Effect of probiotic bacteria on the reduction of aflatoxin risks in milk

Abstract

Dairy products such as raw milk, Kariesh cheese, and yoghurt are considered is considered as health food that supports part of the human needs of protein, minerals, and vitamins. This study was taken to investigate mold contamination in raw milk, Kariesh cheese, and yoghurt retailed in Zagazig city, Egypt. In addition, isolation and identification of the different mold genera were further conducted. Besides, total aflatoxins (AFTs) were estimated in the examined samples, and their daily intakes and health risk assessment were calculated. An experimental trial was conducted to investigate the antifungal activities of three probiotics strains, namely, Lactobacillus acidophilus, L. rhamnosus, and L. plantarum. The obtained results indicated that raw milk had the highest mold contamination rate at 40%, followed by Kariesh cheese at 30%, and yoghurt samples at 10%. The prevalent mold genera were Aspergillus spp., Penicillium spp., Cladosporium spp., Alternaria spp., Mucor spp., Rhizopus spp., Absidia spp., and Fusarium spp. The most dominant mold genera among the identified molds were Aspergillus spp., (raw milk (20.82%), Kariesh cheese (15.62%), and yoghurt (6.25%). Further identification of the Aspergillus isolates revealed five Aspergillus species. The identified Aspergilli were A. niger, A. flavus, A. fumigatous. A. ochracous, and A. terreus. AFTs were detected in raw milk samples at 20%, Kariesh cheese at 10%, and yoghurt at 6. None of the contaminated samples exceeded the international permissible limit of total AFTs. The tested probiotics strains exhibited clear antifungal activities.