基于GC-IMS技术鉴别超高压杀菌沃柑汁

Authentication of Ultra High Pressure Sterilized Orah Mandarin Juice Based on GC-IMS Technology

为探讨经超高压杀菌的沃柑汁与非杀菌沃柑汁的鉴伪方法,防止非超高压杀菌沃柑汁的市场欺诈,利用气相色谱-离子迁移谱(GC-IMS)技术,对不同超高压条件下处理的沃柑汁和未经处理的沃柑汁挥发性风味物质进行测定,寻找特征差异成分。沃柑汁样品共检测出35种挥发性成分,包括10种醛类、8种酮类、8种醇类、5种酯类和4种烯烃类,超高压杀菌后沃柑汁风味物质在含量上有所变化,但无新物质生成。对挥发性风味成分数据集进行多元统计分析发现,正交偏最小二乘判别分析(OPLS-DA)可使超高压杀菌前后沃柑汁实现明显区分,结合变量投影重要度(VIP)可筛选出庚醛(二聚体)和正己醇2个合适的差异标记物(VIP>1)。沃柑汁GC-IMS指纹图谱显示,乙酸异戊酯、己醛(单体和二聚体)、2-庚酮(单体和二聚体)、Z-3-己烯醇(单体和二聚体)、α-蒎烯(单体)、乙酸乙酯(二聚体)、庚醛(二聚体)和正己醇,这8种物质在不同超高压杀菌条件下,含量变化趋势不改变,属于潜在差异标记物,其中庚醛(二聚体)和正己醇在指纹图谱上超高压前后的差异极显著,被认为是鉴别超高压杀菌沃柑汁与非杀菌沃柑汁的理想标记物质,与OPLS-DA分析得到的结论一致。综上,基于GC-IMS技术,可以实现超高压杀菌沃柑汁及非杀菌沃柑汁的鉴别。

In order to explore the authentication method of ultra high pressure sterilized and non-sterilized Orah mandarin juice and prevent the market fraud of non-ultra high pressure sterilized Orah mandarin juice,the volatile flavor substances of processed Orah mandarin juice under different ultra high pressure conditions and untreated Orah mandarin juice were determined by gas chromatography ion mobility spectrometry(GC-IMS)to find the characteristic difference components.A total of 35 volatile components were detected in citrus juice samples,including 10 aldehydes,8 ketones,8 alcohols,5 esters and 4 olefins.After ultra high pressure sterilization,the flavor substances of Orah mandarin juice changed in content,but no new substances were generated.Multivariate statistical analysis of the volatile flavor component data set found that orthogonal partial least squares discriminant analysis(OPLS-DA)can significantly distinguish Orah mandarin juice before and after ultra high pressure sterilization.Combined with variable projection importance(ViP),two suitable differential markers of heptanal(dimer)and hexan-1-ol(ViP>1)can be screened out.The fingerprint of volatile components of Orah mandarin juice showed that isoamyl acetate,hexanal(monomer and dimer),2-heptanone(monomer and dimer),Z-3-hexenol(monomer and dimer)α-pinene(monomer),ethyl acetate(dimer),heptanal(dimer)and hexan-1-ol,these eight substances,under different conditions of ultra high pressure sterilization,the content change trend does not change,and they belong to potential differential markers.Among them,heptanal(dimer)and hexan-1-ol have extremely significant differences before and after ultra high pressure on the fingerprint,which is considered to be an ideal marker for distinguishing ultra high pressure sterilized Orah mandarin juice from non-sterilized Orah mandarin juice.It is consistent with the conclusion of the OPLS-DA analysis.In summary,the authentication of ultra high pressure sterilized Orah mandarin juice and nonsterilized Orah mandarin juice can be realized based on GC-IMS technology.