Membrane degumming of crude rice bran oil: Pilot plant study

Abstract

The procedure for the classical chemical refining of vegetable oils consists of degumming, alkali neutralization, bleaching, and deodorization. Conventional refining of rice bran oil using alkali gives oil of acceptable quality, but the refining losses are very high. A critical work has been carried out to study the application of membrane technology in the pretreatment of crude rice bran oil. Oils intended for physical refining should have a low phosphorus content, and this is not readily achievable by the conventional acid/ water degumming process. The application of membrane technology for the pretreatment of rice bran oil has been investigated. The process has already been successfully applied to other vegetable oils. Ceramic membranes, which are important from the commercial point of view, were examined for this purpose. The results showed that the membrane-filtered oils met the requirements of physical refining, with a substantial reduction in color. It was observed that most of the waxy material was also rejected. Experiments were carried out to establish the relationship between permeate flux and rejection with membrane pore size, trans-membrane pressure and micellar solute concentration.

A new method for simultaneous estimation of unsaponifiable constituents of rice bran oil using HPTLC

“…The RRBO sample used here was produced in the laboratory following the physical refining method recommended to retain the bioactive phytochemical or the unsaponifiable constituents [8]. RBO consists of triacylglycerols (68 -71%), diacylglycerols (2 -3%), monoacylglycerols (5 -6%), FFA (2 -3%), waxes (2 -3%), glycolipids (5 -7%), phospholipids (3 -4%), and unsaponifiables 3 -4% [7]. These acyl glycerols or the saponifiables did not interfere with the USC, primarily due to selection of the solvent system and optimization of the conditions.…”

“…Solvent-extracted rice bran oil (RBO) contains these phytochemicals, high levels of wax, phosphatides, and free fatty acids (FFA) [4,5]. Recent evidence concerning an association between bioactive phytochemicals in the diet and health has imparted impetus to the utilization of rice bran for edible oil, keeping its bioactive phytochemicals intact [6,7]. New methods of physical refining have recently been developed and consequently more and more rice bran is being utilized for oil extraction and refining [8].…”

Review on Recent Trends in Rice Bran Oil Processing

“…Subrahmanyam et al [84] reported degumming of an RBO-hexane miscella obtained after dewaxing of crude RBO by using ceramic membranes, which are superior to polymeric membranes due to their wide range of pH tolerance, chemical inertness and ease of cleaning. Crude RBO (phosphorous 455 ppm and unsap 7.3%) was dewaxed by mixing the oil in hexane (3:7 v/v) and maintained at 8°C for 24 h. The clean supernatant miscella (322 ppm phosphorous) was used for membrane degumming.…”

Effect of saponification on composition of unsaponifiable matter in rice bran oil

“…RBO is exceptionally rich in unsaponifi ables that may account for 4-6 by weight of the oil 24 as compared to the normal range of 0.5-2 in other edible oils. The effect of saponifi cation on USC such as sterols, oryzanols, tocols etc has not been examined before.…”