Optimization of the production of shrimp waste protein hydrolysate using microbial proteases adopting response surface methodology

Protein hydrolysates were produced from shrimp waste mainly comprising head and shell of Penaeus monodon by enzymatic hydrolysis for 90 min using four microbial proteases (Alcalase, Neutrase, Protamex, Flavourzyme) where PR(%) and DH (%) of respective enzymes were compared to select best of the lot. Alcalase, which showed the best result, was used to optimize hydrolysis conditions for shrimp waste hydrolysis by response surface methodology using a central composite design. A model equation was proposed to determine effects of temperature, pH, enzyme/substrate ratio and time on DH where optimum values found to be 59.37 degrees C, 8.25, 1.84% and 84.42 min. for maximum degree of hydrolysis 33.13% respectively. The model showed a good fit in experimental data because 92.13% of the variability within the range of values studied could be explained by it. The protein hydrolysate obtained contained high protein content (72.3%) and amino acid (529.93 mg/gm) of which essential amino acid and flavour amino acid were was 54.67-55.93% and 39.27-38.32% respectively. Protein efficiency ratio (PER) (2.99) and chemical score (1.05) of hydrolysate was suitable enough to recommend as a functional food additive.