Spectrophotometric determination of alkaline contaminant materials (ACM) in frying oil / Fadzillah Haryati Mohamad Yusof

A spectrophotometric based method was optimized to determine the changes in alkaline contaminant materials (ACM) in palm oil, corn oil and sunflower oil during 5 consecutive days of frying. The maximum wavelengths of sodium palmitate in palm oil was obtained at 592nm and for corn oil and sunflower oil the maximum wavelength of sodium oleate was obtained at 596nm. The correlation coefficient (R2) of the curve for palm oil, corn oil and sunflower oil were 0.9548, 0.8952 and 0.9846, respectively. The results showed that there was a significant difference (p<0.05) in ACM content for palm oil, corn oil and sunflower oil during 5 consecutive days of frying. The amount of ACM in 5 consecutive days of frying for palm oil, corn oil and sunflower oil calculated by the regression equation increased from Oppm to 168ppm, Oppm to 5.2ppm and Oppm to 4.8ppm, respectively. The visual colour in Standard solution for palm oil, corn oil and sunflower oil ranged from yellow (Omg/lOOg) to dark green (50mg/100g). The values of Hunter 'L' for palm oil, corn oil and sunflower oil ranged from 56.46 to 82.09, 61.19 to 74.17 and 51.29 to 72.70, respectively. The values of Hunter 'a' for palm oil, corn oil and sunflower oil ranged from -7.24 to -2.03, -1.78 to -4.91 and -0.12 to -4.65, respectively. The values of Hunter 'b' for palm oil, corn oil and sunflower oil was ranged from 34.72 to 58.77, 50.48 to 57.14 and 35.65 to 59.83, respectively.