Identification of major odorants in shrimp stock-based tom yum kung and potential of shrimp stock on saltiness enhancement to tom yum kung

The World Health Organization (WHO) has set a global target to reduce population sodium intake by 30% by 2030. Tom Yum Kung (TYK), a traditional Thai prawn soup, is commonly prepared using shrimp stock (SS) instead of plain water to enhance aroma and taste. This work aimed to 1) study the effect of SS on saltiness intensity of TYK and 2) identify the major odour-active compounds in SS and shrimp stock-based Tom Yum Kung (SS-TYK) using solvent-assisted flavour evaporation (SAFE), aroma extract dilution analysis (AEDA), gas chromatography-olfactometry/FID (GC-O/FID) and gas chromatography triple quadrupole mass spectrometry (GC-MS/MS). Sensory test showed that TYK prepared from SS was saltier than those prepared from water. The major odour-active compounds with high flavour dilution factor (FD) of both SS and SS-TYK were 3-(methylthio)propanal and 4-hydroxy-3-methoxybenzaldehyde. For SS, many compounds contributed mainly to musty and fishy notes such as 3-(methylthio)propanal, 1-octen-3-one, 4-hydroxy-2,5-dimethyl-3(2H)-furanone, and (E,E)-2,4-decadienal that were previously reported as odour-induced saltiness enhancement (OISE). For SS-TYK, there were many compounds that contributed herb odours of herbal ingredients such as sotolon and geranial. This work provided evidence of odour-induced taste enhancer in SS and its potential use as a sodium reduction ingredient in savoury foods.