Abstract:
The dominant volatile off-flavor compounds of pea and soy milk were investigated by gas chromatography-olfactometry-mass spectrometry (GC-O-MS), sensory evaluation, and odor-activity values (OAVs), which led to the identification of their differences. We identified 11 aroma compounds as important odorants with OAVs greater than 1 in pea and soy milk. OAVs contribution rate demonstrated that 6 compounds contributed most to the characteristic off-flavor of pea milk, among which 2-methoxy-3-isopropyl-(5 or 6)-methyl pyrazine, hexanal, (E,E)-2,4-nonadienal, and (E,E)-2,4-decadienal contributed more than others. For soy milk, 1-octen-3-one, hexanal, (E,E)-2,4-nonadienal, and (E,E)-2,4-decadienal showed more important contributions. These odor-active compounds were divided into non-lipoxygenase (non-LOX) and LOX pathways based on their synthesis. Several endogenous enzymes that are important to the LOX pathway were identified by liquid chromatography tandem mass spectrometry (LC-MS/MS), and the contents of key off-flavor compounds were found to be related to the enzyme activities, while the lipid content was not an important factor.
摘要:
通过气相色谱-嗅觉-质谱(GC-O-MS)研究了豌豆和豆浆的主要挥发性异味化合物,感官评价,和气味活性值(OAV),这导致了他们差异的识别。我们确定了11种香气化合物是重要的气味剂,在豌豆和豆浆中OAVs大于1。OAVs贡献率表明,6种化合物对豌豆乳的特征异味贡献最大,其中2-甲氧基-3-异丙基-(5或6)-甲基吡嗪,己醛,(E,E)-2,4-壬烯,和(E,E)-2,4-decadienal比其他人贡献更多。对于豆浆,1-octen-3-1,己醛,(E,E)-2,4-壬烯,和(E,E)-2,4-decadienal显示出更重要的贡献。这些气味活性化合物根据其合成分为非脂加氧酶(非LOX)和LOX途径。通过液相色谱串联质谱(LC-MS/MS)鉴定了对LOX途径重要的几种内源性酶,发现关键异味化合物的含量与酶活性有关,而脂质含量不是一个重要因素。