Functional Properties Of Riboflavin Enriched Fermented Soymilk And Its Effect On Riboflavin Deficiency And Gut Microbiota In Mice

Riboflavin(Vitamin B₂)as a water-soluble vitamin participates in many important physiological and metabolic pathways,and its deficiency can lead to a variety of diseases.As a common soy-product,soymilk is rich in nutrients,however,the B₂content in soymilk cannot meet the daily needs of human body.Riboflavin bio-enriched fermentation can effectively remedy this defect transform soymilk into functional food.Therefore,three kinds of functional lactic acid bacteria(Lactobacillus plantarum UFG169,Lactobacillus plantarum UFG10,and Lactobacillus fermentum UFG12)were exploited to prepare the B₂ enriched soy-yogurt with improved flavor and increased nutritional value which was also confirmed in vivo to improve the B₂ deficiency and gut microbiota of mice.Initially,this study evaluated the effects of fermentation on the nutritional and functional value of soymilk from several aspects under in vitro conditions.During the fermentation,the p H of soymilk decreased significantly,proteins agglutinated,apparent viscosity increased,the soymilk was transformed into soy-yogurt.B₂ in fermented soymilk was notably increased from 0.2 to 3.81?g/m L for L.fermentum UFG169 and to 1.89?g/m L for L.plantarum UFG10.The off-flavor volatile substances(hexanal and nonanal)were significantly reduced in fermented soymilk.Furthermore,a large amount of glucoside form isoflavones was deglycosylated into bioactive aglycones.B₂ content and isoflavones could synergistically improve the antioxidant status of fermented soymilk.To summarize,B₂ producing lactobacilli could positively influence the nutritional and functional status of bio-enriched fermented soymilk.For the further in vivo confirmation,B₂-deficiency BALB/c mouse model was constructed using a B₂-deficient diet.During the three-week modeling process,the mice showed symptoms such as stomatitis,canthus inflammation,and hair thinning.From4^th to 8^thweek,commercial B₂aqueous solution and bio-enriched fermented soymilk were fed to mice for model recovery.During the supplementation,the B₂ deficiency symptoms in mice were improved,the whole blood glutathione reductase activity coefficient(BGRAC)was decreased,inflammation in liver and colon was alleviated,the expression of inflammatory cytokines related genes was decreased,and oxidative stress was improved due to protective effects of B₂ enriched fermented soymilk.Interestingly,the B₂ bio-enriched soymilk could effectively improve gut microbiota,avoid the intestinal flora damage caused by single riboflavin,and improved the content of short-chain fatty acids content.To summarize,riboflavin bio-enriched soymilk exerted better therapeutic effect and showed higher application potential than commercial B₂,which provide a theoretical basis for B₂deficiency treatment using dietary intervention.As a non-dairy product,B₂-enriched soymilk has the potential to be recognized as a novel functional food with high market value for its extended health-promoting benefits.