查看更多>>摘要：Tef flour has been considered a good alternative raw material to improve the quality of gluten-free bread due to its attractive nutritional profile. The influence of tef variety (DZ-Cr-37, DZ-Cr-387 and DZ-01-99) and incorporation level (100, 75 and 50%) on rheological and thermal properties of maize starch-based gluten-free doughs, and their impact on bread characteristics was investigated. The addition of tef brought about a structuring effect of doughs leading to higher viscoelastic moduli and steady-state viscosities and to lower tan delta values and instantaneous and retarded compliances. These effects were magnified with the increase of tef level in the dough. Tef addition led to an increase in dough gelatinization temperature and a decrease of gelatinization enthalpy, especially in the case of DZ-01-99 variety. Tef incorporation at 50 and 75% level led to well-developed bread which volume and crumb grain properties were significantly affected by the tef variety. DZ-Cr-37 variety led to the highest bread volume but to a less regular and poorer crumb grain. However, the bread made with 100% DZ-Cr-37 reached the highest overall acceptance score. This work demonstrates tef flour incorporation up to 100% level is a feasible procedure to reach technologically viable and sensory acceptable gluten-free bread.
查看更多>>摘要：The effects of four edible mushrooms, Volvariella volvacea (Vv), Hypsizygus marmoreus (Hm), Pleurotus ostreatus (Po) and Agaricus bisporus (Ab), on beef paste quality were investigated. In this experiment, 50 g/kg dried mushroom powders were added to the beef paste, separately. The results showed that Vv and Po could reduce the hardness, chewiness, and gumminess of beef paste. Both free amino acid and volatile compound contents of the samples exhibited remarkable changes after mushroom powders were added. Compared with the control, the total free amino acid contents increased 1.31-, 1.10-, 1.67- and 1.14-fold and the essential amino acid contents increased 2.51-, 3.31-, 4.41-, and 1.69-fold in the beef samples treated with 5% Vv, Hm, Po and Ab, respectively. Up to 35 volatile compounds were identified in beef paste with 5% Vv, while only 14 volatile compounds were detected in the control. The mechanism was ascribed to the flavoring substances and the enzymes in the edible mushrooms. The above results indicated that edible mushrooms not only supply flavor components but also promote the formation of flavor substances in meat products.
da Costa, Mateus Matiuzzide Miranda, Juliana OliveiraCordeiro de Lira-Alencar, Nayara ReisAvila Queiroz, Mario Adriano...
7页
查看更多>>摘要：Sodium is essential for the production of meat derivatives. However, the relationship between sodium and health problems has driven the meat industry to seek alternatives to reducing sodium in its products. Alternative salts with lower sodium contents have been used for this purpose. The aim of this study was to evaluate the effect of using four different types of salt (100% NaCl, T1; 100% Himalayan salt, T2; 50% NaCl + 50% KCl, T3 or 50% NaCl + 25% KCl + 20% MgCl2 + 5% CaCl2, T-4) on physicochemical, textural, microbiological and sensory characteristics of frozen goat sausage. Sodium content was lower (17.6%) in T3 and T4 (P < 0.01). There was no treatment effect and no interaction between treatments and storage time (1, 30, 60 and 90 days) for instrumental color, pH and lipid oxidation (P > 0.05) was found in T2. There was no treatment effect (P < 0.05) on water activity, water holding capacity and sensory analysis. The reduction of sodium by replacing NaCl with chloride salts at the studied levels had no negative influence on the physicochemical, microbiological and sensory characteristics of frozen goat sausage.
Collaco, Ana Cristina A.Aguieiras, Erika C. G.Cavalcanti, Elisa D. C.Freire, Denise M. G....
7页
查看更多>>摘要：In the present study, monoglycerides (MAG) and diglycerides (DAG) were produced by an enzymatic esterification reaction of palm fatty-acid distillate (PFAD) (co-product) with glycerol, using a dry fermented solid (DFS) with lipase activity obtained by solid-state fermentation in palm cake and fiber (co-products) in an integrated process. The reaction using DFS as biocatalyst was optimized by a central composite rotatable design. MAG and DAG yields of 25% and 40% were obtained, respectively, in a reaction with molar ratio of 2:1 (glycerol: PFAD), 9.6 wt% water content, and 20 wt% DFS at 50 degrees C after 48 h. MAG and DAG synthesis using the commercial biocatalyst Lipozyme (R) RM-IM (immobilized lipase from Rhizomucor miehei) was also evaluated. The highest MAG and DAG yields in reactions with Lipozyme RM-IM were attained in a molar ratio of 1:1 (glycerol: PFAD), 3 wt% enzyme at 50 degrees C after 10 h (MAG and DAG yields of 27.9% and 53.05%, respectively). Results obtained with DFS and Lipozyme RM-IM were close to the WHO (World Health Organization) guidelines, in which these mixtures must contain at least 70% MAG + DAG and a minimum of 30% MAG.
查看更多>>摘要：This work aimed to apply microcrystalline cellulose (MCC) and gellan gum to improve the physical and thermal stability of cloudy ginkgo beverages. The stability of each beverage samples was characterized in terms of particle size, size distribution, zeta potential, rheological properties, Turbiscan Stability Index (TSI), and changes in backscattered light intensity (Delta BS). Our results indicate that an irreversible phase separation occurred in the beverage sample, induced by increased particle size, decreased zeta potential, and decreased viscosity during the sterilization process. Although the addition of either MCC or gellan improved beverage stability by decreasing particle size and increasing zeta potential, this improvement was limited; the aggregation and sedimentation of suspended particles still occurred, as revealed by large Delta BS and TSI changes. Beverage samples added with a mixture of MCC and gellan exhibited different physical and thermal stability values depending on the ratio of MCC to gellan. The addition of MCC (0.3%, w/w) combined with a small amount of gellan (0.05% or 0.08%, w/w) effectively prevented drastic thermal damage and improved physical and thermal beverage stability in comparison to MCC combined with the larger amount of gellan. This study provides some suggestions for the industrial production of cloudy beverages.
查看更多>>摘要：This study aimed to evaluate the efficiency of gamma ray irradiation (1.5, 3.0, and 4.5 kGy) on the microbiological safety and shelf life of sodium-reduced hot dog wieners. The effects of this technology on quality parameters (color, lipid oxidation, texture, and sensory acceptance) were studied. The results showed that irradiation had a significant effect on reducing the red color (a*) of the wieners; higher levels of lipid oxidation were also observed at the initial time of storage (ranging from 0.5 to 1.34 mg malonaldehyde per kilogram of sample) when higher doses were applied. Sensory acceptance was not impaired by higher radiation doses. A significant, dose-dependent reduction of the microbial load was observed. Irradiation at a minimal dose provided up to 6 log cycle reductions of lactic acid bacteria. The application of 1.5 kGy is effective at assuring microbial safety without changing the quality of the product.
查看更多>>摘要：Manufacturing of fish sauce results in a large number of underutilized by-products. The fish sauce by-products (FSBs) contain peptides derived from enzymatic hydrolysis of the fish proteins by proteases from their gastrointestinal tract and halophilic microorganisms. Commercial fish sauce can be divided into different grades based on their fermentation period. The 1st, 2nd and 3rd grade FSBs are solid wastes produced after the 1st, 2nd and 3rd grade fish sauce fermentation. This work aims to evaluate the effect of fermentation periods on antioxidant and angiotensin I-converting enzyme (ACE) inhibitory activities of the FSBs. Based on bioassays against different mechanisms, the 1st grade FSB possessed stronger DPPH and hydroxyl radical scavenging activities and reducing ability than the 2nd and 3rd grades. The top two grades of FSB showed higher % ACE inhibition than the 3rd grade FSB. All FSBs had equally strong H2O2 quenching and iron chelating abilities. It was observed that FSB fractions with smaller molecular weight and higher hydrophobicity possessed higher antioxidant and anti-ACE activities. This work demonstrated that the manufacturing fermentation time affected activities of FSB peptides. Understanding of composition and bioactivities of the FSBs may lead to the development of value-added functional products from these manufacturing wastes.
查看更多>>摘要：Cyclodextrin is widely used in the food industry due to its excellent physicochemical properties. Organic solvents are usually used as complexing agents in the enzymatic production of cyclodextrin. Because they form inclusion complexes with the cyclodextrin products, these solvents reduce product inhibition, change the product (alpha-, beta- and gamma-cyclodextrins) ratio and increase the cyclodextrin yield. In this study, the effects of twenty five alcohols, including linear and branched-chain monohydric alcohols and diols, on the yield and cyclodextrin ratio were systematically investigated. The stability of the inclusion complexes formed were also measured and compared. Although almost all of the alcohols increased cyclodextrin yield and many increased alpha-cyclodextrin selectivity, the effects of linear monohydric alcohols on alpha-cyclodextrin synthesis were greater than those of the branched-chain monohydric alcohols and diols with similar numbers of carbon atoms. The linear alcohols also showed the best correlation between inclusion complex formation and increased alpha-cyclodextrin selectivity. This study provides a theoretical basis for the selection of compound agents in producing alpha-cyclodextrin.
查看更多>>摘要：Beans are often processed before consumption, and germination is one such processing method. The objective of this study was to investigate the effect of germination on the immunoreactivity of black gram (BG) and mung bean (MB) vicilins. BG and MB seeds were germinated for ten days. Immunoreactivity of the seed proteins was analyzed by enzyme-linked immunosorbent assay (ELISA) and Western blot using rabbit anti-whole BG soluble protein antiserum and rabbit anti-BG vicilin polyclonal antibodies. Electrophoretic analysis of sprouted BG and MB soluble proteins exhibited a gradual decrease in the 40-60 kDa polypeptides with a concomitant increase in the 9-26 kDa polypeptides. Non-germinated MB registered 68% immunoreactivity as compared to the corresponding BG control designated as 100%. Upon germination, the vicilin immunoreactivity of BG remained stable for eight days, while that of MB decreased by 41% on day one. On the tenth day, germinated BG and MB vicilins exhibited 55% and 74% reduction in immunoreactivity, respectively. Western blot and ELISA results collectively showed that BG vicilin was more resistant than MB vicilin to proteolysis during germination. Vicilin degradation resulted in the appearance of an immunoreactive 23 kDa polypeptide. In conclusion, germination significantly decreased, not eliminated, immunoreactivity of BG, and MB vicilins.
NSTL
Elsevier