Classifications

• • C—CHEMISTRY; METALLURGY
  • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
  • C11B—PRODUCING, e.g. BY PRESSING RAW MATERIALS OR BY EXTRACTION FROM WASTE MATERIALS, REFINING OR PRESERVING FATS, FATTY SUBSTANCES, e.g. LANOLIN, FATTY OILS OR WAXES; ESSENTIAL OILS; PERFUMES
  • C11B3/00—Refining fats or fatty oils
  • C11B3/02—Refining fats or fatty oils by chemical reaction
• • C—CHEMISTRY; METALLURGY
  • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
  • C11B—PRODUCING, e.g. BY PRESSING RAW MATERIALS OR BY EXTRACTION FROM WASTE MATERIALS, REFINING OR PRESERVING FATS, FATTY SUBSTANCES, e.g. LANOLIN, FATTY OILS OR WAXES; ESSENTIAL OILS; PERFUMES
  • C11B3/00—Refining fats or fatty oils

Definitions

• the present invention relates to a method for processing edible oils and fats.
• the present invention relates to a modified method for processing edible oils and fats, i.e., a method for controlling the amount of 3-chloro-1,2-propanediol or ester thereof (3-MCPD/3-MCPD FE) during the refinement of oils and fats.
• Crude oil generally refers to the oils and fats extracted from plant or animal through leaching or pressing process while containing certain inedible or industrial impurities.
• the main component of crude oil is a mixture of triglyceride fatty acids, which generally known as neutral oil.
• crude oil further comprises non-glyceride substances (collectively called as impurities).
• the impurities can roughly be classified by their types, properties and states into three categories, i.e., mechanical impurities, fat-soluble impurities and water-soluble impurities.
• Refining oil and fat generally refers to the refinement of crude oil. Impurities in crude oil not only affect the edibleness and safe storage of the oils and fats, but also make intensive processing difficult. Meanwhile, rather than removing all of the impurities, refining is aimed at the removal of the impurities that are deleterious to edibleness, storage and industrial production, etc., including gossypol, proteins, phospholipids, slimes, water and the like, while keeping the beneficial "impurities” such as tocopherol, etc. Therefore, the purpose of refining oils and fats is to remove undesirable and deleterious impurities from the oils and fats for the producing of oil products that satisfy certain quality standard(s) based on various requirements and applications.
• 3-MCPD is a carcinogenic contaminant commonly acknowledged worldwide, which is mainly produced during the processing of food product.
• the refining process of oils and fats greatly increases the content of 3-MCPD; the presence of which in oils and fats is primarily in the forms of alcohol and ester, with ester as the dominant form.
• the amount of it varies among different oils.
• Chemical & Veterinary Test Agency (CVUA, Germany) classifies the amount of 3-MCPD in the common plant oils and fats into the following three levels:
• the refined palm oil contains 4-30 mg/kg of 3-MCPD, the highest level in all of the oils.
• TDI tolerable daily intake
• the present invention is to provide a method for effectively controlling 3-MCPD and 3-MCPD FE during refining oils and fats without undue increasing of the factorial production cost.
• the methods of the subject invention can be used in industrial production of food, thereby achieving an industrial production.
• Another purpose of the subject invention is to provide an optimized process and refined oils and fats of high quality produced by the optimized process.
• the amount of water used in step (E1) is in the range of 0.5-30 wt%, such as 0.5-20 wt%, 0.5-10 wt%, 2-20 wt%, or the like, of the bleached oil.
• the mixing in step (E1) is performed at a temperature of not higher than 100°C, such as not higher than 95°C.
• the mixing step is performed at temperature in the range of 60-100°C, preferably 70-95°C, and best 80-95°C.
• the transesterification step (E2) comprises heating the bleached oil obtained from step (D) to 60-120°C and adding a catalyst in an amount of 0.1-2 wt% of the bleached oil.
• the catalyst may be sodium methoxide.
• the catalyst may also be (1) NaOH and (2) alkali metal (they are generally used in combination with glycerin).
• the transesterification step is carried out under vacuum for 15-60 minutes, such as 30 minutes, and then the reaction is terminated. After terminating the reaction, the oil is washed with water until a neutral pH is obtained.
• the transesterification step (E2) comprises flowing the bleached oil from step (D) through a packed column (immobilized enzyme such as lipozyme TL IM, etc.) in countercurrent or warming it to 40°C-60°C, adding a transesterification enzyme in an amount of 0.1-2 wt% of the bleached oil and reacting under vacuum for 30-120 minutes (such as 30 minutes), and then the reaction is terminated. After terminating the reaction, the product is washed with hot water for 3 times until a neutral pH is obtained. The oil phase is isolated by centrifugation.
• a packed column immobilized enzyme such as lipozyme TL IM, etc.
• the transesterification enzyme used in the present invention includes various commercially available immobilized enzymes or the corresponding fermentation broth, such as lipozyme TL IM, Lopozyme RM and others available from Novozymes, and immobilized enzymes or the corresponding fermentation broth from AMANO Enzyme.
• the degumming step includes a process of mixing the crude oil, degumming medium and water, etc.
• the degumming medium may be selected from the group consisting of citric acid solution, phosphoric acid solution and degummase. If a degummase is used, the reaction system is generally held at 50-80°C, with pH 5-6 for 2-4 hours. In industrial production, citric acid buffer (NaOH) may be used to adjust the pH to 5-6.
• the degumming medium is used in an amount of no less than 0.05 wt% of the crude oil.
• the water is used in an amount of no less than 0.5 wt% of the crude oil.
• the concentration of acid in the degumming medium is no less than 5 wt% based on the total weight of the solution.
• the degumming medium is not higher than 2 wt% of the crude oil.
• the amount of water used in each degumming step is not higher than 30 wt% of the oil, such as in the range of 0.5-20 wt%, 0.5-10 wt%, 5-25 wt%. Said amount of water does not include the water in the degumming medium.
• the concentration of acid is not higher than 80 wt%, such as in the range of 5-65 wt%, 10-60 wt% or 20-50 wt%. Degumming with water only may be difficult to reduce the amount of phospholipid in the oils and fats (unable to remove non-hydratable phospholipids via the conversion to hydratable phospholipid).
• the bleaching medium used in the bleaching step (D) may be selected from the group consisting of natural clay, activated clay, activated carbon, attapulgite clay, etc., preferably the low-acidity clay activated by sulfuric acid (having a pH close to neutral).
• the bleaching step (D) comprises:
• the amount of water used in step (E1) is equal to or larger than 0.5 wt% of the bleached oil from step (D), generally within 30 wt%, such as 0.5-20 wt%, 0.5-10 wt%, and 5-25 wt%.
• the mixing is carried out at 60-120°C, generally not higher than 100°C (such as 95°C). For example, the mixing is performed at 70-95°C or 80-95°C.
• the present invention provides a method for controlling the formation of 3-MCPD and 3-MCPD FE as well during the deodorizing of oils and fats, including, prior to the deodorizing step, a rinsing step (E) to rinse the bleached oil with water.
• the rinsing step comprises a mixing step (E1) with water and/or a transesterification step (E2), and a step (F) to isolate the water phase and dry the resultant oil phase.
• the bleached oil may be commercially available or obtained through conventional refining techniques.
• the method further comprises, after the deodorizing step, a step (E) of further contacting the deodorized refined oil with water, wherein step (E) comprises (E1) mixing with water and/or (E2) transesterification step; and a step (F) of drying the resultant water-containing oil phase.
• step (E1) and (E2) may be performed as mentioned above.
• the present invention also provides a method for refining oils and fats comprising the following steps:
• the method for refining oils and fats further comprises, between step (A) and step (D), an alkali refining step (B) in which an alkali solution is added to neutralize the oil phase from step (A-1), a soap-removing step (C) in which hot water is added to the oil phase from step (B) to remove soap stock, and an isolating and drying step (C-1) in which the water phase is removed and the oil phase from step (C) is dried.
• Steps (E1) and (E2) and the degumming step are as described above.
• the degumming medium is used in an amount of no less than 0.05 wt% of the crude oil.
• the water is used in an amount of no less than 0.5 wt% of the crude oil.
• the concentration of acid is not less than 5 wt% based on the total weight of the solution.
• the degumming medium is not higher than 2 wt% of the crude oil.
• the amount of water used in each degumming step is not higher than 30 wt% of the oil, such as in the range of 0.5-20 wt%, 0.5-10 wt%, 5-25 wt%. Said amount of water does not include the water in the degumming medium.
• the concentration of acid generally is not higher than 80 wt%, such as in the range of 5-65 wt%, 10-60 wt% or 20-50 wt%.
• the degumming step (D) includes:
• the amount of water used in step (E1) is equal to or larger than 0.5 wt% of the bleached oil from step (D), generally within 30 wt%, such as 0.5-20 wt%, 0.5-10 wt%, and 5-25 wt%.
• the mixing is carried out at 60-120°C, generally not higher than 100°C (such as 95°C). For example, the mixing is performed at 70-95°C or 80-95°C.
• the crude oil or the bleached oil used in the present invention may be oils and fats extracted from plant oil material or animal through leaching or pressing processes, including but not limited to vegetable oils and fats and animal oils and fats, such as soybean oil, rapeseed oil, sunflower oil, coconut oil, peanut oil, safflower oil, cottonseed oil, rice bran oil, corn oil, olive oil, hydrogenated oils and fats, palm oil, etc., or mixtures thereof.
• vegetable oils and fats and animal oils and fats such as soybean oil, rapeseed oil, sunflower oil, coconut oil, peanut oil, safflower oil, cottonseed oil, rice bran oil, corn oil, olive oil, hydrogenated oils and fats, palm oil, etc., or mixtures thereof.
• the refined oil obtained from the method of the present invention comprises less than 0.5 ppm of 3-MCPD and 3-MCPD FE, based on the total weight of the refined oil.
• a step (E) of rinsing the bleached oil is performed between the bleaching step (D) and the deodorizing step (G), wherein the step (E) is referring to a rinsing step (E1) by mixing with water or water-containing substance, such as an ethanol solution, or a chemical or physical process comprising a step of contacting the bleached oil with water, such as the transesterification step (E2).
• water or water-containing substance such as an ethanol solution
• a chemical or physical process comprising a step of contacting the bleached oil with water, such as the transesterification step (E2).
• the oil from the deodorizing step may be subjected to freezing crystallization processing.
• the oil to be bleached may be subjected to freezing crystallization processing.
• the freezing crystallization processing can be performed with the methods well known in the art.
• the freezing crystallization processing can be performed according to the methods described in Examples 14 and 15 herein.
• the amount of 3-MCPD or 3-MCPD FE in the refined oil may be advantageously reduced during the refinement of oils and fats if water is incorporated into the oil phase, specifically prior to the deodorizing step, and then isolating the water phase, followed by drying the oil phase before the deodorizing processing.
• the degumming step is a step of degumming through acidifying and rinsing, which could effectively reduce the amount of the substances such as phospholipids, thereby further reducing the amount of 3-MCPD or 3-MCPD FE in the refined oil.
• alkali refining step or neutralizing step
• soap-removing step are optional.
• the present inventors find that the alkali refining step and the subsequent soap-removing step may contribute to reducing the amounts of phosphorous substances and the precursors of 3-MCPD or 3-MCPD FE, such as chlorine ions, thereby further reducing the amount of 3-MCPD or 3-MCPD FE in the refined oil.
• the present invention provides a method for controlling the formation of 3-MCPD and 3-MCPD FE during deodorizing of oils and fats, and the method comprises a rinsing step (a) and a drying step (b) before a deodorizing step, in the rinsing step (a) the bleached oil is mixed with pure water for rinsing at a temperature of not higher than 95°C and then the oils and fats were isolated through centrifugation, wherein the water comprises 0.5 wt% or more of the bleached oil, and in the drying step (b) the oil phase is warmed to 80-110°C for 5-30 minutes and kept under vacuum to obtain the rinsed and dried oil.
• the inventors point out that, effectively controlling the amount of the phosphorus-containing substances, such as phospholipid, during the refining process may advantageously reduce the amount of 3-MCPD or 3-MCPD FE in the refined oil.
• lower amount of the phosphorus-containing substances in the oils and fats before the deodorizing step is in favor of reducing the amount of 3-MCPD or 3-MCPD FE.
• the bleached oil mentioned in the above methods comprises less than 5 ppm, preferably less than 3 ppm, best less than 1 ppm of phosphorus (PHOS), the amount of 3-MCPD or 3-MCPD FE may be reduced to a distinguish level, such as lower than 0.5 ppm.
• the bleached oil used in the present invention may be oils and fats extracted from plant or animal through leaching or pressing processes and having been subj ected to refining and bleaching, including but not limited to vegetable oils and fats and animal oils and fats, such as soybean oil, rapeseed oil, sunflower oil, coconut oil, peanut oil, safflower oil, cottonseed oil, rice bran oil, corn oil, olive oil, hydrogenated oils and fats, palm oil, etc., or mixtures thereof.
• vegetable oils and fats and animal oils and fats such as soybean oil, rapeseed oil, sunflower oil, coconut oil, peanut oil, safflower oil, cottonseed oil, rice bran oil, corn oil, olive oil, hydrogenated oils and fats, palm oil, etc., or mixtures thereof.
• steps (a) and (b) are duplicated for 1 or 2 or more times.
• a step (c) may be performed by introducing nitrogen gas or vapor as deodorizing medium under a vacuum degree of not higher than 25 mBarA at a suitable temperature to carry out the deodorization for 45-90 minutes.
• the vacuum may be released at a temperature below 50°C and the refined oil after deodorization could be obtained through filtration.
• the present invention also provides a method for producing refined oils and fats, comprising the following steps:
• the amount of phosphorus (PHOS) in the bleached oil obtained in step (D) is 5 ppm or less, preferably 3 ppm or less, best 1 ppm or less.
• step (A) of the above method is repeated for 2 or 3 times.
• steps (A) to (G) of the above method are repeated for 2 or 3 times.
• the method for refining oils comprises the following steps:
• the amount of phosphorus (PHOS) in the bleached oil obtained in step (6) is 5 ppm or less, preferably 3 ppm or less, more preferably 1 ppm or less.
• step (1) of the above method is repeated for 2 or 3 times.
• steps (1) to (9) of the above method is repeated for 2 or 3 times.
• the alkali solution in step (3) may be any alkali solution, preferably selected from the group consisting of NaOH solution and KOH solution.
• the alkali solution has a concentration of not higher than 35 wt%.
• the hot water used in step (4) may have a temperature of 50°C or higher.
• the degumming medium used in the degumming step is a citric acid solution with the concentration of the acid not less than 5 wt% based on the total weight of the solution.
• the degumming medium is no less than 0.05 wt% of the crude oil and water is no less than 0.5 wt% of the crude oil.
• the bleaching step may be carried out with conventional bleaching methods in the art.
• the bleaching agent may contain but is not limited to natural clay, activated clay, activated carbon, attapulgite clay, etc., preferably the clay activated by sulfuric acid.
• a further rinsing step is carried out after the deodorizing step (9), and then the oil is dried to ensure that the final refined oil is water-free.
• steps including rinsing following by water isolating and oil phase drying are identical to steps (7) and (8) in the method of the present invention.
• a step of transesterification (including rinsing) with drying may be incorporated into any stage of the process.
• the step of transesterification with drying may be a conventional method in the art, such as, but is not limited to mixing the oil and fat with sodium methoxide, terminating the reaction with citric acid solution, rinsing the mixture to a neutral pH, obtaining the oil phase by centrifugation, and drying the oil at an elevated temperature under vacuum.
• the "crude oil” refers to oils and fats extracted from plant or animal through leaching or pressing processes, including but not limited to vegetable oils and fats and animal oils and fats, such as soybean oil, rapeseed oil, sunflower oil, coconut oil, peanut oil, safflower oil, cottonseed oil, rice bran oil, corn oil, olive oil, hydrogenated oil and fat, palm oil, etc., or mixtures thereof.
• the amount of 3-MCPD in the crude oil is 0.3 ppm or more based on the total weight of the crude oil.
• crude palm oil with not higher than 3 wt% of free fatty acids is preferred.
• refined oil refers to the oils and fats comprising less than 1 ppm of 3-MCPD, based on the total weight of the refined oil.
• the refined oil obtained from the method of the present invention comprises less than 0.5 ppm of 3-MCPD and/or 3-MCPD FE, based on the total weight of the refined oil.
• the present invention also incorporates a method for transporting the oil and fat, including the steps of degumming through acidifying, alkali refining, rinsing and drying, wherein the oil and fat obtained after rinsing and drying are transported under normal temperature or with refrigeration.
• the rinsed and dried oil and fat are subjected to freezing crystallization, re-bleaching and re-deodorizing treatments.
• the above steps such as degumming through acidifying, alkali refining, rinsing and drying, bleaching, and deodorizing, may be performed according to the methods described herein.
• the freezing-crystallization may be performed, for instance, according to the methods described in Examples 14 and 15 of the present invention.
• the unit of the percent weight in volume is well known in the art. For example, it means the weight of a solute in 100 ml of a solution.
• the quantity of 3-MCPD is determined by an indirect measuring approach which means several pre-treatments before GC-MS measurement (gas chromatography-mass spectroscopy).
• Test example 1 the relationship between the amount of phospholipid and the amount of 3-MCPD in the refined oil and fat
• Table 1 The quality of a crude oil is shown in Table 1.
• Example 1 Dry degumming (without rinsing and drying)-a control example
• This example indicates that the formation of 3-MCPD in the bleached oil obtained from the conventional dry degumming method has substantially been enhanced upon the deodorizing step.
• Example 2 Degumming through acidifying and rinsing with a combination of physical refining
• This example illustrates that the step of degumming through acidifying and rinsing may suppress the formation of 3-MCPD during deodorizing step.
• Example 3 Dry degumming with a combination of rinsing the bleached oil
• Example 4 Degumming through acidifying and rinsing with a combination of rinsing the bleached oil
• This example displays that degumming through acidifying and rinsing along with rinsing and drying the bleached oil may effectively control the formation of 3-MCPD in the deodorizing step.
• Test example 1 The crude oil used in Test example 1 was employed.
• Test example 1 The crude oil used in Test example 1 was employed.
• Pure water was prepared using reverse osmosis (R/O) membrane.
• Example 7 Degumming through acidifying and rinsing + transesterification
• Test example 1 The crude oil used in Test example 1 was employed.
• Pure water was prepared using reverse osmosis (R/O) membrane.
• Pure water was prepared using reverse osmosis (R/O) membrane.
• Example 9 Degumming through acidifying and rinsing + alkali refining + rinsing
• the amount of 3-MCPD in the final refined product could be effectively controlled by rounds of degumming through acidifying and rinsing, alkali refining, using activated clay with weak acidity and the subsequent rinsing.
• Example 10 Dry degumming + rinsing + bleaching
• Test example 1 The crude oil of Test example 1 was used.
• Example 11 Bleaching + deodorizing VS bleaching + rinsing + deodorizing
• the feed material was the material used in Test example 1.
• Example 12 crude oil ⁇ (rinsing) ⁇ deodorizing
• the feed material used was the same as in Test example 1.
• the solid fat has a lowest amount of 3-MCPD and thus provides a higher safety.
• the processes were as follows: 1. Degumming through acidifying and rinsing: adding citric acid solution (50 wt%), in an amount of 0.1 wt% of the oil, and deionized water in an amount of 10 wt% of the oil into the oil, stirring at 80°C for 30 minutes, centrifuging at 4500 rpm for 15 minutes, and collecting the oil-containing light phase; repeating this step twice and the light phase proceeding to the next refining step; 2.
• Rinsing stirring the oil with deionized water in an amount of 20 wt% of the oil at 90°C for 10 minutes, wherein the deionized water needs to be pre-heated to 85°C; 4. Drying: stirring at 90°C for 1 hour under vacuum; 5.
• Freezing crystallization placing the neutralized oil into a crystallizer and being freezing crystallized according to the following: Temperature (°C) Time for cooling (min) Time of constant temperature (min) Duration (min) 65 / / 240 65 / 60 60 50 60 / 60 40 60 / 60 30 60 60 15 120 300 420 15 / 300 300 Upon the completion of the above freezing crystallization, liquid oil and solid fat were obtained by pressure filtering through a plate-and-frame filter. 6. Bleaching: adding 1 wt% of Taiko Supreme 1B into the resultant liquid oil and solid fat, respectively, stirring for 30 minutes at 110°C under vacuum, obtaining the bleached oils by suction filtration while the oils were hot; 7.
• Deodorizing introducing nitrogen gas (as a stirring and deodorizing medium) into the bleached oils under a vacuum degree of 1-20 mBarA, maintaining at 240°C for 1 hour and then removing the heating jacket, releasing the vacuum at 50°C or below and then stopping the introduction of nitrogen gas, obtaining the refined oils by filtration;
• palm oil is separated into liquid oil and solid fat to ease applications with different requirements.
• the freezing crystallization is generally performed after the deodorizing step, as described in Example 14.
• the resultant liquid oil and solid fat will comprise lower amount of 3-MPCD and have favorable acid value and flavor. Palm oil is mainly produced outside China.
• the refined oil and fat could still be processed by the freezing crystallization, bleaching and deodorizing even after 30 days of transportation for the purpose of acquiring excellent product qualities in various aspects. Therefore, the above process could solve the problem about poor quality of the refined palm oil obtained from the refining process as a result of the quality deterioration during long term transportation.
• Example 16 Clay with strong acidity as the bleaching medium
• this example indicated that using clay with a near neutral pH may control the amount of 3-MCPD in the refined oil and fat more effectively.

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• 2010
  • 2010-07-16 CN CN201010228009.XA patent/CN102334563B/zh active Active
• 2011
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