Fermented Shrimp Waste Hydrolysates: Promising Source of Functional Molecules with Antioxidant Properties

Protein hydrolysates were prepared through fermentation of shrimp waste. The protein-rich liquid hydrolysate was further dried using two methods: oven drying at 70°C and freeze drying. The functional properties and in vitro antioxidant activities of the two hydrolysates were then investigated. Slight modifications in solubility, emulsifying properties, and oil retention capacity were distinguished between the two dried hydrolysates. The antioxidant activities were evaluated at different concentrations, using various in vitro assays. The dried hydrolysates possessed varying degrees of antioxidant activity. In fact, the two hydrolysates exhibited high DPPH radical scavenging activity comparable to the positive control BHA. The oven-dried hydrolysate (ODH) present higher reducing power than the freeze-dried hydrolysate (FDH), while the latter showed much higher ability to prevent bleaching of β-carotene than did ODH but little higher Fe2+-chelating ability. Therefore, fermented hydrolysates from shrimp processing by-products could be used as a promising source of functional molecules with antioxidant properties.