In an aspect, a method is disclosed that includes contacting a composition with an aqueous solution to yield a mixture, where the composition includes one or more of animal fats, animal oils, plant fats, plant oils, vegetable fats, vegetable oils, greases, and used cooking oil, about 5 wt. % or more of free fatty acids, about 10 wppm or more of total metals, about 8 wppm or more phosphorus, about 20 wppm or more of nitrogen, and the aqueous solution includes ((NH.sub.4).sub.2H.sub.2EDTA, (NH.sub.4).sub.4EDTA, a monoammonium salt of diethylenetriaminepentaacetic acid, a diammonium salt of diethylenetriaminepentaacetic acid, a triammonium salt of diethylenetriaminepentaacetic acid, a tetraammonium salt of diethylenetriaminepentaacetic acid, (NH.sub.4).sub.5DTPA, a combination of citric acid and Na.sub.4EDTA, a combination of citric acid and Na.sub.2H.sub.2EDTA, a combination of citric acid and a monosodium salt of diethylenetriaminepentaacetic acid, a combination of citric acid and a disodium salt of diethylenetriaminepentaacetic acid, a combination of citric acid and a trisodium salt of diethylenetriaminepentaacetic acid, a combination of citric acid and a tetrasodium salt of diethylenetriaminepentaacetic acid, a combination of citric acid and Na.sub.5DTPA, or a combination of any two or more thereof, where the method further includes centrifuging the mixture to yield a first treated composition, wherein the first treated composition has less total metals and less phosphorus than the composition.

Process for refining vegetable oil, to suppress the formation of monochloropropanediol esters (MCPDe) and reduce the content of glycidyl esters, comprising first and second refinement stages, wherein the first refinement stage comprises: a) providing a crude vegetable oil having a combined MCPDe and glycidyl ester content below 0.2 ppm; b) degumming the crude vegetable oil to produced degummed vegetable oil; c) bleaching of the degummed vegetable oil with activated bleaching earth under reduced pressure to yield bleached vegetable oil; d) adding a base to the bleached vegetable oil and subsequent stripping and deodorizing under reduced pressure at a temperature below 255° C. to yield an intermediate refined vegetable oil; and a second refinement stage comprising the steps of: e) bleaching of the intermediate refined vegetable oil using activated bleaching earth under reduced pressure to yield a bleached vegetable oil; and f) deodorizing at a temperature below 220° C. to yield fully refined vegetable oil, wherein the fully refined vegetable oil has a combined MCPDe and glycidyl ester content below 4 ppm.

Process for refining vegetable oil, to suppress the formation of monochloropropanediol esters (MCPDe) and reduce the content of glycidyl esters, comprising first and second refinement stages, wherein the first refinement stage comprises: a) providing a crude vegetable oil having a combined MCPDe and glycidyl ester content below 0.2 ppm; b) degumming the crude vegetable oil to produced degummed vegetable oil; c) bleaching of the degummed vegetable oil with activated bleaching earth under reduced pressure to yield bleached vegetable oil; d) adding a base to the bleached vegetable oil and subsequent stripping and deodorizing under reduced pressure at a temperature below 255° C. to yield an intermediate refined vegetable oil; and a second refinement stage comprising the steps of: e) bleaching of the intermediate refined vegetable oil using activated bleaching earth under reduced pressure to yield a bleached vegetable oil; and f) deodorizing at a temperature below 220° C. to yield fully refined vegetable oil, wherein the fully refined vegetable oil has a combined MCPDe and glycidyl ester content below 4 ppm.

In an aspect, a method is disclosed that includes contacting a composition with an aqueous solution to yield a mixture, where the composition includes one or more of animal fats, animal oils, plant fats, plant oils, vegetable fats, vegetable oils, greases, and used cooking oil, about 5 wt. % or more of free fatty acids, about 10 wppm or more of total metals, about 8 wppm or more phosphorus, about 20 wppm or more of nitrogen, and the aqueous solution includes ((NH.sub.4).sub.2H.sub.2EDTA, (NH.sub.4).sub.4EDTA, a monoammonium salt of diethylenetriaminepentaacetic acid, a diammonium salt of diethylenetriaminepentaacetic acid, a triammonium salt of diethylenetriaminepentaacetic acid, a tetraammonium salt of diethylenetriaminepentaacetic acid, (NH.sub.4).sub.5DTPA, a combination of citric acid and Na.sub.4EDTA, a combination of citric acid and Na.sub.2H.sub.2EDTA, a combination of citric acid and a monosodium salt of diethylenetriaminepentaacetic acid, a combination of citric acid and a disodium salt of diethylenetriaminepentaacetic acid, a combination of citric acid and a trisodium salt of diethylenetriaminepentaacetic acid, a combination of citric acid and a tetrasodium salt of diethylenetriaminepentaacetic acid, a combination of citric acid and Na.sub.5DTPA, or a combination of any two or more thereof, where the method further includes centrifuging the mixture to yield a first treated composition, wherein the first treated composition has less total metals and less phosphorus than the composition.

There is provided a novel method for suppressing coloration of an oil and fat composition when a food ingredient is fried using the oil and fat composition. This method includes a step for adding a preparation oil to an edible oil and fat, and is such that: the preparation oil is a substance that has been subjected, in a step for refining a crude raw oil obtained from olives serving as an oilseed raw material, to (1) an optionally implemented neutralization step, (2) an optionally implemented bleaching step, and (3) an optionally implemented deodorization step in the stated order, without a degumming step having been implemented, where at least one of the (2) bleaching step and the (3) deodorization step is implemented; and an absorbance difference of the preparation oil is 0.05 or more, the absorbance difference being obtained by subtracting the absorbance at a wavelength of 750 nm from the absorbance at a wavelength of 660 nm, with isooctane used as a control.

A process for the production of a refined oil having a reduced content of glycidyl esters and hydroperoxides characterized in that it comprises subjecting an edible oil to the following steps, a bleaching step, a deodorization step, re-bleaching step on the deodorized oil, and a further refining step, wherein the further refining step is carried out by passing the bleached edible oil obtained in step c) through an oil refining equipment consisting of a stripping column with packing and not more than one oil collection tray.

A process for the production of a refined oil having a reduced content of glycidyl esters and hydroperoxides characterized in that it comprises subjecting an edible oil to the following steps, a bleaching step, a deodorization step, re-bleaching step on the deodorized oil, and a further refining step, wherein the further refining step is carried out by passing the bleached edible oil obtained in step c) through an oil refining equipment consisting of a stripping column with packing and not more than one oil collection tray.

A method is disclosed of purifying a recycled or renewable organic material, wherein the recycled or renewable organic material contains more than 20 ppm Cl. Exemplary methods include (a) providing the recycled or renewable organic material; (b) purifying the organic recycled or renewable organic material to obtain a purified recycled or renewable organic material, and (c) hydrotreating the purified recycled or renewable organic material in a presence of a hydrotreating catalyst at a temperature from 270 to 380° C. under pressure from 4 to 20 MPa and under continuous hydrogen flow; to obtain purified hydrotreated recycled or renewable organic material.

A method is disclosed of purifying a recycled or renewable organic material, wherein the recycled or renewable organic material contains more than 20 ppm Cl. Exemplary methods include (a) providing the recycled or renewable organic material; (b) purifying the organic recycled or renewable organic material to obtain a purified recycled or renewable organic material, and (c) hydrotreating the purified recycled or renewable organic material in a presence of a hydrotreating catalyst at a temperature from 270 to 380° C. under pressure from 4 to 20 MPa and under continuous hydrogen flow; to obtain purified hydrotreated recycled or renewable organic material.

[Problem] To provide: a method for suppressing the coloration of oils and fats during frying; and a coloring inhibitor. [Solution] A method for suppressing the coloration of an oil/fat composition for frying, the method comprising a step for adding a prepared oil to an edible oil or fat, wherein the prepared oil is obtained through (1) a degumming step, (2) a neutralization step which may or may not be performed, (3) a bleaching step which may or may not be performed, and (4) a deodorizing step, in this order, in the process of refining a crude oil obtained from an oil feedstock, and the absorbance difference determined by subtracting the absorbance at a wavelength of 750 nm from the absorbance at a wavelength of 660 nm of the prepared oil obtained from step (3) is at least 0.030 when isooctane is used as the control. A coloring inhibitor characterized by containing said prepared oil.