Dissertation
Dissertation > Industrial Technology > Light industry,handicrafts > Food Industry > Food processing industry > Legume system for food > Soy-based food

Studies on the Biological Activity of Soybean Flour Processed by Lactic Acid Fermentation and Enzymatic Hydrolysis

Author WangNaiFu
Tutor LeGuoWei;ShiYongZuo
School Jiangnan University
Course Cereals, Oils and Vegetable Protein Engineering
Keywords Soybean meal Lactic acid bacteria Ferment Enzyme Antioxidant Angiotensin-converting enzyme inhibitory peptides Isolation and identification of Piglets Weaning stress
CLC TS214.2
Type PhD thesis
Year 2007
Downloads 1163
Quotes 5
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Soybean products is an important vegetable protein human resources. Lactic acid bacteria fermentation can significantly improve the nutritional value of soybean products, but the current domestic and international research has focused on lactic acid fermentation of nutrients and flavor of soy products change, few studies reported other biologically active lactic acid bacteria fermented soy products, such as antioxidant and ACE inhibition of activity. This paper first breeding lactic acid bacteria suitable for solid-state fermentation of soybean meal, on this basis, the lactic acid bacteria in solid-state fermentation of soybean meal, nutrition changes and the fermentation process, fermented soybean meal antioxidant and ACE inhibitory activity, fermentation product of ACE inhibitory and antioxidant activity of the preparation and purification of the peptide, fermented soybean powder of the active peptide inhibitory mechanisms of biological macromolecules and in vitro culture of thymus cells from oxidative damage, and lactic acid fermentation hydrolysis soybean meal remission experimental animals weaning stress were studied. Soy flour producing strains of lactic acid bacteria fermentation hydrolysis and fermentation conditions optimization of this article first suitable for solid-state fermentation soybean meal lactic acid bacteria breeding, by comparing the different strains of lactic acid bacteria growth and acid production in the soybean meal, and fermentation proteolysis product, bred Lactobacillus Bacillus Lp6 (L.plantarum Lp6) as the final fermentation strains by single factor and orthogonal optimization experiments obtained the LP6 solid-state fermentation of soybean meal optimal conditions for inoculation was 0.2 %, the water content was 55%, the acidic protease dosage of 0.5%, the natural pH value of the fermentation for 72 h 37 ° C airtight. Lactic acid bacteria fermentation process of hydrolysis soybean meal composition changes in study Lactobacillus plantarum the LP6 solid-state fermentation enzymatic soybean meal, protein and other nutrients in the fermentation process. Lactic acid bacteria can significantly improve the in vitro digestibility of soybean meal protein molecular weight distribution analysis showed that the degradation of proteins in soybean meal, to generate small peptides. At the same time, soy flour free amino acid content increased significantly. Fermentation can also make soybean meal reduced total sugar content, reducing sugar content increases, stachyose and raffinose flatulence factor decreased significantly. The content of anti-nutritional factor analysis showed that the lactic acid bacteria fermented soybean meal can significantly reduce trypsin inhibitor factor, phytic acid and urea enzyme content of anti-nutritional factors. 3 active peptide preparation of lactic acid bacteria fermentation of lactic acid bacteria fermentation hydrolysis soybean meal enzymatic significantly enhanced the soybean meal ACE inhibition activity and DPPH · OH radical scavenging capacity, but its Fe 2 chelating The ability to influence is not significant. The fermented soy protein extract by macroporous adsorption resin desalination, sugar and lower ash content, in addition to the sugar, after the processing of the hollow fiber ultrafiltration membrane, the protein content increased, wherein a molecular weight of less than 1500 Da peptide content of 90% or more, and ACE inhibitory and antioxidant activity was significantly increased. Active peptides by digestive enzymes and the ACE processing remains a strong ACE inhibiting activity, mainly containing the suppression of ACE inhibitory peptides, and the possibility of having to enter the blood circulation through the gastrointestinal tract, and thus play a hypotensive effect in vivo . 4 active peptide fermentation hydrolysis soybean meal antioxidant studied the enzymatic hydrolysis of lactic acid bacteria fermented soybean meal in active peptide can inhibit the open ring and chain DNA plasmid pBR322 DNA generated inhibit the production of bovine serum albumin carbonyl, reduce oxidant causing oxidative damage. Mouse thymocytes with lactic acid bacteria fermented soybean powder of the active peptide processing, can improve the H 2 O 2 damage cell activity, improve the T-AOC, SOD, GSH-Px and CAT activity, reducing of ROS and MDA content and increase cellular GSH content and GSH / GSSG value, fermented soybean powder of the active peptide lowered the level of p53 mRNA expression in cells, inhibition of p53 gene-mediated cell apoptosis, reduce oxidative damage to cells. This thesis, separation and purification of fermentation hydrolysis soybean meal in the separation and purification of bioactive peptides and structural identification has been a strong ACE inhibitory and antioxidant activity of peptide fermented soybean meal. The sample is separated by Sephadex G-15 gel column, with OLC separation, through MALDI-TOF-MS/MS and amino acid composition analysis to determine the active peak 7 - II-f-R2 of the amino acid sequence VPDALR ACE inhibition and · OH Clear activity IC 50 values ??were 29.3μg/mL, 83.2μg/mL. Lactic acid bacteria fermented the enzymatic hydrolysis soybean meal alleviate weaning stress research lactobacillus fermentation hydrolysis soybean meal in weaned pigs, a significant increase in weaning piglets ADG and improved the FCR, lower piglet plasma TG levels, increase HDL levels, but the CHOL and LDL impact, not significant. The same time, it is also possible to increase the weaned piglets antioxidant enzyme activities, enhance the body's antioxidant capacity. Piglet intestinal flora analysis showed that diets supplemented with lactic acid bacteria fermentation hydrolysis soybean meal, increase the number of lactobacilli in the gut, reducing the number of E. coli, but had no significant effect on the number of bifidobacteria. Add fermented soybean meal, can increase piglet intestinal digestive enzyme activities of to reduce intestinal contents pH value to increase the content of volatile fatty acids. Small intestinal morphology analysis showed that diets supplemented with fermented soybean meal, can significantly increase the small intestinal villus height, villus height and crypt depth ratio is also significantly increased. These results indicate that lactic acid bacteria fermentation hydrolysis soybean meal can effectively alleviate weaning stress caused by the animals.

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