加工工艺对菜籽油主要挥发性风味成分的影响

采用固相微萃取（Solid Phase Microextraction,SPME）方法顶空萃取富集预榨菜籽毛油、浸出菜籽毛油、一级菜籽油、冷榨菜籽油和脱皮冷榨菜籽油中的挥发性成分,经气相色谱-质谱联用仪（Gas Chromatography-Mass Spectrometry,GC-MS）检测和初步分析发现,硫甙降解产物、氧化挥发物（醛、醇、烃、酮等）、杂环类物质是构成菜籽油的主要挥发性风味成分;2-甲代-1-丙烯基-氰、5-己腈、1-丁烯基-异硫氰酸酯、苯基丙氰、2-苯基乙基异硫氰酸酯是主要硫甙降解产物;反2-反4-庚二烯醛、反2-反4-癸二烯醛、4-羟基-3,5-二甲氧基苯甲醛、壬醛等醛类物质是氧化挥发物中的主要成分。加工工艺对菜籽油风味影响显著,经高温蒸炒、压榨获得的预榨毛油中杂环类物质种类和相对含量明显高于其它菜籽油。毛油经脱胶、脱酸、脱色、脱臭、脱水等处理后,一级油中产生的醛、醇、酮、烃等氧化挥发物种类增多,相对含量提高;在一级油中未检测到硫甙降解产物。

Processing effects on volatile flavor composition of rapeseed oil

The volatile flavor compounds of canola oil samples were analyzed using gas chromatography-mass spectrometry （GC-MS）.The oil samples were extracted through solid-phase microextraction （SPME） method.They included pre-pressed crude oil,extracted crude oil,salad oil,cold-pressed oil and dehulled-cold pressed oil of rapeseed.The results showed that main volatile flavor compositions were degraded glucosinolate products,oxidation volatiles and heterocyclic compounds.The main degraded glucosinolate products involved methallyl cyanide,5-cyano-1-pentene,1-butene-4-isothiocyanate-,benzenepropanenitrile,2-Phenylethyl isothiocyanate,etc.Aldehydes including 2,4-heptadienal,（E,E）,2,4-decadienal,（E,E）,benzaldehydroxy-3,5-demethoxy and nonanal were the main volatile oxidation components.After the rapeseed was cooked and pressed under high temperature,the grade and contents of heterocyclic compounds of pre-pressed oil were higher than those of others.After the crude oil was refined （degumming,deacidification,decoloration,deodorization and dehydration）,the grade and contents of oxidation volatiles （aldehydes,alcohols,ketones,hydrocarbons,etc） in salad oil were increased.There was no degraded glucosinolate product detected in salad oil.