Obtaining of functional components from cooked shrimp (Penaeus vannamei) by enzymatic hydrolysis

Non-commercial cooked Whiteleg shrimp (Penaeus vannamei) was valorized by application of protein hydrolysis treatments with different proteases (Giant catfish (Pangasianodon gigas) viscera proteases, commercial trypsin, and Alcalase®) for the obtainment of functional components (protein hydrolysates and carotenoids). Functional properties and in vitro inhibitory effect of the resulting protein hydrolysates on Dipeptidyl Peptidase-IV (DPP-IV) and Prolyloligopeptidase (PO) were evaluated. After hydrolysis, more than 73% of protein was recovered in soluble form, whereas 11-15% was insoluble. Carotenoids, determined as astaxanthin, were mainly present (>97%) in the insoluble protein fraction, presumably in form of complexes of high molecular weight. Protein hydrolysates showed excellent solubility (>97%) in a wide pH range (3-10), good oil holding capacity (0.86-1.83 g oil/g hydrolysates) and discrete inter-facial properties. Besides, all shrimp hydrolysates at concentration of 1 mg/mL provided DPP-IV inhibition activity (22.7-61.7%) and those prepared with trypsin and Alcalase® also inhibited PO (35-40% inhibition). The enzymatic processing of non-commercial boiled shrimp could be a useful way to valorize it, obtaining soluble proteins/peptides, potential hypoglycemic and antidepressant compounds (DPP-IV and PO inhibition peptides) and astaxanthin with interesting functional properties for food applications.