基于GC-O-MS及感官评价分析脱皮核桃仁关键风味物质

Analysis of Key Flavor Compounds in Peeled Walnut Kernel Based on GC-O-MS and Sensory Evaluation

脱皮核桃仁因其食用便捷、风味优良深受消费者喜爱,其中风味是评价核桃品质的重要指标。为研究脱皮核桃仁的关键风味物质,选取3个品种核桃原料(清香、温185、大泡)分别进行脱皮和低温烘烤,采用九点标度法进行感官评价,并通过气相色谱-嗅闻-质谱法分析脱皮核桃仁的挥发性风味物质。研究结果表明:脱皮核桃仁整体感官上呈现脂味、甜味和奶香味,且苦味低;采用顶空固相微萃取在3个品种脱皮核桃仁中共检测出25种挥发性风味化合物,包括醛类6种、酮类2种、醇类9种、酯类2种、烃类4种、呋喃类1种和醚类1种。进一步采用溶剂辅助风味蒸发结合嗅闻技术明确了其中的9种关键致香成分,包括己醛、辛醛、壬醛、糠醛、苯甲醛、1-己醇、1-戊醇、2,3-丁二醇和2-庚醇,这些成分使核桃呈现生青味、脂香、焦香味和甜味;将9种致香成分与感官属性进行相关性分析,发现壬醛、己醛、2-庚醇、2,3-丁二醇和1-戊醇是导致不同品种核桃仁感官差异的关键物质。研究结果旨在为核桃仁风味品质的提升和脱皮核桃仁休闲食品的研发提供理论指导。

Peeled walnut kernels are popular among consumers for their easy consumption,wide application scenarios and excellent flavor,of which flavor is an important index for evaluating walnut quality.To study the key flavor substances of peeled walnut kernels,three varieties of walnut raw materials(Qing Xiang,Wen 185 and Da Pao)were selected for peeling and low temperature roasting,and sensory evaluation analysis was carried out by nine-point scale method,and volatile flavor compound of peeled walnut kernels were analyzed by gas chromatography-olfactometry-mass spectrometry.The results indicated that the peeled walnut kernels showed an overall sensory taste of fatty,sweet and creamy flavor with low bitterness.A total of 25 volatile flavor compounds,including 6 aldehydes,2 ketones,9 alcohols,2 esters,4 hydrocarbons,1 furan and 1 ether,were detected in three varieties of peeled walnut kernels by headspace solid phase microextraction.The nine key flavor components,including hexanal,octanal,nonanal,furfural,benzaldehyde,1-hexanol,1-pentanol,2,3-butanediol and 2-heptanol,were further clarified using solvent-assisted flavor evaporation combined with olfactometry to give the walnuts a raw green,fatty,burnt and sweet flavor.Correlation analysis was performed between the nine key flavor components and sensory attributes,and it was found that nonanal,hexanal,2-heptanol,2,3-butanediol and 1-pentanol were the key substances causing sensory differences in walnuts of different varieties.The results of this paper provided important support for the improvement of the flavor quality of walnut kernels and the creation of peeled walnut kernel snacks.