Characterisation of taste-active compositions, umami attributes and aroma compounds in Chinese shrimp

Chinese shrimp is one of the most important aquatic resource in China due to its unique flavour and high nutritional value. In this study, the taste-active components including free amino acids (FAAs), 5'-nucleotides, organic acids, inorganic ions, trimethylamine oxide (TMAO) and betaine were analysed. The synergistic effect between amino acids and 5'-nucleotides was determined by partial least squares (PLS) analysis. The taste activity value (TAV) and equivalent umami concentration (EUC) were calculated to analyse the major taste-active components and umami attributes. Then, the aroma compounds were extracted by simultaneous distillation extraction (SDE), head-space solid-phase microextraction (HS-SPME) and supercritical fluid extraction (SFE) methods, respectively, and identified by gas chromatography-mass spectrometry (GC-MS). Arginine (Arg), glycine (Gly), guanosine 5'-monophosphate (5'-GMP), inosine-5 '-monophosphate (5'-IMP), de-nosine-5 '-monophosphate (5'-AMP), succinic acid, lactic acid and inorganic ions with TAV higher than 1 contributed greatly to the taste. The umami intensity for 100 g of Chinese shrimp was equivalent to 4.58 g monosodium glutamate (MSG), indicating that Chinese shrimp had relatively high umami taste value. Ninety-seven volatile compounds including esters, alcohols, acids, aldehydes, ketones, heterocycles, aromatics and alkanes were identified. This research might help consumers to understand the flavour compositions and promote the development of flavour products of Chinese shrimp.