Studies On The Multi-functional Plant Small Peptides

Vegetable protein (soybean protein and peanut protein) was used as the raw material in this study. Microfluidization homogenizing technology combining with complex enzymolysis was used to prepare functional small peptides. The optimal processing condition was studied. The structure and functional properties of the small peptides were represented and analyzed. Besides, the structure-function relationship of multi-functional small peptides was initially explored.1. Plackett-Burman design was used based on single-factor experiments. Using acid-soluble protein yield as the response value, the factors affecting vegetable protein hydrolysis were screened.10 related factors were chosen in this study to screen, and the results showed that the substrate protein concentration, pH of the first enzymolysis and temperature were the main affecting factors.2. Response Surface Methodology analysis was used based on Plackett-Burman design. Using acid-soluble protein yield as the response value, the optimal levels of the three key factors-substrate protein concentration, pH of the first enzymolysis and temperature were optimized. The quadratic regression equation solution indicated that when the substrate protein concentration was 8.90%, pH of the first enzymolysis was 8.04, and temperature was 57.80℃, the highest acid-soluble protein yield was 88.11%, correlation coefficient was 0.9516, and the model was extremely significant(p<0.0008).3. Sephadex G-25 gel chromatography was used to separate and purify the hydrolysate, and small peptides were obtained. Its relative molecular weight was measured by HPLC. The results showed that the small peptides main concentrated in the range of 400Da or so, of which the small peptides had the function of scavenging DPPH and lowering cholesterol. The scavenging rate of DPPH was 44.78% and inhibition of micellar cholesterol was 73.2%.4. HPLC-MS was used to primarily study the structure of M3 and M4. The results revealed that M3 contained SQR or SRK, DHI or DHL, while M4 was almost amino acids. Two possible amino acids were found in the mass-spectrogram, they were alanine, and isoleucine or leucine.5. As to the products development of functional vegetable protein, oral liquid was developed in this study. The plant protein hydrolysate was used to prepare the small peptide oral liquid, which indicators were in line with national standard. In addition, it was with good taste and could be easily assimilated, and it would be health products of a new generation.