Cholesterol oxidation and astaxanthin degradation in shrimp during sun drying and storage

Abstract

Dried salted shrimps are made from raw shrimps, which are cooked and dried under direct sunlight. The preparation and storage include treatments and conditions that can promote oxidative changes in different components. The aim of this study was to monitor the formation of major cholesterol oxidation products and the changes in the astaxanthin content and fatty acid profile in dried salted shrimp during cooking, sun drying and storage. During sun drying, most of the astaxanthin (75%) was degraded in cooked shrimp, while cholesterol oxidation products (COPs) showed a dramatic increase (8.6-fold), reaching a total concentration of 372.9 ± 16.3 μg/g of lipids. Further storage favoured both astaxanthin degradation (83%) and COPs formation (886.6 ± 97.9 μg/g of lipids after 90 days of storage). The high degradation of astaxanthin and the elevated formation of COPs during sun drying and storage indicate the necessity to re-evaluate the processing and storage conditions of salted dried shrimp.

Keywords: 20-HC; 20-Hydroxycholesterol; 25-HC; 25-Hydroxycholesterol; 5,6α-Epoxycholesterol; 5α-Hydroperoxycholesterol; 5α-OOH; 7-KC; 7-Ketocholesterol; 7α-HC; 7α-Hydroperoxycholesterol; 7α-Hydroxycholesterol; 7α-OOH; 7β-Hydroperoxycholesterol; 7β-OOH; Astaxanthin degradation; COPs; CT; Cholestanetriol; Cholesterol oxidation; Cholesterol oxidation products; DHA; Docosahexaenoic acid; EPA; Eicosapentaenoic acid; MUFA; Monounsaturated fatty acids; PUFA; Polyunsaturated fatty acids; SFA; Saturated fatty acids; Shrimp; Storage; Sun drying; α-CE.