Effect of Chemical Hydrolysis on Degree of Hydrolysis and Functional Properties of Protein Hydrolysates Extracted from Leiognathus Equulus (Forsskål, 1775)

Abstract

In the present study, two hydrolysis methods, acid and alkali were evaluated to produce fish protein hydrolysates (FPH) from 16.05±0.67% protein in wet-weight basis of silver belly fish (Leiognathus equulus). Acid hydrolysis was carried out by hydrochloric acid (pH 2) at 110 °C for 24 hrs. Alkali hydrolysis was performed by NaOH (pH 12.5) at 95 °C for 20 h. Results shown 8.60 to 16.90% degree of hydrolysis (DH) and 4.22 to 46.06% yield for acid hydrolysis. Alkali hydrolysis had shown 8.40 to 22.80 DH and

6.66 to 59.51% yield. Acid hydrolysis exhibited higher emulsion properties (64.73±0.92%) at 1% concentration compared to acid. The foaming properties were obtained highest (69.00±1.41%) at 2% concentration in alkali hydrolysis.Thus the results revealed that alkali hydrolysis is a suitable and efficient as it rapidly hydrolysed the protein yielding higher DH and yield. Among the different hydrolysates extracted, frame and mince hydrolysate showed better functional properties.