环境地球化学国家重点实验室知识库

To improve the flavour of traditional tobacco sheets, aroma-producing bacterial including Bacillus subtilis MT-1, B. amyloliquefaciens MT-3, and B. licheniforms MT-2 isolated from Maotai Daqu (a kind of distiller's yeast for brewing Moutai spirit, a type of Chinese spirit) were cultured on wheat medium at 37 °C, 46 °C, and 55 °C respectively for 2 days. The authors prepared tobacco sheets by using the extracted fermentation products, tobacco waste, and an adjunct (Sheet 1). Afterwards, the tobacco sheets were compared with those tobacco sheets to which no fermentation products had been added (Sheet 2) in terms of physical and chemical properties and sensory quality. The substances present in Sheets 1 and 2 were extracted by using supercritical CO2 and the extracted products analysed by gas chromatography-time of flight mass spectrometry (GC-TOF(MS)). The results showed that microbial fermentation extracts manifested little effect on the physical properties of tobacco sheets; the content of total sugars and the sugar:nicotine ratio of Sheet 1 were higher than those of Sheet 2; besides, the sensory quality score of the tobacco in Sheet 1 increased by 1.4 compared to Sheet 2; moreover, twelve aromatic substances were detected in both the fermentation extracts and Sheet 1. They were proved to be the main factor which contributed to the significant improvement in the sensory quality of Sheet 1.