Autocatalytic esterification of free fatty acids (FFA) in rice bran oil (RBO) containing high FFA (9.5 to 35.0% w/w) was examined at a high temperature (210°C) and under low pressure (10 mm Hg). The study was conducted to determine the effectiveness of monoglyceride in esterifying the FFA of RBO. The study showed that monoglycerides can reduce the FFA level of degummed, dewaxed, and bleached RBO to an acceptable level (0.5 ± 0.10 to 3.5 ± 0.19% w/w) depending on the FFA content of the crude oil. This allows RBO to be alkali refined, bleached, and deodorized or simply deodorized after monoglyceride treatment to obtain a good quality oil. The color of the refined oil is dependent upon the color of the crude oil used.

B K DE

D K BHATTACHARYYA

University of Calcutta (informally known as Calcutta University or CU) is a collegiate public state university located in Kolkata, West Bengal, India.&nbsp;Within India it is recognized as a &quot;Five-Star University&quot; and accredited &quot;A&quot; Grade by National Assessment and Accreditation Council.

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The University of Calcutta has secured the Fifth position among the Universities of India in the prestigious &quot;Indian University Ranking 2019&quot; list, released by the NIRF of the Ministry of Human Resource Development, Government of India.

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It was established on 24 January 1857, and was one of the first institutions in Asia to be established as a multidisciplinary and Western-style university. Its alumni and faculty include several heads of state, heads of government, social reformers, prominent artists, only academy award winner and Dirac medal winner in India, many Fellows of the Royal Society and five Nobel laureates as of 2019 which is highest in South Asia.

University Of Calcutta

JAOCS, Journal of the American Oil Chemists' Society

Rice bran oil (RBO) is popular in several countries such as Japan, India, Korea, China and Indonesia as a cooking oil. It has been shown that RBO is an excellent cooking and salad oil due to its high smoke point and delicate flavor. The nutritional qualities and health effects of rice bran oil are also established. RBO is rich in unsaponifiable fraction (unsap), which contains the micronutrients like vitamin E complexes, gamma oryzanol, phytosterols, polyphenols and squalene. However, the high FFA and acetone-insoluble content of RBO made it difficult for processing. Therefore, in recent years, research interest has been growing in RBO processing to obtain good quality oil with low refining loss. This review article deals with detailed reports on RBO processing including membrane-based techniques from the production and quality point of view. © AOCS 2007.

Review on recent trends in rice bran oil processing

Physical refining of rice bran oil (RBO) with acidity between 4.0 and 12,4% has been investigated in relation to degumming and dewaxing pretreatments. It appears that physical refining after combined low-temperature (10°C) degumming-dewaxing produces good-quality RBO with respect to color, free fatty acid, oryzanol, and tocopherol content.

Physical refining of rice bran oil in relation to degumming and dewaxing

Aqueous enzymatic extraction was investigated for recovery of oil from mustard seed and rice bran. The extraction process was reproducible based on statistical analysis of extraction data under different extraction conditions. The most significant factors for extraction were the time of digestion with enzymes, seed or bran concentration in water, volume of hexane added before recovery, and amount of enzyme(s) used. The pretreatment steps of each material before enzyme digestion influenced oil yield. Quality of enzyme-extracted mustard oil was better with respect to color and odor than commercial expeller-extracted and Soxhlet-extracted oils. Most of the characteristics of rice bran oil were identical to those of commercial solvent-extracted oils, but rice bran oil had a lower content of colored substances and higher acidity (free fatty acid). Enzymatic extraction led to recovery of a protein concentrate with increased protein and reduced fiber and ash contents in the mustard and rice bran meals.

Enzymatic extraction of mustard seed and rice bran

The biorefining process under optimum conditions de-acidified the high-acid mohua oil by nearly 85% with considerable improvement of color. The process, in combination with alkali-refining, bleaching and deodorization, yielded excellent oil with respect to color, unsaponifiable matter content and triglyceride content. The combination of biorefining and physical refining significantly reduced the loss of oil, and the color, unsaponifiable matter and diglyceride content increased while triglyceride content decreased. The physical refining process alone, on the other hand, produced oil with considerably darker color, increased unsaponifiable matter and diglycerides, and decreased triglyceride. Biorefining followed by alkali-refining, bleaching and deodorizing steps or by physical refining can be regarded as a much better alternative refining process than the physical refining process alone for oils of high acidity. © 1992 AOCS Press.

Journal of the American Oil Chemists' Society

A comparative study between biorefining combined with other processes and physical refining of high-acid mohua oil

Rice bran oil with a high free fatty acid content (FFA) after degumming and dewaxing can be converted into edible quality oil of satisfactory refining characteristics by first adopting the biorefining process to reduce the major portion of the FFA by converting them into neutral glycerides with the aid of 1,3-specific lipase under optimum conditions and later deacidifying the residual FFA of the biorefined oil by alkali neutralization. © 1989 American Oil Chemists' Society.

Journal of the American Oil Chemists Society

Biorefining of high acid rice bran oil

Rice bran oils of 15 to 30% free fatty acid can be deacidified to low levels by reesterification with glycerol after degumming and dewaxing. The reesterification can by combined with conventional alkali neutralization and bleaching to produce light color edible oil. © 1987 AOCS Press.

Journal	JAOCS, Journal of the American Oil Chemists' Society
Publisher	American Oil Chemists' Soc, Champaign
ISSN	0003-021X