Analysis of the flavor components during the processing of almond roasting and storage | 美国大杏仁烘烤和贮存过程中的香气成分分析

Chinese. 研究美国大杏仁烘烤和烘烤后贮存过程中香气成分及其含量的变化，为美国大杏仁的加工及贮存提供理论依据。通过氯化钙柱吸附法制备样品，采用气相色谱-质谱联用仪对美国大杏仁烘烤前、后及烘烤后贮存3个月和6个月的风味成分及其含量进行分析。美国大杏仁烘烤前的主要挥发性物质有25种，烘烤后的主要挥发性物质有44种，烘烤后贮存过程中的主要挥发性物质有50种；美国大杏仁中的挥发性香气成分主要为芳香醛类、脂肪族醛类、芳香醇类、脂肪族醇类、吡嗪类及其衍生物，苯甲醛是美国大杏仁挥发性成分的主要特征香气组分。纸袋包装的烘烤美国大杏仁在37 ℃下贮存6个月时已经氧化变质，高含油量及高不饱和脂肪酸的存在是引起烘烤杏仁变质的主要原因，壬醛、己醛、2-辛烯醛、辛醛及庚醛等脂肪族醛类物质是烘烤美国大杏仁氧化酸败后产生不良气味的主要组分；壬醛和己醛的组分含量可以作为油脂氧化程度及确定烘烤美国大杏仁货架期的检测指标。

English. Analysis of the change of flavor components during the processing of almond roasting and storage was carried out to provide a theoretical basis for processing and storage of almonds. The volatiles of raw and roasted almonds were extracted by Tenax (Vigreux) column, and the extracts were analyzed by combination gas chromatography-mass spectrometry. Twenty-five compounds were identified from raw almond volatiles, forty-four compounds from fresh roasted almond volatiles, and fifty compounds from roasted almond volatiles which had been stored for three or six months; aromatic aldehydes, aliphatic aldehydes, aromatic alcohol, aliphatic alcohols, pyrazines and their ramifications were the main flavor components of almonds; and benzaldehyde seemed to make the largest contribution to the aroma of raw and fresh roasted almonds. Roasted almonds, packaged with paper bags, have been oxidized, and rancidity after six months’ storage might have been induced by high oil content and polyunsaturated fatty acids and produced volatile aliphatic aldehydes such as nonanal, hexanal, 2-octenal, octanal, and N heptanal compoents to come off-flavors. This study showed nonanal and hexanal might be a better peroxide index for shelf life of roasted almonds kernels.