Abstract:

To address the uncertainty in the aging period of the characteristic flue-cured tobacco variety ‘CB-1’ lamina under northern climate conditions, which affects the suitability of raw materials for cigarette production, this study aimed to explore its optimal aging duration. Using redried lamina of middle leaves (C3F) and upper leaves (B2F) of ‘CB-1’ from Longyan, Fujian, natural aging was conducted for 24 months in the aging warehouse of Shandong Tobacco Industry. Regular measurements were taken for appearance quality, main chemical components, and sensory evaluation quality, with comprehensive assessment performed using cluster analysis. The findings showed: (1) As aging progressed, the color of leaves from both positions deepened, oil content decreased, and color intensity increased. For middle leaves, total sugar and reducing sugar contents peaked at 12 months of aging, increasing by 0.74 and 0.81 percentage points respectively compared to before aging, while total nitrogen and nicotine contents consistently declined throughout the aging period. For upper leaves, reducing sugar, nicotine, and total nitrogen showed a decreasing trend during aging. (2) The sensory scores for middle leaves in terms of concentration, aroma quality, aroma quantity, sweetness, and overall sensory quality reached their highest values at 12 months of aging, increasing by 0.2, 0.8, 0.5, 0.9, and 6.25 points respectively compared to pre-aging. The overall sensory quality score for upper leaves peaked at 18 months of aging, with an increase of 5.50 points. (3) Cluster analysis indicated that middle leaves aged for 12 and 18 months were grouped into one category, while upper leaves aged for 18 months clustered with those aged for 12 and 24 months. In conclusion, the optimal aging period for ‘CB-1’ middle leaves is 12 months (with 18 months as an alternative), and for upper leaves it is 18 months (with 12 and 24 months as alternatives). Future research could integrate temperature and humidity control, microbial community dynamics, and metabolic patterns of aroma substances to further elucidate the aging mechanisms of tobacco under northern climate conditions, thereby providing support for precise raw material management.

Key words: ‘CB-1’, aging period, tobacco lamina, northern climatic conditions, appearance quality, internal quality, cluster analysis