Change Difference of Pigment and Polyphenol Contents between Bulk-curing Barn and Traditional Flue-curing Barn during Curing Process

Experiments were conducted to explore the change differences of pigment and polyphenol substances contents between bulk-curing barn and traditional flue-curing barn during curing process.The experiment measured pigment contents, polyphenol oxidase activities and polyphenols contents at critical temperature points during curing process.The results showed that contents of total chlorophyll, chlorophyll a and chlorophyll b had little differences between the two curing processes.Bulk-curing barn had more carotenoid contents during curing process.The ratio of carotenoid and chlorophyll increased firstly and then decreased, and at the end of curing process, the ratio of carotenoid and chlorophyll was high.During bulk-curing barn curing process, polyphenol oxidase activities were lower and polyphenol substances contents were higher than traditional flue-curing barn.Therefore, flue-cured tobacco leaves in bulk-curing had higher yellowing degree, less browning reaction, and in favor of tobacco leaves turning yellow.