Adulteration of butterfat: validity of Reichert-Meissl, Polenske and iodine values

Abstract

Buffaloe's milkfat was obtained during the winter and the summer seasons. The beef tallow (Heart fat) was purchased from the local market. Beef tallow was added to the summer milkfat in the ratios 5%, 10%, 15% and 50% w/w. Thin layer chromatography was applied to obtain the triglycerides fraction of each sample obtained. Gas chromatography was used to identify the fatty acid content of the winter, summer and the admixtures. Reichert-Meissl (RM), Polenske (P) and Iodine values were also determined for each sample. It was concluded that the (RM) of the winter and the summer milkfat were 25.52±0.511 and 28.74±0.568, respectively. The (P) and iodine values were 1.94±0.162, 2.53±0.146 and 42.1±0.85, 30.33±0.839 in the same respect. The addition of beef tallow to the milkfat in the ratios 5% and 10% did not affect the (RM) and (P) values of the resultant admixtures. The presence of 15% beef tallow in milkfat slightly affected the (RM), (P) and iodine values. The addition of 50% beef tallow to the milkfat got the values of (RM) and (P) out of the normal range. The iodine values was still within the normal range of milkfat. It was also observed that the addition of beef tallow in the ratios 5%, 10% and 15% to summer milkfat, improved the fatty acid pattern of the milk fat, while the 50% beef tallow in milkfat, decreased all the short chain fatty acids. The determination of the (RM), (P) and iodine values to detect the beef tallow as an adulterant in pure milkfat is not sufficient at 5% and 10% beef tallow in milkfat.