Examination of Natamycin Content in Iranian Yoghurt Drink (Doogh) produced in dairy processing plants in Isfahan, Iran

"Natamycin" is a preservative used in Iranian Yoghurt Drink (Doogh) to control the yeast and mould growth. The usage of preservatives is forbidden in Doogh due to some adverse affect on consumer health referring to Iran- Food and Drug Organization rules. But some food manufacturers use preservative such as natamycin in Doogh. In summer 2012, the present study was aimed to investigate the natamycin content in 39 Doogh produced in 19 active dairy processing plants with different hygiene conditions by RP-HPLC in Isfahan, Iran. The assessment of hygiene conditions was performed by Prerequisite Programme check list (PRPs) approved by Iran-Food and Drug Organization in dairy processing plants. The checklist is classified in four sections as follows: first) 8 questions for hygiene of workers; second) 17 questions for production and processing; third) 8 questions for washing/ disinfectant/ cleaning; fourth) 11 questions for hazard identification and verification. The dairy processing plants were divided to four grades including a) completely desirable; b) desirable; c) medium and d) undesirable. Natamycin was found in 4 samples produced in dairy processing plants with grade "medium". Regarding with the results of grading, 3 (15.7%), 6 (31.5%), 6(31.5%) and 4 (21.3%) of dairy processing plants had grade "completely desirable, desirable, medium and undesirable", respectively. We conclude that employing the hygiene conditions accompanied with HACCP implementation could control the microbial contamination in food stuff. Therefore the usage of preservative would be limited in Doogh.