Antimicrobial activity of disinfectants commonly used in the food industry in Mexico

Objectives Disinfectants are widely used in food processing environments for microorganism control; their activity can vary according the microorganism and their used in the appropriated concentrations is vital. Hence, the aim of this study was determined the effectiveness and minimum inhibitory concentration (MIC) of 15 disinfectants commonly used in the food industry in Mexico. Methods The antimicrobial activity and the MIC were determined according to AOAC and CLSI, respectively, with approved strains. Results Most disinfectants reduced 99.999% of microorganisms in suspension after 30 s of contact, so reduction rate corresponded at least 5 Log₁₀. Only for Pseudomonas aeruginosa ATCC 15442, did all disinfectants have 99.999% effectiveness. For the MIC, only the third generation quaternary ammonium compounds (QACs) in acid medium did not have values within the range in which is used in the food industry for Staphylococcus aureus ATCC 25923. In addition, for all disinfectants the MIC at 5 min was two to four times greater than the concentration with the same effect at 10 min; moreover, in most cases there was no difference in the MIC at 10 and 15 min (p > 0.05). Conclusions At recommended concentrations, disinfectants had bactericidal activity for at least three of the six microorganisms evaluated. However, the MIC was affected by the exposure time: it was bigger at 5 min than at 10 min; moreover, in the majority of the cases, it was equal at 10 and 15 min; with the results we could have a better understanding of disinfectants use in food processing environments.