Enzymes-dependent antioxidant activity of sweet apricot kernel protein hydrolysates
Chuanqing Huang, Xiaoyue Tang, Zeyu Liu, Wenqian Huang, Yong Ye
Abstract
The bioactive peptides derived from sweet apricot kernel residue after oil extraction exhibit different bioactivities, but their structure-activity relationships have not yet been established. In this research, the antioxidant activities (hydroxyl, superoxide anion, DPPH radical scavenging capacity and iron-binding ability) of sweet apricot kernel protein hydrolysates (SAKPHs) obtained by different enzymes at the temperature range (37–70 °C) were evaluated. The amino acid sequences of the hydrolysates by different enzymes were identified by LC-ESI-MS/MS. The results showed that five novel antioxidant peptides with Lysine at the C-terminal end were found in the Neutrase’ SAKPHs. Two peptides with Serine-terminal end in the Alcalase’ SAKPHs and with N-terminal end in the Papain’ SAKPHs were obtained respectively. Three atypical peptides were detected in the Flavourzyme’ SAKPHs. The SAKPHs by the Alcalase (SAKPHs-A) at 50 °C had highest degree of hydrolysis and a relatively smaller molecular weight distribution compared with the other three proteases, and presented the higher antioxidant activity. The N-terminal peptide SHNLPILR containing a side chain combination of aspartic acid and histidine contributes to the stronger antioxidant activities of SAKPHs-A. This research supplies a guideline for functional peptides released from dietary proteins by the utilization of specific enzymes in the food industry.