Study On Lipid Lowering Effect Of Bacterial Cellulose And Its Application In Dietary Fiber Yogurt Drink

Bacterial cellulose(BC)has good water retention,rehydration,and good emulsification stability.It also has functions of lowering blood sugar,blood lipids,and adsorbing toxic substances.It has huge application prospects in the food industry.In this thesis,dietary fiber BC was prepared by strain Acetobacter xylinum,and its performance and adsorption capacity in vitro were studied.At the same time,the improvement effect of BC on lipid metabolism in hyperlipidemia mice was studied,and the mechanism of lipid reduction was explored.At the same time,BC yogurt drink was prepared and its stability performance was studied.The main research contents and results are as follows:(1)BC was prepared by fermentation with strain Acetobacter xylinum,and Fourier transform infrared spectroscopy,X-ray diffraction,thermogravimetry,scanning electron microscopy,and water holding capacity of BC was studied.The BC adsorption capacity of cholesterol,sodium cholate,unsaturated fats,and heavy metal ions was studied by simulating the gastrointestinal environment in vitro.The results show that BC has a dense layered structure and a clear three-dimensional network structure of fiber bundles,and it shows good heat resistance and crystallinity.The water holding capacity(WHC)of BC is 68±1.80 g/g,the adsorption capacity of BC to cholesterol is 9.879 mg/g under acidic conditions,the adsorption capacity of BC to cholesterol is 11.910 mg/g under neutral conditions;the adsorption capacity of BC to sodium cholate is 11.791 mg/g Under the low concentration condition,the adsorption capacity of BC to sodium cholate is 16.149 mg/g Under the high concentration conditions,the adsorption capacity of BC to unsaturated oil is 238.337 mg/g Under neutral conditions;BC's adsorption of Cr6+ is 1.809 mg/g under acidic conditions,BC's adsorption of Cr6+is 0.304 mg/g under neutral conditions;BC's adsorption capacity of Pb2+is 1.525 mg/g under acidic conditions,BC's adsorption capacity of Pb2+is 0.661 mg/g Under neutral conditions.This shows that BC has a certain absorption of cholesterol,sodium cholate,unsaturated oils and heavy metal ions in a simulated gastrointestinal environment in vitro.(2)The effect of BC on blood lipid metabolism in hyperlipidemic mice was studied.The results show that BC can effectively reduce the levels of total cholesterol(TC),triglyceride(TG),low density lipoprotein cholesterol(LDL-C),and increase high density lipoprotein cholesterol(HDL-C)level,BC plays a good role in the regulation of abnormal lipid levels in hyperlipidemia;BC can also regulate the levels of alanine aminotransferase(ALT),aspartate aminotransferase(AST),and superoxide dismutase(SOD)in mice,and it can regulate liver function effect;the results of histopathological observation of the liver indicate that BC has a certain improvement effect on liver injury in hyperlipidemia mice.(3)The results of intestinal flora diversity analysis showed that the BC intervention group significantly improved the activity of intestinal microflora at the door level,resulting in an increase in the abundance of Bacteroidetes,a decrease in the abundance of Firmicutes and Proteobacteria;the BC intervention group Compared with the PG group,the abundance of Lactobacillus in the HDG group is greatly improved and the abundance of Lachnospiraceae and Prevotellaceae is also greatly reduced.In general,BC The influence of microbial flora activity is beneficial.(4)BC yogurt drink was prepared by using fresh raw milk as raw material and adding BC fermentation.The morphology of the product was observed by SEM,and the influence of environmental stress on its stable performance were also studied.The results show that the optimal preparation process of BC yogurt drink is as follows:the content of fermented milk is 35%,the amount of BC addition is 3%,the compound stabilizer CMC/xanthan gum=1:1,and the total compound stabilizer is 0.5%.Under this process condition.The BC yoghurt drink has good stability and a good effect on improving the quality of yoghurt drink.Through the research in this paper,the characteristics of BC dietary fiber and its ability to reduce lipids in vitro are clarified;the role and mechanism of BC in improving lipid metabolism in hyperlipidemia mice is preliminary explored;The optimal preparation process of BC yogurt drink is obtained,and the influence of environmental stress on the stability of BC yogurt drink is clarified.The completion of the paper provides a theoretical and technical basis for the development of BC-based functional foods,expands the application of BC in the food field,and provides new diets for residents' healthy diet and disease prevention,which has good social benefits.