Evaluation of the synergism among volatile compounds in Oolong tea infusion by odour threshold with sensory analysis and E-nose

• Published in: Food chemistry Vol. 221; pp. 1484 - 1490
• Main Authors: Zhu, JianCai, Chen, Feng, Wang, LingYing, Niu, YunWei, Xiao, ZuoBing
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 15.04.2017
• Subjects: Camellia sinensis - chemistry; Drug Synergism; Electronic Nose - utilization; Odour threshold; Oolong tea infusions; Smell; Synergism; Tea - chemistry; Volatile compound; Volatile Organic Compounds - chemistry; Volatile compound; Odour threshold; Synergism; Oolong tea infusions
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2016.11.002

•The interactions exist among sub-threshold aroma compounds in Oolong tea.•The sub-threshold aroma compounds can significantly affect the aroma of a mixture.•E-nose is employed to discriminate the variation aroma of Oolong tea. Twenty-four kinds of representative aroma compounds in Oolong tea were selected to evaluate the interactions by the variation in the threshold values of these compounds before, and after, they were mixed. Result demonstrated that the ratios of the referenced threshold values of heptanal, β-damascenone, and methional to their determined thresholds were larger, namely, 5, 3.85, and 2.5, respectively. On the other hand, the mixed compounds with similar structure and aroma mainly presented a synergistic effect and additive action. Moreover, a masking effect was found among compounds with different structures. (E)-2-hexenal was added to tea infusion at a concentration below its threshold level to investigate whether, or not, the sub-threshold compounds affected the overall odour sensation of Oolong tea by sensory analysis and electronic nose (E-nose). The result indicated that the aroma of the tea infusion with added (E)-2-hexenal had changed before, and after, they were mixed.