Study On The In Vitro Simulated Digestion Behavior Of Cooked Product And Polysaccharide Of Boletus Auripes

Boletus auripes is a wild edible and medicinal fungi rich in polysaccharide,protein and other nutrients as well as esters,aldehydes and other flavor components,which tastes delicious after being cooked.However,the changes of the nutritional composition in B.auripes after being cooked,and its nutritional bioaccessibility after ingestion and digestion have not been reported,which is not conducive to the scientific diet of B.auripes.In addition,due to its biological activities,Boletus polysaccharide has attracted increasing attention,while the research on B.auripes polysaccharide(BAP)is still in the initial stage of extraction and antioxidant activity,etc.,so the utilization of B.auripes polysaccharide resources needs to be further explored from the aspects of structure,digestion and glycolysis characteristics.Therefore,this topic uses six home cooking methods to process B.auripes,to explore the changes of nutritional components in the cooking process,and the bioaccessibility of nutritional components and bioactivity after simulated digestion in vitro.Meanwhile,the B.auripes polysaccharide was extracted and characterized,and further explore its digestive behavior and regulation effect on intestinal flora.The main research results are as follows:1.After steaming,boiling,microwave,stir-frying,frying and roasting,the nutrient content of B.auripes has altered,and the latter three cooking samples with oil as the cooking medium have higher protein loss.After digestion,the degree of protein hydrolysis and the bioaccessibility of amino acids were the highest in microwave group and the lowest in frying group.Fatty acid profile changed and linoleic acid decreased significantly,especially in the boiling group.The bioaccessibility of minerals varied with species and cooking methods.The lowest bioaccessibility of Fe(13.33%)and the highest bioaccessibility of Mg(91.43%)were found in the boiling group.Cooking promoted the release of carbohydrates but had little effect on their digestion,with higher bioaccessibility(17.21%)and lower digestibility(6.23%)in the roasting group.Although the microwave group had the lowest antioxidant activity after consuming the same amount of cooking product,it had the significant hypoglycemic activity.In conclusion,from the point of view of nutritional value and biological activity,steaming,boiling and microwave cooking are more suitable for B.auripes,especially microwave cooking.2.No reducing sugar was released in the stage of oral digestion,and the chemical composition and structure of B.auripes polysaccharide(BAP)showed no significant changes,indicating that BAP may be a non-starch polysaccharide.With the progress of gastrointestinal digestion,the chemical composition,monosaccharide composition and molecular weight of BAP altered slightly,but there was no significant change in infrared spectrum.The antioxidant and hypoglycemic activities of BAP were slightly weakened.In general,BAP could hardly be digested.Additionally,BAP can be decomposed and utilized by intestinal flora to produce acetic acid,propionic acid,butyric acid and other short-chain fatty acids(SCFAs),resulting in the p H value of fecal cultures to decline.Simultaneously,BAP can regulate the intestinal flora’s composition,observably up-regulating the ratio of Bacteroidetes to Firmicutes,and promoting the growth of Bacteroides,Dialister and other beneficial bacteria.In summary,BAP can regulate intestinal flora and has the potential as a prebiotic.