الفهرس 
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Abstract
Mycotoxins are secondary toxic metabolites produced mainly by fungi belonging to the Aspergillus, Penicillium, Fusarium, Alternaria and Claviceps genera. When animals are given feed contaminated with mycotoxins, these toxic compounds are metabolized and transferred to animal-derived food, including milk.The presence of AFB1 that related to bad storage of grains in animal feed is metabolized, bio-transformed, and secreted in milk in the form of AFM1or “milk toxin and the contamination levels depends on geographical region, season, environmental conditions, level of development, farming systems diversity, green forage availability, and consumption of feed concentrates. The risk of contamination by AFM1 is an important food safety concern for milk. Therefore, our research investigation has been conducted to study the occurrence of AFM1 in milk.The survey was done using a total of fifty-six samples (500 ml per sample) of whole buffalo raw milk were collected randomly during the four seasons of the year (14 samples in the winter, 14 samples in the spring, 14 samples in the summer and 14 samples in the autumn) in a period between March and October 2021 from different locations of whole buffalo raw milk production at Sohag city. The procedure was taken out using aflatoxin M1 Elisa 96t, SINOGENECLON CO., Ltd transferred to the central laboratory of forensic medicine and toxicology department of the veterinary medicine, Assuit university.
This survey was done using a total of fifty-six samples (500 ml per sample) of whole buffalo raw milk. They were collected randomly during the four seasons of the year (14 samples in the winter, 14 samples in the spring, 14 samples in the summer and 14 samples in the autumn), in a period between March and October 2021 from different locations of whole buffalo raw milk production at Sohag city. The procedure was taken out using aflatoxin M1 Elisa 96t, SINOGENECLON CO., Ltd at the central laboratory of forensic medicine and toxicology department of the veterinary medicine, Assuit university. Validation of ELISA was carried out by determination the recovery and the mean variation coefficient for fresh milk spiked with different concentrations of AFM1 (20, 100, 300 ng/L) and analysis of AFM1 in fresh milk.
The examined level of aflatoxin M1 showed range of concentration between 0.0 - and 0.9 μg/kg with a mean value of 0.48± 0.31 μg/kg for winter milk samples. In spring milk samples, the level of aflatoxin M1 revealed a range value between 0.03 -1.2μg/kg with a mean level of 0.33±0.48 μg/kg. The examined level of aflatoxin M1 in summer milk samples showed range levels between 0.06 - 0.8μg/kg with a mean level of 0.23±0.30 μg/kg. In autumn milk samples, the level of aflatoxin M1 revealed a range value between 0.028 - 0.9 μg/kg with a mean level of 0.20±0.31 μg/kg.
The average values of the examined aflatoxin M1 of showed a significant difference at P < 0.05 between the winter, spring, summer and autumn milk samples. Also, there is a significant difference at P < 0.05 between spring, summer and autumn milk samples. There is not significance difference at P < 0.05 between the average levels of aflatoxins M1 of summer and autumn milk samples.
The frequency distribution detection percentage was 85.7, 64.2, 78.5. 78.5 % for aflatoxin M1 in winter, spring, summer and autumn milk samples. However, in comparison with the international MRLs, the percentages of aflatoxin M1 samples exceeding MRL of European Union (Eu) (2006), are 78,57, 100 and 64% in winter, spring, summer and autumn milk samples, respectively, where the limit for AFM1 MRL is 0.05 μg/kg. In comparison with the MRL of Codex Alimentarius (FDA/WHO) (2001), the percentage of aflatoxin M1 samples exceeding the limit are 78, 57, 100 and 64% in winter, spring, summer and autumn milk samples, respectively, where, AFM1 MRL is 0.05 μg/kg. The percentage of aflatoxin M1 samples exceeded the MRL of the US FDA, (2011) limit for AFM1 are 50, 28, 21 and 14%, in winter, spring, summer and autumn milk samples, respectively, where AFM1 MRL is 0.5 μg/kg. The percentage of aflatoxin M1 samples exceeded the MRL of Egyptian regulation (ER) (2010) 2010/7136 last updated, are 78, 57, 100 and 64% in winter, spring, summer and autumn milk samples, respectively, where, AFM1 MRL is 0.05 μg/kg.
Previous studies conducted in Egypt showed an infrequent occurrence of AFM1 contamination when compared to that in our study. This may be attributed to differences in location, as most of the previous studies were conducted within the delta region. This area lies in northern Egypt, where fertile soil and green fodders are available as feed supplement to dairy cattle nearly year-round. This is in contrast to the Upper Egypt location of our study, where the dry seasons allow farmers to provide their animals green fodders only during a few winter months. Thus, the main feed supplements are grains and concentrated feed that were stored inappropriately. These factors may explain the similar results we obtained for milk samples from Sohag, as the samples’ AFM1 levels showed minimal significant differences. The milk samples investigated in the current study were collected from the Upper Egyptian city of Sohag, which is located in southern Egypt. This city experience extremely high temperatures, extended dry seasons, and low availability of green fodder. Thus, farmers in these regions often depend on the use of feedstuffs that have been inappropriately stored, which leads to aflatoxin contamination.
In conclusion, this study suggested that there is a serious public health hazard under Egyptian regulation due to AFM1-contaminated milk. All samples tested were positive for AFM1 and the concentrations were high compared with those obtained in studies previously conducted in Egypt. Finally, ingesting dairy products contaminated with this toxin poses a serious danger for public health, which is especially true for children, as they have the maximum consumption of milk from all age groups. Therefore, it is necessary to routinely monitor AFM1 levels in dairy products as a quality control measure to protect public health.