Employment of differential scanning calorimetry in detecting lard adulteration in virgin coconut oil.

摘要

Lard (LD) has been commonly used as an adulterant in fats and oils. The similar physical characteristic of virgin coconut oil (VCO) to LD makes LD a desirable adulterant in VCO. Differential scanning calorimetry (DSC) provides unique thermal profiling for each oil and can be used to detect LD adulteration in VCO. In the heating thermogram of the mixture, there was one major endothermic peak (peak A) with a smaller shoulder peak embedded in the major peak that gradually smoothed out to the major peak as the LD% increased. In the cooling thermogram, there were one minor peak (peak B) and two major exothermic peaks, peak C which increased as LD% increased and peak D which decreased in size as the LD% increased. From Stepwise Multiple Linear regression (SMLR) analysis, two independent variables were found to be able to predict LD% adulteration in VCO with R 2 (adjusted) of 95.82. The SMLR equation of LD% adulteration in VCO is 293.1 -11.36 (T_eA) -2.17 (T_rD); where T_eA is the endset of peak A and T_rD is the range of thermal transition for peak D. These parameters can serve as a good measurement index in detecting LD adulteration in VCO.