Handling and Curing Characteristics of Cut-Strip Tobacco. Part 1: Effect of Strip-Size, Packing Density and Mode of Orientation

Previous work has demonstrated potential handling and curing efficiencies in the use of cut-strip tobacco. The present work considers further the effect of cut-strip size, packing density and mode of orientation on cured leaf chemistry (starch, reducing sugars, and total alkaloids) and leaf quality. Results showed that cured leaf chemistry of 15.2 × 22.9 cm cut-strip more closely matched properties of whole leaf than pieces 15.2 × 15.2 cm or smaller. Starch contents were significantly higher for the smaller cut-strip sizes, perhaps due to edge drying effects, while alkaloids were significantly lower. Within the range of 194 to 292 kg/m, packing density had little effect on leaf chemistry, with the exception that reducing sugars were slightly lower for the higher packing densities. This could be due to a longer time for the drying front to move through the more tightly packed tobacco, and hence more respiratory loss of sugars. Government grades and average market prices of cured strips were essentially unaffected over the range of strip sizes or packing densities tested. Based on airflow resistance measurements and observed drying characteristics, vertical orientation of strips was far superior to horizontal orientation, both with vertical airflow through the tobacco. The higher packing density reduced specific energy use (kWh/kg green tobacco) by as much as 22%, indicating potential energy savings for cut-strip over whole leaf curing.