Investigation of aflatoxin M1 binding levels of ultrasound activated and heat, acid, ultrasound inactivated lactic acid bacteria in milk

Aflatoxins in human and animal nutrition cause significant economic losses and pose serious health risks due to their toxic effects. The way to mitigate these effects is to prevent the digestion or absorption of aflatoxins. In this context, the aim of the study was to investigate the efficacy of aflatoxin M1 binding in Lactobacillus acidophilus, Limosilactobacillus reuteri, Lacticaseibacillus rhamnosus (individually and in combination) under different activation (ultrasound) and inactivation (heat, acid, and ultrasound) treatments in an ultra-high temperature (UHT) skim milk medium. The study found that the aflatoxin M1 binding rate in all treatment groups was statistically significant compared to the control groups (p<0.05). Additionally, in the groups where ultrasound was applied in UHT skim milk medium, the aflatoxin M1 binding level was significantly higher than in the control groups (p<0.01). The aflatoxin M1 binding rate of the groups subjected to ultrasound in UHT skim milk medium (34-43.5%) was statistically significantly higher than that of the live, heat-, and acid-inactivated groups, as well as those activated/inactivated by ultrasound in phosphate-buffered saline medium (16.5-27.5%) (p<0.01). In the UHT skim milk medium, no statistically significant difference was observed in the binding rates within the group where bacteria were inactivated by ultrasound, either individually or in combination (p>0.05). However, in the group activated by ultrasound in the UHT skim milk medium, a statistically significant difference was observed between the group where bacteria were used in combination (34%) and the Lactobacillus acidophilus group (43%) (p<0.05). A statistically significant difference was also detected between the binding rate of bacteria activated together in UHT skim milk medium (34%) and the binding rate of bacteria inactivated together (43%) (p<0.05). Furthermore, the highest binding was observed in the Lacticaseibacillus rhamnosus group inactivated by ultrasound in UHT skim milk medium (43.5%), while the lowest binding was found in the group where bacteria were used in combination and activated by ultrasound (34%) (p<0.05). Among the bacteria activated by ultrasound in UHT skim milk medium, the highest binding capacity was recorded in Lactobacillus acidophilus (43%), while among those inactivated by ultrasound, the lowest binding rate was also observed in Lactobacillus acidophilus (40.5%) (p>0.05). Except for the groups treated with ultrasound in UHT skim milk medium, no statistically significant difference was detected in the binding rates of bacterial species (except for live and heat-inactivated Limosilactobacillus reuteri) among the groups (p>0.05). However, a statistically significant difference was found between the binding rate of live Limosilactobacillus reuteri (28%) and that of heat-inactivated Limosilactobacillus reuteri (16.5%) (p<0.05). The study demonstrated that ultrasound treatment in UHT skim milk medium was more effective than other methods (p<0.01). This study suggests that probiotic bacteria can be used for aflatoxin M1 detoxification in milk through different activation and inactivation methods.