Analysis and Evaluation of Nutrient Composition, Flavor and Taste Characteristics of Crayfish Head

To make full use of crayfish head and other by-products, explore the feasibility of crayfish head as food processing ingredients. In this paper, the head of crayfish cultured in rice fields in Guangxi were used as raw materials. The basic nutrients such as protein, fat, ash, amino acids and fatty acids in crayfish head were determined by national standards, the contents of flavor nucleotides and organic acids in crayfish head were determined by high performance liquid chromatograph. The overall taste and odor of fresh crayfish head were analyzed by electronic tongue and gas chromatography ion mobility spectrometry (GC-IMS). The results showed that: From the perspective of nutritional composition, crayfish head is rich in nutrients, which mainly consists of crude protein (10.92 g/100 g) and crude fat (9.05 g/100 g), and the fat contains phospholipid 4.67 mg/g. There were 17 kinds of amino acids in crayfish head, and the total content was 97.28 mg/g, among which there were 7 kinds of essential amino acids, accounting for 50.01% of the total amino acids. A total of 19 kinds of fatty acids (9 kinds of saturated fatty acids and 10 kinds of unsaturated fatty acids) were detected, and the unsaturated fatty acids contained 57.94%. In terms of flavor composition, amino acids, phospholipids and fatty acids were important flavor precursors. In addition, the total content of free amino acids in fresh crayfish head was 900.70 mg/100 g, and the fresh and sweet amino acids accounted for 39.88%. The flavor nucleotides and organic acids in the crayfish head also provided a richer taste. The umami response value of the electronic tongue of shrimp head was 13.55, indicating that the umami taste was obvious. A total of 23 volatile flavor compounds were identified in the crayfish head, including aldehydes, ketones and alcohols, etc., which had a certain aroma of oil, meat, similar to grass and fruit, and earthy smell. In general, crayfish head was nutritious and healthy, and contained rich flavor precursors and taste substances. It had certain potential and feasibility in the processing and utilization of crayfish head and the development of condiments.