Investigation of Koku impact compounds in sweet cream on the basis of sensory evaluation and separation techniques

Abstract

The thick and deep tastes of dairy products such as sweet cream and cheese are important factors, and they are expressed by the word Koku in Japan. To identify compounds that have an impact on Koku, sweet cream was fractionated using solvent-assisted flavor evaporation, solvent extraction, and chromatography and the resulting fractions were screened by performing sensory evaluation at each step. The Koku-containing fractions selected by sensory evaluation were analyzed by gas chromatography-mass spectroscopy, and 7 long-chain fatty acids (decanoic acid, dodecanoic acid, tetradecanoic acid, hexadecanoic acid, octadecanoic acid, oleic acid, and linoleic acid), 3 long-chain aliphatic delta-lactones (5-dodecanolide, 5-tetradecanolide, and 5-hexadecanolide), and cholesterol were identified as main components. Reconstitution experiments performed with these 11 compounds revealed that the long-chain fatty acids and long-chain aliphatic delta-lactones contribute to the Koku of sweet cream.