Detection of milk fat adulteration with coconut oil depending on some physical and chemical properties

Abstract

Background and Objective: Milk fat adulteration has always been a serious problem in the food industry because of the economic advantages of partly replacing high-priced fats with low-priced oils. So, the aim of this research was to attempt the detection of milk fat adulteration with coconut oil depending on some physical and chemical properties of different adulterated products. Methodology: Different adulterated milk fat treatments with coconut oil were prepared using cow, (CB) and buffalo milk fat. Six treatments of adulterated milk fat were prepared according to incorporate the ratio added of coconut oil. Milk fat samples of either cow as buffalo milk were adulteration by adding coconut oil in ratios of 25, 50 and 75% of total fat. Puree cow, buffalo and coconut oils (100%) were used as reference fats (controls). All samples were analyzed for chemical (acid value, iodine value, saponification number, peroxide value, fatty acids profile) and physical (refractive index, melting point) properties. Results: The results indicated that, most of the milk fat properties were significantly affected with adulteration with different ratios of coconut oil. Increasing the percentage of adulterated coconut oil into milk fat either cow or buffalo gradually decreased the refractive index, melting point, acid value, iodine value, peroxide value and unsaturated fatty acids (%). On the other hand, addition of coconut oil to pure milk fat either cow or buffalo led to significant increase of saponification number, total short chain (TSC) and saturated fatty acids (%). However, these values were gradually increased by increasing the ratio of added coconut oil to milk fat. Conclusion: It could be concluded that, some physical and chemical methods such as; melting point, iodine value, saponification number, percentage of TSC, saturated and unsaturated fatty acids may be useful to determine the adulterated of milk fat with different ratios of coconut oil. it could be calculated the ratios of adulteration in the cow and buffalo's milk fat with coconut oil by using different equations depended on the different of some physical and chemical properties between milk fat and coconut oil.