Optimization of Decolorization Process of Antarctic Krill Peptides by Response Surface Methodology

In order to optimize the decolorization process of Antarctic krill peptides and improve the product quality, activated carbon adsorption method was used to remove the pigment from the Antarctic krill peptides solution. Taking the decolorization rate and protein retention rate as the evaluation indexes, the influence of four independent variables including dosage of activated carbon, pH, decolorization temperature and decolorization time on the decolorization effect were investigated respectively. On the basis of single factor experiment, three independent variables including dosage of activated carbon, pH and decolorization time were optimized by the response surface methodology under the decolorization temperature of 50 ℃. Results showed that powdered activated carbon was more suitable for the removal of pigment from Antarctic krill peptides when compared with granular activated carbon, and the optimal conditions determined by response surface methodology were as follows: dosage of activated carbon 4.0%, pH1.5 and decolorization time 1.0 h. Under the optimal conditions, the decolorization rate was 82.19%±0.20% and the protein retention rate was 90.93%±2.28%. The decolorization treatment had no obvious effects on the proportion of essential amino acids and nonessential amino acids in the amino acid compositions as well as the molecular weight distribution of Antarctic krill peptides. This research would provide scientific support for the development of high-quality Antarctic krill peptides products.