Effects of short-term low salinity stress on non-volatile flavor substances of muscle and hepatopancreas in Portunus trituberculatus

Abstract

In order to determine the effects of different short - term low salinity stress on non - volatile flavor substances of Portunus trituberculatus, four salinity levels (24‰, 16‰, 12‰ and 8‰) were selected. The contents of free amino acids (FAA), nucleotides and lactic acid in both muscle and hepatopancreas of P. trituberculatus were determined by HPLC and spectrophotometry respectively. Results showed that muscle contained a relatively higher level of sweetish free amino acids (SFA), however short - term low salinity stress greatly increased the level of bitter free amino acid (BFA); hepatopancreas contained a higher level of umami free amino acids (UFA) and a higher equivalent umami concentration (EUC) value, which increased significantly with the decrease of salinity level and the degree of umami flavor reached the highest when salinity dropped to 8‰. The lactic acid content in muscle increased at 12‰ and then decreased significantly at 8‰ while no significant differences were observed in hepatopancreas. Results above revealed the flavor change in two edible parts of P.trituberculatus under short - term low salinity stress which provided a guidance for more systematic nutritional flavor evaluation in breeding process and consumption demand.