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In order to improve the phenomenon that frozen cooked noodles are susceptible to the formation of ice crystals and quality deterioration during storage, the effects of mannosylerythritol lipids (MELs) versus sucrose ester (SE) on the proportion of freezable water, water distribution, quality characteristics, gelatinization characteristics of wheat flour and the secondary structures of proteins in frozen cooked noodles were investigated. The results showed that the addition of 0.30%–1.10% (m/m) MELs could promote the conversion of free water to bound water in frozen cooked noodles, reduce the proportion of freezable water, and increase the binding of water to macromolecules such as protein and starch. Compared with the blank and SE groups, the quality of frozen cooked noodles made with 0.70% MELs was better, and the hardness was (4 335.317 ± 48.047) g, which was 25.36% higher than that of the blank group. The tensile force and tensile distance at break were (11.22 ± 0.15) g and (69.09 ± 1.34) mm, respectively. The water absorption rate increased significantly, and the cooking loss rate was the smallest, suggesting MELs to be more effective in improving the cooking quality of noodles than SE. At the same time, MELs could effectively delay the retrogradation rate of wheat flour starch, increase the proportions of the secondary structure fractions β-sheet and α-helix, and strengthen the gluten network structure.

The antibacterial activity and mechanism of rhamnolipids (RLs) against Bacillus cereus spores were analyzed from the aspects of appearance, morphology, and cell membrane state. The results showed that minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of RLs were 80.0 and 160.0 mg/L, respectively. Both concentrations of RLs caused severe shrinkage and depression on the surface of spores, and disrupted the integrity and permeability of the spore cell membrane, leading to the leakage of intracellular electrolytes, DNA and proteins. In addition, RLs inhibited and inactivated B. cereus spores by various mechanisms such as decreasing heat resistance, generating oxidative stress, reducing surface adhesion, and binding to and interfering with DNA molecules. The results of this study will contribute to the development and application of RLs in the field of food safety.

为提高茶皂苷的提取率，扩大茶皂苷的应用范围，以脱脂油茶籽饼为原料，采用超声-微波辅助法提取茶皂苷。以油茶皂苷提取率为考察指标，在单因素试验的基础上，采用Plackett-Burman试验设计筛选出具有显著影响的试验因素，再通过响应面法对茶皂苷提取工艺进行优化。另外，将超声-微波辅助法提取茶皂苷的工艺与超声辅助法和微波辅助法提取工艺进行了对比。结果表明：超声-微波辅助法提取茶皂苷的最佳工艺条件为乙醇体积分数59%、料液比1∶ 12、提取液pH 7、超声功率475 W、超声时间4 min、超声工作2 s间隔2 s、微波功率480 W、提取温度59 ℃、微波提取时间8 min，在此条件下茶皂苷提取率为98.40%，产品纯度为64.7%；超声辅助法和微波辅助法茶皂苷的提取率分别为69.06%和71.40%。与超声辅助法和微波辅助法相比，超声-微波辅助法能够显著提高茶皂苷提取率。 In order to improve the extraction rate of tea saponins and expand the application of tea saponins, tea saponins was extracted by ultrasound-microwave assisted method from defatted oil-tea camellia seed cake. The extraction rate of tea saponins was taken as the index, a Plackett-Burman test design was used to screen out the test factors with significant effects based on a single-factor experiment, then the process parameters were optimized by response surface methodology. In addition, the ultrasound-microwave assisted extraction process of tea saponins was compared with ultrasound assisted process and microwave assisted extraction process. The results showed that the optimal extraction parameters of ultrasound-microwave assisted method were as follows: ethanol volume fraction 59%, solid-liquid ratio 1∶ 12, extraction solution pH 7, ultrasonic power 475 W, ultrasonic time 4 min, 2 s interval and 2 s ultrasonic work, microwave power 480 W, extraction temperature 59 ℃, microwave extraction time 8 min. Under these optimal parameters, the extraction rate and purity of tea saponins were 98.40% and 64.7%, respectively. The extraction rates of tea saponins by ultrasonic assisted method and microwave assisted method were 69.06% and 71.40%, respectively. Compared with ultrasound assisted method and microwave assisted method, ultrasound-microwave assisted method can significantly improve the extraction rate of tea saponins.

A large number of grains are contaminated with aflatoxin B1 (AFB1) every year, which causes great harm to the health of humans and livestock. The biodegradation of AFB1, which has the advantages of strong substrate specificity and mild reaction conditions, has attracted considerable attention. Microorganisms safe for consumption should be used to degrade AFB1 in grains in order to avoid introducing new contaminants. Therefore, edible fungi that can secrete laccase are a good choice to degrade AFB1. Based on the NCBI (National Center for Biotechnology Information) and the Uniprot (Unified Protein Database) databases, edible fungi with laccase gene or amino acid sequences are selected, and the reported edible fungi capable of secreting laccase are summarized in this article. Then, the methods used to screen for edible fungi that can secrete laccase are reviewed. In addition, the structure and physicochemical properties of laccase from edible fungi are outlined, and recent progress in understanding the role of laccase in the growth of edible fungi and applying laccase from edible fungi for the degradation of AFB1. It is expected that this review can provide theoretical support for the safe, efficient, and green degradation of AFB1 by laccase from edible fungi.

In order to explore the effect of waxy corn starch on the quality of dumpling wrappers, the effects of adding different amounts of waxy corn starch on the color, toughness, freezable water content and microstructure of dumpling wrappers and the cooking quality of unfrozen and frozen dumpling wrappers were investigated. The results showed that waxy corn starch addition could significantly improve the brightness (L*) value, toughness and starch binding capacity, and reduce the content of freezable water in dumpling wrappers. Moreover, waxy corn starch addition significantly shortened the cooking time, reduced the cooking loss, increased the shear hardness, and improved the sensory quality of frozen dumpling wrappers. The transparency, cooking loss, shear hardness and chewiness of frozen dumpling wrappers were better than those of unfrozen dumpling wrappers. In summary, the quality of frozen dumpling wrappers can be improved by adding 4%–6% waxy corn starch, which provides a theoretical basis for the development of waxy corn starch in the food industry.

Background and Objective: There is a growing interest in incorporating whole grain highland barley (HB) to wheat bread for improving nutrients and potential health benefits. However, the qualities and sensory properties of whole grain‐based bread were reduced compared to refined wheat‐based bread due to the strong water absorption and large particle size of dietary fiber in whole grain. Therefore, ultra‐fine ground whole grain HB partially substituted 5%–40% wheat flour to make bread, and the relevant dough properties and bread qualities were studied. Findings: The increased addition of ultra‐fine ground whole grain HB from 5% to 40% to wheat increased dough development time, whereas, decreased dough stability time, elasticity, pH, G′ modulus, and G″ modulus. The increased substitution of ultra‐fine ground whole grain HB to wheat further reduced the specific volume, cohesiveness, elasticity, and resilience of bread, whereas, increased the hardness, adhesiveness, and chewiness of bread. Conclusions: The partial substitution of wheat with ultra‐fine ground whole grain HB from 5% to 40% wheat significantly affected wheat‐HB dough properties and resultant bread qualities mainly due to weakened gluten networking. Significance and Novelty: The 5%–10% substitution of wheat by ultra‐fine ground whole grain HB showed the optimum dough properties and bread qualities compared to other treatments, which substituted 20%–40% wheat flour. [ABSTRACT FROM AUTHOR]

In this study, the effects of microwave treatment on protease activity, dough properties and protein quality in sprouted wheat were investigated. Microwave treatment led to a significant (p < 0.05) reduction in protease activity in sprouted wheat. Proteases with a pH optimum of 4.4 (cysteine proteinases) were more susceptible to microwave heating, which contributed mostly to protease inactivation. Significant improvements (p < 0.05) in the dough properties and gluten quality of sprouted wheat were observed, which are probably attributable to the synergistic effectiveness of protease inactivation and heat-induced gluten cross-linking. After microwave treatment, the decrease in the solubility and extractability of protein in sprouted wheat indicated protein polymerization, which was induced by intermolecular disulfide bond cross-linking. The changes in gliadin were less pronounced due to the relatively low temperature of the microwave treatment. The cross-linking in sprouted wheat that occurred after microwave treatment seemed to mainly involve glutenin, especially B/C low-molecular-weight glutenin subunits (B/C-LMW-GSs) in the range of 30–50 kD. [ABSTRACT FROM AUTHOR]

BACKGROUND: Corn, being an important grain, is prone to contamination by aflatoxin B1 (AFB1), and AFB1‐contaminated corn severely endangers the health of humans and livestock. Trametes versicolor, a fungus that can grow in corn, possesses the ability to directly degrade AFB1 through its laccase. This study aimed to optimize the fermentation conditions for T. versicolor to degrade AFB1 in corn and investigate the effect of T. versicolor fermentation on the nutritional composition of corn. AFB1‐contaminated corn was used as the culture substrate for T. versicolor. A combination of single‐factor experiments and response surface methodology was employed to identify the optimal conditions of AFB1 degradation. RESULTS: The optimal conditions of AFB1 degradation were as follows: 9 days of fermentation, a fermentation temperature of 26.7 °C, a moisture content of 70.5% and an inoculation amount of 4.9 mL (containing 51.99 mg of T. versicolor mycelia). With the optimal conditions, the degradation rate of AFB1 in corn could reach 93.01%, and the dry basis content of protein and dietary fiber in the fermented corn was significantly increased. More importantly, the lysine content in the fermented corn was also significantly increased. CONCLUSION: This is the first report that direct fermentation of AFB1‐contaminated corn by T. versicolor not only efficiently degrades AFB1 but also improves the nutritional composition of corn. These findings suggest that the fermentation of corn by T. versicolor is a promising, environmentally friendly and efficient approach to degrade AFB1 and improve the nutritional value of corn. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]