Study of Storage Conditions Effect (Light-Heat) on Natamycin Co ntent and Stability in Some Dairy Products (Cheese-Yoghurt)

The study aims to determine changes of Natamycin content in some dairy products (cheese-yoghurt) from different local companies in refrigeration conditions (4oC ± 2oC) or different temperatures (25oC ± 2oC , 40oC ± 2oC) and during exposure to sunlight at room temperature (25oC ± 2oC) using ultraviolet spectrophotometer method. This study was based on the collection of samples at the same day (the same type from the same batch) and used to study the effect of temperature and light on natamycin content in these pervious products. Results of analysis showed that exposure to sunlight and different temperature conditions significantly affected the stability of natamycin. A significant negative correlation exists between natamycin and storage time. Natamycin content was more stable in cheese and yoghurt products when stored under refrigeration conditions (4oC ± 2oC) in a dark place. A little significant effect on natamycin content during exposure to room temperature (25oC ± 2oC) without exposure to sunlight. A more significant effect on natamycin content was found during exposure to high temperatures (40oC ± 2oC) compared to effect of sunlight at 25oC ± 2oC. These results showed that dairy products containing natamycin should be kept away from sunlight and high temperatures.