Study On Preparation Of Hemp Protein And Its Inhibitory Activity Of α-Glucosidase

As a by-product of hemp oil extracted from hemp seed,hemp seed meal has the characteristics of low cost,high protein content,rich in amino acid,and has the potential value of human protein nutrition supplements and functional food raw materials.In this paper,the extraction technology,functional characteristics and digestive characteristics of hemp seed meal protein were analyzed.The process of enzymatic preparation of active enzyme hydrolysates withα-glucosidase inhibition was optimized,and the physical and chemical properties,antioxidant activity,inhibition mechanism and processing and digestion stability of the hydrolysates were elucidated.The active peptides in the enzymatic hydrolysates were separated,purified,identified,virtual screening and verified by synthesis.The inhibition effect of the enzymatic hydrolysates onα-glucosidase activity and glucose transport in Caco-2 cells was investigated,in order to provide theoretical basis for the further processing and utilization of sesame seed meal.The specific research contents and conclusions are as follows（1）The optimum extraction process of hemp protein（NDHP）from non-dehulled hemp seed mealwas as follows:solid to liquid was 1:10,50℃,3 h and the initial p H is 12.0.The protein recovery was 46.94%and the protein content was 81.97%;The optimum extraction process of hemp protein（DHP）from dehulled hemp seed meal was as follows:solid to liquid was 1:10,40℃,3 h and the initial p H was 12.0,and the protein recovery was 89.41%,the protein content was 88.56%.The two kinds of hemp protein had the lowest solubility near p H5.0.The water and oil holding capacity of DHP is better than that of NDHP.The hemp protein had low foaming and foam stability,and the emulsification of two kinds of hemp was basically the same,while DHP has better emulsification stability and higher in vitro simulation gastrointestinal digestion than NDHP.（2）Considering the hydrolysis effect and cost control,the optimum enzymatic hydrolysis process was as follows:solid-liquid ratio 1:10（w/w）,temperature 55℃,6 h,enzyme addition（w/w）1.00%and p H 8.0.The IC₅₀ value of the enzymatic product forα-glucosidase is 2.83mg/m L.Polypeptides with molecular weight between 500 and 1000 Da were the main part of enzymatic hydrolysis products,accounting for 53.95%.The half scavenging concentrations of DPPH and ABTS of enzymatic hydrolysis products were 2.27 mg/m L and 0.92 mg/m L,respectively.The hydrolysates inhibitedα-glucosidase activity belongs to reversible inhibition,and the inhibition type belongs to mixed inhibition.（3）The enzymolysis product has good temperature and acid-base stability,and also has good stability to low concentration metal ions.Simulated digestion is helpful to inhibit the increase of activity.The supernatant obtained from ethanol grading is the best component for further study.Using high-resolution liquid liquid combination can identify 345 polypeptides from the enzymatic product,and there are 49 compared to the peak area greater than 0.5%polypeptide.Six potentialα-glucosidase inhibitory peptides were further screened by virtual screening.It was found that TGLGR,SPVI,FY and FR hadα-glucosidase inhibitory activity by synthesizing polypeptides.（4）The hydrolysates had certain inhibitory effect on sucrase and maltase in Caco-2 cells,The enzymatic hydrolysates of certain concentration of hemp seed meal had certain inhibitory effect on glucose transport at different concentrations,and the inhibitory effect was better at low glucose concentration.