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

Abstract

Rice bran oil (RBO) is rich in a variety of bioactive phytochemicals otherwise known as unsaponifiable constituents (USC). Oryzanols, phytosterols, tocols, etc. are the major USC in RBO; the methods presently used for their estimation involve different techniques and require pretreatment of the sample. In this paper standardization of a simple method for simultaneous estimation of USC directly from RBO using HPTLC is presented. The method involves a two-stage separation of USC on a precoated silica gel 60 F(254 )TLC plate viz.: TLC-1 to separate sterols, oryzanols and tocols; TLC-2 to separate steryl esters, wax, and squalene. Calibration plots using the respective standards were made to determine LOD, LOQ, and linear regression equations. Recovery studies were also conducted and the values ranged from 93.45 to 101.97%. The LOD and LOQ values showed the sensitivity of the method. The instrumental precision was found to be in the range of 0.30 to 1.18 CV%. Quantitative estimation of USC in crude RBO and refined RBO using this method gave a concentration of 52.80 mg/g of USC in the crude and 33.48 mg/g in the refined oil. The present method for estimation of USC using HPTLC is fast, simple, accurate, precise, and sensitive, as demonstrated here.

Lipid Profiling of the Carob Fruit (Ceratonia Siliqua L.)Using GC/LC/QTOF Accurate Mass Spectrometry

“…Unsaponifiable matters from the lipid extract were analyzed using the standard AOCS method [13]. Oil samples were saponified by refluxing with 0.5 (N) ethanolic potassium hydroxide for 2 hours on a water bath the unsap matters were extracted with petroleum ether, washed with water, dried over anhydrous sodium sulfate and analyzed by GCMS at the same condition described above.…”

“…We have shown previously [13] that mass spectral fragmentation can provide information about the stereochemistry and region specific identification of the TAGs. Based on our finding on the fragmentation of standard authentic TAGs and available published work [13][14][15] that ions corresponding from the loss of fatty acids from the sn1and sn3 positions are much more abundance the ion corresponding to the loss of fatty acid at the sn2 position. In addition, the fact that each fatty acid chain produces an RCO+ ion, if two or three of the chains are different, two or three different RCO+ are found but more for the sn1 and sn3 positions.…”

Simultaneous Determination of Vitamin E and γ-Oryzanol in Rice Bran Oil via HPSEC-PDA without Sample Pretreatment

“…Interference of acylglycerols (especially triacylglycerol) is a limitation of direct chromatographic analysis. Pretreatment methods such as saponification, liquidliquid extraction, and fractionation by chromatographic techniques (which are time-consuming) have been used for the removal of acylglycerols prior to analysis 11,12) . In addition, alteration of vitamin E and γ-oryzanol during saponification has been reported 11,13) .…”