Zhang Li, Mi Si, Liu Ruo-Bing, Sang Ya-Xin, Wang Xiang-Hong
Department of Food Science and Technology, Hebei Agricultural University, Baoding 07001, China.
Int J Anal Chem. 2020 Jul 13;2020:3242854. doi: 10.1155/2020/3242854. eCollection 2020.
The volatile composition of yogurt produced by fermentation at different time points was investigated by gas chromatography-mass spectrometry combined with simultaneous distillation and extraction. A total of 53 volatile compounds including 11 aldehydes, 10 ketones, 8 acids, 7 benzene derivatives, 13 hydrocarbons, and 4 other compounds were identified in all of the samples. Ketones and hydrocarbons were the predominant volatile components in the early stage, whereas acids were the predominant volatiles in the late stage. The importance of each volatile was evaluated based on odor, threshold, and odor activity values (OAVs). Twenty-nine volatiles were found to be odor-active compounds (OAV > 1), among which (E, E)-2,4-decadienal had the highest OAV (14623-22278). Other aldehydes and ketones such as octanal, dodecanal, 2-nonen-4-one, and 2-undecanone also showed high odor intensity during fermentation. Heat map analysis was employed to evaluate the differences during fermentation. The results demonstrated that the volatile profile based on the content and OAVs of volatile compounds enables the good differentiation of yogurt during fermentation.
采用气相色谱 - 质谱联用结合同时蒸馏萃取法，研究了不同时间点发酵生产的酸奶的挥发性成分。在所有样品中，共鉴定出53种挥发性化合物，包括11种醛类、10种酮类、8种酸类、7种苯衍生物、13种烃类和4种其他化合物。酮类和烃类是早期的主要挥发性成分，而酸类是后期的主要挥发性成分。根据气味、阈值和气味活性值（OAV）评估了每种挥发性物质的重要性。发现29种挥发性物质为气味活性化合物（OAV > 1），其中（E, E）-2,4-癸二烯醛的OAV最高（14623 - 22278）。其他醛类和酮类，如辛醛、十二醛、2-壬烯-4-酮和2-十一酮在发酵过程中也表现出较高的气味强度。采用热图分析来评估发酵过程中的差异。结果表明，基于挥发性化合物含量和OAVs的挥发性成分图谱能够很好地区分发酵过程中的酸奶。
