Identification of key umami-related compounds in Yangtze Coilia ectenes by combining electronic tongue analysis with sensory evaluation

The Yangtze Coilia ectenes is a delicious fish known for its distinctive aroma, intense umami taste and high nutritional value. The analysis of Yangtze Coilia ectenes flesh extract using an e-Tongue indicated that saltiness and umami taste were the primary sensory attributes. The relationship between umami-related components and umami taste of this fish was studied by using an electronic tongue (e-Tongue) and sensory perception analysis. As free amino acids, nucleotides and inorganic ions are the main contributors for umami, their contents in Yangtze Coilia ectenes flesh extract were quantified instrumentally and a synthetic sample composed of similar contents of free amino acids, nucleotides and inorganic ions was prepared subsequently. No significant difference in umami taste between that of the synthetic sample and the flesh extract were observed by using the e-Tongue and sensory analysis (p < 0.05). Our further analysis using an omission test indicated nine components including Glu, Gly, AMP, IMP, GMP, K+, Na+, Cl- and PO43- are the key umami-related components with a proportion of 1 : 5 : 40 for amino acids, nucleotides and inorganic ions, respectively. Our results indicated that a simplified synthetic extract can replicate the umami taste of Yangtze Coilia ectenes flesh which provides solid evidence for the preparation of new flavor enhancers in the future.