhancement of dough strength after GOX addition, for instance, half of the increase in dough stability compared to AX. Briefly, AX showed more interference with gluten formation than cellulose. Although the function was disturbed in bran component containing dough, GOX still improved the strength and structure of gluten.
查看更多>>摘要：Coffee is a very popular and highly traded commodity that is targeted by fraudulent practices, affecting global production and economy. A common practice involves the substitution of the more expensive Arabica coffee with the less popular Robusta. Various physiochemical and DNA-based technologies have been used for coffee authentication; yet detection of adulterants in coffee still faces limitations in terms of the raw material used, the level of processing, and the sensitivity of available analytical tools. Additionally, DNA-based methodologies cannot be successfully used in the presence of strong inhibitors in brewed coffee. Herein, we designed an Internal Transcribed Spacer region 2 (ITS2)-based marker that allowed coffee authentication, even from the brewed beverage, when coupled with High Resolution Melting (HRM) analysis. The developed methodology could effectively detect differences in Arabica/Robusta admixtures, as low as 1% (v/v) DNA content. Direct species identification from the brewed beverage was enabled by the use of an inhibitor-tolerant DNA polymerase with enhanced sensitivity, without prior DNA purification. In the context of food safety, this novel approach could advance coffee authentication methods for safeguarding coffee producers and consumers.
NSTL
Elsevier