Preferential extractability of γ‐oryzanol from dried soapstock using different solvents

BACKGROUND: γ‐Oryzanol from rice bran has lately gained potential importance because of its proven health benefits. Thus the extractability of γ‐oryzanol from the soapstock of crude rice bran oil is important from the perspective of future large‐scale production, which would give value addition to this by‐product obtained from the rice bran oil industry. The aim of the present study was to investigate the extraction of γ‐oryzanol from the drum‐dried soapstock of rice bran oil using various solvents. RESULTS: It was found that γ‐oryzanol could be extracted most effectively using ethyl acetate, followed by dichloromethane and ethyl methyl ketone. All components of γ‐oryzanol have an alcohol group in the ferulate portion giving rise to relatively high polarity, thereby increasing the extraction in more polar solvents efficiently. Ethyl acetate showed maximum extractability of γ‐oryzanol by the Soxhlet method. To quantify γ‐oryzanol, reverse phase high‐performance liquid chromatography (RP‐HPLC) was used for fingerprinting the γ‐oryzanol analogues with respect to standard γ‐oryzanol. CONCLUSION: A new RP‐HPLC method for determining the individual components of γ‐oryzanol has been reported that can be used for performing an online characterisation of γ‐oryzanol analogues by liquid chromatography/mass spectrometry.