Hydrolysis of Nyamplung (Calophylluminophyllum) protein and their antioxidant activity

Abstract

Abstract. The seedcake of nyamplung seeds still contains high protein. Recent studies show that protein hydrolysate has many useful effects, such as an antioxidant. The protein was isolated by the isoelectric precipitation method, further on hydrolysed into short chain peptides. The chemical composition of seedcake and the protein content of extract were analysed. The hydrolysis of the extract was carried out in a various condition such as substrate concentration, pH, and temperature for a different length of hydrolysis and the degree of hydrolysis was determine by TNBS method. The protein isolation process performed on the defatted seedcake produced 52.84 ± 0.07% of protein extract with a brownish colour. The degree of hydrolysis (DH) was increased by increasing the length of hydrolysis and showed the optimum DH with 6.15mg/mL substrate concentration. The increase of temperature also increased the DH, however at 70°C with 240 min time reaction, the DH tended to decrease. The pH of reaction between papain showed the similar DH among various pH of the reaction, with pH 7 showed the stable increasing DH till 240 min of reaction. The antioxidant activity showed an increase to 90% of inhibition by the addition of the hydrolysate to the system until 1300 ppm. However, the addition of more than 1300 ppm showed a reduction activity