Evaluation of functional properties of bioactive peptides produced from shrimp wastes in processing centers using protamex enzyme in different degrees of hydrolysis

The aim of this study was to investigate the functional properties of bioactive peptides produced from shrimp wastes in processing centers in three degrees of hydrolysis. For this purpose, the wastes of shrimp processing centers were hydrolyzed in three times of one, two and three hours using protamex enzyme and the functional properties of the resulting peptides (SPH1, SPH2 and SPH3) were evaluated. The results showed that with increasing the hydrolysis time from one to two and three hours, the degree of hydrolysis and nitrogen recovery of the process increased significantly (p<0.05). According to the findings, the solubility of SPH3 was significantly higher than SPH1 and SPH2 and its maximum was reported at pH=10, equal to 97.82±1.54% (p<0.05). SPH1 had higher emulsifying activity and emulsion stability index than SPH2 and SPH3. In this peptide, the highest value of emulsifying activity index was reported 68.15±2.84 m2/g, which was related to pH=10. But the maximum emulsion stability index was reported at pH=6 (166.84±5.08 minute). The highest measured foaming activity was 165.52±5.91% which was recorded at SPH1 and pH=10. Also, the maximum foam stability among the peptides was measured 118.32±3.23%, which was related to SPH1 at pH=6. SPH1 had a higher oil absorption capacity (5.92±0.33 ml/g) than SPH2 and SPH3 (p<0.05). The highest water holding capacity (5.18±0.71 ml/g) was related to SPH3 (p<0.05). According to the findings, the functional properties of peptides produced from wastes of shrimp processing centers using protamax enzyme are at an acceptable level for use in various foods.