Liu Bing-Bing, Wu Hai-Long, Chen Yue, Wang Tong, Yu Ru-Qin
State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, 410082, People's Republic China.
Anal Methods. 2023 Jan 26;15(4):502-511. doi: 10.1039/d2ay01767a.
As a common fruit juice, grape juice is delicious and nutritious, making it very popular among consumers. However, some illegal manufacturers used shoddy products to lower costs and obtain high profits, which seriously threatens the health and interests of consumers. Hence, this paper proposed excitation-emission matrix (EEM) fluorescence spectroscopy combined with chemometric methods for the rapid identification and classification of commercial grape juices. Spectral characterization of different samples was achieved using the alternating trilinear decomposition (ATLD) algorithm, and chemically meaningful information was obtained and analyzed. Although both reconstituted and sweetened grape juices contain methyl anthranilate (MA) and 2'-aminoacetophenone (-AAP), the content of MA in sweetened grape juice far exceeds that in reconstituted grape juice, and the MA in sweetened grape juice mainly comes from artificially added grape essence. Then two chemometric methods of hierarchical cluster analysis (HCA) and partial least squares discriminant analysis (PLS-DA) were used for the classification of reconstituted and sweetened grape juices. The results showed that the supervised classification model had a higher correct classification rate (CCR) than the unsupervised classification model, with PLS-DA obtaining 100% CCRs in both training and prediction sets. Therefore, the proposed strategy can be used as a powerful analytical method for the identification and classification of reconstituted and sweetened grape juices and provides a reliable scientific means for ensuring the authenticity and safety of the juice market.
作为一种常见的果汁，葡萄汁美味且营养丰富，在消费者中非常受欢迎。然而，一些不法制造商使用劣质产品来降低成本并获取高额利润，这严重威胁到消费者的健康和利益。因此，本文提出了激发-发射矩阵（EEM）荧光光谱法结合化学计量学方法用于市售葡萄汁的快速鉴别和分类。使用交替三线性分解（ATLD）算法实现了不同样品的光谱表征，并获取和分析了具有化学意义的信息。虽然复原葡萄汁和加糖葡萄汁都含有邻氨基苯甲酸甲酯（MA）和2'-氨基苯乙酮（-AAP），但加糖葡萄汁中MA的含量远超过复原葡萄汁中的含量，且加糖葡萄汁中的MA主要来自人工添加的葡萄香精。然后使用层次聚类分析（HCA）和偏最小二乘判别分析（PLS-DA）这两种化学计量学方法对复原葡萄汁和加糖葡萄汁进行分类。结果表明，监督分类模型的正确分类率（CCR）高于无监督分类模型，PLS-DA在训练集和预测集中的CCR均达到100%。因此，所提出的策略可作为一种强大的分析方法用于复原葡萄汁和加糖葡萄汁的鉴别和分类，并为确保果汁市场的真实性和安全性提供可靠的科学手段。
