Evaluation of Color Stability in Palm Oil Catalytic Hydrogenation

Applications of fatty oils (triglycerides) in food industry and wax (candles) based on palm oil is dependent on the quality of color and color stability of the product (heat stability). Commercially, in addition to the desired color is more pale palm oil, palm oil quality parameters that are not less important is the stability of color. Heat Stability is an indication of the stability of the color of palm fatty oil after heating. The color change is likely to occur due to oxidation after the stage of the process such as hydrogenation, as it passes through stages of storage, transportation or other factors. Hydrogenation process aims to reduce the number of iodine (IV) which is an indication of a double bond or the saturation level of triglycerides in palm oil compounds. Hydrogenation is the process of termination or replacement carbon double bond group (unsaturated compounds) into a single bond carbon clusters (compound saturated) fat oil by reacting with hydrogen. The process of hydrogenation which is maintained in this experimental study took place in an autoclave (reactor), where the vacuum pressure and temperature of 150-200 °C, This reaction is using Nickel as a catalyst. The oil color and color stability (heat stability) measured by a calorimeter or Lovibond Cell, which reads color in units of red and yellow (R / Y). Hydrogenation of fatty oils in this study provide the initial color (R / Y = 1.5 / 9.6), from the initial conditions (R / Y = 1.92 / 1.19). Cooling process is added at the end of phase hydrogenation of palm oil is able to provide the same quality oil colors, but has a value of better color stability (R / Y = 3.8 / 25.7), compared to the hydrogenation process without cooling (R / Y = 4.2 / 29.1). In order to meet the specification of heat stability and for export commodities as well as storage for a long time, the process should be continued with the holding stage filtration using adsorbents (activated carbon and citric acid). The test of palm oil’s stability after this stage shows that the heat stability of the adsorbent filter with citric acid showed the better stability of oil color.