基于GC-IMS与电子感官的不同产地百里香特征风味物质分析OA

[Objective]To elucidate the flavor differences of Thymus mongolicus Ronn.from different origins and identify their key aroma compounds.[Methods]Gas chromatography-ion mobility spectrometry(GC-IMS)combined with electronic nose and electronic tongue was used to analyze the volatile compounds in Thymus mongolicus Ronn.samples from three origins:Luoyang(Henan),Kunming(Yunnan),and Guangzhou(Guangdong).Odor activity values(OAV)were then employed to screen the characteristic aroma compounds.[Results]A total of 101 compounds were identified,predominantly alcohols(23),aldehydes(19),and ketones(19).Both the number and total content of volatile compounds in Thymus mongolicus Ronn.from Henan and Guangdong were higher than those from Yunnan.Significant differences in the contents of characteristic aroma compounds were observed among samples from different origins.Eighteen common characteristic aroma compounds meeting both VIP>1 and OAV≥1 were identified,notably thymol,(Z)-2-hexenal,methyl isovalerate-D,and(E)-2-hexenal.Yunnan samples showed higher relative contents of alcohols,ketones,and heterocyclic compounds,with a relatively balanced aroma;Henan samples had the highest contents of phenols,aldehydes,and sulfur-containing compounds,accompanied by pronounced bitterness and astringency;Guangdong samples were rich in alkenes and esters,exhibiting prominent umami and saltiness.Geographical and climatic conditions significantly influenced the contents of characteristic flavor compounds.A significant positive correlation was found between latitude and(E)-2-hexenal,whereas a significant negative correlation was observed between latitude and isobutyraldehyde.In addition,higher temperatures promoted the accumulation of methyl isovalerate-D.[Conclusion]GC-IMS combined with electronic sensory techniques can rapidly discriminate Thymus mongolicus Ronn.from different origins,offering a valuable reference for the traceability and further application of its characteristic flavor compounds.