The Effect Of Dynamic High Pressure Microfluidization On The Physicochemical Properties And Structure Of Glycation Of Bovine Serum Albumin

With the development of economy and the improvement of people’s living standards, many natural protein functional properties can’t meet the requirements of food production and consumption, functional properties of protein in the food processing and storage process plays a very important role. Therefore, improve the functional properties of protein to satisfy the needs of food production and consumption has become a goal by many food science workers. Glycosylation reaction is a good way to improve protein functional properties of protein. It can also give new features at the same time. In addition, the early stage of the research study shows that dynamic high pressure micro?uidization can promote‘glycosylation reaction of protein.Therefore, the glucose, lactose, dextran and bovine serum albumin(BSA) were as the raw material in this paper, we researched on the BSA-glucose, BSA-lactose and BSA-dextran system glycosylation reaction effect of pretreatment by dynamic high pressure micro?uidization(DHPM), and the glycosylation protein functional properties and structure of the mutual connection to provide theoretical basis for DHPM promotes protein glycosylation reaction and certain technical reference in the food field for modification of protein. The main research contents and conclusions are as follows:(1)With BSA and glucose as raw material, we researched the effect of protein-monosaccharide glycosylation reaction by DHPM pretreatment and determineed the functional properties and structure of the protein before and after the reaction. Results showed that DHPM could obviously promote the production of intermediate and final products of BSA-glucose glycosylation reaction, and increase the degree of glycosylation reaction. After DHPM treatment, the content of free amino group of BSA-glucose glycosylation product significantly reduced, and first decreased then increased with the pressure increasing, the lowest at 120 MPa. The performance of foaming of BSA were improved after DHPM treatment, but it is not obvious after glucose glycation. BSA glycosylation product emulsifying properties were further improved by DHPM treatment. Thermal stabilityof BSA increased significantly after glycosylation, denaturation temperature increased from 87.2 ℃ to 104.1 ℃, and thermal denaturation temperature of glycosylation productis become lower after DHPM treatment. Infrared spectroscopy showed that BSA covalent cross-linking with glucose, Fluorescence spectra showed the structure of protein have changed. The aggregation state of BSA was damaged in different degree, which showed DHPM promoted glycosylation of BSA-glucose system.(2)With BSA and lactose as the raw material, the effect of protein-disaccharide glycosylation reaction by DHPM pretreatment was researched. The functional properties and structure of glycosylation product under different reaction time were determined. The results showed that the reaction of BSA- lactose system was slowly by DHPM pretreatment in 0-16 h, 16-32 h reaction speed. DHPM promoted the production of final products of BSA-lactose glycosylation reaction. Emulsifying properties of BSA- lactose Glycosylation inproved while decreased after DHPM treatment, but the overall trend was still higher than BSA. The thermal stability of BSA- lactose glycosylation products increased, rising from 82 ℃ to 93.1 ℃. The thermal stability of glycosylation products increased further after DHPM pretreatment. Infrared spectroscopy showed that BSA covalent cross-linking with lactose. Intrinsic ?uorescence spectrum showed that there was no significantly change of the fluorescence intensity and maximum emission wavelength in 0-16 h, intrinsic fluorescence intensity sharply reduce, and maximum absorption wavelength obvious blue shift in 16-32 h, which indicated tertiary structure changed obviously in the late reaction.(3)With BSA and glucan as raw material, the effect of protein-polysaccharide glycosylation reaction by DHPM pretreatment was also researched. The functional properties and structure of glycosylation product under different reaction time and the same pressure pretreatment were determined. Results show that the pressure of DHPM promoted production of final products of BSA- lactose glycosylation reaction in advanced. Foaming performance of BSA-glucan glycosylation product was improved significantly, the foaming performanceof glycosylation products increased further after DHPM pretreatment. And the emulsifying performance was lower, but overall was higher than normal. Thermal stability of BSA- glucan glycosylation played a role of negative after DHPM treatment. Infrared spectrum showed that BSA covalent cross-linking with dextran. Near ultraviolet circular dichroism spectrum showed that the tertiary structure of BSA-glucan after glycosylation changes, BSA-glucan glycosylation product has difference after DHPM treatment.