从市售异味玉米果汁饮料中分离、筛选嗜酸耐热菌，对其进行分子生物学鉴定，并研究分离菌株对玉米果汁饮料挥发性成分和色度的影响。结果表明，市售异味玉米果汁饮料中分离筛选出一株嗜酸耐热芽孢杆菌，该菌最适生长温度为45~50 ℃，最适pH为3.5~4.0，16S rDNA测序鉴定为酸土脂环酸芽孢杆菌。将分离菌株接种于正常样品于45 ℃培养30 d，气相色谱-质谱联用技术（Gas Chromatograph-Mass Spectrometer，GC-MS）分析表明，正常样品和接种样品挥发性成分的种类相似，但在关键性气味物质的含量上有显著差异。接种样品中14种挥发性物质含量极显著高于正常样品，其中愈创木酚和邻乙氧基苯酚具有类似草药、消毒水等异味，且两种物质在接种样品中气味活度分别高达1696.58和398.40，为酸土脂环酸芽孢杆菌污染该饮料产生的特征性异味物质。色差分析表明接种样品L值显著高于正常样品，表明污染饮料产生异味的同时产品白度增加。

Thermoacidophilic bacterium were selected and screened from commercial maize beverage with smoky, antiseptic or disinfectant like flavor taints. A strain of Alicyclobacillus was isolated from spoilage samples with an optimum growth temperature of 45~50 ℃ and optimum growth pH of 3.5~4.0. The strain was identified as Alicyclobacillus acidoterrestris by 16S rDNA sequencing and inoculated to normal samples. Then inoculated samples were cultured at 45 ℃ for 30 days. Volatile compounds and colorimetric characteristics of the beverage were studied by gas chromatograph-mass spectrometer and colorimeter. Total amount of volatile compounds was similar among normal and inoculated samples but showed variation on key aromas. The concentrations of 14 volatile compounds in inoculated samples were significantly higher than normal samples. Among them, guaiacol and o-ethoxyphenol had an offensive smelling and their odor activity values were 1696.58 and 398.40, respectively. Colorimetric analysis showed that the white intensity increased in inoculated samples and the L value was significantly improved.

国家自然科学基金资助项目（31201414）；华中农业大学自主科技创新基金环境食品学培育专项（2013PY098）资助