该研究以脱皮后湿咖啡豆为原料，用不同类型酿酒酵母CMCC 1793、CMCC 1425、CMCC 1557、CMCC 32762、四种混合菌与未接种处理对半干法加工的咖啡样品进行处理，经过干燥、脱壳、烘焙得到中度烘焙豆，样品编号分别为GK、HK、JK、ZK、MK、CK。采用顶空固相微萃取气相色谱/质谱联用（HS-SPME/GC-MS）、香气活度值（OAV）、感官评价及理化特性对样品进行评价。结果表明：不同酿酒酵母所接种的烘焙豆中挥发性物质存在差异，共鉴定出81种挥发性化合物。其中CK 49种、GK 52种、HK 50种、JK 52种、MK 58种和ZK 46种，含量分别为301.03、286.31、223.15、333.05、262.22、372.51 μg/g。其中吡嗪类化合物在JK样中含量最高达到122.99 μg/g，酮类化合物在JK样中总含量居于第二位，含量达到53.02 μg/g。OAV分析表明，OAV值不小于1的物质有12种，其中以3-乙基-2,5-二甲基吡嗪、2,6-二甲基吡嗪、2-乙酰基吡咯、2,5-二甲基吡嗪在JK样中OAV值较高，这些化合物对咖啡香气体系的贡献作用较大。感官评价分析表明，接种酿酒酵母所得咖啡样品杯品得分整体上均高于未接种样品，JK余韵、均衡感得分均高于其它。综上所述，CMCC 1557菌可以作为咖啡半干法加工过程中的最适微生物发酵剂。这也为咖啡初加工工艺升级改进及产品风味品质提供了理论依据和技术支撑。

Semi-dry dehulled coffee beans were treated with different Saccharomyces cerevisiae CMCC1793, CMCC1425, CMCC1557, CMCC32762 strains to ascertain differences in the volatile compounds under exposure. Beans were dried, shelled, and medium-roasted to obtain six samples: GK, HK, JK, ZK, MK, and CK, which were then subjected to headspace solid-phase microextraction/gas chromatography-mass spectrometry (HS-SPME/GC-MS), odor activity value (OAV), and sensory evaluation, after which the physical and chemical characteristics were used to evaluate the samples. The results showed different volatile compounds for roasted beans inoculated with different S. cerevisiae strains, and of the 81 volatile compounds identified, 49, 52, 50, 52, 58, and 46 volatile compounds were identified in CK, GK, HK, JK, MK, and ZK with contents of 301.03, 286.31, 223.15, 333.05, 262.22, and 372.51 μg/g, respectively. Pyrazine compound content was highest in JK at 122.99 μg/g, with ketone compounds the second highest at 53.02 μg/g. OAV analysis indicated the presence of 12 compounds with OAV values not less than one, of which 3-ethyl-2,5-dimethylpyrazine, 2,6-dimethylpyrazine, 2-acetylpyrrole and 2,5-dimethyl pyrazine showed the highest values in JK. These compounds contribute greatly to the coffee aroma system. Sensory evaluation showed that coffee samples inoculated with S. cerevisiae generally had higher scores than the uninoculated samples, and the scores for aftertaste and balance were higher in JK than the other coffee samples. In conclusion, CMCC 1557 is the most suitable microbial starter for the semi-dry processing of coffee. This study provides a theoretical basis and technical support for upgrading and improving the primary processing and flavor quality of coffee.

海南省自然科学基金面上项目（320MS107）；海南省重点研发计划项目（ZDYF2021XDNY147）；中央级公益性科研院所基本科研业务费专项（1630142022010）