Abstract
The mycotoxins produced by filamentous molds are associated with economic losses and numerous health risks in the human food chain. Biological methods of eliminating the danger posed by mycotoxins to the health of humans and animals are being developed. In this context, kefir (i.e., milk fermented by kefir grains), kefir cell-free supernatant (CFS), and neutralized kefir CFS (CFS-pH7) were tested for their antifungal activities against Aspergillus flavus and A. carbonarius, which produce mycotoxins. Results showed that the pH increased and the titratable acidity decreased during 24 h of fermentation. Moreover, data showed that 10% kefir has the potential to inhibit the growth of A. flavus and A. carbonarius by 93.88% and 100%, respectively. Kefir CFS inhibited the growth of A. flavus and A. carbonarius by 51.11% and 46.66%, respectively. No inhibition of the growth of A. carbonarius was observed when the pH of the CFS was adjusted to 7, while minor inhibition (10%) of the growth of A. flavus was noted. The production of OTA by A. carbonarius was completely (100%) suppressed by kefir, and it reduced the production of AFB1 by A. flavus by 99.98%. CFS and CFS-pH7 reduced AFB1 and OTA production by 99.94-92.90% and 27.98-8.76%, respectively. The present findings suggest that kefir could be utilized to control A. flavus and A. carbonarius and thus the production of AFB1 and OTA, enhancing the safety of the human food chain.