ObjectiveTo explore the sources of the microbial community in Fuyu-flavor Daqu and to elucidate the key microorganisms in Daqu.MethodsFuyu-flavor Daqu was used as the research object, and high-throughput sequencing combined with microbial source-tracking techniques was employed to analyze the sources of microorganisms in Daqu.ResultsThe microbial community structures of the Daqu crust and core were similar; however, there were substantial differences in their dominant taxa. Source-tracking results showed that bacteria on the Daqu crust were mainly derived from workers' hands (22.68%), the surface of koji-pressing machines (17.58%), the air around the koji-pressing machines (13.09%), the surface of shelves in fermentation rooms (10.69%), and wheat flour (10.39%). In contrast, bacteria in the Daqu core were mainly derived from the floor of fermentation rooms (22.60%) and the air in corridors outside the fermentation rooms (15.30%). Fungi on the Daqu crust were mainly derived from the surface of shelves in fermentation rooms (62.40%) and unknown environments (18.10%). The fungal community in the Daqu core was relatively stable and less affected by the initial production environment and microorganisms from raw and auxiliary materials, with a high proportion of unknown sources (95.00%).ConclusionChanges in temperature and humidity during the Daqu cultivation process are key factors affecting the fungal community structure in the core.
ObjectiveTo explore the optimal microwave-assisted enzymatic extraction process of total flavonoids from Paeonia suffruticosa Jinge, and to evaluate their antioxidant activity.MethodsTaking the extraction rate of total flavonoids from peony petals as the evaluation index, this study investigates the effects of enzyme dosage, hydrolysis time, solid-liquid ratio, hydrolysis temperature, and microwave power on total flavonoid extraction rate. Then, response surface methodology is incorporated to optimize the extraction process, followed by an antioxidant activity analysis.ResultsThe optimum process parameters are as follows: a microwave power of 348 W, an enzyme addition of 1.7%, a solid-liquid ratio of 1∶80 (g/mL), a hydrolysis temperature of 55 ℃, and a hydrolysis time of 120 min. Under these conditions, the flavonoid extraction rate is 5.415%, while the DPPH, hydroxyl, and ABTS free radical scavenging rates are 84.18%, 36.80%, and 95.36%, respectively.ConclusionThe process optimized by response surface methodology is reasonable and feasible, and the P. suffruticosa Jinge petal extract exhibits potent antioxidant activity.
Jujubosides are a class of compounds with unique bioactivities in Ziziphi Spinosae Semen, mainly consisting of tetracyclic and pentacyclic triterpenoid saponins. Various extraction processes have been developed, and their efficiencies differ. The combined use of multiple extraction methods is expected to improve extraction performance. Jujubosides exhibit significant biological activities, including improvement of insomnia, alleviation of cognitive impairment, antidepressant, anticancer, anti-aging, antioxidant, and hepatoprotective effects. Research on their structure-activity relationships is still being continuously deepened. This article reviews the structures, extraction processes, and biological activities of jujubosides, and prospects the in-depth development and efficient utilization of Ziziphi Spinosae Semen in fields such as health product development and drug research.
Selenium, an essential trace element for humans, plays a crucial role in maintaining redox balance and immune homeostasis. As safe and effective selenium supplements, selenium-enriched foods play an irreplaceable role in human metabolism and are essential for sustaining physiological homeostasis. The gut microbiota, a vast and complex microbial ecosystem, is regarded as a "super organ" within the human body, and its structural homeostasis and metabolic functions directly determine the nutritional and health status of the host. This article systematically reviews the major forms of selenium in selenium-enriched foods and their mechanisms of reshaping gut microbiota structure and regulating metabolism, and further elucidates the biological pathways through which the "gut-organ axis" improves human health.
ObjectiveTo shorten the extraction cycle of Lentinus edodes polysaccharides and increase their content.MethodsL. edodes mycelia are used as the raw material for liquid-state fermentation. With mycelial biomass and mycelial polysaccharide content as evaluation indicators, the liquid-state fermentation process is optimized by response surface methodology. The in vitro physiological activities of the obtained polysaccharides are then evaluated.ResultsThe optimal process conditions for liquid-state fermentation of L. edodes mycelial polysaccharides are corn starch of 43 g/L, yeast extract of 20 g/L, FeSO4 of 2 g/L, and fermentation with shaking at 150 r/min for 7 days. Under these conditions, the mycelial polysaccharide content and mycelial biomass of L. edodes are 3.81% and 7.33 g/L, respectively. In addition, the polysaccharides at 2.5 g/L show the DPPH radical scavenging rate of 90.46% and the inhibition zone diameters of 11.57 mm and 10.71 mm against Escherichia coli and Saccharomyces cerevisiae, respectively.ConclusionThis liquid-state fermentation process enables the efficient production of L. edodes mycelial polysaccharides, which have strong DPPH radical scavenging ability and antibacterial effects.
