Abstract

Flavour compounds in fermented garlic were identified by physicochemical analysis and gas chromatography (GC) after pre-treatment. Reducing sugars, acids, polyphenols and 5-hydroxymethyl furfural (5-HMF) were detected in fermented garlic, and 5-HMF was identified to be the key aroma compounds. To further improve the flavour quality of fermented garlic, the influence of pre-treatment method, fermentation temperature and fermentation humidity on the 5-HMF formation was studied, and then single factor tests and response surface methods were employed to optimize the fermentation process. The results showed that the best flavour was obtained when the pre-treatment was done by low temperature freezing, the fermentation temperature was 61.8°C and the humidity was 40.2%. Under the optimum condition, the content of 5-HMF reached 3.6 mg/g with a high quality score of 19.

Key words: Flavour enhancement, 5-hydroxymethyl furfural (5-HMF), response surface methodology (RSM).