Optimization of Alcalase for Krill Byproduct Hydrolysis and Antioxidative Activities by Response Surface Methodology

Abstract

Krill byproduct was hydrolyzed with Alcalase 2.4L to produce functional ingredients for high antioxidative activities against 1,1-dimethyl-2-picryl-hydrazyl (DPPH) radical and Fe. The objective of this study was to investigate the optimum condition for degree of hydrolysis and antioxidative activity of enzymatic hydrolysate produced with the commercial Alcalase using response surface methodology (RSM) with a central composite rotatable design (CCRD). The ranges of independent variables were pH 7.6～10.4 for initial pH and 50.9～79.1 o C for hydrolysis temperature and their dependent variables were degree of hydrolysis, Brix, amount of phenolic compounds, DPPHscavenging activity and Fe-chelating activity. RSM with CCRD was well designed to investigate the optimum condition for functional ingredients with high antioxidative activities using Alcalase 2.4L because of their high R 2 values of the range of 0.93～0.99 except the R 2 value of 0.50 for the amount of total phenolic compounds. The optimum hydrolysis conditions were pH 9.5 and 62 o C for degree of hydrolysis (DH) and pH 9.1 and 64 o C for DPPH-scavenging activity by response surface methodology. The yield of DH and DPPH-scavenging activity were 14.1±0.5% and 10.5±0.2%, respectively. It is advantageous to determine the optimum hydrolysis conditions of krill and its by-products for the creation of different kinds of food products, as well as to increase the usage of marine protein sources.

Use of Alcalase in the production of bioactive peptides: A review

“…Alcalase hydrolysis of krill processing byproducts was optimized by response surface methodology in order to improve the degree of hydrolysis and the antioxidant activity of the produced enzymatic hydrolysate [314]. Optimum hydrolysis conditions were pH 9.5 and 62°C and pH 9.1 and 64°C for degree of hydrolysis of 14.1±0.5% and DPPHscavenging activity of 10.5±0.2% [314].…”

“…Alcalase hydrolysis of krill processing byproducts was optimized by response surface methodology in order to improve the degree of hydrolysis and the antioxidant activity of the produced enzymatic hydrolysate [314]. Optimum hydrolysis conditions were pH 9.5 and 62°C and pH 9.1 and 64°C for degree of hydrolysis of 14.1±0.5% and DPPHscavenging activity of 10.5±0.2% [314]. In another paper, Alcalase was employed to obtain antioxidant hydrolysates from defatted echinoderm byproducts, including viscera of Atlantic sea cucumber (Cucumaria frondosa) and digestive tract and non-commercial grade gonads of green sea urchin (Strongylocentrotus droebachiensis) [315].…”

Two-Step Enzymolysis of Antarctic Krill for Simultaneous Preparation of Value-Added Oil and Enzymolysate

“…The enzymolysis-assisted extraction, which can release more oil based on the destruction of the raw material structure, is now an emerging lipid extraction technology. At present, the main enzymes used for lipid extraction are all proteases [ 17 ]. Among them, alkaline protease and compound protease have been proved to improve the yield of AKO significantly [ 18 , 19 ].…”