Rice brain oil. I. Oil obtained by solvent extraction

1. Freshly milled rice bran has been extracted with commercial hexane and the recovered oil and extracted meal examined for their respective content of wax. The oils were refined and bleached by standards as well as several special methods. The crude, caustic soda refined, and several refined and bleached oils were examined spectrophotometrically.
2. When freshly milled rice bran of good quality is extracted with commercial hexane, an oil of relatively low free fatty acid content is obtained. This oil possesses good color and is as stable as other similar types of crude oils.
3. If the oils is extracted from the brain at a temperature below about 10°C. and the extraction is discontinued at the right time, the extracted oil represents 90–95% of the total lipids in the brain and contains very little wax. This wax, which is readily extracted with hot commercial hexane as well as other types of solvents, amounts to about 3–9% of the total extractable lipids.
4. When subjected to ordinary caustic soda refining methods, good rice brain oils behave much like cottonseed oils of comparable free fatty acid content. Both caustic soda refining in a hydrocarbon solvent and refining with sodium carbonate result in refining losses approximating the absolute or Wesson loss.
5. Some of the refined oils when bleached according to usual practice produce products acceptable for use in the edible trade. However, refined rice bran oil has a definitely greenish cast resulting from the presence of chlorophyll, but this color can be removed by bleaching with a small amount of activated acidic clay.