Department of Food Science , University of Minnesota , St. Paul , Minnesota 55108 , United States.
MNMR Center , University of Minnesota , Minneapolis , Minnesota 55455 , United States.
J Agric Food Chem. 2018 Mar 14;66(10):2473-2479. doi: 10.1021/acs.jafc.7b00093. Epub 2017 Jun 6.
In this study, highly predictive LC-MS features (retention time_ m/ z) derived from untargeted chemical fingerprinting-multivariate analysis (MVA) previously used to model flavor changes in citrus fruits related to aging (freshness) were further isolated and analyzed for sensory impact, followed by structural elucidation. The top 10 statistical features from two MVA approaches, partial least-squares data analysis (PLS-DA) and Random Forrest (RF), were purified to approximately 70% via multidimensional liquid chromatography-mass-directed fractionation to screen for sensory activity. When added to a 'fresh' orange flavor model system, 50-60% of the isolates were reported to cause a sensory change. From the subset of the actives identified, two compounds were selected, on the basis of statistical relevance, that were further purified to >97% for identification (MS, NMR) and for sensory descriptive analysis (DA). The compounds were identified as nomilin glucoside and a novel ionone glucoside. DA evaluation in the recombination orange model indicated both compounds statistically suppressed the perceived intensity of the "orange character" attribute, whereas the novel ionone glycoside also decreased the intensity of the floral character while increasing the green bean attribute intensity.
在这项研究中,先前用于模拟与老化(新鲜度)相关的柑橘类水果风味变化的非靶向化学指纹图谱-多变量分析(MVA)得出的高度可预测的 LC-MS 特征(保留时间_ m/z)被进一步分离和分析以评估其感官影响,随后进行结构解析。通过多维液相色谱-质量导向馏分收集对两种 MVA 方法(偏最小二乘数据分析(PLS-DA)和随机森林(RF))的前 10 个统计特征进行纯化,纯度约为 70%,以筛选出具有感官活性的化合物。当添加到“新鲜”橙汁风味模型系统中时,据报道,约 50-60%的分离物会引起感官变化。在所鉴定的活性物质中,根据统计相关性选择了两种化合物,进一步将其纯化至 >97%,以进行鉴定(MS、NMR)和感官描述性分析(DA)。这两种化合物被鉴定为诺米林糖苷和一种新型香叶基糖苷。在重组橙汁模型中的 DA 评估表明,这两种化合物均能显著抑制“橙子特征”属性的感知强度,而新型香叶基糖苷还降低了花香特征的强度,同时增加了绿豆特征的强度。