Which method is appropriate for lard detection in halal foods: Fourier transform infrared, differential scanning calorimetry, or polymerase chain reaction?

Background and objective: Lard is commonly used in food industry due to its availability, low cost, and ability to enhance food quality. However, certain religious groups such as Muslims do not eat it and consider lard as non-halal food. In the present study, for the first time, we conducted chemical and molecular analysis to detect different percentages of lard simultaneously. Materials and methods: To determine origin of a sample containing lard, various percentages of lard including ۱۰۰, ۵۰, ۴۰, ۳۰, ۲۰, ۱۰, ۵, ۳, ۱ and ۰% w/w were prepared in triplicate and tested for Fourier transform infrared, differential scanning calorimetry, and polymerase chain reaction analysis. Fourier transform infrared spectral analysis was carried out in the mid-infrared range (۲-۲۵ µm). Differential scanning calorimetry analysis was done from -۶۰ to ۶۰ ºC at scan rate of ۱۰ ºC/min. The reactions in polymerase chain reaction analysis were amplified by specific primers which designed from cow and pig. Results and conclusion: Our results demonstrated that all three methods could detect various quantities of lard, but Fourier transform infrared and differential scanning calorimetry had some exceptions in their results. In comparison, polymerase chain reaction could amplify the pig-specific band (۲۱۲ bp) in all samples containing lard. Therefore, our results showed that polymerase chain reaction approach is more reliable and accurate than two other methods.

Keywords:

Differential Scanning Calorimetry , Fourier transform infrared , Halal , lard , Polymerase Chain Reaction