Effect of frozen storage temperature on lipid stability of hepatopancreas of Eriocheir sinensis

Abstract

In order to investigate and predict the quality of hepatopancreas of Eriocheir sinensis during frozen storage, fatty acid content, peroxide value (POV), acid value (AV) and anisidine value (AnV) were determined at −20, −40 and −80 °C, respectively. According to the investigative results, lipid oxidation indexes at −20 °C was higher than at −40 and −80 °C, and the degree of lipid oxidation was the least at −80 °C. In the meantime, the back propagation neural network with 10 neurons was developed to predict lipid stability of the samples during frozen storage with low MSE (0.00023) and high R2 (0.999). Besides, the changes to nutritional quality were evaluated using the index of atherogenesis (AI) and the index of thrombosis (TI). Furthermore, tri-step spectroscopy was applied to analyze and characterize the degree of lipid oxidation. The profile of characteristic peak was spatially revealed by the stereomicroscopy with group-peak at 2924 cm−1, 2854 cm−1, 1745 cm−1, 1641 cm−1, 1461 cm−1 and 1158 cm−1 and were unveiled by the second derivative infrared spectroscopy (SD-IR) for higher resolution, the samples stored at different temperatures were further identified through two-dimensional correlation infrared spectroscopy (2DCOS-IR).