Isolation and Evaluation of Stearin and Olein Fractions from Rice Bran Oil Fatty Acid Distillate by Detergent Fractionation and Conversion into Neutral Glycerides by Autocatalytic Esterification Reaction

Abstract

Detergent fractionation (Lanza process) offers a valuable separation process for edible oils that contain varying amounts of saturated and unsaturated fatty acids. The rice bran oil fatty acid distillate (RBOFAD), obtained as a major byproduct of rice bran oil deacidification refining process, was fractionated by detergent solution into a fatty acid mixture as follows: low‐melting (19.00 °C) fraction of fatty acids as olein fraction (44.50 g/100 g) and high‐melting (49.00 °C) fatty acids as stearin fraction (37.15 g/100 g). A high amount of palmitic acid (42.75 wt%) is present in stearin fraction, while oleic acid is higher (48.21 wt%) in the olein fraction. The stearin and olein fractions of RBOFAD with very high content of free fatty acids are converted into neutral glycerides by autocatalytic esterification reaction with a theoretical amount of glycerol at high temperatures (130–230 °C) and at a reduced pressure (30 mmHg). Acid value, peroxide value, saponification value, and unsaponifiable matters are important analytical parameters to identity for quality assurance. These neutral glyceride‐rich stearin and olein fractions, along with unsaponifiable matters, can be used as nutritionally and functionally superior quality food ingredients in margarine and in baked goods as shortenings.

Enzymatic pretreatment of rice bran acid oil before ?-oryzanol recovery

“…polarity) to the γ-oryzanol (Narayan, Barhate, & Raghavarao, 2006). Thus, they are required to be removed or at least reduced before the γ-oryzanol recovery (Joshi et al, 2016;Kaewboonnum, Vechpanich, Santiwattana, & Shotipruk, 2010;Narayan et al, 2006;Sahu, Ghosh, & Bhattacharyya, 2019;Xu & Godber, 2001) Hydrolysis is the common method which has been employed to remove glycerides in RBAO, in which glycerides are converted into more separable FFAs and glycerol (Meedam, Usaku, Daisuk, & Shotipruk, 2020). This reaction can be conducted with/without a catalyst.…”