Optimization of Vitamin E Extraction from Rice Bran Oil Deodorizer Distillate using Response Surface Methodology

Laichheang Yort¹, Riantong Singanusong¹, Jitkunya Yuenyong², Phumon Sookwong² and Sudarat Jiamyangyuen^1*

¹Department of Ago-Industry, Faculty of Agriculture, Natural Resources, and Environments, Naresuan University, Phitsanulok, Thailand.

²Rice and Cereal Chemistry Research Laboratory, Department of Chemistry, Faculty of Science, Chiang Mai University, Chiang Mai, Thailand

Corresponding Author E-mail: sudaratj@nu.ac.th

Rice bran oil deodorizer distillate (RBODD) is the low valuable secondary product of refinery rice bran oil. However, RBODD contains bioactive compounds such as vitamin E, gamma-oryzanols, and phytosterols. To increase value of vitamin E obtained from underutilized product, tocopherols and tocotrienols were extracted from RBODD using ethanol followed by a freezing step. The response surface method (RSM) is known as a potential tool for optimizing processing parameters in order to save time, energy, and chemical material. In current study, vitamin E extract (VEE) was extracted using ethanol and response surface method (RSM) was employed to investigate the optimum condition. The ratio of RBODD: ethanol (1:5, 1:10, and 1:15) and the incubation temperature (0, -20, and -40℃) of vitamin E extraction were used to design the experiment using a central composite design (CCD). Once the optimization process was completed, the RSM was executed using the following 5 responses simultaneously: VEET3, VEEToc, VEETot, RecoveryVEE, and YieldVEE. Results showed that values of each parameter were VEET3 (10.69-89.60 mg/g), VEEToc (2.85-23.37 mg/g), VEETot (13.53-112.97mg/g), RecoveryVEE (16.15-134.76%), and YieldVEE (12.64-44.48%). All model predictions were significant, with non-significant lack of fit (> 0.05). In addition, the values of R2 and R2(Adj) of model were in the range of 0.922-0.988 and 0.893-0.982, respectively. According to these findings, response values were associated with RBODD:ethanol ratio and the incubation temperature. The ratio 1:9.5 (RBODD: Ethanol) and incubation temperature at -26.5 ℃ provided the optimal condition for vitamin E extraction from RBODD. At this optimum condition, it was determined that the predicted responses for VEET3, VEEToc, VEETot, RecoveryVEE, and YieldVEE were 81.87 mg/g, 23.70 mg/g, 103.64 mg/g, 123.63 %, and 20.05%, respectively. The obtained product with high content of tocopherol and tocotrienol can be used as ingredient in food as well as pharmaceutical applications.

Response surface methodology; Rice bran oil deodorizer distillate; Vitamin E extraction

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