通过研究牛肉腐败过程中挥发物的变化，确定表征牛肉新鲜度的特征性挥发成分。将样品分别置于0 ℃和10 ℃下恒温贮藏，每2 d取样，采用顶空固相微萃取-气-质联用（HS-SPME-GC-MS）法测定挥发性成分，对结果进行主成分分析（PCA），并与总挥发性盐基氮（TVBN）、菌落总数、pH值和感官评分相结合。结果显示：0 ℃肉样共检测出37种挥发物，10 ℃肉样检测出40种挥发物。确定出7种成分（丙酮、壬烷、2-戊酮、2,3-丁二酮、2-戊酮、3-甲基-1-丁醇和壬醛表）为新鲜牛肉的特征性成分，13种成分（2,3-丁二醇、二甲基二硫、二甲基三硫、二氧化硫、对乙基苯乙烯、间二乙烯苯、对二乙烯苯、甲苯、苯甲醛、间二氯苯、2-丁基噻吩、苯乙醇和苯酚）为腐败牛肉的特征性成分。研究结果可为牛肉新鲜度的判别提供依据。

The changes in volatile compounds in beef during the decay process were examined, and based on these, the characteristic volatile components that characterize the degree of beef freshness were determined. Samples were stored at one of two temperatures 0 ℃ and 10 ℃ and sampling was performed every two days. Volatile components were determined using the headspace solid phase microextraction-gas-mass spectrometry (HS-SPME-GC-MS) method. The results were analyzed by principal component analysis (PCA); total volatile base nitrogen (TVBN) values, the total number of colonies, and pH values were also recorded, and sensory evaluation was performed. The results showed 37 and 40 types of volatiles were detected in the samples stored at 0 ℃ and 10 ℃, respectively. Seven components (acetone, nonane, 2-pentanone, 2,3-butanedione, 2-pentanone, 3-methyl-1-butanol, and nonyl aldehyde) were identified as components characteristic of fresh beef. Thirteen components (2,3-butanediol, dimethyl disulfide, dimethyl trisulfide, sulfur dioxide, p-ethyl styrene, m-divinyl benzene, p-divinyl benzene, toluene, benzaldehyde, dichlorobenzene, 2-butyl thiophene, phenethyl alcohol, and phenol) were components characteristic of decaying beef. The results provide a basis for the determination of the degree of beef freshness.

国家科技支撑计划（2015BAD16B08）；山东省自主创新及成果转化专项（2014ZZCX02701）