Detection of Milk Fat Adulteration

Abstract

Milk fat has been acclaimed as an indispensable superfood as its nutritional and sensory attributes offer plenty of health benefits (Achaya, 1997). It possesses good flavour, pleasant aroma, high calorific value, besides being a source of valuable nutrients such as fat-soluble vitamins and essential fatty acids. The prices of milk fat have shown upward trend due to the growing demand for it in developed countries which has been attributed to the shift in the opinion of the health concern related to its consumption (OECD/FAO, 2018). International Dairy Federation (IDF) has also noted that over the years there has been a shift in demand from vegetable oil based substitutes to butter and dairy fat due to positive health assessment of milk fat and its sensory properties (IDF, 2018). Increased price and fluctuation in its seasonal availability offers an advantage to the milk fat manufacturers to fraudulently adulterate it with cheaper oils/fats to reduce production costs and increase profit margins. Economic advantage of replacing high-priced fats and oils with low-priced oils without labeling the product accordingly escalates the adulteration of expensive oils and fats such as milk fat. This also poses a risk to human health and decreases its functional value (Ntakatsane, Liu, & Zhou, 2013). Characterization of milk fat for its purity is an absolute necessity in order to ensure a constant well-defined quality. Detection of adulterants in milk fat has always been a challenge because of the variable composition of the triglycerides present. The challenge to detect foreign fats in milk become bigger because of the seasonal, species or breeds related variation in the properties of milk fat. Further, the advent of hydrogenated vegetable oil (HVO) industry in the middle of the twentieth century led to large scale adulteration of milk fat with HVO due to the matching physical properties of both fats. Studies related to the detection and quantification of foreign fats in dairy products have been conducted for many decades and constitute priority areas in many research centers (Fontecha, Mayo, Toledano, & Juarez, 2006; Lipp, 1996; Parodi, 1971; Rebechi, Velez, Vaira, & Perotti, 2016; Timms, 1980).