Shelf-life extension of pre-cooked shrimp (Litopenaeus vannamei) by oregano essential oil during refrigerated storage

Abstract

The present study evaluated the use of alginate–based coating with or without addition of oregano essential oil (OEO), as an antimicrobial treatment for shelf-life extension of pre-cooked shrimp stored under refrigeration for a period of 16 days. Four different treatments were tested: TC, control sample, TA, alginate–based coating and T05, T10, coated samples with alginate–based coating incorporated with 0.5% OEO and 1.0% OEO (v/v), respectively. With regard to the chemical freshness indices determined, total volatile basic nitrogen (TVBN) and trimethylamine nitrogen (TMAN) values of OEO treated pre-cooked shrimp samples were significantly lower compared to control samples during the entire refrigerated storage period. Based primarily on sensory evaluation (odor), the use of T10 and T05 extended the shelf-life of pre-cooked shrimp by 12 and 14 days, respectively, compared to 8 days in TC treatment samples, extending the shelf-life of T10 and T05 by 2 and 4 days, respectively.