Dr. Tayseer Abdelraheem Sulieman is a highly experienced Quality and Food Safety professional with over 15 years of expertise in dairy production, food technology, and animal resources. He is currently serving as Head of Quality and Safety at Al Kadaro Slaughter for Meat Export, Sudan, where he oversees implementation of ISO 9001, ISO 14001, ISO 45001, ISO 22000, and HACCP systems to ensure international food safety and export quality standards. He holds a PhD in Dairy Production and Technology from the University of Khartoum, with specialized research on milk composition, chemical contamination, and dairy product quality. His professional background includes extensive laboratory analysis, microbiological testing, risk assessment, quality control, and statistical data analysis using SPSS. Dr. Sulieman has published several research articles in international journals related to dairy safety, processed cheese quality, and milk contamination. He has also participated in international food safety conferences and completed advanced certifications in HACCP, food security, and quality management systems. With strong leadership, research, and compliance management skills, he has contributed significantly to food safety advancement and quality assurance in Sudan’s dairy and meat export sectors.

Chemical Preservatives, Adulterants, and Antibiotic Residues in Raw Cow’s Milk in Khartoum State, Sudan   Objective: This study investigates the influence of season on the occurrence of adulteration by chemical preservatives and antibiotic residues (beta-lactam, tetracycline and sulfonamides) in the raw milk in the main towns of Khartoum State, Sudan. Chemical Preservatives, Adulterants, and Antibiotic Residues in Raw Cow’s Milk in Khartoum State, Sudan Objective: This study investigates the influence of season on the occurrence of adulteration by chemical preservatives and antibiotic residues (beta-lactam, tetracycline and sulfonamides) in the raw milk in the main towns of Khartoum State, Sudan. Methods: The milk samples (n= 270) were randomly collected from farms (90 samples), groceries (90 samples) and vendors (90 samples) during late summer and winter seasons, 135 samples during each season. The samples were placed in cool cracked ice and transported immediately to the laboratory for analysis. Results: Data revealed a high presence of the added water in the milk collected from vendors during late summer season (7.70± 9.46%). Also, hydrogen peroxide, starch and formalin were detected only in the milk obtained from vendors. However, the higher percentages of salt (32%) and ammonium sulphate (28%) were obtained in the milk samples collected from the groceries during late summer season, while the occurrence of ammonium sulphate was 26% in the samples collected from vendors during winter season. On the other hand, 93% of the milk samples examined during late summer season were positive for the occurrence of antibiotic residues compared to 55% that was detected during winter season. The highest percentage of antibiotic residues (26%) was found in milk from groceries during the winter season. Milk samples from vendors during late summer season contained beta-lactam, tetracycline, and sulfonamide in 19%, 13%, and 1% of samples, respectively, while these figures were 20%, 2%, and 3%, respectively, during winter season. Conclusions: The addition of water followed by the presence of salt and antibiotics are the most adulterants found in raw milk sold in Khartoum State especially from vendors during late summer season. : The milk samples (n= 270) were randomly collected from farms (90 samples), groceries (90 samples) and vendors (90 samples) during late summer and winter seasons, 135 samples during each season. The samples were placed in cool cracked ice and transported immediately to the laboratory for analysis. Results: Data revealed a high presence of the added water in the milk collected from vendors during late summer season (7.70± 9.46%). Also, hydrogen peroxide, starch and formalin were detected only in the milk obtained from vendors. However, the higher percentages of salt (32%) and ammonium sulphate (28%) were obtained in the milk samples collected from the groceries during late summer season, while the occurrence of ammonium sulphate was 26% in the samples collected from vendors during winter season. On the other hand, 93% of the milk samples examined during late summer season were positive for the occurrence of antibiotic residues compared to 55% that was detected during winter season. The highest percentage of antibiotic residues (26%) was found in milk from groceries during the winter season. Milk samples from vendors during late summer season contained beta-lactam, tetracycline, and sulfonamide in 19%, 13%, and 1% of samples, respectively, while these figures were 20%, 2%, and 3%, respectively, during winter season. Conclusions: The addition of water followed by the presence of salt and antibiotics are the most adulterants found in raw milk sold in Khartoum State especially from vendors during late summer season. : This study investigates the influence of season on the occurrence of adulteration by chemical preservatives and antibiotic residues (beta-lactam, tetracycline and sulfonamides) in the raw milk in the main towns of Khartoum State, Sudan. Methods: The milk samples (n= 270) were randomly collected from farms (90 samples), groceries (90 samples) and vendors (90 samples) during late summer and winter seasons, 135 samples during each season. The samples were placed in cool cracked ice and transported immediately to the laboratory for analysis. Results: Data revealed a high presence of the added water in the milk collected from vendors during late summer season (7.70± 9.46%). Also, hydrogen peroxide, starch and formalin were detected only in the milk obtained from vendors. However, the higher percentages of salt (32%) and ammonium sulphate (28%) were obtained in the milk samples collected from the groceries during late summer season, while the occurrence of ammonium sulphate was 26% in the samples collected from vendors during winter season. On the other hand, 93% of the milk samples examined during late summer season were positive for the occurrence of antibiotic residues compared to 55% that was detected during winter season. The highest percentage of antibiotic residues (26%) was found in milk from groceries during the winter season. Milk samples from vendors during late summer season contained beta-lactam, tetracycline, and sulfonamide in 19%, 13%, and 1% of samples, respectively, while these figures were 20%, 2%, and 3%, respectively, during winter season. Conclusions: The addition of water followed by the presence of salt and antibiotics are the most adulterants found in raw milk sold in Khartoum State especially from vendors during late summer season.