Yu Xiangying, Chen Xiaochun, Li Yuting, Li Lin
Engineering Research Center of Health Food Design & Nutrition Regulation, School of Life and Health Technology, Dongguan University of Technology, Dongguan 523808, China.
Foods. 2022 Sep 1;11(17):2662. doi: 10.3390/foods11172662.
To reflect the volatile differences of dried citrus peel as affected by cultivars and drying methods, the volatile compounds of dried citrus peel of two cultivars ( "Chachi" and "Ponkan"), prepared under three drying methods (sun-drying (SD), hot-air-drying (AD), and freeze-drying (FD)), were analyzed by GC-MS, odor activity values (OAVs), and GC-IMS. GC-MS data indicated that SD was favorable to preserve terpenic alcohols (linalool, α-terpineol and terpinene-4-ol), β-cymene, methyl methanthranilate, and monoterpenes; while AD was favorable to preserve aliphatic aldehydes and sesquiterpenes; and SD was more similar with AD in GC-MS analysis of volatile profile (of higher MW) for both cultivars from the PCA outcome. Furthermore, significant difference in volatile isomeric composition of different samples was also clearly demonstrated through extracted ion chromatogram (EIC) by GC-MS analysis. GC-IMS analysis showed the favorability of FD to preserve ketones, phenols, esters, and aromatic aldehydes; and SD was more similar with FD in GC-IMS analysis of volatile profile (of smaller MW) for both cultivars from the PCA outcome. Moreover, the OAVs indicate that 2-methoxy-4-vinylphenol contributed much to the flavor of dried Ponkan peel, while 2-methoxy-4-vinylphenol, methyl methanthranilate, and methyl anthranilate played an important role in the flavor of dried Chachi peel; and the highest OAVs for monoterpenes were observed at SD for both cultivars. Thus, the combination of GC-MS and GC-IMS analyses with PCA in this paper suggested the superiority of SD to preserve volatiles and characteristic aroma in dried citrus peel, and that SD contributed much to the quality of dried Chachi peel.
为反映不同品种和干燥方法对陈皮挥发性成分差异的影响，采用气相色谱 - 质谱联用仪（GC-MS）、气味活性值（OAVs）和气相色谱 - 离子迁移谱（GC-IMS）对两个品种（“茶枝柑”和“椪柑”）在三种干燥方法（晒干（SD）、热风干燥（AD）和冷冻干燥（FD））下制备的陈皮挥发性成分进行了分析。GC-MS数据表明，晒干有利于保留萜烯醇（芳樟醇、α-松油醇和萜品烯 - 4 - 醇）、β- 对异丙基甲苯（β- 伞花烃）、邻氨基苯甲酸甲酯和单萜类化合物；而热风干燥有利于保留脂肪醛和倍半萜类化合物；从主成分分析（PCA）结果来看，在两个品种较高分子量挥发性成分的GC-MS分析中，晒干与热风干燥更为相似。此外，通过GC-MS分析的提取离子色谱图（EIC）也清楚地表明了不同样品挥发性异构体组成的显著差异。GC-IMS分析表明，冷冻干燥有利于保留酮类、酚类、酯类和芳香醛类化合物；从PCA结果来看，在两个品种较低分子量挥发性成分的GC-IMS分析中，晒干与冷冻干燥更为相似。此外，气味活性值表明，2 - 甲氧基 - 4 - 乙烯基苯酚对椪柑干皮的风味贡献较大，而2 - 甲氧基 - 4 - 乙烯基苯酚、邻氨基苯甲酸甲酯和甲基邻氨基苯甲酸对茶枝柑干皮的风味起重要作用；两个品种的单萜类化合物在晒干条件下气味活性值最高。因此，本文中GC-MS和GC-IMS分析与PCA的结合表明，晒干在保留陈皮挥发性成分和特征香气方面具有优势，且晒干对茶枝柑干皮的品质贡献较大。
