Optimization of Preparation Process of Antarctic Krill Hydrolysate with Delicate Taste by Compound Enzyme Method

In this paper, defatted Antarctic krill powder was used as raw material to prepare hydrolysate with delicate taste by compound enzyme method. By means of sensory evaluation, peptide yield and degree of hydrolysis, the screening of exogenous enzymes and single factor experiments were carried out. In order to further optimize the taste of enzymatic hydrolysate, the total amount of amino acids with delicate flavor was used as the index to optimize the enzymatic hydrolysis condition. The results showed that the optimal hydrolysis conditions were as follows: The ratio of trypsin and pepsin 1:100, the total amount of enzyme 2800 U/g, the liquid and material ratio 1:4 g·mL⁻¹, the pH of enzymatic hydrolysis 7.0, the temperature of enzymatic hydrolysis 40 ℃, and the time of enzymatic hydrolysis 3 h. Under these conditions, the content of free amino acids with delicate taste in the hydrolysate was 331.79 mg/100 mL. Except tryptophan, the remaining eight essential amino acids accounted for 63.66% of the total amino acids. Free bitter amino acids accounted for 27.83% of the total amino acids, and free sweet amino acids accounted for 26.22% of the total amino acids. Free glutamic acid and free aspartic acid, which played a key role in the formation of umami taste, accounted for 10.26% of the total free amino acids. This study could provide theoretical basis and technical guidance for the development of Antarctic krill flavoring products.