A process for the preparation of food‐grade rice bran wax and the determination of its composition

Abstract

A two-step method was developed for the preparation of food-grade wax. The first step involved the solventdefatting of crude wax, which gave a dark brown, dry, powdered wax with a m.p. of 75-79°C. The major impurity in the defatted wax was the dark brown resinous matter. In the second step, the resinous matter was removed by bleaching with sodium borohydride in isopropanol. This step yielded a pale yellow, odorless wax with purity higher than 99% and with a m.p. of 80-83°C. The resinous matter was a mixture of aliphatic aldehydes, fatty alcohols, and FA. High-temperature GC analysis of the purified rice bran wax indicated that it contained 11 major and 9 minor types of saturated wax esters. The major and minor peaks contained C 44 -C 64 and C 45 -C 59 wax esters, respectively. Rice bran wax was mainly a mixture of saturated esters of C 22 and C 24 FA and C 24 to C 40 aliphatic alcohols, with C 24 and C 30 being the predominant FA and fatty alcohol, respectively. The alcohol portion of the wax esters also contained small amounts of branched and odd carbon number fatty alcohols.

Effects of Crude Rice Bran Oil Components on Alkali‐Refining Loss

“…Crude RBW was the gift of Thai Edible Oil Co., Ltd. (Bangkok, Thailand). The crude wax was purified by washing two times with hot hexane and one time with isopropanol to remove triglycerides, FFA, and other lipid constituents [13] and then dried in a hot air oven (B60°C) before use. Purity was about 98% (Fig.…”

Comparative Studies between Conventional and Microwave Assisted Extraction for Rice Bran Oil

“…It is white to yellowish in color and can be made available in flakes form. It can be obtain by dewaxing step in refinery process 14 . It can be again separated from oil using filtration and centrifuge process 15 .…”

Untitled

“…Purification of crude rice bran wax to get foodgrade rice bran wax [10] The purification of rice bran wax involves a two-step process commencing from the removal of residual oil with the help of solvent n-hexane followed by isopropanol. The defatted wax is then bleached with sodium borohydride to yield a white compound which can be used further.…”