Abstract: The characteristic taste compounds of traditional non-fermented and fermented milk cakes were clarified by analyzing free amino acids and free fatty acids using an amino acid analyzer and gas chromatography (GC), respectively as well as calculating taste intensity value (TAV). Furthermore, sensory evaluation was conducted, and the correlation between characteristic taste substances and sensory attributes was analyzed. The results showed that the TAVs of glutamic acid, histidine and kunic acid, lauric acid, myristic acid, oleic acid and linoleic acid in milk cakes were greater than 1, indicating their important contribution to the taste of milk cakes. Significant variation in sensory attributes and taste compounds was found between the two milk cakes. The overall taste intensity of fermented milk cakes was higher than that of traditional yogurt cakes (P < 0.05), and the sensory attributes mainly included sourness, sweetness, bitterness and umami taste. However, traditional milk cakes had an unpleasant odor. Correlation analysis between characteristic taste compounds and sensory attributes using partial least squares (PLS) regression indicated a high correlation between sensory attributes and free amino acids. The saltiness of traditional milk cakes was significantly positively correlated with arginine, and the unpleasant odor was significantly positively correlated with glycine, decanoic acid and palmitoleic acid. Similarly, there was a significant positive correlation between the sourness of fermented milk cakes and stearic acid and linoleic acid, between the sweetness and aspartic acid, threonine, serine, glutamic acid, alanine and linoleic acid, between the bitterness and valine, methionine, isoleucine, amino acid, tyrosine and myristic acid, and between the umaminess and aspartic acid, glutamic acid and alanine (P < 0.05). In conclusion, fermentation improves the taste of milk cakes by promoting the decomposition of protein and fat.

Key words: traditional sour milk cake; fermented milk cake; taste compounds; sensory evaluation; partial least squares