Assessment of energy and biological value of Cherax quadricarinatus meat after feeding crayfish with different types of feed

Abstract

Cultivation of the Australian red-clawed crayfish Cherax quadricarinatus has become popular in many countries due to the rapid growth rate, high nutritional and biological value of the meat, and quite significant demand among consumers. The aim of our study was to determine the chemical, amino acid and fatty acid composition of Cherax quadricarinatus crayfish meat and its energy value when fed with different types of feed. The fatty acid composition of crayfish meat was determined by the chromatographic method, and the amino acid composition by the capillary electrophoresis method. It was established that when feeding crayfish with the developed Decapodafood feed, the energy value of crayfish meat was 4.3 kcal more than when feeding crayfish with aquarium feed Ancistrus menu. Feeding with Decapodafood promotes a higher content of essential amino acids compared to feeding with commercial aquarium food Ancistrus menu. In particular, a higher content of essential amino acids such as threonine, valine, methionine, lysine in the meat was statistically probable. In addition, a high biological value and digestibility of crayfish meat was found, as the sum of ΣEAA/ΣNEAA in all samples was more than 80%, which is on average 20% more than the standard indicator recommended by FAO/WHO. Feeding crayfish with Decapodafood helps to reduce saturated fatty acids in meat and increase unsaturated ones. In particular, a 1.9 times lower content of lauric acid and 1.5 times lower margaric acid was found in the meat of crayfish fed Decapodafood, compared to crayfish fed Ancistrus menu aquarium food, and myristic and pentadecanoic acid were on average 1.3 times smaller. Among unsaturated fatty acids, a probable increase of 1.4 times was noted for palmitoleic and docosahexaenoic acids, compared to their content in control meat. The content of other polyunsaturated fatty acids (linoleic and eicosapentaenoic), although higher, was insignificant. Therefore, feeding Cherax quadricarinatus crayfish with Decapodafood helps to improve the energy and biological value of the obtained meat, which makes it a highly digestible and delicate product. Key words: Cherax quadricarinatus, crayfish meat, Decapodafood, amino acid, fatty acid composition of meat.