Deacidification Rice Bran Oil Using Deep Eutectic Solvent (DES) and Natural Deep Eutectic Solvent (NADES)
Firdia Maulita, Afifatul Jannah, Siti Zullaikah, M. Rachimoellah
Chemical Engineering Department, Industrial Technology Faculty, Sepuluh Nopember Institute of Technology, Surabaya, Indonesia
Abstract
Rice bran has a high content of antioxidants and vitamin E so that it can reduce cholesterol levels, become an antidote to free radicals, and is good for skin health. This rice bran can be processed into edible oil, but too high a level of FFA can disrupt the quality of crude rice bran oil as it causes a rancid odor. Deasidification is a process to eliminate high levels of Free Fatty Acid (FFA) in crude rice bran oil (CRBO). There is a biological deasidification process using enzymes, but enzymes are still considered too expensive to use. The chemical and physical deasidification process is a commonly used process. The chemical deasidification method is carried out by adding alkaline solutions to oils containing low FFA with the advantage of leaving FFA of 0.5-2%, but can significantly eliminate the content of neutral oils and bioactive components such as oryzanol. Physical deasidification using distillation requires high energy, although the results obtained are quite good. Another physical deasidification method being developed is liquid-liquid extraction (LLE) which can minimize energy consumption levels and lose bioactive components. Physically deasidification using the liquid-liquid extraction method will be applied in this study using green solvents which are non-toxic, non-volatile, non-flammable, recyclable. The green solvent used is Deep Eutectic Solvent (DES) from Choline Chloride - Ethylene Glycol with a ratio of 1: 2 molar ratio and Natural Deep Eutectic Solvent (NADES) from Betaine Monohydrate - Glycerol with a 1: 8 molar ratio. The purpose of this study is to study the DDRBO deasidification process using DES and NADES in single extraction and multiple extraction, the effect of DES and NADES on the rate of FFA and recovery γ-oryzanol at each stage, and the effect of initial FFA levels (5%, 10%, 20 %, 30%, 40% and 60%) of using DES and NADES in eliminating FFA. Rice bran oil containing the initial FFA content will be mixed with a solvent then stirred while heated at 50oC for 240 minutes. The results obtained at each stage were tested using saponification value analysis and gas chromatrography mass spectrophotometry analysis to determine the level of FFA in oil, as well as UV-Visible Spectrophotometer to determine oryzanol levels in oil. With the deasidification process in this study, FFA in CRBO can be completely removed without disturbing the composition of bioactive components using the method of liquid-liquid extraction multi extraction with green solvent which is safer for the environment.
Keywords: Betaine Monohydrate, Choline Chloride, Deacidification, Liquid-liquid Extraction, Rice Bran Oil
Topic: Chemical Engineering