花生微波烘烤香气成分分析方法的建立与应用

建立了烤制花生香气成分分析的顶空固相微萃取/气相色谱-质谱(HS SPME/GC-MS)分析方法。优化的实验条件:HP-5色谱柱,萃取平衡温度80℃,萃取时间40 min,解析时间5 min。采用该方法对四粒红、大白沙、鲁花3种花生进行微波炉焙烤后产生的挥发性香气成分进行分析,共鉴定出29种成分,其中主要包括杂环类化合物9种,醛类化合物7种,醇类化合物3种,烯类化合物3种,酚类化合物2种,酯类化合物3种,其他化合物2种。根据上述风味物质对花生香味的贡献大小,选择7种主要特征香气成分2,5-二甲基吡嗪、2-乙基-3,5(6)-二甲基吡嗪、2-乙基-6-甲基吡嗪、2-戊基呋喃、2,3-二氢苯并呋喃、苯甲醛和苯乙醛进行定量分析,其标准曲线相关系数均超过0.997,标准物质的加标回收率为85%~101%,RSD不大于6.9%,检出限为0.63~13.4μg/L。比较了不同花生品种的香气差异,并通过分析不良风味成分苯乙醛的含量,发现以大白沙花生的特征香气浓度最高,苯乙醛含量最低,更适宜利用微波烘焙技术生产咸干花生食品。

Quantitative Analysis of Volatile Flavoring Compounds on Microwave Roasted-peanuts

A headspace solid-phase micro extraction gas chromatography-mass spectrometric(HS SPME/GC-MS) method was built to analyze the volatile compounds of microwave roasted-peanuts.The effect of experimental factors,including chromatographic column,extraction time,resolution time and extraction temperature were investigated.The best experimental conditions were obtained by using extraction temperature of 80 ℃,extraction time of 40 min,resolution time of 5 min and HP-5 column.Under the optimal conditions,three typical roasted peanuts,including Silihong,Dabaisha and Luhua were analyzed.The results indicated that there were totally 29 components,including 9 heterocyclics,7 aldehydes,3 alcohols,3 enes,2 phenols,3 esters and other 2 compounds were identified.The seven main volatile flavoring compounds,e.g.2,5-dimethylpyrazine,2-pentyl-furan,2-ethyl-6-methylpyrazine,2-ethyl-3, 5(6)-dimethyl-pyrazine,2,3-dihydro-benzofuracoumaran,benzaldehyde and phenylaldehyde,were quantified by GC-MS under selective ion monitoring mode.The calibration curves were obtained with correlation coefficients of more than 0.997.The average recoveries were in the range of 85%-101% with RSDs not more than 6.9%.The detection limits were in the range of 0.63-13.4 μg/L.Comparing with the difference of three varieties of roasted-peanuts by quantitative detection of seven above volatile compounds,the Dabaisha microwave roasted-peanuts showed the highest content of flavoring compounds and lowest content of off-flavor(phenylaldehyde).