Optimization of Low-Temperature Methanol Crystallization for Unsaturated Fatty Acids Separation from Crude Palm Fatty Acids Mixture Using Response Surface Methodology

Abstract

This current work studies the separation of unsaturated fatty acids from crude palm fatty acids mixture by methanol crystallization. Separation conditions of unsaturated fatty acid were optimized through the adoption of the response surface method and the optimal model was developed. The percentages of unsaturated fatty acids recovered under the optimal condition were higher than 95 ± 0.3 % with the yield of product percentage 55.2 ± 0.8 %. The optimized condition comprised of three essential aspects methanol-to-fatty acids ratio of 15:1 (mL:g), crystallization temperature of −15 ºC and crystallization time of 20.8 h, respectively. The unsaturated fatty acids composition isolated from crude palm fatty acids mixture consisted of 76.3 % oleic acid (C18:1), 18.3 % linoleic acid (18:2) and 0.2 % linolenic acid (C18:3). Only 4.9 ± 0.3 % of saturated fatty acids was discovered in the product. The iodine value of separated unsaturated fatty acids had increased from 54.0 ± 0.1 mg/g to 94.4 ± 0.2 mg/g. The results have demonstrated that low-temperature methanol crystallization is very active, low cost, stable and obtainable, and comparatively ease to recover for the separation of unsaturated fatty acids from an oil mixture of fatty acids.