Antioxidant potential of protein hydrolysates from canola (Brassica napus L.) seeds

Abstract

The antioxidant potential of a protein hydrolysate depends on the composition and sequence of antioxidant peptides produced during hydrolysis and the interaction of these peptides with other oxidative compounds. There are few studies on the antioxidant potential of canola (Brassica napus L.); however, as a source rich in protein (30–40%), canola paste is suitable to produce hydrolysates with this function. The objective of this work was to obtain hydrolysates using the sequential pepsin-pancreatin (PP) system, to determine some chemical characteristics and their antioxidant potential. Limited hydrolysates with a degree of hydrolysis of less than 10 (DH < 10) were obtained for canola protein hydrolysates at 5 min of reaction (CPH5min) with 7.97% and for canola protein hydrolysates at 10 min of reaction (CPH10min) with 9.78%. Regarding its amino acid (AA) composition, a high proportion of the amino acid His was found with 21.1% for CPH5min and 22.8% for CPH10min, as well as other hydrophobic amino acids in lower concentrations. In electrophoresis, it was found that 2S napin and 12S cruciferin, typical of canola, were still present. The hydrolysates also presented a high content of phenolic compounds (CPH5min with 190 mg EAG/100 g and CPH10min with 220 mg EAG/100 g), which along with the antioxidant activity evaluated with DPPH radicals (CPH5min with 29.01% and CPH10min with 35.6%) and ABTS, (CPH5min 5.45 mM TEAC/g and CPH10min 5.45 mM TEAC/g) were higher compared to the canola protein concentrate (CPC) used as a substrate to obtain the hydrolysates.