荔枝新品种‘离娘香’与三个常规品种果实香气物质差异比较

Comparison of the Difference in Fruit Aroma Compounds between the New Lychee Cultivar ‘Liniangxiang’ and Three Common Cultivars

摘要:

为明确荔枝新品种香气成分特点，该研究以‘离娘香’和代表性品种‘桂味’、‘糯米糍’和‘凤山红灯笼’等为试验材料，采用顶空固相微萃取（Headspace Solid-Phase Microextraction, HS-SPEM）结合气相色谱-质谱联用（Gas Chromatography Mass Spectrometry, GC-MS）进行检测，通过正交偏最小二乘法判别分析（Orthogonal Partial Least Squares Discrimination Analysis, OPLS-DA）建立模型，并基于变量投影重要性分析值（Variable Importance in Projection, VIP）、差异倍数值（Fold Change, FC）结合香气活力值（Odor Activity Value, OAV）共同筛选‘离娘香’与其他3个品种的特征香气物质。结果显示，共检出16类645种挥发性物质，以萜类化合物为主；通过VIP和FC值筛选出391种差异挥发性物质；进一步结合OAV＞1筛选出41种差异特征香气物质，聚类热图分析显示这41种差异特征香气物质分为4个差异区域，其中区域I的甲酸-3-巯基-3-甲基丁酯、反式-2-壬醛、反,顺-2,6-壬二烯醛、δ-杜松烯和对甲酚等18种特征香气挥发性物质能够将‘离娘香’和其他3个品种有效区分，可能是‘离娘香’呈现独特风味的重要原因。通过该研究能为荔枝新品种的推广和利用提供参考。

Abstract:

To characterize the aroma compounds of the new lychee cultivar, headspace solid-phase microextraction (HS-SPEM) combined with gas chromatography-mass spectrometry (GC-MS) technology was used to analyze the fruit aromas of ‘Liniangxiang’ and the common cultivars ‘Guiwei’, ‘Nuomici’, and ‘Fengshanhongdenglong’. Discriminant models were established using orthogonal partial least squares discrimination analysis (OPLS-DA). Characteristic aroma compounds of ‘Liniangxiang’ were identified based on their variable importance in projection (VIP), fold change (FC), and odor activity value (OAV) values. The results showed that a total of 645 aroma compounds belonging to 16 chemical classes were detected in the four varieties, with terpenes identified as the predominant compounds. 391 distinct volatile compounds were identified using VIP and FC values. Further screening based on OAV>1 revealed 41 characteristic aroma compounds. Cluster heat map analysis indicated that these 41 compounds could be categorized into 4 distinct regions. Among them, region I contained 18 characteristic aroma volatile compounds such as 3-mercapto-3-methylbutyl formate ester, trans-2-nonanal, trans-2,cis-6-nonadienal, δ-cadinene, and p-cresol, which effectively distinguished ‘Liniangxiang’ from the other three varieties. This distinction may contribute significantly to the unique flavor of ‘Liniangxiang’. This study provides valuable references for promoting and utilizing the new lychee variety.