顶空固相微萃取-气相色谱-质谱联用法分析 欧李果实挥发性成分

【目的】 优化前处理影响因素,分析欧李果实挥发性成分,明确挥发性成分特点并对果实特征性香气成分进行评价。【方法】 以欧李果实为试材,采用顶空固相微萃取-气相色谱-质谱联用法（HS-SPME-GC-MS）测定其挥发物成分,通过优化前处理影响因素,确定最佳试验条件。利用解卷积系统（AMDIS）与NIST11质谱数据库以及保留指数（RI）对其挥发性成分进行鉴定,内标法确定挥发物含量,并计算香气强度值（OAVs）,评价欧李果实香气品质与特征。【结果】 在欧李果实中累计鉴定出63种挥发物,含量范围为0.01—3.25 μg·kg ^-1。挥发物以酯类、烷类为主,并有少数醇类、芳香类、醛类、萜类、酸类、酮类,其中苯甲酸乙酯含量最高。通过参考相关挥发物香气阈值并计算部分挥发物OAVs可知,己酸乙酯、乙酸苯乙酯、β-芳樟醇、乙酸己酯、壬醛等物质对欧李果实香气成分构成具有重要作用,而烷烃不具有特征性香气。欧李果实香气主要为青香、花香、果香、脂蜡香和其他少数香型（木香型、芳香油香型等）,并以青香、花香、果香型物质为主,三者总含量达到挥发物总量的80%。【结论】 优化确立的试验条件为：果肉去核切碎处理,取样量5 g,萃取温度50℃,萃取时间与平衡时间均为30 min。SPME前处理条件对果实挥发性成分检测到的种类与含量有较大影响,通过优化试验条件可以获得最佳检测结果。欧李果实挥发物组成复杂,除烃类物质香气品质较弱外,多数具有特征香气,且香气强度属中高级,酯类物质是欧李果实的重要挥发物组成,清香型、花香型和果香型是欧李果实香气成分的主要特点。

Analysis of Volatile Components in Cerasus Humilis (Bge.) Sok by Headspace Solid Phase Microextraction-Gas Chromatography-Mass Spectrometry

【Objective】 The objective of this study was to optimize the pretreatment conditions and to analyze the volatiles of Cerasus Humilis (Bge.) Sok, further to evaluate the characteristics of the main aroma components.【Method】 The fruit of Cerasus humilis (Bge.) Sok was used as material, the volatiles were determined by headspace solid phase microextraction coupled with gas chromatography-mass spectrometry (HS-SPME-GC-MS), and the pretreatment conditions were optimized. Automatic Mass Spectral Deconvolution and Identification System (AMDIS), NIST11 database and retention index (RI) were applied to volatiles identify, internal standard to contents calculate, final the odor-activity values (OAVs) and aroma qualities were evaluated.【Result】 Total of 63 volatiles were identified, namely main of esters and alkanes, few of alcohols, arenes, aldehydes, terpenes, acid and ketone, with ranges from 0.01 to 3.25 μg·kg ^-1, in which ethyl benzoate as the highest. The OAVs showed ethyl hexanoate, phenethyl acetate, β-linalool, hexyl acetate, and nonanal were the main aroma components, alkanes almost the odorless. Green, fruity, floral, waxy and less woody and oily aromatic formed the odor qualities, while the former three performed the main odors reached 80% content. 【Conclusion】 The conditions were optimized as follows: samples loading for 5 g after cored and chipping, extraction temperature was 50℃, and both extraction and balance time was 30 min. The pretreatment had great influence on the volatiles detection, and preferable results would be yield by optimizing conditions. Results showed esters were the main components, except alkanes, and the most of them had aroma characteristics, presented medium or high strength, while green, fruity, floral were the major odor types.