Food or edible material: processes – compositions – and products – Inhibiting chemical or physical change of food by contact... – Treating liquid material
Reexamination Certificate
1998-05-28
2001-03-06
Paden, Carolyn (Department: 1761)
Food or edible material: processes, compositions, and products
Inhibiting chemical or physical change of food by contact...
Treating liquid material
C426S417000, C426S490000, C426S601000
Reexamination Certificate
active
06197357
ABSTRACT:
FIELD OF THE INVENTION
The invention relates to methods for producing refined edible oils such as vegetable oils, and extracts thereof.
BACKGROUND OF THE INVENTION
Vegetable oils have a variety of uses as food constituents and cooking aids, and are typically refined before use. Crude vegetable oils are generally refined to remove free fatty acids and other undesirable components by one of two broad methods, chemical and physical refining. Chemical refining is most commonly accomplished by the use of caustic refining compounds, such as by treating a crude oil with a sodium hydroxide solution. Physical refining is commonly accomplished by distillative neutralization, in which the free fatty acids are removed by water vapor.
Many vegetable oils degrade over time when left in contact with oxygen. Degradation can be slowed by adding one or more antioxidants to the oil. Common synthetic antioxidants include butylated hydroxytoulene (BHT), butylated hydroxyanisole, tertiary butylated hydroquinone, and propyl gallate. However, many consumers prefer natural antioxidants, such as tocopherals (vitamin E), tocotrienols, ferulates, e.g., gamma oryzanol, and sulfur-containing amino acids. These natural antioxidants are present in many crude oils, but are typically removed along with the free fatty acids during standard refining methods. Tocotrienols, ferulate esters of triterpene alcohols, e.g., gamma oryzanol, and ferulates are unsaponifiables with cholesterol-lowering properties.
SUMMARY OF THE INVENTION
The invention is based on the discovery that by treating a crude vegetable oil, e.g., an oil of plant origin, with a weak acid salt, the resulting oil is refined, and thus low in free fatty acids, but nevertheless retains most of the desirable unsaponifiables present naturally in the crude oil.
In general, the invention features a method of obtaining a refined vegetable oil having a high level of unsaponifiables and a low level of free fatty acids, and the refined vegetable oil so produced. The method includes combining a vegetable oil with a first solution that includes a weak acid salt to produce a residue. The residue is separated from the vegetable oil to produce a refined vegetable oil, and contains a high level of free fatty acids.
The high level of unsaponifiables can be from 50% to 100% by weight, e.g., 75% to 100%, of the unsaponifiables found in the crude vegetable oil that is refined by these new methods. The unsaponifiables can include gamma oryzanol, tocotrienols, and tocopherols.
The low level of free fatty acids can be 0% to 5% by weight, e.g., 0% to 2% or 0% to 1% by weight, of the refined vegetable oil.
The first solution can have a pH between 6.0 and 11.0, e.g., between 8.0 and 8.5. The weak acid salt can be a food grade base. The weak acid salt can be derived from, for example, sodium bicarbonate, ammonium bicarbonate, or potassium bicarbonate.
The vegetable oil can be, physically refined rice bran oil, rice bran oil, corn fiber oil, corn oil, olive oil, barley oil, soybean oils, oat bran oil, canola oil, sunflower seed oil, palm oil, cashew nut oil, or dill oil.
The method can also include a preliminary extraction step in which the vegetable oil is extracted from a plant source, e.g., by a solvent. The method can also include a degumming step, e.g., by citric acid, and a deodorification step.
The invention also features a method of producing a concentrate and the concentrate so produced. The refined vegetable oil produced as above is mixed with a second solution that includes a strong acid salt. The second solution has a pH of at least 11.0. The concentrate has a high level of unsaponifiables and a low level of free fatty acids and is separated from the refined vegetable oil after the refining step. The concentrate can be separated into gamma oryzanol, tocotrienol, and tocopherol components, e.g., by column chromatography.
The concentrate's high level of unsaponifiables can be from 30% to 100%, e.g., 75% to 100%, of the unsaponifiables found in the crude vegetable oil. The concentrate's low level of free fatty acids can be between 0% and 5%, e.g., 0% to 1% or 0% to 0.5%, by weight of the refined vegetable oil. The concentrate can have less than 10% neutral oil. The strong base can be sodium hydroxide.
In another aspect, the invention features a method of preserving an edible oil. The edible oil and the refined oil produced as above are combined and mixed for a time sufficient to obtain a homogenous stabilized edible oil.
In another aspect, the invention features a method of preserving an edible oil including combining the edible oil and the concentrate produced as above.
In another aspect, the invention features a method of stabilizing a polymer and the polymer so stabilized. The polymer and the concentrate produced as above are combined to obtain a homogeneous stabilized polymer.
In another aspect, the invention features a refined oil derived from a crude vegetable oil. The refined oil has greater than 50% of the unsaponifiables naturally present in the crude vegetable oil by total weight of the refined oil. The refined oil also contains less than 5% free fatty acids by weight.
In another aspect, the invention features a concentrate derived from a crude vegetable oil. The concentrate has greater than 30% of the unsaponifiables naturally present in the crude vegetable oil. The concentrate also contains less than 5% free fatty acids by weight.
In another aspect, the invention features a method of lowering the cholesterol of a mammal by administering to the mammal a portion of the concentrate.
In another aspect, the invention features a method of lowering the cholesterol of a mammal by administering to the mammal the refined oil produced above.
A vegetable oil is any oil derived or extracted from a plant, e.g., a plant seed, bran, fruit, fiber, meal, husk, or other plant source. Thus, vegetable oil can be made from all vegetables, seeds, grains, and fruits, for example, corn, rice, barley, olive, soybean, oats, canola, sunflower, palm, cashew nut, rye, triticale, wheat, and from spices and herbs, for example, dill.
“Extracted oil” is any vegetable oil that has been physically or chemically removed or separated from its plant source. “Crude oil” is extracted oil that has not been refined. “Refined oil” is oil that has been treated to remove at least some undesirable constituents, e.g., free fatty acids, naturally present in crude oil.
Unsaponifiables include those substances frequently found dissolved in fats and oils which cannot be saponified by the usual caustic treatment, but are soluble in ordinary fat and oil solvents. Included in this group of compounds are higher aliphatic alcohols, sterols, pigments, hydrocarbons, and antioxidants such as gamma oryzanol, tocotrienols, and tocopherols.
The terms “high level of unsaponifiables,” “low level of free fatty acids,” and “high level of free fatty acids” are dependent on the type of oil involved, as each crude oil contains a different natural level of unsaponifiables and free fatty acids. A high level of unsaponifiables indicates a significant portion of the unsaponifiables naturally present in the crude oil, e.g., about 10% or more by weight, or about 25% or more of the naturally present unsaponifiables remain in the refined oil or concentrate after refinement. A low level of free fatty acids indicates a majority of the free fatty acids found in the crude oil are no longer present. A high level of free fatty acids indicates that a majority of the free fatty acids are present.
A weak acid salt is a salt of an acid that is weaker than free fatty acids normally found in vegetable oils and stronger than unsaponifiables. While not being limited to theory, it is believed that the mechanism of selective extraction is due to intermolecular interaction between the weak acid salt component and the free fatty acid which causes deprotonation of the free fatty acid and increases its solubility in the extractant. On the other hand, the weak acid salt does not efficiently deprotonate the unsaponifiables, which are even weake
Lawton Carl W.
McCarthy Stephen
Nicolosi Robert
Fish & Richardson P.C.
Paden Carolyn
University of Massachusetts
LandOfFree
Refined vegetable oils and extracts thereof does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Refined vegetable oils and extracts thereof, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Refined vegetable oils and extracts thereof will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2497964