Detection of lard contamination in five different edible oils by FT-IRspectroscopy using a partial least squares calibration model

Abstract

Lard is defined as animal fat acquired from the adipose tissue of pigs and is not permitted for human consumption or external use by certain religions such as Islam and Judaism. Due to its low-cost availability for commercial use, it is often mixed with other vegetable oils mistakenly or deliberately and causes loss of consumer trust; hence, its detection in food products is essential. Consumers tend to know the authenticity of commercially available edible oils. However, edible oils are subjected to adulteration risks with lard, which breaches consumer rights. In the present study, we designed a transmission Fourier transform infrared spectroscopy (FT-IR)-based method for the rapid detection of lard in sunflower, canola, coconut, olive, and mustard oils. For this purpose, the selected oils were adulterated with lard in different concentration ratios (10:0, 9:1, 7:3, 6:4, 4:6, 3:7, 0:10). A single calibration model was developed for 35 standards (seven standards from each individual five oils) in the frequency range between 1078.01 and 1246.75 cm −1 to determine the relationship between actual adulterant concentration and FT-IR predicted concentrations using a partial least squares (PLS) method. The results of the present study indicated that FT-IR in combination with PLS has the potential to evaluate adulteration of edible oils with lard through single calibration as a rapid, nondestructive, and effective alternative method.

Adulteration detection technologies used for halal/kosher food products: an overview

“…In 2012, Xu et al, obtained the best classification performance for discrimination using PLSDA (partial least squares discriminant analysis) with SNV (standard normal variate) spectra (sensitivity 0.913 and specificity 0.929) and LS-SVM (least squares support vector machine) with second derivative spectra (sensitivity 0.957 and specificity 0.929) in terms of prediction sensitivity and specificity [ 150 ]. Recently, the FTIR spectrum technique was used in combination with a partial least squares (PLS) method for the rapid detection of lard in sunflower, canola, coconut, olive, and mustard oils [ 151 ]. Moreover, a research aimed to developing an analytical method using FTIR spectrophotometry in combination with chemometrics to analyze lard content in grilled and steamed beef sausage with pork has been reported in the literature [ 152 ].…”

Analytical methods used for the characterisation of specific features of biological tissues related with obesity: A review

“…The results were comparable to the concentration of lard in binary mixtures with other oil. The correlation coefficient of 0.9577 was produced in the wavenumber region of 1078.01-1246.75 cm -1 [87].…”

Formulation and tribological performance of engine oil blended with various non‐edible vegetable oils

“…26 Bands that appear at 2922-2954 cm À1 are caused by C H vibrations, specifically the asymmetrical stretching of CH(CH 2 ) and the asymmetrical stretching of CH 3 . 27,28 The absorption spectrum intensity maps of the two non-edible vegetable oils; C100 and J100; were similar as shown in Figure 2. The small hump at 586 cm À1 was caused by the stretching vibrations of C O in the carbohydrate and glycoside groups.…”