Antioxidative and Functional Properties of Kariya (Hildergadia barteri) Protein Hydrolysates Obtained with Two Different Proteolytic Enzymes

Abstract

Enzymatic hydrolysates of kariya protein isolate were prepared by treatment with pancreatin and pepsin. The functional and antioxidant properties of the protein hydrolysates were investigated. Pancreatin (PcKPH) and pepsin (PsKPH)-treated kariya protein hydrolysates exhibited maximum solubility (PcKPH, 81.98%; PsKPH 79.17%), emulsifying activity index (PcKPH, 47.87 m2/g; PsKPH, 44.24 m2/g), emulsion stability (PcKPH, 341.08%, PsKPH, 223.11%), foaming capacity (PcKPH, 118.75%; PsKPH, 125.00%) and foaming stability (PcKPH, 81.25%; PsKPH, 87.50%) at pH 10. Also, PcKPH and PsKPH demonstrated high DPPH (2,2-diphenyl-1-picrylhydrazyl) radical-scavenging activity (IC50: 1.55 and 7.30 mg extract/mL, respectively), metal chelating (IC50: 1.23 and 1.04 mg extract/mL, respectively) and ferric reducing antioxidant power (FRAP) (0.40 and 0.21 AAE μg/g, respectively) activities. The results showed that PcKPH had significantly higher solubility, emulsifying properties, metal chelating and FRAP than PsKPH. High functional and antioxidant properties exhibited by the KPHs could make them useful ingredients in food systems and as natural sources of antioxidative peptides. Practical Applications The study compares the bioactivity of peptides produced from kariya seeds (an underutilized oil seeds) using two different proteolytic enzymes (pepsin and pancreatin). The result showed that kariya seed protein hydrolyzed with pancreatin has better functional properties than those hydrolyzed with pepsin. However, kariya seed protein hydrolyzed with pepsin has better antioxidant properties than those hydrolyzed with pancreatin. Both results compare favorably with that of other oilseeds. Therefore, good functional and antioxidant properties can be produced from hydrolyzed kariya proteins.