Ethanolamines and other amino‐ and hydroxyl‐containing compounds in the refining of rice oil

Abstract

Summary In the alkali‐refining of rice oil by the usual procedure employed for cottonseed and similar oils excessive losses occur. A rice oil containing about 5% of free fatty acids may refine with a loss of over 40% by the cup method. A series of experiments has been performed which shows that the adding of certain organic compounds to the crude oil just before carrying out the regular refining procedure greatly reduces the refining losses. The technique was effective in both batch and continuous processes. Depending on the refining process used, reductions in the refining loss of 32 to 55% have been obtained. The organic compounds used as additives contained NH2 and OH groups. Sucrose or blackstrap molasses appears to be the most practical material to use. However ethanolamines and various glycols and alcohols may also be employed.

Review on Recent Trends in Rice Bran Oil Processing

“…The reason for inordinately high refining losses using a conventional sodium hydroxide solution encountered in the case of RBO in comparison to other vegetable oils with a similar FFA content has been the subject of numerous investigations [50][51][52]. A report by Cousins et al [51] contains the observation that the foots formed from crude RBO have an unusual inability to cohere and settle out of the oil clearly and it tends to emulsify the oil under the conditions of refining.…”

“…A report by Cousins et al [51] contains the observation that the foots formed from crude RBO have an unusual inability to cohere and settle out of the oil clearly and it tends to emulsify the oil under the conditions of refining. In a later report, an assumption was made that the high refining losses for RBO was due to the presence of saponins [52] but without any experimental evidence to support this statement.…”

Origin of problems encountered in rice bran oil processing

“…Cousins et al [2] stated in 1955, that losses of a comparatively good rice oil (FFA content 5.5%) due to the refining could be add up to more than 50%. Cousins et al [2] stated in 1955, that losses of a comparatively good rice oil (FFA content 5.5%) due to the refining could be add up to more than 50%.…”

“…Cousins et al [2] stated in 1955, that losses of a comparatively good rice oil (FFA content 5.5%) due to the refining could be add up to more than 50%. Cousins et al [2] observed that the foots formed from crude rice bran oil by alkali refining were unusual in their inability to cohere and settle out of the oil cleanly, and attributed this peculiar behavior to "some unknown material in the crude oil that tends to emulsify the oil under the conditions of refining". Unfortunately, the statement is still valid even today.…”

Enzymatic degumming of rice bran oil

“…Chemical refining of rice bran oil generally results in losses that are considerably higher than those encountered with other vegetable oils (3,4). These higher losses are attributed to the presence of larger amounts of FFA and nonoily constituents.…”