不同木屑对四川烟熏腊肉中挥发性物质的影响

Effect of Different Wood Chips on Volatile Compounds in Sichuan-style Smoked Bacon

为探究不同木屑(柏叶屑、柏木屑、松木屑、苹果木屑和混合木屑(柏叶屑和苹果木屑质量比1∶1))对四川烟熏腊肉风味的影响,采用闷燃发烟工艺制备腊肉,在生物质组分检测和感官评价的基础上,采用电子鼻和气相色谱-质谱(gas chromatography-mass spectrometry,GC-MS)技术结合主成分分析和相关性分析法对不同木屑熏制腊肉风味特征进行分析。结果表明:与其他干材相比,柏叶屑中蛋白质、油脂和木质素含量较高,熏制腊肉风味较好,烟熏风味强度较高,但腊肉色泽不具备明显优势;利用GC-MS在6组腊肉中共检出187种挥发性化合物,柏叶屑和混合木屑熏制腊肉中的萘及其衍生物、含氮化合物相对含量高于其他干材熏制腊肉,酚类化合物相对含量低于其他干材熏制腊肉;主成分分析结果表明,萘及其衍生物、含氮化合物的相对含量差异是区分柏叶屑熏制腊肉与干材熏制腊肉的主要依据;相关性分析结果显示,半纤维素对挥发性物质中酚类相对含量的作用大于木质素,萘及其衍生物相对含量与油脂、蛋白质、木质素含量均呈正相关,但相关性均不显著(P>0.05),因此木屑种类对腊肉中萘及其衍生物产生的影响可能大于木屑生物质组成对其的影响。本研究结果为四川再造林木在烟熏食品加工中的应用提供了参考依据。

This study was performed in order to investigate the effect of different wood chips(cypress leaves,cypress wood,pine wood,apple wood,and a mixture of cypress leaves and apple wood(1:1,m/m))on the flavor of Sichuan-style smoked bacon,which was prepared by the smoldering process.The biomass components of the wood chips were detected.The flavor characteristics of the smoked bacon were analyzed by sensory evaluation,electronic nose and gas chromatographymass spectrometry(GC-MS)combined with principal component analysis(PCA)and correlation analysis.The results showed that compared with the other trunk chips,cypress leaves had higher protein,fat and lignin contents and the smoked bacon prepared with it had better flavor and higher intensity of smoked flavor,but had no significant advantages in terms of color.Altogether,187 volatile substances were detected in the five smoked bacons and unsmoked bacon by GC-MS,and the percentage contents of naphthalene,its derivatives and nitrogenous compounds were higher in the smoked bacon prepared with the mixture of cypress leaves and apple wood than in those prepared with the other wood chips.PCA showed that differences in the percentage contents of naphthalene,its derivatives and nitrogenous compounds were the main basis for distinguishing between cypress leaf smoked bacon and those smoked with the other trunk chips.Correlation analysis showed that hemicellulose had a greater effect on the percentage content of volatile phenols than did lignin,and the percentage contents of naphthalene and its derivatives were positively but not significantly correlated with oil,protein and lignin contents(P>0.05).Hence,the production of naphthalene and its derivatives in smoked bacon may be more influenced by the type of wood chips than by their biomass composition.The results of this study provide the basis for the application of reforested trees in smoked food processing in Sichuan.