Abstract:
【Objective】 This study aimed to explore the material basis for the quality differences in tobacco leaves of two cigar varieties after air-curing in Wuzhishan area of Hainan, providing theoretical support for the future selection and breeding of cigar varieties, improvements in raw material production techniques and enhancement of quality characteristics. 【Method】 Based on high performance liquid chromatography-tandem mass spectrometry(HPLC-MS/MS), the nontargeted metabonomics method and the sensory quality evaluation method of China Tobacco Sichuan Industrial Co., Ltd., the differences in metabolites, metabolic pathways conventional chemical component and sensory quality in the tobacco leaves of cigar varieties Haiyan 101 and Haiyan 201 after air-curing in Wuzhishan area were analyzed. 【Result】 The differences in the conventional indexes such as total nitrogen, total sugar, reducing sugar, nicotine, potassium and chlorine in air-cured tobacco leaves of the two cigar varieties were minor. However, after air curing, the total polyphenol content in Haiyan 201 leaves was 2.54%, significantly higher than that of Haiyan 101(
P<0.05, the same below). In addition, the overall color transformation of Haiyan 201 tobacco leaves was darker and more uniform, with notably better appearance quality. The sensory quality evaluation showed that Haiyan 201 tobacco leaves were superior to Haiyan 101 in terms of aroma, aroma richness, miscellaneous gas and quality characteristics, with notable differences in the overall sensory quality. A total of 1138 metabolites were detected in air-cured tobacco leaves of the two cigar varieties, with 404 metabolites showing significant differences in content. In the HMDB database, 133 differential metabolites were successfully annotated for classification and function, including 80 up-regulated differential metabolites and 53 down-regulated differential metabolites. The differential metabolites in air-cured tobacco leaves were mainly enriched in phenylpropanoid biosynthesis and flavone and flavonol biosynthesis pathways, with extremely significant(
P<0.0001) differential metabolites including the polyphenols such as scopoletin, caffeic acid, ferulic acid and p-coumaric acid, as well as flavonoids such as kaempferol, quercetin, kaempferin and trifolin. 【Conclusion】 The sensory quality and metabolic profiles of air-cured tobacco leaves of two cigar varieties are significantly different under the same ecological conditions. In particular, the relative contents of certain polyphenols and flavonoid metabolites may be related to the formation of sensory quality differences between the cigar tobacco leaves of two cigar varieties.