Optimization of hazelnut oil impurities with silica aerojel by response surface methodology

Alkaline neutralization is generally used in free fatty acid removal which is one of the refining stages of vegetable oils and the other stages is bleaching soils which used in decolorization. There have significant neutral fat lossess occur during neutralization. In order to obtain better quality oil instead of using bleaching soils during the color removel, silica containing adsorbents are prefferred. Silica aerogels ownered extensive surface area which have been used in the adsorption of various impurities and intens work on in recent years. Magnesium and calcium silicates in silica adsorbents have adsorption capacities on adsorbing color and polar compounds especially such as free fatty acids, monoglycerids and diglycerids. Silica aerogels which have homogeneous particle size in which the calcium and magnesium existing at the same time can increase the free fatty acids and color removel capacity from fats. In this study, with the use of calcium + magnesium metal added silica aerogel as an adsorbent which is frequently used in oil and other industries which can benefit from the refining problems of oil industries considerably and the adsorption analysis of free fatty acid and color removal of raw hazelnut oil by applying Box-Behnken method. According to the results, the optimum value about removing free fatty acid of raw hazelnut oil were found to be 60 minutes for time, 40.5℃ for temperature and 1.9% for racio (adsorbent) and free fatty acid removel of 28.4%, respectively. When only analyzing for color removal in the same experimental conditions, the optimum critical values of red, L, a and b were 4.40, 70.4, 7.01 and 32.7, respectively. And in this case three factors such as temperature were 89.3℃, time were 60 minutes and racio were 3% according to the Box-Behnken method. As a result, it has been shown that the calcium + magnesium silica aerogel which used in this study could be effectively perform in removing free fatty acids and color from raw hazelnut oil. Key Words: Hazelnut oil ,Box-Behnken Method, metal doped silica aerogel, silica aerogel