Microbiological screening of tobacco raw materials for rolling of cigarettes

In the modern market of tobacco products worldwide, there is a trend towards increased consumption and trade in cut tobacco for manual rolling of cigarettes (RYO tobacco), including and from unregulated producers. This hides additional risks for the health of the consumers due to the possibility to use low-quality and uncontrolled raw materials, including and with increased presence of pathogenic and conditionally pathogenic microorganisms.

The aim of the study was to determine the total amount of heterotrophic bacteria (microbial count), the amount of microscopic fungi and the most common species in the raw material for tobacco RYO, distributed on the Bulgarian market.

The microbiological analyzes were performed by classical methods accepted in sanitary microbiology. In all samples, spores of the genus Bacillus showed mass development, and according to the macro-morphological characteristics of the colonies, the predominant species can be attributed to B. cereus. The detected amounts of microscopic fungi in the tested tobacco mixtures were significant at strong presence of species of the genus Aspergillus, over 85.48%. Macroscopically, species were defined as A. flavus (41.94%), A. niger (27.42%) and A. fumigatum (16.13%). The relative share of species of the genus Penicillium was 9.68% and of species of the genus Mucor -4.84%. The studied tobacco raw material for manual rolling of cigarettes had significant contamination by microorganisms that had the rank of pathogens. Quantitative microbial assessment suggests a potential health risk for consumers.