Methods to differentiate between cotton tract area ghee and cotton seed oil adulterated ghee

Ghee, the clarified butter fat is one of the principal dairy products in India. In some places of India, cotton seed is fed extensively to dairy animals which changes the physico-chemical constants and fatty acid profile of the milk fat. Ghee is often adulterated with cotton seed oil and is marketed as cotton tract area ghee. Physico-chemical constants like RM value, Polenske value, BR reading, saponification value, iodine value and colorimetric tests i.e., Halphen and DPPH radical test were employed to differentiate ghee adulterated with cotton seed oil and that from cotton tract area. Chromatographic techniques like HPLC and GC-MS were also explored. Physico-chemical constants were not useful to differentiate the two types of ghee. Cyclopropenoic acids were observed only in ghee adulterated with cotton seed oil and not in cotton tract ghee. The RP-HPLC could able to distinguish the cotton tract area ghee from ghee adulterated with cotton seed oil on the basis of presence of β-sitosterol in the latter. Halphen test was positive for cotton tract ghee, but not for the cotton seed oil adulterated ghee. Methylene blue reduction and DPPH radical test were also found to be useful to distinguish both types of ghee.