Study on preparation of chickpea peptide and its effect on blood glucose

Abstract

Chickpeas are the third largest bean in the world and are rich in protein. In this study, chickpea peptides were prepared by the enzyme-bacteria synergy method. Taking the peptide yield as the index, we first screened 8 strains suitable for the fermentation of chickpea peptides from 16 strains, carried out sodium dodecyl sulfate polyacrylamide gel electrophoresis, and then screened 4 strains with the best decomposition effect of chickpea protein. The molecular weight, amino acid content, and α-glucosidase inhibitory activity of the chickpea peptides fermented by these four strains were detected. Finally, the strains with the best α-glucosidase inhibitory activity were obtained, and the inhibitory activities of the different molecular weight components of the chickpea peptides fermented by the strains with the best α-glucosidase inhibitory were detected. It was found that Bifidobacterium species had the best fermentation effect, and the highest peptide yield was 52.99 ± 0.88%. Lactobacillus thermophilus had the worst fermentation effect, and the highest peptide yield was 43.22 ± 0.47%. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) showed that Bifidobacterium species, Lactobacillus acidophilus, Lactobacillus rhamnosus, and Lactobacillus paracasei have a better effect on the decomposition of chickpea protein in the fermentation process, and the molecular weight of their fermented peptides is basically below 20 KDa. Among the four strains, the α-glycosidase inhibition of chickpea peptide fermented by Lactobacillus acidophilus was the best, which was 58.22 ± 1.10% when the peptide concentration was 5.0 mg/ml. In chickpea peptide fermented by Lactobacillus acidophilus, the influence of molecular weight on the inhibitory activity is not obvious when the molecular weight is <10 kD, and the molecular weight range of the best inhibitory effect is 3-10 kD, and the inhibitory rate of α-glucosidase is 37 ± 1.32% at 2.0 mg/ml. This study provides a theoretical basis for the study of a new preparation method for chickpea peptide and its hypoglycemic effect.

Keywords: chickpea; fermentation strains; molecular weight; peptide; α-glucosidase.