PENETAPAN PARAMETER KUALITATIF DAN KUANTITATIF MINYAK GORENG CURAH DAN MINYAK GORENG KELAPA YANG MENGALAMI PEMANASAN BERULANG

Cooking oil is one of the media for frying and one of the daily basic needs for Indonesian people. Cooking oil that is still often used by the people of Indonesia is bulk cooking oil and coconut cooking oil. Along with the repeated use of cooking oil, the quality of the oil will also decrease due to the oxidation and hydrolysis of the oil. This study aims to determine the levels of free fatty acids, levels of peroxides, and the functional group spectral profile of bulk cooking oil and coconut cooking oil subjected to repeated heating using an FTIR spectrophotometer. This research is a laboratory experimental study that examines free fatty acids, peroxide numbers, and FTIR spectral profiles of samples of bulk cooking oil and coconut cooking oil which are subjected to repeated heating every 20 minutes. The test methods used are acid-base titration, iodometric titration, and Fourier Transform Infra Red (FTIR) Spectroscopy. The results were then statistically tested using the SPSS test (One Way ANOVA, Dunnett Test). The results showed that repeated heating had an effect on increasing levels of free fatty acids and peroxide values. The levels of free fatty acids and peroxide levels of bulk cooking oil in all samples did not meet the standards of SNI 7709:2012, which were above 0.3% and 10 mek O2/kg. The yield of free fatty acids of bulk cooking oil from before heating to heating (5) was 0.3002%; 0.3232%; 0.3466%; 0.3695%; 0.3924%; 0.4156%. For the peroxide content of bulk cooking oil from before heating to heating (5), respectively, namely 10.3113 mek O2/kg; 12.3506 mek O2/kg; 14,4133 mek O2/kg; 16.4894 mek O2/kg; 18.5605 mek O2/kg; 20.5894 mek O2/kg. For sample coconut cooking oil which is within the standard limits of SNI only up to heating (1), the yield of free fatty acids of coconut cooking oil from before heating to heating (5) is 0.2539%; 0.2771%; 0.3001%; 0.3231%; 0.3464%; 0.3693%. For the peroxide content of coconut cooking oil from before heating to heating (5), respectively, namely 6.1905 mek O2/kg; 8.2451 mek O2/kg; 10,3002 mek O2/kg; 12.3866 mek O2/kg; 14.4321 mek O2/kg; 16.4785 mek O2/kg. The results of the functional group spectral profiles of bulk cooking oil and coconut cooking oil that were subjected to repeated heating were the aliphatic C-H, C-H, C=O ester, cis C=C, CH3 CH2, C-O ester functional groups, and the trans C=C functional group