Pink and white shrimps from the Brazilian coast: pigment identification, antioxidant activity and microbial quality under different freezing-times

Abstract

Shrimps fishing, especially the pink (Farfantepenaeus brasiliensis and F. subtilis) and the white (Litopenaeus schmitti) ones, are relevant for the Brazilian Northeast economy, and their price depends on their aspect-quality. They are rich in lipids/proteins, which are a target for autolytic and microbial enzymes. These may not change the shrimps' appearance but generate substances that may cause poisoning, as histamines. This work compared the microbial quality of fillets and shells of these three shrimps, harvested in two years, after cooking and storage under different freezing times (0-90 days), as well as the total carotenoids (TC) and antioxidant activity (AA%) of ethanolic extracts from all the samples, using spectrophotometry and DPPH test. None histaminogenic and few mesophilic bacteria were isolated (all Gram+ species of Corynebacterium, Listeria, Arthrobacter, Bacillus and Erysipelothrix), but in lower number than the tolerability limit. The TC and AA% of fresh shells from time "zero" were always higher than those of fillets, mainly for F. subtilis. Cooking increased TC and AA% of fillets, but reduced them in shells, and both parameters declined along the freezing. Thin-layer chromatography and spectrophotometric scanning of all the extracts and standards evidenced astaxanthin as the main carotenoid.

Shrimp Waste Upcycling: Unveiling the Potential of Polysaccharides, Proteins, Carotenoids, and Fatty Acids with Emphasis on Extraction Techniques and Bioactive Properties

“…Carotenoids are widely distributed pigments found in various organisms. They are characterized by 40 carbon atoms and conjugated double bonds, making them lipid-soluble tetraterpenoids [217]. They have been effectively extracted from shrimp waste employing conventional and alternative extraction techniques [218].…”