烹饪方式对烤羊排脂肪酸组成及挥发性风味物质的影响

Effects of Cooking Methods on Fatty Acid Composition and Volatile Substances in Oven-Roasted Lamb Chops

为探究风味物质的形成机制,以直接烤制和过热蒸-烤制2种烹饪方式的电烤箱烤羊排为研究对象,采用描述性感官分析、电子鼻、顶空固相微萃取-气相色谱-质谱联用技术以及气相色谱-嗅闻技术分析其感官特性、脂肪酸组成及挥发性风味物质差异。感官分析和电子鼻结果显示两样品的香气轮廓存在差异,其中直接烤制样品具有更强的烤香、脂香和羊肉味(P<0.05)。在两种烤羊排中共检测到44种挥发性化合物,直接烤制样品中醛类、醇类、含氮化合物等挥发性物质的含量均高于蒸烤结合样品。采用香气提取物稀释分析-气相色谱-嗅闻共鉴定出35种香气活性化合物,其中强势香气活性化合物包括癸醛、己醛、辛醛、壬醛、(E,Z)-2,6-壬二烯醛、(E,E)-2,4-癸二烯醛、(E,E)-2,4-壬二烯醛、1-辛烯-3-酮、3-辛烯-2-酮、2-壬酮、庚酸、2-甲基吡嗪、3-甲硫基丙醛、苯并噻唑、2-戊基呋喃。两种样品香气活性化合物的种类相似,但稀释因子不同。直接烤制羊排的脂肪酸总含量显著高于蒸烤结合样品(P<0.05),其中多不饱和脂肪酸和饱和脂肪酸含量的比值为40.66%,具有更高的营养价值。Pearson相关性分析结果表明,油酸、亚油酸、亚麻酸、花生三烯酸等不饱和脂肪酸的氧化降解与烤羊排特征风味物质的形成密切相关。

Roasted lamb chops were prepared by superheated steam roasting(SSR)and direct roasting(DR).To explore the formation mechanism of flavor substances,descriptive sensory analysis(DSA),an electronic nose(E-nose)system,head-space solid phase microextraction combined with gas chromatography-mass spectrometry(HS-SPME-GC-MS),and gas chromatography-olfactometry(GC-O)were employed to analyze the sensory properties,fatty acid composition and volatile compounds of the SSR and DR samples.The DSA and E-nose results consistently revealed variations in aroma profiles between the two samples.The DR sample showed stronger roasted,fatty,and mutton-like aroma(P<0.05).A total of 44 volatile compounds were identified from both samples.The contents of aldehydes,alcohols,and nitrogen-containing compounds in the DR sample were higher than those in the SSR sample.Totally 35 aroma-active compounds were identified by aroma extract dilution analysis(AEDA)combined with GC-O analysis,among which,decanal,hexanal,octanal,nonanal,(E,Z)-2,6-nonadienal,(E,E)-2,4-decadienal,(E,E)-2,4-nonadienal,1-octen-3-one,3-octen-2-one,2-nonanone,heptanoic acid,2-methylpyrazine,3-(methylthio)propanal,benzothiazole,and 2-pentylfuran were the major ones.The types of aromaactive compounds in the two samples were similar,but their flavor dilution(FD)factors were different.Compared with the SSR sample,the content of total fatty acids in the DR sample significantly increased(P<0.05).The content ratio of polyunsaturated fatty acids to saturated fatty acids(PUFA/SFA)in the DR sample was 40.66%,indicating higher nutritional value.Pearson’s correlation analysis showed that the oxidative degradation of unsaturated fatty acids such as oleic acid,linoleic acid,linolenic acid,and eicosenoic acid was closely related to the formation of the characteristic flavor in roasted lamb chops.