Prediksi Penurunan Kualitas Minyak Goreng Kelapa Sawit menggunakan Fourier Transform Infrared (FTIR) Spectroscopy dengan Analisis Multivariat

Abstract

This study aims to investigate the FFA value, peroxide value, and spectroscopic profile of frying oil during short term of frying and to find out their relationship using multivariate statistics. Two batches of commercial palm frying oil are used to fry cat fish for nine times. Each frying is done at 185o C for 15 minutes. The control sample and the odd frying number samples are taken to undergo analysis of FFA value, peroxide value, and spectroscopics profile. In batch 1, the FFA value is decreased from 0,80 mg NaOH/ g sample in control sample to 0,22 mg NaOH/ g sample in the ninth frying samples. In batch 2, the FFA value is decreased from 0,66 mg NaOH/ g sample in control sample to 0,30 mg NaOH/ g sample in the ninth frying samples. The peroxide value shows increasing and then decreasing trend. In batch 1, the third frying sample contains the highest peroxide value (23,93 meq O2/ kg sample) before it decreases on the ninth frying sample (4,83 meq O2/ kg sample). In batch 2, the third frying sample contains the highest peroxide value (27,48 meq O2/ kg sample) before it decreases on the ninth frying sample (5,87 meq O2/ kg sample). The main peak positions from FTIR spectroscopy are located on 722, 872, 912,5, 966, 1032, 1091, 1400,5, 1418, 1654, 1729, 2974,36, 3005,54, 3474,91, and 3530 cm-1. These peaksare correlated with oil functional groups such as alkyl, esther, saturated and unsaturated fatty acid. The correlation of FFA value and percentage of absorbance’s intensity shows equation with R2 = 0,955 and P value 0,042. While the equation for the peroxide value one shows R2 = 0,963 and P value 0,030. Both of the equation use significance level 5%.