Impact of different drying processes on the lipid deterioration and color characteristics of Penaeus vannamei.

Fresh shrimp (Penaeus vannamei) deteriorates easily, and the drying process is an important processing method to prolong the shelf life of shrimp. The traditional drying method is hot-air-drying (HD), which can cause some problems such as nutrient loss, discoloration, and lipid oxidation. In recent years, freeze-drying (FD) has been popular for removing moisture from food at lower temperatures, maintaining the structure of raw materials, and improving storage stability of products. In this study, the effects of HD and FD on lipid and color of Penaeus vannamei and the mechanisms involved were investigated.FD caused less lipid oxidation compared to HD, consequently, FD-processed shrimps had lower levels of primary and secondary oxidation products as well as acid value (AV), and higher contents of triacylglycerol (TAG), phosphatidylcholine (PC), phosphatidylethanolamine (PE), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) than HD-processed samples. Lipase and lipoxygenase (LOX) played a role in the oxidation and hydrolysis of lipids during drying process. FD-processed shrimps had lower yellowness value and chromatic aberrations, but higher whiteness value than HD-processed samples. Correlation analysis showed that lipid oxidation, astaxanthin degradation, and Maillard reaction contributed to the changes of color. Principal component analysis (PCA) indicated that FD caused less deterioration in quality compared to HD.In this study, FD is recommended for preserving shrimp color and lipid nutrition in terms of lipid oxidation control. This article is protected by copyright. All rights reserved.