Optimization of the Extraction of Coconut Protein and the Evaluation of Antioxidant and ACE Inhibitory Activities of its Enzymatic Hydrolysates

Abstract

The extraction of proteins from coconut meat was performed utilizing alkaline extraction. On the basis of single factor experiment, an orthogonal experiment was designed to optimize the extraction conditions (including extraction time, temperature, NaOH concentration and liquid to solid ratio). The highest extraction rate (7.3%) was obtained at 120 min, 45 °C, 0.1 M and liquid-solid ratio 25:1. Coconut protein was consequently hydrolyzed with four commercial enzymes (alcalase, trypsin, pepsin, papain). Furthermore, activities of hydrolysates on DPPH radical scavenging and ACE inhibition were assayed respectively. The results indicated that pepsin hydrolysate exhibited the highest DPPH radical scavenging activity (100%, 1 mg protein/mL), and trypsin hydrolysate possessed the most potent ACE inhibitory activity (40.2%, 1 mg protein/mL).