Sterol and Squalene as Indicators of Adulteration of Milk Fat with Palm Oil and Its Fractions

Milk fat, one of the expensive fatty matters, might be sometimes adulterated with other edible fats, particularly palm oil or its fractions, which can be a major problem for the dairy industry, especially in Iran. The aim of this study was to investigate the adulteration of milk fat based on some minor components present in unsaponifiable matters, namely, sterols and squalene. Different concentrations of palm oil and its fractions (0, 1, 2, 5, 10, 20, 50, and 100%) were added to pure milk fat. Sterol and squalene contents were determined by the application of GC and HPLC, respectively. The experimental data showed that β-sitosterol was the main phytosterol in palm oils and it could be a good indicator for detection of adulteration by palm oil as low as 5%. The result also indicated that squalene was not identified in milk fat, so, it can be considered as a good indicator to show the presence of palm oil as low as 1%. According to the results, it might be concluded that sterols and squalene could be used as important indicators to find the presence of palm oil and its fractions in milk fat.