Rice bran oil is characterized by its unique composition of unsaponifiable matter such as oryzanol, squalene, sterols, tocopherols and fatty alcohols. Rice bran oil fatty acid distillate (RBOFAD) is an important by-product of physical refining plants. In the present study, an appropriate fractionation methodology is proposed for isolating the unsaponifiable matter into two fractions, squalene, phytosterols and fatty alcohols as fraction 1; tocopherols and γ- oryzanol as fraction 2. The two fractions together constitute the total unsaponifiable matter in the RBOFAD. The individual unsaponifiable matter components (γ-oryzanol 1.78g/100g, squalene 209.63 mg/100g, tocopherol 2.45mg/100g, total phytosterols 3.79g/100g and fatty alcohols 94.23g/100g) were isolated from RBOFAD by combining a chemical esterification process and liquid-liquid extraction process with 95% ethanol which extracted tocopherol, γ-oryzanol, sterols, squalene, FFA, monoglycerides; later with hexane extraction of the alkaline phase to remove squalene, sterols and fatty alcohols. The alkaline salts of tocopherols and γ-oryzanol are decomposed by the acidification and extraction of the unsaponifiable matter with n-hexane.

Rice bran oil fatty acid distillate (RBOFAD) is an important by-product obtained from the physical refining process. This fatty acid distillate contains high a amount of Unsaponifiable Matter (γ-oryzanol 3.27 gm/100gm UM; total tocopherol 10.93 mg/100 g UM; total phytosterol 21.81 g/100g UM; squalene 1.15 g/100 g UM and total fatty alcohol 73.34 g/100 g UM) and free fatty acids. Antioxidant-rich Oleogels were obtained from rice bran wax (RBW), rice bran oil fatty acid distillate (RBOFAD) and refined rice bran oil. The main objective of this study was to utilize the antioxidant-rich unsaponifiable matter of RBOFAD (UMRBOFAD) as an organogelator along with rice bran wax, which also acts as a good organogelator. Antioxidant-rich oleogel was prepared using UMRBFAD, ethylcellulose (EC) and RBW at 2%, 2%, 3% on weight basis, respectively, in refined rice bran oil and this antioxidant-rich oleogel was compared with rice bran oil oleogel using RBW at 7% on weight basis of rice bran oil. These oleogels were evaluated using a combination of techniques such as differential scanning calorimetry (DSC), polarized light microscopy (PLM), Viscosity, synchrotron radiation X-ray diffraction (SR-XRD) and FTIR Spectroscopy. The differential scanning calorimetry (DSC) measured the thermal properties of rice bran oil oleogel and high antioxidant-rich oleogel. Polarized light microscopy images revealed needle-like crystals for RBW. SR-XRD measurements were used for clarification of the crystal structures of the building blocks of these oleogels. The antioxidant activities of oleogels were evaluated involving DPPH and ABTS assays.

Detergent fractionation (Lanza process) offers a valuable separation process for edible oils that contain varying amounts of saturated and unsaturated fatty acids. The rice bran oil fatty acid distillate (RBOFAD), obtained as a major byproduct of rice bran oil deacidification refining process, was fractionated by detergent solution into a fatty acid mixture as follows: low‐melting (19.00 °C) fraction of fatty acids as olein fraction (44.50 g/100 g) and high‐melting (49.00 °C) fatty acids as stearin fraction (37.15 g/100 g). A high amount of palmitic acid (42.75 wt%) is present in stearin fraction, while oleic acid is higher (48.21 wt%) in the olein fraction. The stearin and olein fractions of RBOFAD with very high content of free fatty acids are converted into neutral glycerides by autocatalytic esterification reaction with a theoretical amount of glycerol at high temperatures (130–230 °C) and at a reduced pressure (30 mmHg). Acid value, peroxide value, saponification value, and unsaponifiable matters are important analytical parameters to identity for quality assurance. These neutral glyceride‐rich stearin and olein fractions, along with unsaponifiable matters, can be used as nutritionally and functionally superior quality food ingredients in margarine and in baked goods as shortenings.