Unravelling the α-glucosidase inhibitory properties of chickpea protein by enzymatic hydrolysis and in silico analysis

Abstract

Vegetables consumption in human diets is rapidly increasing due to their proven health benefits and their environmentally friendly character. Chickpea (Cicer arietinum) is an important pulse crop grown consumed worldwide. In this work, different enzymatic treatments were employed to obtain chickpea protein hydrolysates with increased solubility and α-glucosidase inhibitory activity. A sequential hydrolysis with subtilisin and trypsin up to a degree of hydrolysis of 20% showed the highest inhibition (IC50 value of 1.43 ± 0.08 mg/mL) compared to the hydrolysis with single enzymes, or used simultaneously. This hydrolysate was fractionated by size exclusion chromatography. Peptides from 500 to 1100 Da were responsible of the highest level of inhibition, showing an IC50 value of 0.52 ± 0.03 mg/mL. An in silico hydrolysis of the sequences of the major proteins allowed to identify the potential peptides contained in the most active fractions based on their molecular features. The identified peptides were characterized employing different bioinformatics tools to determine which peptides would be most inhibitory ones. These peptides could be potentially employed as ingredient regulating the glycaemic index in food formulation.