Application of Fast Gas Chromatography and Fourier Transform Infrared Spectroscopy for Analysis of Lard Adulteration in Virgin Coconut Oil

Abstract

Lard (LD) and virgin coconut oil (VCO) share some similarities such as having transparent to yellowish color and are solid at room temperature; hence, as a consequent, LD may be a potential oil adulterant in VCO. This study highlights the application of fast gas chromatography with surface acoustic wave detector (GC-SAW system) and Fourier transform infrared (FTIR) spectroscopy combined with chemometrics to analyze the presence of LD in VCO. Binary admixtures of LD in VCO in various percentage concentrations ranging from 1% to 50% (v/v) were assayed using the fast GC-SAW system and FTIR spectroscopy. Using the fast GC-SAW system, ten different chromatogram peaks were identified as the adulterant peaks. One peak in the fast GC-SAW system chromatogram was found to have the best relationship, with a coefficient of determination (R 2 ) value of 0.9344. Furthermore, FTIR spectroscopy coupled with partial least square (PLS) and discriminant analysis (DA) can be successfully developed for quantification and classification of LD in VCO. The results showed that PLS able to predict the LD contents in VCO with equation of y ¼ 0:999 Â þ0:006, for the correlation between actual value of LD (x) and FTIR predicted value (y) with R 2 of 0.9990 at frequency regions of 3,020-3,000 cm −1 and 1,120-1,000 cm −1 . DA can classify VCO and that adulterated with LD using the FTIR spectra at the same frequency regions used in quantification.

Physico‐chemical properties and fatty acid profile of seed oils from pomegranate (Punica granatum L.) extracted by cold pressing

“…GC‐SAW analyzes volatile compounds (input) via chromatography, the peaks from which are transformed into a radial plot of SAW detector response (aroma intensity) with the retention time as an angular variable (Fig. ) . The radial plot is unique to the particular substances analyzed and in turn can be the basis for identifying volatile compounds in the sample.…”

“…The radial plot is unique to the particular substances analyzed and in turn can be the basis for identifying volatile compounds in the sample. In addition, oil sample volatile compounds can be recognized based on their specific retention time, also known as Kovats indices .…”

“…Alkane standards were run and compared to the measurement of retention time from the n ‐alkane vapor standard, also known as Kovats indices. All data acquisition were performed in four replicates and presented in Kovats indices .…”

A review on the application of chromatographic methods, coupled to chemometrics, for food authentication

“…PLS-LDA was also used in this work for the detection of adulteration with a 1% detection limit and 90% prediction ability. Mansor et al (2011) investigated the application of GC with surface acoustic wave detector (GC-SAW system), combined with chemometrics, to analyze the presence of lard in virgin coconut oil. Different lard and virgin coconut oil mixtures ranging from 1% to 50% (v/v) were subjected to a fast GC-SAW system.…”

Signal Enhancement Evaluation of Laser-Induced Breakdown Spectroscopy of Extracted Animal Fats Using Principal Component Analysis Approach

“…6 This situation lowered the quality of the products and confused the consumer who really care about the ingredients of the products. 7 In addition, Muslims and Hindus are forbidden to consume any products containing pig and beef derivatives, respectively. 8 Several techniques therefore have been developed to discriminate different type of animal fats.…”