Yang Xiao, Yang Fan, Liu Ye, Li Jian, Song Huan-Lu
Beijing Engineering and Technology Research Center of Food Additives, School of Food and Health, Beijing Technology and Business University, No. 11, Fucheng Road, Haidian District, Beijing 100048, China.
Foods. 2020 Feb 20;9(2):227. doi: 10.3390/foods9020227.
Thermally treated watermelon juice (TW) presents a strong unpleasant smell, resulting in poor consumer acceptance. It is necessary to identify the key off-flavor compounds in TW. Solid-phase microextraction (SPME) and solvent-assisted flavor evaporation (SAFE) coupled with gas chromatography-olfactometry-mass spectrometry (GC-O-MS) were applied to the extraction and analysis of the volatile compounds in TW. Five aroma-active compounds and seven off-flavor compounds were quantitatively analyzed by the standard curve method. Based on the flavor dilution factor (FD), odor attribute, odor activity value (OAV) of volatile compounds, and partial least-squares regression (PLSR) analysis, seven key off-flavor compounds were preliminarily identified as follows: (E)-2-heptenal, decanal, octanol, diisopropyl disulfide, hexanol, (E)-2-decenal, and (E)-2-octenol. Aroma recombination proved that these off-flavor compounds above had a negative impact on the overall flavor in TW. Omission experiments were taken to confirm them further. Finally, octanol, diisopropyl disulfide, and (E)-2-decenal were identified as the most potent off-flavor compounds in TW.
热处理西瓜汁（TW）呈现出强烈的难闻气味，导致消费者接受度较低。有必要鉴定TW中的关键异味化合物。采用固相微萃取（SPME）和溶剂辅助风味蒸发（SAFE）结合气相色谱-嗅觉-质谱联用（GC-O-MS）技术对TW中的挥发性化合物进行提取和分析。采用标准曲线法对5种香气活性化合物和7种异味化合物进行了定量分析。基于风味稀释因子（FD）、挥发性化合物的气味属性、气味活性值（OAV）以及偏最小二乘回归（PLSR）分析，初步鉴定出7种关键异味化合物如下：（E）-2-庚烯醛、癸醛、辛醇、二异丙基二硫醚、己醇、（E）-2-癸烯醛和（E）-2-辛烯醇。香气重组证明上述异味化合物对TW的整体风味有负面影响。进行了省略实验以进一步证实它们。最后，辛醇、二异丙基二硫醚和（E）-2-癸烯醛被鉴定为TW中最主要的异味化合物。
