Department of Food Science and Technology, 317 Parker Food Science & Technology Building, The Ohio State University, 2015 Fyffe Rd., Columbus, OH 43210, United States.
Department of Food Science and Technology, 317 Parker Food Science & Technology Building, The Ohio State University, 2015 Fyffe Rd., Columbus, OH 43210, United States.
Food Chem. 2019 Dec 15;301:125250. doi: 10.1016/j.foodchem.2019.125250. Epub 2019 Jul 24.
Untargeted LC/MS flavoromic profiling was utilized to identify compounds that positively impact coffee quality. The chemical profiles of eighteen coffee samples and the corresponding Specialty Coffee Association (SCA) cup scores were modeled by orthogonal partial least squares (OPLS) analysis with good fit and predictive ability (RY > 0.9, Q > 0.9). Four highly predictive chemical compounds positively correlated to cup score were subsequently isolated and purified (>90%) by multi-dimensional preparative LC/MS fractionation. Sensory recombination analysis by certified SCA Q-graders (n = 5) confirmed three out of four compounds significantly increased cup score when added to a control coffee (p < 0.001). Based on accurate mass spectrometry and NMR experiments, the compound structures were identified as novel compounds 3-O-caffeoyl-4-O-3-methylbutanoylquinic acid, and the corresponding lactone 3-O-caffeoyl-4-O-3-methylbutanoyl-1,5-quinide, as well as an unknown phenolic derivative containing a 3-methylbutanoyl moiety ([M-H], m/z 671). No direct flavor activity was observed for each compound, indicating these compounds act as flavor-modifiers.
采用非靶向 LC/MS 风味组学分析方法来鉴定能够改善咖啡品质的化合物。通过正交偏最小二乘法（OPLS）分析对 18 个咖啡样本的化学特征和相应的特种咖啡协会（SCA）杯测评分进行建模，该模型拟合度和预测能力良好（RY>0.9，Q>0.9）。随后，通过多维制备 LC/MS 分级分离，从模型中分离和纯化出与杯测评分呈正相关的 4 种高预测性化学物质（>90%）。经过 SCA 认证 Q 级品鉴师的感官重组分析（n=5），当将这 4 种化合物中的 3 种添加到对照咖啡中时，有 3 种化合物显著提高了杯测评分（p<0.001）。根据精确质谱和 NMR 实验，确定了这 4 种化合物的结构分别为新型的 3-O-咖啡酰-4-O-3-甲基丁酰奎宁酸及其相应的内酯 3-O-咖啡酰-4-O-3-甲基丁酰-1,5-喹宁，以及一种含有 3-甲基丁酰基部分的未知酚类衍生物([M-H]，m/z 671)。每种化合物均未表现出直接的风味活性，表明这些化合物起到了风味修饰剂的作用。
