为了研究玉米储藏期间气味变化情况，采用优化的顶空固相微萃取-气质联用法（HS-SPME-GC-MS）分析玉米在常温（25 ℃）密闭储藏过程中的主要挥发性成分组成。检出的物质主要包括烃类、醛类、酯类、醇类、酮类、酸类和少量杂类物质。结果表明，在储藏过程中烃类物质总相对含量在储藏末期比储藏初期有所增加。酸类物质相对含量呈缓慢上升但含量较低。酮类物质相对含量较低且呈逐渐降低趋势。醇类挥发性成分在储藏120 d前呈现增加趋势，在120 d后有所降低。醛类和酯类物质相对含量呈现先升高后降低，二者相对含量较高，储藏180 d后的相对含量接近于0 d，是玉米风味的主要贡献物质。而烃类和醇类风味阈值较高，不是玉米储藏期间风味的主要贡献物质。25 ℃下密闭储藏180 d后的玉米其气味与储藏0 d的玉米相比，并未发生人嗅觉可感知的明显异味变化。

Optimized headspace solid-phase microextraction combined with gas chromatography-mass spectrometry (HS-SPME-GC-MS) was used to analyze changes in relative content of volatile components in maize during airtight storage at 25 ℃. The major components identified could be categorized into seven groups: alkanes, aldehydes, esters, alcohols, ketones, acids, and small amounts of other compounds. The results showed that relative content of alkanes increased; while that of acids remained at a low level, in spite of a slow increase; whereas ketones decreased slowly and remained at a low level. The relative content of alcohol, aldehydes, and esters increased during the initial 120 d storage, and then decreased. As primary contributors to the volatile components of maize during storage, the total relative content of aldehydes and esters at 180 d approximated that at 0 d. Alkanes and alcohols were not considered to be major contributors due to their high odor thresholds. After airtight-storage at 25 ℃ for 180 d, no significant off-flavors were detected as compared to that at 0 d, probably due to the moderate storage conditions.

国家高技术研究发展计划（863计划）项目（2012AA101705-2）