Assessment of the hygienic condition of the environment and the production line of the grain processing plant, and changes in the microbiological indicators of the final product under different environmental conditions

SUMMARY Assessment of the hygienic condition of the environment and the production line of the grain processing plant, and changes in the microbiological indicators of the final product under different environmental conditions Giedrė Griesė Master’s Thesis Aim of the thesis: Assess the hygienic condition of the environment and the production line of the grain processing plant, and changes in the microbiological indicators of the final product under different environmental conditions. Study methods and materials: The results of two years of monitoring the physical and microbiological indicators of the environment and the hygienic condition of the environment and the production line of the grain products X processing plant were analysed. Microbiological contamination and mycotoxin concentrations were determined in the fragments formed during different stages of the technological process: aflatoxin B1 (AFB1), zearalelnone (ZEA), and deoxynivalenol (DON). The link between the microbiological contamination of the final product and the physical parameters of the environment has been established. Study results and conclusions: ambient temperature and relative humidity in the workshop did not exceed the established limits, a positive correlation was established between them (r=0,3236, p<0,0001). Microbiological air parameters were within normal limits. A positive relationship was found between physical and microbiological parameters of the environment: in two zones out of three. After testing 1235 samples during the monitoring of the production line and the environment, no Salmonella spp. was detected, the count of enterobacteria (EC) exceeded the established norm by 6,1% in all samples tested. The EB count differed with statistical significance with the samples taken on different days of production (p<0,001). A weak correlation was identified between ambient temperature and relative humidity and the EB count determined on production surfaces. After the comparison of the microbiological contamination rates of the two different products during the production process, the maximum number of aerobic colonies was 5,9 log cfu/g identified in product B, the sample from the mixer 48 hours after the commencement of the production, the maximum EC count was 3,1 log cfu/g - in product A, in a sample from the mixer 48 hours after the commencement of production. The concentration of mycotoxins in the tested product fragments did not exceed the established limits, the highest detected amount was of DON in the fragments of product A. Correlation analysis of microbiological contamination and environmental parameters of the final product showed that the EB count of