Persea Americana Mill seed extracts: Understanding insights into the antioxidant and antityrosinase activities and effects on preserving qualities of whiteleg shrimp (Litopenaus vannamei) during refrigerated storage.

An ethanol extract of avocado seed (TN-1) and six smaller fractions (PD-1 to PD-6) were prepared. Most of the extracts exhibited scavenging DPPH radical, reducing Fe3+ to Fe2+, and inhibiting polyphenoloxidase, consistently matching with their high polyphenolic content (p < 0.05). Most of the 47 compounds identified from TN-1 were classified into phenolic acid, condensed tannin, flavonoid, fatty acids, and alkaloids. Two extracts TN-1 and PD-2 (0.025%, w/v) were used to treat white-leg shrimp and the quality changes were evaluated compared to those treated with sodium metabisulfite (1.25%, w/v) and controls (without treatment) during 8-day storage at 2 °C. Changes in melanosis scores, lipid peroxidation, pHs, microorganisms, and nutrient in shrimps treated with the extracts were comparable to or even much better than others. These results promise a potential use of avocado seed extract as a cost-effective, eco-friendly, and effective alternative to commercial additives in shrimp storage.