基于指纹图谱的欧拉羊肉挥发性风味物质定量分析

欧拉羊分布在青藏高原东部,生活环境特殊,羊肉品质独特,但其挥发性风味物质组成尚不明确。为研究欧拉羊肉熟制时的挥发性风味物质,并构建相应指纹图谱,以欧拉羊、湖羊、杜泊羊和滩羊羊肉为研究对象,利用顶空固相微萃取、结合气相色谱质谱联用法,对羊肉挥发性风味物质进行定性定量分析,并通过嗅辨仪鉴定出呈香化合物。运用主成分分析和聚类分析,将欧拉羊与湖羊、杜泊羊、滩羊羊肉的风味进行比较,从而明确欧拉羊肉的挥发性风味物质,并建立指纹图谱。结果表明,在欧拉羊肉中检测到醛类、酮类、醇类、杂环类、烷烃类等共53种挥发性物质,其中77%具有气味活性。所有物质中醛类有20种,在整体风味物质中的相对含量占比达62%,对风味贡献最大。欧拉羊肉整体风味物质轮廓与其他3种羊肉有显著区别,其特征性风味物质主要包括(E)-2-己烯醛、(E,E)-2,4-庚二烯醛、(E,E)-2,4-辛二烯醛、3-辛烯-2-酮等不饱和醛酮,4-异丙基甲苯等烷烃类,以及苯并噻唑等其他呈味物质,它们共同贡献了水果香、坚果味、青草味等令人愉悦的气味。

Quantitative Analysis of Oula Lamb Meat Volatile Compounds Based on Fingerprint

Distributed in the eastern Qinghai-Tibet plateau where the environmental condition is unique, Oula lamb is of distinction owing to the quality of its meat. Aiming to establish the fingerprint of volatile flavor for Oula lamb meat. The lamb meat was obtained from four kinds of lamb: Oula lamb, Hu lamb, Dorper lamb and Tan lamb. Extraction and analysis of the volatile compounds were carried out by headspace solid phase microextraction and gas chromatography-mass spectrometry respectively. At the same time, gas chromatography-olfactometry was used to assess the fragrant compounds. Principal component analysis and cluster analysis were applied to determine the chemical variability among four kinds of lamb meat. The results showed that 53 volatile components of Oula lamb meat were identified and quantified, including aldehydes, heterocycles, hydrocarbons, alcohols and ketones, among which 77% possessed perceptible aromas. Totally 20 kinds of aldehydes with their content accounting for 62% contributed the most to flavor. Grouping of samples highlighted a good classification of the results, providing a significant separation between Oula lamb meat and other three kinds of lamb meat. Characteristic flavor compounds of Oula lamb meat mainly included (E)-2-hexenal, (E,E)-2,4-heptadienal, (E,E)-2,4-octadienal, 3-octen-2-one and other unsaturated aldehydes and ketones, together with some hydrocarbons, such as p-cymene, and other flavor compounds such as benzothiazole, providing fruits, nuts and grass odors. The findings provided the volatile fingerprint of Oula lamb meat, which can promote the development of related products of Oula lamb.