Influence Of Microbial Fermentation And Dynamic High-Pressure Microfluidization On The Properties And Structure Of Dietary Fiber

The modification of bean dregs dietary fiber could make its physiological function more superior, while expanding okara dietary fiber application fields. At present the modification methods of dietary fiber are mainly chemical method, biological method and physical method, most modification studies of all used a single modification methods, using a variety of modified means for the okara dietary fiber research is less. In this thesis, we adopt the composite technology that are microbial fermentation and DHPM to modify the dietary fiber, we study the changes of the composition dietary fiber,character and molecular structure, and further to explored the reasons of DHPM and microbial fermentation action of dregs dietary fiber, to search for new tools and improve the conversion of dietary fiber and other biological macromolecules processing performance, physical activity provide a theoretical basis and technical support,and provide a new way for insoluble dietary fiber change to soluble dietary fiber in other light food waste (pomace, vegetable residue, wheat bran, rice bran, etc.). The results of this paper are as follows:1. We studied the best fermentation conditions which lactobacillus fermented okara as the content of TDF, SDF and IDF to be the target. During the fermentation we found the culture temperature and incubation time had obvious effects. The study of lactic acid bacteria fermentation showed that the optimum process conditions of bean curd are:the culture temperature was 42℃, the pH was 6.6, inoculated quantity was 4%, incubation time was 9 days, on this condition, the content of TDF, SDF, IDF respectively was 83.51%.10.37%.73.14%.2. After bean dregs were fermented, the content of soluble sugar increased from 26.41%to 48.26%, reductive sugar increased from 0.72%to 3.68%. After the fermentation of okara dietary fiber and HPM treatment, the content of soluble sugar and reductive sugar increased with the pressure increased. At the pressure 160 MPa, the content of soluble sugar was 64.52%, and the content of reductive sugar was 10.14%. 3. We used enzymes-weight method to analyze the content of various components of dietary fiber. The research shows that:after fermentation, the content of TDF and SDF in the okara both increased the proportion of SDF and IDF increased from 2.43% to 14.21%. After the fermentation of okara and HPM treatment, the content of TDF and SDF first increased then decreased with the pressure increased, the content of IDF continuously decreased. At the pressure 100 MPa, the content of SDF was highest, the ratio of SDF and IDF was 29.17%.4. After fermentation and the treatment of DHPM, the water swelling capacity^ water holding capacity and water combination capacity of okara dietary fiber are obtained with different degrees of improvement. After fermentation, the okara dietary fiber apparent viscosity increased. After DHMP treatment, the apparent viscosity of dietary fiber significantly increased, has the character of the pseudo-plastic fluid.5. After fermentation, the grain of dietary fiber was refined, the structure slightly loosed After the treatment of DHPM, the structure of dietary fiber was seriously damaged, it was to be floc structure; The particle size increases and then decreases with the pressure increases, atl00MPa,the minimum particle size was 389.5nm.6. After fermentation, the okara dietary fiber had no obvious crystallization peak, the crystalline structure disappeared, and the structure of dietary fiber was amorphous state. After the treatment of DHPM, the structure of dietary fiber showed a characteristic peak again, and the peak is more intense, the peak height decreases with increasing pressure.7. The infrared experimental study found:after fermentation at the wave number for 1415.0 cm-1,893.8 cm-1 the okara dietary fiber's features in absorption peaks was weakened. After the treatment of DHPM, dietary fiber at the wave number for 1415.0 cm-1 absorption peak shifted to higher wave number, the characteristics of 893.8 cm-1 absorption peak disappeared.