Palm Oil Quality Determination During Fish Frying by Fourier Transform Infra Red Spectroscopy

Abstract

Determination of frying oil quality by Fourier transform infra red spectroscopy (FTlR) is rarely studied. FTIR profiles of frying oil during short term of fish frying and their free fatty acid (FFA) and peroxide values were investigated, and their relationship using multivariate statistics was determined to confirm the oil quality. Two batches of commercial palm oil were used to fry cat fishes for nine times. Each frying was done at 185 °C for 15 min. Samples were analyzed FFA and peroxide value by standard AOAC method. FTIR spectra were collected in wavenumber 400-4000 cm-1 by using 32 scans and at resolution of 1.9 cm-1. This analysis was done with XLSTAT 2011 software from Microsoft Excel Series. The tools used is OLS (Ordinary Least Square) analysis. The main peak positions observed in FTIR spectra mentioned the oil functional groups such as alkyl, ester, single and double bonds of carbon atoms. According to FFA and peroxide values, the worse oil quality showed the higher values. The correlation between absorbance values of peaks in FTIR spectra and FFA values exhibited a significant correlation (R2= 0.955) at Pvalue 0.042 obtained by multivariate analysis, whilst the correlation with peroxide values showed a significance at R2 = 0.963 with Pvalue 0.030. Based on these results, FTIR spectroscopy can be used to analyze the quality of palm oil after frying