Effect of Pasteurization and Gamma irradiation on some pathogens and sensory characteristics of milk

Awad, Salwa; Saudi, Adel; S, Khalid; Zahran, Dalia

doi:10.21608/vmjg.2017.355278

Effect of Pasteurization and Gamma irradiation on some pathogens and sensory characteristics of milk

Document Type : Original Article

Authors

¹ Food Hygiene Department, Animal Health Research Institute, Giza, Egypt

² Food Hygiene Department, Faculty Veterinary Medicine, Cairo University

³ National Centre for radiation Research and Technology

10.21608/vmjg.2017.355278

Abstract

The aim of this study was to compare between the efficiency of pasteurization and Gamma irradiation treatments for their antimicrobial effects on three important foodborne pathogens including L. monocytogenes, S. aureus and E. coli in milk. Additionally, the effect of these treatments on sensory characteristics of milk were also monitored before and after treatments. Milk samples were inoculated with the reference strains of L.monocytogenes "ATCC7644", E. coli "ATCC25922" and S. aureus "ATCC6538" with the inoculated dose of 10’Logyo cfu/ml milk (Control sample). Milk samples were subjected to pasteurization at 63°C for 30 minutes and to gamma irradiation at concentration of 2, 3, 4 and 5 kGy. A three trials based experiment was designed to each treatment and statistical analysis was performed. The: obtained results showed that pasteurization process was the most significant result as all inoculated pathogens under: study were completely eliminated. Otherwise, the organisms could not be detected any more after application of | pasteurization, while all examined samples are positive for inoculated pathogens after gamma irradiation treatments even with the highest dose of 5 KGy, the reduction increased with the increasing of irradiation dose. Moreover, the obtained results reveal that Gamma irradiation had no adverse effect on sensory characteristics of milk while pasteurization induces adverse effects.

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