Modeling the Effect of Selected Microorganisms’ Exposure to Molasses’s High-Osmolality Environment

Abstract

In this research series, several sugar beet molasses of different osmolalities were inoculated with a mix of the following microorganisms, Escherichia coli, Salmonella spp. and Listeria monocytogenes, to develop mathematical models and correlations of the effect of different levels of osmolality and different exposure time to the viability of the selected microorganisms. The respective enumerations of Escherichia coli, Salmonella spp., Listeria monocytogenes, Enterobacteriaceae, and total plate count were conducted on inoculated molasses samples of different osmolalities (from 5500 to 7000 mmol/kg) and at different exposure times (from 0 to 5 h). The results showed that by increasing molasses osmolalities, all the selected microorganisms’ exposure time viability measures statistically decreased significantly. Salmonella spp. showed the highest viability of all the tested microorganisms in a high osmotic environment. In contrast, Listeria monocytogenes showed the least resilience to osmotic stress, with a reduction in the numbers below the detection limit. The developed mathematical models of microorganisms’ viability exposed to molasses’s high-osmolality environment were statistically significant, allowing for the good prediction of a number of microorganisms based on exposure time and osmolality levels. The obtained results describe molasses’s excellent microbial load-reducing capability and provide the potential for applications in the production of safe foods.