Structural and functional characterization of protein isolate from Lepidium sativum with antioxidant and antidiabetic activities

Abstract

The extraction of protein from Lepidium sativum (LS) seed cake was optimized to obtain a yield of 18.32% at an alkali concentration of 0.16 M, buffer to sample ratio of 1/25 (w/v), a period of extraction of 15 min at 25°C. The physicochemical attributes, amino acid composition as well as functional properties of Lepidium sativum protein isolate (LSPI) were evaluated. Determining amino acid composition indicated that the isolated protein is a decent source of dietary essential amino acids with 41.36% being essential amino acids. The secondary structure of LSPI was mainly constituted by β-structures. Further, the protein isolate exhibited an excellent solubility profile at basic pH. Experimental data obtained from physicochemical analysis implies that the LSPI had excellent water holding and oil absorption capacity, emulsification property, foaming capacity and stability. LSPI exhibited significant antioxidant, anti-diabetic and protein digestibility activities making them an excellent candidate for nutritional food development.