Production of Peptides with Radical Scavenging Activity and Recovery of Total Carotenoids Using Enzymatic Protein Hydrolysis of Shrimp Waste

Abstract

The enzymatic hydrolysis of shrimp waste by the commercial protease Alcalase was evaluated as an alternative for recovery of valuable components, protein and astaxanthin. The influence of temperature (40–70C) and enzyme : substrate ratio (2.0–6.0%, g enzyme/100 g protein) on degree of hydrolysis, recovery of protein and antioxidant activity of hydrolysate was studied. The total carotenoids content in each insoluble fraction obtained after centrifugation of raw hydrolysate were also determined. All variables had significant effect on the responses. To obtain maximum antioxidant activity of hydrolysate and recovery of protein and total carotenoids in sediment, the following optimum conditions are suggested, 55C and 4.0%. Under these conditions, degree of hydrolysis, antioxidant activity and recovery of protein and total carotenoids were determined, obtaining values of 3.63%, 66.8%, 39.53 μmol Trolox equivalents/g protein and 72.67%, respectively. Practical Applications Shrimp wastes, removed during processing, represent up to 50% of the weight of raw material. These discards are normally used to obtaining low-value products, such as animal feed and fertilizers. Since they contain valuable components such as protein, chitin and astaxanthin carotenoid, significant amounts of nutrients are underused. Thus, better utilization of these discards through the manufacture of value-added products can result in expansion of aquaculture industry, maximization of economical benefits and reduction of environmental pollution. Enzymatic hydrolysis of shrimp waste represents a potencial process for recovery of total carotenoids in the insoluble fraction and obtaining a hydrolysate that can be used as protein supplementation and/or antioxidant component in food systems.