Analysis and Evaluation of Seasonal Changes on Nutrient Composition in Muscle of Quasipaa spinosa

The analysis of the nutritional composition of the muscle of Quasipaa spinosa in four seasons aimed to provide theoretical basis for the further processing of Quasipaa spinosa. In the processing process, Quasipaa spinosa in the appropriate season could be selected according to the product requirements. Samples of Quasipaa spinosa in four seasons were collected to analyze the differences of muscle basic nutrient composition, amino acids, fatty acids by Soxhlet extraction, Kjeldahl nitrogen determination and chromatography. The results showed that the nutrient composition varied greatly in different seasons. The contents of crude protein (24.79±0.32 g/100 g) and crude fat (1.19±0.17 g/100 g) were the highest in winter, and the contents of water and ash were the highest in autumn. However, 17 kinds of amino acids were all contained in muscles in different seasons, and the contents of lysine (8.73~10.20 g/100 g) was the highest in essential amino acids, and methionine+cysteine was the lowest. The total amino acids (TAA), essential amino acids (EAA) and flavor amino acids (DAA) were the highest in autumn. Valine and methionine+cystine were limiting amino acids, but the first and the second limiting amino acids were different in different seasons. Fatty acids were the most in autumn (18 kinds), and oleic acid (C18:1n9c) content was the highest, while linoleic acid (C18:2n6c) content was the highest in the other three seasons. The muscle nutrient composition of Quasipaa spinosa was significantly affected by seasonal changes.