查看更多>>摘要：Effects of irradiation and superfine grinding wall disruption treatment on quality parameters and antioxidant activity of pine pollen during storage at 55 degrees C for 8 weeks were investigated. Results showed that irradiation slowed the reduction of taxifolin and ascorbic acid levels and the increase of ferric-ion reducing antioxidant power (FRAP), but accelerated the increase of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity over storage. In addition, superfine grinding wall disruption accelerated the rise of p-coumaric acid and naringenin contents and the decline of taxifolin level in pine pollen during storage. Moreover, superoxide dismutase activity, FRAP value, naringenin, malondialdehyde, total saturated and polyunsaturated fatty acids content were increased both in untreated and treated pine pollen, whereas the total spins, taxifolin, and ascorbic acid contents were decreased. The changes of parameters in endogenous antioxidant system indicated that metabolism in pine pollen was triggered in response to damage induced by processing and storage. These results would help improve the quality and commercial values of pine pollen in the food and pharmaceutical industries.
查看更多>>摘要：The use of natural dyes such as anthocyanins in foods has disadvantages due to their relatively high costs and low stability. Striking advantages, however, include natural origins and favourable bioactivities. Therefore, the use of a pigment extract from coloured-flesh potatoes is proposed here as a natural dye in dairy foods. The phenolic compound composition, antioxidant activities, and sensorial parameters under different storage conditions were evaluated. In milk stored at room temperature (20 degrees C) and yogurt, a decrease between 26% and 32% in anthocyanin concentrations was observed after eight weeks, whereas in cooled milk (4 degrees C), the pigments were stable throughout the same storage time. Similar tendencies were observed between total phenolic compounds and antioxidant activities in milk and yogurt, suggesting that other phenolic compounds contained in dairy foods and potato extract are also affected by storage conditions. In the case of yogurt, the addition of the potato pigment extract did not affect the organoleptic properties. Based on these results, phenolic extracts from coloured-flesh potatoes are an optimal natural and stable alternative for colouring dairy food products, which also provides added value through the addition of biologically active anthocyanins.
查看更多>>摘要：The aim of this research is to develop composite (CG-TA) films by using chitosan (CS)/gelatin (GL)/tannic acid (TA), for fresh-cut apples preservation. TA was used as the crossing-linking agent to improve the mechanical and barrier properties, and as the active substance to improve the anti-ultraviolet and antioxidant abilities of the chitosan/gelatin (CG) film. With the incorporation of TA from 0 to 1 wt%, the tensile strength of the CG film was increased while the water vapor and oxygen permeability of the film were decreased. The CG-TA films containing more than 0.5 wt% of TA could effectively block most of UV light. The DPPH radical scavenging assay significant increased to 89.3% when the concentration of TA reached 2 wt%. Finally, CG and CG-TA films, as an active packaging material, were used to preserve the cold-stored fresh-cut apples. Compared with CG film, the CG-TA films obtained better performance on decreasing weight loss, delaying browning degree, inhibiting the lipid oxidase activity and decreasing the malondialdehyde content during 10 d of storage under 4 degrees C. Therefore, CG-TA films were expected to be a new active packaging material for preserving fresh-cut apples.
查看更多>>摘要：The black gram mill by-product is a valuable protein-rich source that is generally discarded. Therefore, this study was conducted to extract the protein from this underutilized source and further improve its functionality by using ultrasound and micronization techniques. Protein micronized at 110 degrees C had maximum water absorption (from 2.79 to 4.83 g/g) and emulsifying activity (from 9.94 to 38.32 m(2)/g). Ultrasonicated proteins for 10 min and 30 min exhibited the highest oil absorption (3.18-3.66 g/g) and foaming capacity (53.7-91.25%), respectively. When compared to ultrasonication, micronization particularly at 150 degrees C, was very effective in improving zeta potential (-18.7 to -24.95 mV). Thermal properties suggested structural changes, particularly in ultrasonicated proteins. FT-IR spectra showed no marked alteration in the secondary structure, while the electrophoretic pattern showed slight reduction in the intensity of the major band in modified proteins. The findings indicated that these techniques substantially enhanced the functionality of by-product protein, thus might increase its utilization in various food systems.
查看更多>>摘要：The objective of this study was to investigate the volatile and non-volatile compounds of stewed pork with different processing methods (TS: traditional stewing, TSE: traditional stewing with enzymatic degradation, TSEM: traditional stewing with enzymatic degradation and Maillard reaction, HS: high-temperature stewing, HSE: high-temperature stewing with enzymatic degradation, HSEM: high-temperature stewing with enzymatic degradation and Maillard reaction). The odor compounds results showed that HS, HSE and HSEM had higher types and contents of volatile compounds than TS, TSE and TSEM, especially HSEM. All stewed pork from traditional and high-temperature stewing methods were classified into two groups using an electronic nose due to different flavor characteristics. Non-volatile compounds results displayed the contents of total amino acids in HS, HSE and HSEM were higher significantly (P < 0.05) than those of TS, TSE and TSEM, of which the contents of Asp and Glu related to umami taste were the most in HS and HSEM. In contrast, there were the lower contents of 5'-nucleotides and fatty acids in HS, HSE and HSEM. These findings indicated that the high-temperature stewed pork method could be used as an effective method to improve the flavor of pork, among which HSEM processing method was particularly remarkable.
查看更多>>摘要：This study aimed at addressing the effect of quinoa sprouting on saponins which are considered the main responsible for quinoa bitterness and astringency, and consequently on quinoa taste. Whole quinoa was sprouted for 12, 24, 48, and 72 h at 22 degrees C and dried at 55 degrees C for 6 h. Quinoa taste was assessed by electronic tongue and mainly related to the amount of saponins that were evaluated by thin layer chromatography (TLC) and mass spectrometry (MS). Sprouting decreased quinoa bitterness and astringency, with the main changes occurring within the 48 h of treatment. Both semi-quantitative (by TLC) and quantitative (by MS) analysis revealed that changes in quinoa taste upon sprouting was mainly related to the decrease in the amount of saponins, reaching the value of 0.086 mg/100 g after 48 h of treatment. Finally, changes in phenolic compounds seem to play a minor role in affecting the taste traits of sprouted quinoa.
查看更多>>摘要：In this study, changes in the chemical characteristics of milk formula stored at 25 degrees C, 30 degrees C and 40 degrees C during 6 months storage were investigated. Three vitamins degraded to varying degrees at all temperatures with the prolonging of storage time. Lipid oxidation continued to occur during storage. Lipid hydroperoxides content was affected by storage time, while the formation of volatile components was influenced by storage temperature and time. According to the Pearson correlation analysis, propionaldehyde was mainly caused by the degradation of docosahexaenoic acid (C22:6n3, DHA), and hexanal was the primary oxidation product of linoleic acid (C18:2n6, LA) and arachidonic acid (C20:4n6, AA). Fatty acids composition, except polyunsaturated fatty acids (PUFAs), remained stable at all storage temperatures. However, the correlation between PUFAs and volatile components was only shown at 30 degrees C and 40 degrees C. Based on the analysis of physicochemical characteristics, the shelf-life of milk formula was predicted by Multivariate Accelerated Shelf-Life Test combined with Arrhenius model. The commercial shelf-life of milk formula was estimated to be stored at 25 degrees C and 30 degrees C for 12 and 8 months, respectively. Particle size, vitamin A and color difference could be used as indicators for predicting the shelf-life of dairy products with similar matrices.
de Souto, Valter OliveiraFernandes Santos, Miriane MoreiraSoares Lima, Darlinne AmandaBizerra Florentino, Gabrielle Ingrid...
11页
查看更多>>摘要：The aim of this study was to evaluate the effect of partially replacing pork backfat with fresh or pre-emulsified olive oil on the technological and nutritional quality characteristics of free-range chicken ham. Three formulations were studied: normal free-range chicken ham (control), free-range chicken ham with a partial replacement of the animal fat with fresh olive oil (HFRE), and free-range chicken ham with a partial replacement of the animal fat with pre-emulsified olive oil (HPEM). Samples were evaluated for their chemical and physical properties, fatty acid profiles, and oxidative stability. All the samples showed lipid and protein contents within the limits established by Brazilian legislation. The addition of fresh and pre-emulsified olive oil as a fat replacer in free-range chicken ham increased the proportions of mono- and polyunsaturated fatty acids and decreased the percentage of saturated fatty acids. The atherogenicity and thrombogenicity indexes were lower in formulations with fresh and pre-emulsified olive oil, respectively. All evaluated samples showed good oxidative stability over the storage time. We concluded that the products developed exhibit potential to be used as healthy meat products by the food industry and become suitable options to diversify the production of free-range chicken meat.
查看更多>>摘要：A novel controlled-release antibacterial nanofiber was fabricated by electrospinning to load eugenol@cationic starch nanoparticles (EG@CStNPs) into phospholipid nanofibers (EG@CSt/P nanofibers). Taking advantage of the phospholipase and amylase secreted by Bacillus cereus (B. cereus), the controlled release of eugenol in EG@CSt/P nanofibers was achieved through the hydrolysis of the phospholipids in the nanofibers and the cationic starch of the nanoparticles. EG@CStNPs were prepared by nanoprecipitation and characterized by SEM, FTIR, and Raman spectroscopy. The preparation method of phospholipid nanofibers was improved, and nanofibers with enhanced properties were identified through their physical properties. The success of EG@CStNP loading into phospholipid nanofibers was confirmed by FTIR, SEM, AFM and TGA. Subsequently, the success of controlled release was verified by GC-MS, inhibition-zone experiments and TEM. After treatment with EG@CSt/P nanofibers for 5 days, the number of B. cereus decreased by around 2 log(10) reductions at 4 degrees C and 25 degrees C. The results of experiments performed for application in beef further showed that EG@CSt/P nanofibers had significant antibacterial activity against B. cereus and did not damage the color and texture of beef samples.
查看更多>>摘要：In this study, dehydrated strawberries have been proposed as probiotic carriers. Strawberries were cut into halves, incorporated with probiotic Bacillus coagulans BC4 by two alternative methods (impregnation and alginate coating) and submitted to two alternative drying methods (freeze drying - FD - and oven drying - OD). Six treatments were carried out, namely: FD and OD (no probiotic), I-FD, I-OD, C-FD, and C-OD (I- and C- meaning impregnation and coating respectively). While the probiotic incorporation method affected a few properties of the resulting products (mainly the probiotic viability on processing), the drying methods resulted in remarkable differences. The freeze-dried strawberry halves presented higher retention of chemical (ascorbic acid and anthocyanin contents) and physical properties (shape, color, and firmness) as well as a better acceptance and higher probiotic viability, resulting in higher probiotic release into the small intestine. The I-FD treatment resulted in the highest probiotic viability after processing and through a 6-month storage (near 8 log cfu.g(-1)).
NSTL
Elsevier