8个杧果品种胶乳挥发性成分及胶乳的灼伤机制初探

以‘台农1号’‘贵妃’‘金煌’‘玉文’‘红象牙’‘四季蜜杧’‘金穗’和‘红杉林’8个杧果品种的胶乳为材料,利用气相色谱–质谱联用技术对其挥发性成分进行测定,用NIST 11标准谱库对测定的质谱数据进行自动检索对照,保留匹配度大于90%的化合物,并对不同杧果品种的胶乳挥发性成分进行差异性分析,旨在为确定杧果胶乳中灼伤果皮的主要挥发性成分提供科学参考,并采用超景深三维显微镜观察果皮灼伤前后变化,为初步探索胶乳灼伤果皮机制提供参考。结果表明：（1）8个杧果品种共鉴定出30种匹配度大于90%的化合物,这些化合物分为萜烯类、酚类、醛类和烷烃类。其中,萜烯类是主要挥发性成分,酚类、醛类和烷烃类占比极少。8个杧果品种胶乳中共有的化合物有α-蒎烯、3-蒈烯、α-水芹烯、4-蒈烯、(R)-(+)-柠檬烯、桧烯、(1R)-(+)-α-蒎烯、萜品油烯、L-石竹烯和2,4-二叔丁基苯酚共10种。其中,3-蒈烯和萜品油烯为8个杧果品种胶乳的主要挥发性成分。（2）根据8个杧果品种胶乳中各挥发性成分的相对含量为数据源进行主成分分析将其分为5类：第一类为‘贵妃’和‘金煌’,第二类为‘台农1号’和‘四季蜜杧’,第三类为‘红象牙’和‘金穗’,第四类为‘玉文’,第五类为‘红杉林’。同一类别杧果品种其胶乳的主要挥发性成分及相对含量相似,不同类别杧果品种其胶乳的主要挥发性成分及相对含量差异较大。（3）杧果胶乳导致果皮皮孔褐变损伤,‘台农1号’接触胶乳的1 h后发生轻微灼伤,贵妃接触胶乳10 min时明显灼伤。研究结果明确了8个杧果品种乳胶中挥发性成分及其在不同品种中相对含量的差异,为揭示不同杧果品种胶乳灼伤果皮机制提供了基础。

Volatile Components of Latex from Eight Mango Cultivars and Mechanism of Latex

In order to provide scientific references for the identification of main volatile components of mango latex, the latex from eight mango cultivars, including ‘Tainoung No.1’, ‘Guifei’, ‘Chun Hwang’, ‘Yuwen’, ‘Red Ivory’, ‘Sijimi mango’, ‘Jinsui’ and ‘Hongshanlin’, were determined by the GC-MS method. The compounds with matching degree more than 90% were reserved according to NIST 11 standard mass spectrometry library and analyzed the differences among latex from different mango cultivars. The changes before and after peel burned were observed under a VHX-5000 Super-high magnification lens zoom 3D microscope, which provided a reference for preliminary exploration of the mechanism of latex. Thirty kinds of compounds with a matching degree greater than 90% were detected from the cultivars. The compounds were composed of terpenes, phenols, aldehydes and alkanes. The main volatile components were terpenes, and there were a small amount of phenols, aldehydes and alkanes. Ten common compounds were detected in the latex from the cultivars, including α-pinene, 3-carene, α-phellandrene, 4-carene, (R)-(+)-limonene, sabinene, (1R)-(+)-α-pinene, terpinolene, L-caryophyllene and 2,4-Di-tert-butylphenol, among which the main volatile components were 3-carene and terpinolene. The latex from different mango cultivars were clustered into different groups according to the PCA score map. Based on the distance among the cultivars, they were classified into five groups. The first group included ‘Guifei’ and ‘Chun Hwang’, the second group included ‘Tainoung No.1’ and ‘Sijimi mango’, the third group included ‘Red Ivory’ and ‘Jinsui’, the fourth group was ‘Yuwen’, and the fifth group was ‘Hongshanlin’. The distance between two mango cultivars in the same group was small, which indicated the great similarity between them. The distance was large in different groups, which indicated that the main volatile components and relative content were quite different. Mango latex caused browning damage in the lenticels of fruit skin. ‘Tainoung No.1’ had slight burn after contacting with the latex for 1 hour, and ‘Guifei’ had obvious burn after contacting with the latex for 10 min. This study would provide a theoretical basis for revealing the mechanism of latex.