Optimization of hydrolysis conditions (temperature, time, and concentration of alkalase) of rainbow trout viscera using the response surface methodology

This study aimed to optimize the combined effects of temperature, time and enzyme concentration on degree of hydrolysis, protein recovery, supernatant soluble protein, antioxidant properties, and peptide chain length of rainbow trout waste hydrolyzed protein using alkalase. Optimization of hydrolysis conditions was selected using response surface methodology, based on Box Behnken statistical design. Three influential parameters including time (A = 60, 90, and 120 min), temperature (B = 40, 50, and 60 degrees C), and enzyme concentration (C = 1%, 1.5%, and 2%) on the dependent variables were examined. The best states of independent variables for the most favorable conditions of the dependent variables (highest degree of hydrolysis, protein recovery, soluble protein in supernatant, antioxidant activity with DPPH radical scavenging, and shortest peptide chain length) were selected. Two optimal points (opt1: 118 min, 59 degrees C, 2% and opt2: 119 min, 59 degrees C, 1.9%) were determined to achieve the desired hydrolysis conditions. Practical applications The bioactive peptide with animal sources actually has more antioxidant properties. Also, it has less bitterness, and this property made it very usable for functional food products. Therefore, hydrolyzed fish viscera with alkalase can be used as a source of bioactive peptides to improve the functional properties of foods.

Automated summary

This study optimized the conditions for hydrolyzing rainbow trout waste protein using alkalase, determining two optimal points for the highest degree of hydrolysis, protein recovery, soluble protein, antioxidant activity, and shortest peptide chain length. Bioactive peptides from animal sources show excellent antioxidant properties and reduced bitterness, making them suitable for functional food products. Hydrolyzed fish viscera with alkalase can serve as a source of bioactive peptides to enhance the functional properties of foods.