CN109609265B

CN109609265B - Green and accurate blend oil suitable for processing

Info

Publication number: CN109609265B
Application number: CN201811558663.XA
Authority: CN
Inventors: 周盛敏; 刘晓君; 张余权; 姜元荣; 凌国锋
Original assignee: Wilmar Shanghai Biotechnology Research and Development Center Co Ltd
Current assignee: Wilmar Shanghai Biotechnology Research and Development Center Co Ltd
Priority date: 2018-12-19
Filing date: 2018-12-19
Publication date: 2020-04-10
Anticipated expiration: 2038-12-19
Also published as: CN111394176B; CN111349515A; CN109609265A; CN111349515B; CN111394176A

Abstract

The present invention relates to an improved process for the moderate processing of fats and oils and refined fats and oils obtained by the process. The moderate processing method of the grease comprises a moderate alkali refining method of the grease, the method comprises an acid pretreatment step and an alkali treatment step, the acid pretreatment step comprises adding degumming medium, namely acid into the degummed oil with the oil temperature of 70-90 ℃, and uniformly mixing at 70-90 ℃; the alkali treatment step comprises dividing the alkali solution into at least two portions, and sequentially adding the divided portions to the mixture obtained by the acid pretreatment at time intervals of 5 to 15 minutes. The amount of each part of alkali liquor is the same or different. The fat processing method of the present invention also includes a fat mild processing method including the fat mild alkali refining method described herein. The method can furthest reserve trace nutrient components VE and sterol in the grease and can effectively control TFA on the premise of ensuring the quality and flavor of the grease to reach the standard.

Description

Green and accurate blend oil suitable for processing

Technical Field

The invention belongs to the field of grease processing, and relates to green, accurate and moderately processed blend oil.

Background

The annual edible oil consumption of China is nearly 3500 million tons, and the edible oil is a major vegetable oil consumption country. In recent years, with the innovation of grease processing technology and the improvement of refining degree, the conventional quality problem is basically solved, but the potential safety hazard of the quality still exists.

In the process of refining vegetable oil, in order to ensure the quality of products to reach standards and be stable, indexes are controlled excessively and strictly, so that the phenomenon of excessive processing is prominent, and various quality safety hazards are brought. For example, the addition of alkali is large, the addition of clay is large, the deodorization temperature is high, and the deodorization time is long. Not only wastes resources and energy resources, aggravates environmental pollution and increases grease loss, but also loses most of natural beneficial micronutrients in the vegetable oil, and inevitably generates new harmful substances. According to the data of soybean oil production and quality investigation, the average loss of VE refining in the soybean oil is 15%, and the VE refining mainly occurs in a deodorization section; the average loss of sterol refining is 16%, and the sterol refining is evenly distributed in alkali refining, decoloring and deodorizing sections; meanwhile, TFA with the average concentration of 1.25 percent is generated in a deodorization section, so that the nutritional quality of the soybean oil is seriously reduced, and a new food safety problem is caused. Likewise, other vegetable oil refineries face the same problems. The concomitant problems associated with these overcrocesses are not negligible as to the adverse effects on consumer health.

In the case of trans fatty acids, TFA has the major risk of increasing the risk of Coronary Heart Disease (CHD), and other side effects include interference with lipid metabolism, which may increase the risk of type ii diabetes, female infertility, and senile dementia. Investigations of the cooking oil market have found that 90% of the cooking oil samples have a TFA content of no more than 2% and that oils having a TFA content of no more than 0.3% are predominantly olive oil and part peanut oil. The TFA content of soybean oil, rapeseed oil, sunflower seed oil, corn oil and blend oil is between 0.5 and 3 percent, and the TFA content of peanut oil, olive oil, sesame oil and camellia oil is between 0.02 and 1.2 percent, and the oils do not need a high-temperature deodorization link in general in order to maintain the excellent characteristic flavor of oil products. The main countries in Europe and America have legislation for limiting trans fatty acid, China is concerned about the level of trans fatty acid in grease more and more, and the establishment of limit standards is imperative in the future. GB28050-2011 suggests that < 0.3% of trans fatty acids in a pre-packaged food can be marked as "0", i.e. zero trans, and that trans fatty acid content is mandatory to mark when using hydrogenated oils and/or partially hydrogenated oils. The control of trans-fatty acids has become a focus of attention in the whole oil industry, the level of trans-fatty acids in vegetable oil is controlled as early as possible, and the source is kept clear, which is very necessary.

Disclosure of Invention

The invention provides a moderate alkali refining method for grease, which comprises the following steps:

(1) acid pretreatment: adding a degumming medium into the degummed oil with the oil temperature of 70-90 ℃, and uniformly mixing at 70-90 ℃, wherein the degumming medium is acid;

(2) alkali treatment: dividing the alkali liquor into at least two parts, and sequentially adding the alkali liquor into the acid pretreated mixture obtained in the step (1) at intervals of 5-15 minutes, wherein the amount of each part of alkali liquor is the same or different.

In one or more embodiments, the degummed oil of step (1) is obtained by water degumming, acid degumming, and/or enzymatic degumming.

In one or more embodiments, the water degumming comprises degumming with hot water at 70-90 ℃; more preferably, in the hydration degumming, the consumption of the hot water at 70-90 ℃ is 1-5%, preferably 2-4% of the weight of the oil, the temperature of the crude oil is 70-90 ℃, and the stirring time is 15-60 minutes.

In one or more embodiments, in step (1), the acid is phosphoric acid and/or citric acid.

In one or more embodiments, the acid is added in step (1) in an amount of 100-600ppm based on the weight of the degummed oil.

In one or more embodiments, in step (1), the oil temperature is maintained at 70-90 ℃ for 30-90 minutes.

In one or more embodiments, the concentration of lye in step (2) is from 5 to 10%, preferably from 6 to 8%.

In one or more embodiments, the amount of overbase in step (2) is from 0 to 15%, preferably from 0 to 10%.

In one or more embodiments, the oil temperature in step (2) is from 70 to 90 deg.C, preferably from 80 to 85 deg.C.

In one or more embodiments, the lye is added to the mixture obtained in step (1) in two or three portions.

In one or more embodiments, the final addition of lye and caustic refining is followed by soapstock removal, water washing and drying after 5 to 15 minutes.

In a second aspect, the invention provides a neutralized oil, wherein the content of trans fatty acids in the neutralized oil is less than or equal to 0.2% based on the total amount of the neutralized oil; the vitamin E content of the neutralized oil is more than 97.5%, preferably more than 98.0%, more preferably more than 98.5% of the vitamin E content of the degummed oil compared with the degummed oil before moderate alkali refining; the sterol contained in the neutralized oil is 96.5% or more, preferably 97.0% or more, and more preferably 97.5% or more of the sterol contained in the degummed oil.

In one or more embodiments, the neutralized oil is prepared using the mild base refining process for fats and oils described in any of the embodiments herein.

In a third aspect, the present invention provides a mild processing method for fats and oils, comprising a mild alkali refining method for fats and oils according to any one of the embodiments described herein, and any one or more of degumming, dewaxing, decoloring and deodorizing.

In one or more embodiments, the degumming includes hydration degumming, acid degumming, and enzymatic degumming; preferably, the degumming is hydration degumming, more preferably, the hydration degumming comprises the degumming step by using hot water with the temperature of 70-90 ℃, more preferably, in the hydration degumming, the using amount of the hot water with the temperature of 70-90 ℃ is 1-5%, preferably 2-4% of the weight of the oil, the temperature of the crude oil is 70-90 ℃, and the stirring time is 15-60 minutes.

In one or more embodiments, the discoloration is moderate discoloration; preferably: the decolorizing temperature is 100-110 ℃; the consumption of the decolorizing medium is 0.5-3.0 percent based on the weight of the oil; the decolorizing medium is selected from clay, activated carbon, attapulgite and any combination thereof, preferably a combination of clay and attapulgite, preferably the weight ratio of clay to attapulgite is 1:2-2: 1.

In one or more embodiments, the deodorization is mild deodorization; preferably: the deodorization temperature is 190-240 ℃, and preferably 200-230 ℃; deodorizing for 30-120 min, preferably 30-105 min; the vacuum degree is less than or equal to 10 torr, preferably less than or equal to 5 torr; deodorizing by steam stripping, wherein the stripping amount is 0.5-2%, preferably 1-1.5%.

In one or more embodiments, the dewaxing is mild dewaxing; preferably, the dewaxing comprises the steps of cooling the neutralized oil obtained by alkali refining to 10-15 ℃, adding a dewaxing assistant, stirring uniformly, continuously cooling to 5-8 ℃, keeping for 6-15 hours, and filtering to obtain dewaxed oil; preferably, the dewaxing aid is perlite or diatomaceous earth, used in an amount of 0.5 to 1.5%, preferably 0.8 to 1.0% by weight of the oil.

In one or more embodiments, the decolorization is two-stage decolorization, wherein the first-stage decolorization comprises passing the grease with the oil temperature of 100-; the second-stage decolorization is carried out in a decolorization tank for 30 minutes to 1 hour, and the dosage of a decolorization medium is 0.5 to 1.5 percent of the weight of the oil.

In one or more embodiments, the decolorizing comprises: oil with the oil temperature of 100-110 ℃ passes through a filter filled with waste decolorizing soil which is decolorized for the first time to be subjected to pre-decolorization to obtain pre-decolorized oil, then the pre-decolorized oil is decolorized for 30 minutes to 1 hour in a vacuum decolorizing tank by using clay and attapulgite with the weight ratio of 1:2-2:1 and the oil weight of 0.5-1.5%, and the decolorized oil is obtained by filtering.

In one or more embodiments, the deodorization is performed by a two-tower deodorization technique, wherein the two towers are a plate tower and a packed tower in sequence, wherein the decolorized oil at 195-; then the oil flowing out of the plate tower is heated to 235 ℃ and preferably 230 ℃ and 220 ℃ and is conveyed to the packed tower, and steam stripping is carried out for 5 to 20 minutes and preferably for 5 to 15 minutes under the conditions of vacuum degree less than or equal to 10 torr, preferably less than or equal to 5 torr and stripping amount of 0.5 to 2.0 percent.

In one or more embodiments, the mild processing method of grease comprises:

mild caustic refining to obtain a neutralized oil comprising: (1) adding acid into 70-90 deg.C hydrated degummed oil, mixing, and standing at 70-90 deg.C for 30-90 min; (2) dividing the alkali liquor into at least two parts, wherein the amount of each part is the same or different, and the parts are sequentially added into the mixture obtained in the step (1) at the time interval of 5-15 minutes, wherein alkali refining is carried out for 5-15 minutes after the alkali liquor is added for the last time;

optionally mild dewaxing comprising: gradually cooling the neutralized oil to 10-15 deg.C, adding 0.8% -1% of perlite or diatomaceous earth, stirring, continuously cooling to 8 deg.C, maintaining for 8-15 hr, and filtering to obtain dewaxed oil;

moderate decolorization, including: enabling dewaxed oil with the oil temperature of 100-;

mild deodorization, comprising: deodorizing by adopting a double-tower deodorization technology, wherein the sequence of the double towers is that a plate tower is firstly followed by a packed tower, wherein the decolorized oil with the temperature of 195-215 ℃, preferably 200-210 ℃ is conveyed to the plate tower, and steam stripping is carried out for 30-100 minutes, preferably 60-90 minutes under the conditions of the vacuum degree of less than or equal to 10 torr, preferably less than or equal to 5 torr and the stripping amount of 0.5-2.0 percent; then heating the oil flowing out of the plate tower to the temperature of 220 ℃ and 235 ℃, preferably to the temperature of 225 ℃ and 230 ℃, conveying the oil to a packed tower, and carrying out steam stripping for 5-20 minutes, preferably 5-15 minutes under the conditions of the vacuum degree of less than or equal to 10 torr, preferably less than or equal to 5 torr and the stripping amount of 0.5-2.0 percent; cooling and filtering the oil flowing out through the packed tower to obtain proper process oil;

preferably, the hydrated degumming oil is obtained by carrying out hydrated degumming on crude oil at 70-90 ℃ for 10-60min by using hot water at 70-90 ℃ accounting for 1-5% of the weight of the oil.

In a fourth aspect, the invention provides a suitably processed oil or fat having a trans-fatty acid content of 0.3% or less, △ AV (24h) or less, 0.04mgKOH/g or less, △ PV (9h) or less, 5.5mmol/kg or less, △ R (6h) or less, and FFA or less, based on the total amount of the suitably processed oil or fat, and having a vitamin E content of at least 90% by weight and a sterol content of at least 90% by weight, based on the total amount of the suitably processed oil or fat, of the crude oil or fat used for the preparation of the suitably processed oil or fat, and having a vitamin E content of at least 0.7% by weight and a FFA content of at least 0.1% by weight, based on.

In one or more embodiments, the mild processing oil is prepared using the mild processing method for fats and oils described in any of the embodiments herein.

In one or more embodiments, the moderately processed oils and fats are selected from the group consisting of soybean oil, rapeseed oil, corn oil, sunflower oil, and rice oil.

The fifth aspect of the invention provides a blend oil, wherein the blend oil has a trans-fatty acid content of less than or equal to 0.3 percent, △ AV (24h) of less than or equal to 0.04mgKOH/g, △ PV (9h) of less than or equal to 5.5mmol/kg and △ R (6h) of less than or equal to 0.7 percent based on the total amount of the blend oil, and preferably, the blend oil has a saturated fatty acid content of 8-16 percent, an omega-6 unsaturated fatty acid content of 40-47 percent and an omega-3 unsaturated fatty acid content of 4-13 percent based on the total amount of the blend oil.

In one or more embodiments, the blend oil contains at least two neutralized oils or moderately processed fats as described in any of the embodiments herein, and the blend oil contains at least 25% of the neutralized oils or the moderately processed fats, based on the total weight thereof.

In one or more embodiments, the blend oil also contains other oils other than the neutralized oil or the moderately processed oil, preferably one or more of peanut oil, sesame oil, linseed oil, and safflower oil; preferably, the blend oil also contains 0.1-5% of linseed oil and/or safflower oil, 0.1-5% of peanut oil, and/or 0.1-5% of sesame oil.

In one or more embodiments, the blend oil contains at least 25%, at least 35%, at least 45%, at least 55%, at least 65%, at least 75%, at least 85%, at least 90%, at least 95%, or 100% of the neutralized oil of claim 3 and/or the moderately processed grease of claim 8, based on the total amount of the blend oil.

In one or more embodiments, the blend oil is selected from the group consisting of:

(1) a blend oil containing moderately processed rapeseed oil and moderately processed sunflower seed oil; preferably, the blend oil contains at least 15 wt%, preferably 15-30 wt% of moderately processed rapeseed oil and at least 10 wt%, preferably 10-40 wt% of moderately processed sunflower oil; preferably, the sum of the contents of the moderately processed rapeseed oil and the moderately processed sunflower seed oil is at least 25 percent based on the total weight of the blend oil;

(2) a blend oil comprising moderately processed soybean oil, moderately processed corn oil, and moderately processed rice oil; preferably, the blend oil has a moderately processed soybean oil content of at least 15 wt%, preferably 15-60 wt%, a moderately processed corn oil content of at least 5 wt%, preferably 5-20 wt%, and a moderately processed rice oil content of at least 5 wt%, preferably 5-15 wt%; preferably, the sum of the amounts of moderately processed soybean oil, moderately processed corn oil and moderately processed rice oil is at least 35% based on the total weight of the blend oil;

(3) a blend oil comprising moderately processed soybean oil and moderately processed rapeseed oil, preferably the blend oil comprises 15-60% of moderately processed soybean oil and 15-30% of moderately processed rapeseed oil, based on the total weight of the blend oil; more preferably, the sum of the content of the moderately processed soybean oil and the moderately processed rapeseed oil is at least 45 percent based on the total weight of the blend oil;

(4) a blend oil comprising a moderately processed soybean oil, a moderately processed rapeseed oil, a moderately processed corn oil and a moderately processed sunflower oil, preferably the blend oil comprises 15-60% of the moderately processed soybean oil, 15-30% of the moderately processed rapeseed oil, 1-20% of the moderately processed corn oil and 10-40% of the moderately processed sunflower oil, based on the total weight of the blend oil; more preferably, the blend oil comprises 15-60% moderately processed soybean oil, 15-30% moderately processed rapeseed oil, 5-10% moderately processed corn oil, and 10-40% moderately processed sunflower oil, based on the total weight of the blend oil; more preferably, the sum of the contents of the moderately processed soybean oil, the moderately processed rapeseed oil, the moderately processed corn oil and the moderately processed sunflower seed oil is at least 80% based on the total weight of the blend oil; and

(5) a blend oil comprising moderately processed soybean oil, moderately processed rapeseed oil, moderately processed corn oil, moderately processed sunflower seed oil, and moderately processed rice oil; preferably, the blend oil comprises 15-60% of moderately processed soybean oil, 15-30% of moderately processed rapeseed oil, 1-20% of moderately processed corn oil, 10-40% of moderately processed sunflower oil and 1-15% of moderately processed rice oil, based on the total weight of the blend oil; more preferably, the blend oil comprises 15-60% moderately processed soybean oil, 15-30% moderately processed rapeseed oil, 5-10% moderately processed corn oil, 10-40% moderately processed sunflower oil, and 5-15% moderately processed rice oil, based on the total weight of the blend oil; preferably, the sum of the content of moderately processed soybean oil, moderately processed rapeseed oil, moderately processed corn oil, moderately processed sunflower oil and moderately processed rice oil is at least 85%, preferably at least 90%, based on the total weight of the blend oil.

Detailed Description

It is to be understood that within the scope of the present invention, the above-described technical features of the present invention and the technical features described in detail below (e.g., the embodiments) may be combined with each other to constitute a preferred embodiment.

The vegetable oil contains rich natural antioxidants VE and sterol, and the quality of the oil can be comprehensively improved if the trace nutrient components can be furthest reserved and the generation of trace harmful components is controlled. In order to reserve the trace nutrient components to the maximum extent, the invention provides the oil processing method which can reserve the trace nutrient components VE and sterol (the content of both is more than or equal to 90 percent) in the oil to the maximum extent and can effectively control TFA (zero trans, less than or equal to 0.3 percent) on the premise of ensuring the quality and the flavor of the oil to reach the standard. Therefore, the method of processing fats and oils of the present invention is a precise and appropriate method, and preferably, the steps involved in the method of processing fats and oils herein, such as alkali refining, dewaxing, decoloring, deodorizing, and the like, are appropriate steps. As used herein, "accurate moderation" or "moderation" means the ability to maximize the retention of nutrients, remove hazards, and avoid their formation. Herein, the nutritional ingredients include, but are not limited to, VE and sterols.

The precision mild processing method of the present invention is applicable to mild processing of various oils and fats well known in the art, including but not limited to oils and fats extracted from vegetable oils or animals from leaching or pressing processes, such as soybean oil, rapeseed oil, sunflower seed oil, coconut oil, peanut oil, safflower seed oil, cottonseed oil, rice oil, corn oil, olive oil, hydrogenated oils and fats, palm oil, etc., vegetable oils and animal oils and fats, or mixtures thereof. It is to be understood that reference to "oil" in the present invention includes oils and/or fats, such as degummed, neutralized, dewaxed, bleached, and refined oils, and the like, including oils and/or fats.

The invention relates to a moderate processing method of grease, in particular to a moderate alkali refining method of grease. In certain embodiments, the mild caustic refining process of the present invention comprises: (1) acid pretreatment: adding a degumming medium into the degummed oil with the oil temperature of 70-90 ℃, wherein the degumming medium is acid; (2) alkali treatment: dividing the alkali liquor into at least two parts, and sequentially adding the alkali liquor into the acid pretreated mixture obtained in the step (1) at intervals of 5-15 minutes, wherein the amount of each part of alkali liquor is the same or different.

Herein, the acid used in the acid pretreatment step refers to the acid used in the conventional degumming step, including but not limited to phosphoric acid, citric acid and mixtures thereof. Typically, the acid is added in an amount of 100-600ppm based on the weight of the degummed oil. After the acid is added, the oil temperature can be kept at 70-90 ℃, and the mixture is placed for 30-90 minutes for acidification treatment. The concentration of the phosphoric acid aqueous solution is usually 80 to 85%, and the concentration of the citric acid aqueous solution is usually 30 to 50%.

Acidifying, then carrying out alkali treatment, and adding alkali liquor into the oil containing the acid for alkali refining. The lye may be lye as is conventional in the art for alkali refining, such as sodium hydroxide solution and/or potassium hydroxide solution. The concentration of the lye is not more than 15% and may be in the range of 5-10%, preferably 5-7.5%. In the alkali refining, the overbasing amount is controlled within the range of 0 to 15%, preferably 0 to 10%. The alkali addition can be calculated by conventional methods, for example, according to the following formula: alkali addition amount is 7.13 × 10^-4×M_OilxAV x (1+ excess base), wherein M_OilOil weight, AV acid number.

In the present case, the term "excess alkali amount" refers to an amount of alkali that is more than the theoretical amount of alkali that neutralizes free fatty acids in fats and oils, which is added due to the reaction between alkali and triglycerides during the actual alkali refining process.

In the present case, the term "trans fatty acid" refers to an unsaturated fatty acid having one or more "non-conjugated trans double bonds" in its chemical structure, and the "trans fatty acid content" refers to the weight ratio of the trans fatty acid in the fatty acid composition of the vegetable oil/fat composition.

In the present case, the term "△ AV" refers to the change in acid value, usually the increase in acid value, "△ AV (24 h)" refers to the change in acid value obtained by weighing 50.00g of an oil sample into a 100ml dry and clean beaker (diameter: 5cm), then dispersedly injecting 0.500g of distilled water into the beaker with 100ul of a microsyringe, adding 4cm long B-type and polytetrafluoroethylene magnetic stirrer, stirring at a stirring speed of 500 rpm for 2min, taking out the stirrer, heating in a 105 ℃ incubator for 24 hours, taking out the sample, cooling to room temperature, detecting the acid value, taking the average of double parallel detection as the detection result, and comparing with the sample before heating, calculating the increase in acid value (△ AV).

In this case, the term "△ PV" refers to the change in the peroxide value, usually the rise in the peroxide value, "△ PV (9 h)" refers to the change in the peroxide value obtained by adding a 100g oil sample to a 250ml iodine value bottle, placing the bottle in an oven at 90 ℃ open, taking the bottle out after 9 hours, cooling the bottle for 20 minutes, measuring the peroxide value, and calculating the rise in the peroxide value (△ PV) by comparison with the sample before heating.

In this case, the term "△ R" refers to a color change value, usually a color rise value, "△ R (6 h)" refers to a color change value obtained by adding a 100g oil sample to a 250ml iodine value bottle, uncapping the bottle, placing the bottle in an oven at 105 ℃ for 6 hours, taking out the bottle, cooling the bottle for 30 minutes, and then measuring the color, and comparing the measured color with the sample before heating, calculating the color rise value (△ R).

In the present invention, the polar compound means a compound containing a carbon group, a carboxyl group, a ketone group, an aldehyde group, and the like, which are generated by oxidation, polymerization, cleavage, hydrolysis, and the like of edible oil due to continuous repeated use at a high temperature during frying, and these compounds have higher polarity than triglycerides, so that the term "△ polar compound" means an increase in the polar compound.

In the preferred mild caustic refining process of the present invention, the caustic is added in at least two portions at intervals of 5-15 minutes. For example, the alkali liquor may be divided into two or more portions, the amount of each portion of alkali liquor may be the same or different, and then added to the acidified oil or fat in sequence at intervals of 5 to 15 minutes, and alkali refining may be performed for 5 to 15 minutes each time. For example, in certain embodiments, the lye is divided into two parts, which may be present in a weight ratio of 70: 30 to 30: 70, and then adding two parts of lye in sequence at time intervals of 5-15 minutes. When the amounts of the two alkali lye are different, there is no particular restriction on the order of addition. For example, 70% lye may be added first, followed by the remaining 30% lye; or 30% alkali solution can be added firstly, and then the rest 70% alkali solution can be added. In certain embodiments, the lye is divided into three or more portions and added sequentially at time intervals of 5 to 15 minutes; similarly, the amount of each portion of lye may be the same or different and there is no particular limitation on the order of addition of each portion of lye. The refining time per lye can be the same or different and is generally in the range of 5 to 15 minutes. For example, in certain embodiments, the lye is added in two portions, the caustic refining time for each portion of lye being controlled to be 3: 1 to 1: 3, or a salt thereof. The total alkali refining time is usually not more than 60 minutes, such as in the range of 15 to 60 minutes, preferably 15 to 30 minutes. The oil temperature during alkali refining can be in the range of 70-90 ℃, preferably in the range of 80-85 ℃.

In the present invention, "dividing the alkali liquor used for alkali refining into at least two parts, the amounts of the alkali liquor in each part being the same or different, the alkali liquor being added to the mixture obtained in step (1) at time intervals of 5 to 15 minutes" means that the alkali liquor used for alkali refining is divided into a plurality of parts, for example, 2 parts or 3 parts, which are sequentially added to the mixture obtained in step (1) or the mixture obtained in step (1) to which the alkali liquor has been added; specifically, when the alkali liquor is divided into 2 parts, adding 1 part of alkali liquor into the mixture obtained in the step (1), alkali refining for 5-15 minutes, and adding 2 parts of alkali liquor into the mixture subjected to alkali refining for 5-15 minutes; when the alkali liquor is divided into 3 parts, adding 1 st part of alkali liquor into the mixture obtained in the step (1), alkali refining for 5-15 minutes, adding 2 nd part of alkali liquor into the mixture after alkali refining for 5-15 minutes, and adding 3 rd part of alkali liquor into the mixture after 2 times of alkali refining for 5-15 minutes. When the lye used is divided into more portions, it is refined in a manner similar to that described above.

And adding alkali liquor for the last time, and after 5-15 minutes of alkali refining, removing soap, washing and drying (dewatering) can be carried out. The soapstock removal, water washing and drying can be carried out by conventional methods. For example, desponification is carried out by centrifugation. The water temperature for washing can be in the range of 70-90 ℃, and the water consumption can be 1-5% of the weight of the oil. The oil can be dewatered by centrifugation and then vacuum dewatered in a vacuum tank to remove residual water and finally obtain the neutralized oil.

Herein, the degummed oil used for the alkali refining may be a degummed oil obtained by hydration degumming, acidification degumming, and/or enzymatic degumming, and is preferably a degummed oil obtained by hydration degumming. In certain embodiments, the present hydration degumming comprises degumming with hot water at 70-90 ℃, preferably 70-85 ℃. When the hydrated degumming is carried out, the amount of the hot water is usually 1 to 5 percent, preferably 2 to 4 percent of the weight of the oil; the temperature of the crude oil is generally 70 to 90 ℃, preferably 70 to 85 ℃; the stirring time is usually 15 to 60 minutes. In a preferred embodiment, the hydration degumming of the invention comprises mixing 1-5%, preferably 2-4% of hot water at 70-85 ℃ and crude oil at 70-85 ℃ by weight of the oil, stirring for 15-60 minutes, and then centrifuging to obtain the hydration degummed oil.

Compared with the degummed oil before moderate alkali refining, the vitamin E contained in the neutralized oil is more than 97.5 percent of the vitamin E contained in the degummed oil, preferably more than 98.0 percent, and more preferably more than 98.5 percent; the sterol contained in the neutralized oil is 96.5% or more, preferably 97.0% or more, and more preferably 97.5% or more of the sterol contained in the degummed oil.

In certain embodiments, the mild processing methods of the fats and oils of the present invention include the mild caustic refining methods described herein and any one or more of degumming, dewaxing, decolorizing, and deodorizing.

In the present invention, degumming may include hydration degumming, acidification degumming and enzymatic degumming. Preferably, degumming is hydration degumming. More preferably, the hydration degumming comprises a step of degumming with hot water at 70-90 ℃; preferably, in the hydration degumming, the consumption of the hot water at 70-90 ℃ is 1-5%, preferably 2-4% of the weight of the oil, the temperature of the crude oil is 70-90 ℃, and the stirring time is 15-60 minutes. After the hot water treatment is finished, centrifugal separation can be carried out to obtain the degummed oil. Therefore, in some embodiments, the moderate processing method of the oil and fat comprises a degumming step and an alkali refining step, wherein the degumming step comprises the steps of uniformly mixing 1-5%, preferably 2-4% of hot water with the weight of the oil and the crude oil with the weight of 70-90 ℃, preferably 70-85 ℃, stirring for 15-60 minutes, and then carrying out centrifugal separation to obtain hydrated degumming oil; the alkali refining comprises the steps of standing acid for uniformly mixing and degumming and degummed oil with the oil temperature of 70-90 ℃ at 70-90 ℃ for acidification treatment, dividing alkali liquor for alkali refining into at least two parts, wherein the amount of each part is the same or different, and the alkali liquor is sequentially added into the degummed oil subjected to acidification treatment at intervals of 5-15 minutes. More detailed degumming and caustic refining processes may be as described in any of the previous embodiments.

In the present invention, the decolorization is usually carried out at a temperature of 100-110 ℃ and preferably at a temperature of 100-105 ℃. The decolorizing medium includes, but is not limited to, any one or any combination of clay, activated carbon, and attapulgite. In certain preferred embodiments, the present invention uses a combination of clay and attapulgite, preferably in a weight ratio of 1:2 to 2: 1. In general, the decolorizing medium is used in an amount of 0.5 to 3.0%, preferably 1.0 to 2.0%, based on the weight of the oil.

In certain embodiments, the decolorization is a two-stage decolorization, wherein the first stage of decolorization comprises passing the oil having an oil temperature of 100-; the second-stage decolorization is carried out in a decolorization tank for 30 minutes to 1 hour, and the dosage of a decolorization medium is 0.5 to 1.5 percent of the weight of the oil. In a preferred embodiment, the decolorizing comprises: grease with the oil temperature of 100-110 ℃, preferably 100-105 ℃ passes through a filter filled with waste decolorizing soil which is decolorized for the first time to be subjected to pre-decolorizing to obtain pre-decolorized oil, then clay and attapulgite with the weight ratio of 1:2-2:1, which is 0.5-1.5%, preferably 1.0-1.2% of the weight of the oil, are added into the pre-decolorized oil, the mixture is decolorized in a vacuum decolorizing tank for 30 minutes to 1 hour, and the decolorized oil is obtained by filtering. The two-stage decolorization is adopted, so that waste (namely, decolorized soil subjected to one-stage decolorization) can be utilized, and the consumption of a decolorization medium during two-stage decolorization is reduced.

In a preferred embodiment, when the wax content of the neutralized oil is high, dewaxing may be performed prior to the caustic refining, followed by decolorization. Preferably, dewaxing is mild dewaxing. Usually, dewaxing comprises cooling the neutralized oil obtained by alkali refining to 10-15 ℃, then adding a dewaxing assistant, stirring uniformly, continuously cooling to 5-8 ℃, keeping for 6-15 hours, and filtering to obtain the dewaxed oil. Suitable dewaxing aids include, but are not limited to, perlite, diatomaceous earth, and combinations thereof, and are used in total amounts of 0.5 to 1.5%, preferably 0.8 to 1.0% by weight of the oil.

Herein, the deodorization temperature is 190-; deodorizing for 30-120 min, preferably 30-105 min; the vacuum degree is less than or equal to 10 torr, and preferably less than or equal to 5 torr. In some embodiments, the deodorization is performed by steam stripping, wherein the stripping amount is 0.5-2%, preferably 1-1.5%.

In a preferred embodiment, a double-tower deodorization technology is adopted for deodorization, the sequence of the double towers is a plate tower and a packed tower, wherein, the decolorized oil at 195-215 ℃, preferably 200-210 ℃ is conveyed to the plate tower, and steam stripping is carried out for 30-100 minutes, preferably 60-90 minutes under the conditions of the vacuum degree of less than or equal to 10 torr, preferably less than or equal to 5 torr and the stripping amount of 0.5-2.0 percent; then the oil flowing out of the plate tower is heated to 235 ℃ and preferably 230 ℃ and 220 ℃ and is conveyed to the packed tower, and steam stripping is carried out for 5 to 20 minutes and preferably for 5 to 15 minutes under the conditions of vacuum degree less than or equal to 10 torr, preferably less than or equal to 5 torr and stripping amount of 0.5 to 2.0 percent.

Thus, in certain embodiments, the mild processing methods of fats and oils herein comprise:

moderate alkali refining, comprising: (1) adding degumming acid into 70-90 deg.C hydrated degummed oil, mixing, and standing at 70-90 deg.C for 30-90 min; (2) dividing alkali liquor used for alkali refining into at least two parts, wherein the amount of each part is the same or different, and sequentially adding the parts into the mixture obtained in the step (1) at intervals of 5-15 minutes; (3) adding alkali liquor for the last time, refining for 5-15 minutes, removing soap, washing with water and drying to obtain neutralized oil;

optionally mild dewaxing comprising: gradually cooling the neutralized oil to 10-15 ℃, adding 0.8-1% of perlite or diatomite, stirring uniformly, continuously cooling to 8 ℃, keeping for 6-15 hours, and filtering to obtain dewaxed oil;

moderate decolorization, including: enabling the dewaxed oil with the oil temperature of 100-;

mild deodorization, comprising: deodorizing by adopting a double-tower deodorization technology, wherein the sequence of the double towers is that a plate tower is firstly followed by a packed tower, wherein the decolorized oil with the temperature of 195-215 ℃, preferably 200-210 ℃ is conveyed to the plate tower, and steam stripping is carried out for 30-100 minutes, preferably 60-90 minutes under the conditions of the vacuum degree of less than or equal to 10 torr, preferably less than or equal to 5 torr and the stripping amount of 0.5-2.0 percent; then heating the oil flowing out of the plate tower to the temperature of 220 ℃ and 235 ℃, preferably to the temperature of 225 ℃ and 230 ℃, conveying the oil to a packed tower, and carrying out steam stripping for 5-20 minutes, preferably 5-15 minutes under the conditions of the vacuum degree of less than or equal to 10 torr, preferably less than or equal to 5 torr and the stripping amount of 0.5-2.0 percent; cooling and filtering the oil flowing out of the packed tower to obtain refined oil.

In a preferred embodiment, the hydrated degummed oil is obtained using a hydration degumming comprising: heating the crude oil to 70-85 deg.C; adding hot water 1-5% of the oil weight, mixing, and hydrating for 10-60 min; and centrifugally separating to obtain the hydrated degummed oil.

Also included herein is a moderately processed oil (refined oil) having a vitamin E weight of at least 90% of the weight of vitamin E in the crude oil, a sterol weight of at least 90% of the weight of sterols of the crude oil as compared to the crude oil used to prepare the moderately processed oil, examples of moderately processed oils provided herein include, but are not limited to, moderately processed soybean oil, moderately processed rapeseed oil, moderately processed corn oil, moderately processed sunflower oil, and moderately processed rice oil, preferably, the moderately processed oil provided herein has a TFA content of 0.3% or less, preferably 0.28% or less, and satisfies △ (24h) or less 0.04mg KOH/g, △ PV (9h) or less 5.5mmol/kg, △ R (6h) or less 0.7 and FFA or less 0.1% in certain embodiments, the moderately processed soybean oil has a TFA content of 0.3% or less, preferably 0.38% or less, 7% or less, the invention has a TFA content of 0.7% or less, preferably, and satisfies 3% or less than 0.38% or less, 7% or less, and preferably, the invention has a TFA content of 0.7% or less, a TFA content of 0.7 or less, a TFA 0.7 or less, and preferably, a TFA 0.7 or less than 0.7 or less in certain embodiments, a 0.7 or less than 0.7, and preferably, a 0.7 or less than 0.7 or more than 0.7 or less than 0.7 or more, and preferably, and more than 0.7 or less than 0.7 or more than 0.7 or less than 0.7 or more, and preferably, and more than 0.7 or less than 0.7 or more in certain embodiments, a 0.7 or more preferably, a 0.7 or more than 0.7 or less than 0.7 or more preferably, a 0.7 or less than 0.7 or more preferably, and more than 0.7 or less than 0.7 or more than 0.7 or less than 0.

In addition, the mild process oils provided herein have a bland flavor without off-flavors, including no off-flavors such as carclazyte, green grass, beany, sour, oxidized, vegetable fishy, and the like. Preferably, the mild processed fats herein are prepared using the mild processing method of fats herein described in any of the embodiments herein.

The blend oil can be prepared by using the moderately processed oil and fat, and has the trans-fatty acid content of less than or equal to 0.3 percent, △ AV (24h) of less than or equal to 0.04mgKOH/g, △ PV (9h) of less than or equal to 5.5mmol/kg and △ R (6h) of less than or equal to 0.7 based on the total amount of the blend oil.

In certain embodiments, the blend oils of the present invention comprise any one or more of the moderately processed soybean oils, moderately processed rapeseed oils, moderately processed corn oils, moderately processed sunflower oils, and moderately processed rice oils described herein. To achieve desired properties such as frying performance (e.g., slow the tendency of acid value, color and polar compounds to rise during frying and oil absorption by the food product), the level of moderately processed fats and oils of the present invention in the blend can be suitably controlled. Typically, the blend oil contains at least 25%, at least 35%, at least 45%, preferably at least 55%, preferably at least 65%, preferably at least 70%, preferably at least 85%, preferably at least 90%, more preferably at least 95%, more preferably 100% of the aforementioned moderately processed fats and oils, based on 100% weight of the blend oil. The minimum level of the moderately processed fats of the present invention in the blend oil will vary when different moderately processed fats of the present invention or combinations thereof are used, as can be readily determined by one skilled in the art using methods known in the art, as described herein.

Preferably, the blend oils of the present invention contain at least two or at least three of the medium processed soybean oil, medium processed rapeseed oil, medium processed corn oil, medium processed sunflower oil, and medium processed rice oil described herein. For example, the blend oil of the present invention contains the moderately processed rapeseed oil of the present invention and the moderately processed sunflower seed oil. Wherein, the content of the properly processed rapeseed oil is at least 15 wt%, and the content of the properly processed sunflower seed oil is at least 10 wt%. In certain embodiments, the blend oil contains 15-30 wt% moderately processed rapeseed oil and 10-40 wt% moderately processed sunflower oil. In certain embodiments, the combined content of the moderately processed rapeseed oil and the moderately processed sunflower seed oil in the blend oil is at least 25 wt% of the total weight of the blend oil.

In certain embodiments, the blend oil of the present invention comprises the moderately processed soybean oil, the moderately processed corn oil and the moderately processed rice oil of the present invention, wherein the blend oil comprises at least 15 wt% moderately processed soybean oil, at least 5 wt% moderately processed corn oil and at least 5 wt% moderately processed rice oil. In certain embodiments, the blend oil comprises 15 to 60 wt% moderately processed soybean oil, 5 to 20 wt% moderately processed corn oil, and 5 to 15 wt% moderately processed rice oil. In certain embodiments, the combined content of the moderately processed soybean oil, the moderately processed corn oil and the moderately processed rice oil in the blend oil is at least 35 wt%, such as at least 45 wt% or at least 70 wt%, of the total weight of the blend oil.

In certain embodiments, the blend oils of the present invention comprise a medium processed soybean oil, a medium processed rapeseed oil, a medium processed corn oil, a medium processed sunflower oil, and a medium processed rice oil as described herein. Preferably, the blend oil comprises 15-60% moderately processed soybean oil, 15-30% moderately processed rapeseed oil, 1-20% moderately processed corn oil, 10-40% moderately processed sunflower oil, and 1-15% moderately processed rice oil, based on the total weight of the blend oil. More preferably, the blend oil comprises 15-60% moderately processed soybean oil, 15-30% moderately processed rapeseed oil, 5-10% moderately processed corn oil, 10-40% moderately processed sunflower oil, and 5-15% moderately processed rice oil, based on the total weight of the blend oil. Preferably, in certain embodiments, the combined content of said moderately processed soybean oil, moderately processed rapeseed oil, moderately processed corn oil, moderately processed sunflower oil and moderately processed rice oil in the blend oil is at least 85 wt%, such as at least 90 wt% or at least 95 wt%, of the total weight of the blend oil.

The blend oils of the present invention may also contain other oils in addition to the mild process oils described herein, including but not limited to one or more of peanut oil, corn oil, sesame oil, and safflower oil. In certain embodiments, the blend oils of the present invention comprise 0.1-5% flaxseed oil and/or safflower oil, 0.1-5% peanut oil and 0.1-5% sesame oil. Preferably, the other fats present are also moderately processed fats, such as may be other moderately processed fats known in the art.

In a preferred embodiment, the blend oil of the present invention comprises 15-60% moderately processed soybean oil, 15-30% moderately processed rapeseed oil, 1-20% moderately processed corn oil, 10-40% moderately processed sunflower oil, and 1-15% moderately processed rice oil, as well as 0.1-5% linseed oil and/or safflower oil, 0.1-5% peanut oil, and 0.1-5% sesame oil. In a more preferred embodiment, the blend oil of the present invention comprises 15-60% moderately processed soybean oil, 15-30% moderately processed rapeseed oil, 5-10% moderately processed corn oil, 10-40% moderately processed sunflower oil, and 5-15% moderately processed rice oil, as well as 0.1-5% linseed oil and/or safflower oil, 0.1-5% peanut oil, and 0.1-5% sesame oil.

Preferably, the blend oil described herein has a saturated fatty acid content of 8-16%, an omega-6 unsaturated fatty acid content of 40-47%, and an omega-3 unsaturated fatty acid content of 4-13% based on the total weight of the blend oil.

The blend oil has good frying performance, and the frying indexes of △ AV, and the frying index of &ttttranslation = delta "&gtt &ltt/t &gtt R, △ polar compounds and oil absorption rate can be reduced by 10-30%.

The blend oil can be prepared by sequentially adding various oils for preparing the blend oil into a blending tank according to the dosage, maintaining the temperature at 20-40 ℃, slowly stirring for 20-30min, filtering and filling to obtain the finished product of the blend oil.

Compared with the prior art, the invention has the following advantages:

1. in CN 102517142B, the trans-fatty acid of single soybean oil is controlled below 0.5 percent (FDA zero trans labeling standard in the United states) through process optimization, but the invention can realize more strict zero trans (less than or equal to 0.3 percent and GB28050-2011) of various oil types.

2. VE and sterol retention is more than or equal to 90 percent, CN 103451016A mentions the optimized effect of a deodorization section on rapeseed oil α -tocopherol retention, but only mentions that the retention of α -tocopherol is above 172ppm, does not mention retention rate, and does not mention loss and protection measures of sterol in the refining process of rapeseed oil, although the deodorization section in CN 102293264B also adopts low-temperature deodorization, the double-tower temperature is unified, the VE loss rate is 11-16 percent, trans-fatty acid is 0.5-1 percent, and the sterol retention rate is not mentioned, but the VE and sterol retention of the invention can reach more than 90 percent.

3. Good flavor and no peculiar smell: most of existing factory deodorizing equipment is a packed tower-plate tower integrated tower, although most of small molecular aldehyde ketone compounds can be removed under high temperature conditions, in fact, oil can be decomposed under high temperature conditions in the plate tower to generate part of small molecular aldehyde ketone compounds, which has bad influence on the flavor of refined oil, and causes bad flavors such as beany flavor, green grass flavor, vegetable flavor and the like. However, the blend oil of the invention has no peculiar smell such as beany flavor, grass flavor, vegetable flavor, oxidation flavor, atlapulgite flavor and the like.

4. The frying performance is good, the rising trend of acid value, color and polar compounds and the oil absorption rate of food in the frying process can be slowed, and the oil absorption rate of the frying index △ AV, the &ttttranslation = delta "&gtt &/t &tttr, △ polar compounds and food can be reduced by 10-30%.

The present invention will be illustrated below by way of specific examples. It should be understood that these examples are illustrative only and are not intended to limit the scope of the present invention. In the following examples of the present invention, the detection methods were respectively:

acid value: measuring the acid value of GB 5009.229 food safety national standard food;

peroxide number: measuring the peroxide value in GB 5009.227 national food safety standard;

color: GB/T5009.37-2003 edible vegetable oil sanitation standard analysis method;

polar substance content: measuring Polar Components (PC) in edible oil of GB 5009.202 national standard for food safety;

oil absorption: measuring fat in GB 5009.6-2016 food safety national standard food;

VE: GB/T26635-;

sterol: GB/T25223-.

△ AV (24h) 50.00g of oil sample is weighed into a 100ml dry clean beaker (diameter 5cm), 0.500g of distilled water is then dispersedly injected into the beaker by a 100ul microsyringe, 4cm of magnetic stirrer is added, the beaker is stirred for 2min at a stirring speed of 500 rpm, the beaker is placed in a 105 ℃ incubator and heated for 24h, the sample is taken out and cooled to room temperature, the acid value of the sample is detected, and the increase in the acid value is calculated by comparing the sample with the sample before heating (△ AV).

△ PV (9h) 100g oil sample was added to a 250ml iodine value bottle, placed in an oven at 90 ℃ open, and after 9 hours, the PV was measured after cooling and compared to the sample before heating to calculate the PV increase (△ PV).

△ R (6h), 100g of oil sample is added into a 250ml iodine value bottle, the bottle is placed in an oven at 105 ℃ after being uncovered, the bottle is taken out and cooled after 6 hours, and the color is detected and compared with the sample before treatment, and the color rise value is calculated (△ R).

Other methods and materials not mentioned in the examples are conventional in the art.

Example one

The following tables 1-10 show the process steps and associated results for examples 1-25 and comparative examples 1-27, wherein the degumming-caustic refining, bleaching and deodorization processes involved are as follows:

degumming: heating the crude oil, adding hot water, mixing thoroughly, performing centrifugal separation for a period of time to obtain hydrated degummed oil. Specific degumming conditions are shown in tables 1 and 2.

Alkali refining: heating the hydrated degumming oil to a certain temperature, adding a certain content of phosphoric acid/citric acid through high-speed shearing, acidifying for a period of time in an acidification tank, keeping the oil temperature, then carrying out alkali refining, adding alkali liquor with a certain alkali liquor concentration and a certain excess alkali for alkali refining, then carrying out centrifugal separation and soap removal, adding hot water for washing, carrying out centrifugal dehydration, and then carrying out vacuum dehydration in a vacuum tank to remove residual water to obtain the neutralized oil. Specific alkali refining conditions are shown in tables 3 and 4.

Dewaxing: and gradually cooling the neutralized oil to a certain temperature, adding the dewaxing assistant, uniformly stirring, continuously cooling to a certain temperature, keeping for a period of time, and filtering by using a plate frame to obtain the dewaxed oil. Specific dewaxing conditions are shown in tables 5 and 6.

And (3) decoloring: the neutralized dewaxed oil is heated to a certain temperature, firstly is pre-decolorized by a filter filled with waste decolorizing soil which is primarily decolorized, then mixed decolorizing soil (white clay/attapulgite) with a certain proportion of oil weight is added for mixing, and then is decolorized for a certain time in a vacuum decolorizing tank, and the decolorizing oil is obtained by filtering. Specific decoloring conditions are shown in tables 7 and 8.

Deodorizing: the double-tower sequence is that firstly a plate tower and then a packed tower are used, firstly, the decolored oil is directly subjected to heat exchange with the oil discharged from the packed tower through a heat exchanger to a certain temperature, enters the plate tower, is subjected to 0.5-2% direct steam stripping for a certain time, has a vacuum degree of 0-10 torr, flows out of the plate tower, is pumped into a heater to be heated to a certain temperature, flows into the packed tower, is subjected to 0.5-2% direct steam stripping for a certain time, flows out of the packed tower, is subjected to heat exchange through the heat exchanger and is cooled to 30-45 ℃ gradually through cooling water, and is subjected. Specific deodorization conditions are shown in tables 9 and 10.

Table 1: degumming of the examples

Table 2: degumming of comparative examples

Table 3: alkali refining of the examples

Note: a means that alkali liquor is added in two times, and 50 percent of alkali liquor is added each time; b, adding alkali liquor twice, wherein 70% of the total alkali liquor is added for the first time, and the rest 30% is added for the second time; c is that the alkali liquor is added in twice, 30 percent of the total alkali liquor is added for the first time, and the rest 70 percent is added for the second time; d means that the alkali liquor is divided into three portions, and the three portions are added.

Table 4: alkali refining of comparative example

Note: a means that the alkali liquor is added in two times, and 50 percent of the alkali liquor is added each time.

Table 5: dewaxing of the examples

Examples	Dewaxing temperature (. degree.C.)	Dewaxing aid	Auxiliary (%)	Dewaxing time (hours)
					1	10	Perlite	1.0	10
2	10	Perlite	1.0	10
					3	10	Perlite	1.0	10
4	10	Perlite	1.0	10
					5	10	Perlite	1.0	10
6	10	Perlite	1.0	10
					7	10	Perlite	1.0	10
8	10	Perlite	1.0	10
					9	10	Perlite	1.0	10
10	10	Perlite	1.0	10
					11	8	Perlite	1.0	10
12	10	Perlite	1.0	8
					13	10	Perlite	0.8	10
14	8	Perlite	1.0	10
					15	10	Diatomite	1.0	10
16	10	Perlite	0.9	10
					17	12	Perlite	1.0	10
18	10	Diatomite	0.9	10
					19	10	Perlite	1.0	12
20	10	Perlite	1.0	10
					21	10	Perlite	1.0	10
22	10	Perlite	1.0	10
					23	10	Perlite	1.0	10
24	10	Perlite	1.0	10
					25	10	Perlite	1.0	10
26	10	Perlite	1.0	10

Table 6: dewaxing of comparative examples

Comparative example	Dewaxing temperature (. degree.C.)	Dewaxing aid	Auxiliary (%)	Dewaxing time (hours)
					1	10	Perlite	1.0	10
2	10	Perlite	1.0	10
					3	10	Perlite	1.0	10
4	10	Perlite	1.0	10
					5	10	Perlite	1.0	10
6	10	Perlite	1.0	10
					7	10	Perlite	1.0	10
8	10	Perlite	1.0	10
					9	10	Perlite	1.0	10
10	10	Perlite	1.0	10
					11	10	Perlite	1.0	10
12	10	Perlite	1.0	10
					13	10	Perlite	1.0	10
14	10	Perlite	1.0	10
					15	10	Perlite	1.0	10
16	10	Perlite	1.0	10
					17	10	Perlite	1.0	10
18	10	Perlite	1.0	10
					19	10	Perlite	1.0	10
20	10	Perlite	1.0	10
					21	10	Perlite	1.0	10
22	10	Perlite	1.0	10
					23	10	Perlite	1.0	10
24	10	Perlite	1.0	10
					25	10	Perlite	1.0	10
26	10	Perlite	1.0	10
					27	10	Perlite	1.0	10
28	10	Perlite	1.0	10

Table 7: decolorization of the examples

Table 8: decolorization of comparative example

Table 9: quality of deodorized and Final refined oils of the examples

Table 10: quality of deodorized and Final refined oils of comparative examples

Note: in tables 9 and 10, a means tower packed first and then tower packed second, B means tower packed first and then tower packed second, C means light and odorless, D means slightly sour, and E means slightly fishy.

The refined oils obtained after deodorization of each example and comparative example were examined for △ AV (24h), △ PV (9h) and △ R, and the results are shown in Table 11.

TABLE 11

According to the above results, the oils and fats produced in the above examples can satisfy △ AV (24h) or more and 0.04mgKOH/g, △ PV (9h) or more and 5.5mmol/kg, △ R (6h) or more and VE and sterol retentions of 90% or more, and trans fatty acid content of less than 0.3% in comparison with the oils and fats produced in comparative examples, the above requirements cannot be completely satisfied by the scheme of comparative examples, for example, △ AV (24h) or △ R of comparative examples 2, 4, 5, 11, 13 and the like is out of the above-mentioned range by the low-temperature alkali refining scheme.

Example two

Preparation of cooking blend oil: and (3) sequentially adding the different oil types prepared in the above examples or comparative examples into a blending tank according to the proportion shown in the table 12-14, maintaining the temperature at 20-40 ℃, slowly stirring for 20-30min, filtering and filling to obtain the finished blended oil. The blend oil obtained by blending the moderately processed oils of the examples does not have peculiar smell such as beany smell, grass smell, vegetable smell, oxidized smell, and carclazyte smell. Flavor evaluations were scored by 15-20 professional sensory panelists, with results in a median value. The scoring principle was 5 points, 1-very dislike, 2-dislike, 3-general, 4-like, 5-very like. When there is a smell such as beany smell, grassy smell, vegetable smell, oxidized smell, and carclazyte smell, 1 or 2 is selected.

Frying experiment: the VE and sterol in samples with the same formula ratio are first adjusted to the same level, for example, samples 1, 2, 3 and 4 are adjusted to the content of the sample with the highest VE and sterol content by adding VE and sterol externally. The same is true for samples 5, 6, 7 and 8 and 9, 10, 11 and 12. Then, 2500g of samples with consistent VE and sterol adjustments are weighed and put into a pot to be heated to 180 ℃ at constant temperature, 200g of chips are weighed and fried each time, and the samples are taken out after 3min of frying, and one batch is taken out every hour. After frying 10 batches, detecting the acid value, the color, the polar substance content and the oil absorption rate of the oil. The results are shown in tables 12-14 below.

TABLE 12

Watch 13

TABLE 14

Note that in tables 12-14, △ AV, △ R, △ polar compounds, and the oil content of the chips are relative values.

The flavor evaluation shows that the blend oil prepared by the oil properly processed in the embodiment has no peculiar smell such as beany flavor, grass flavor, vegetable fishy flavor, oxidation flavor, carclazyte flavor and the like, and has good flavor.

Frying experiments show that the green, accurate and moderate processing and blending oil has good frying performance, can slow down the rising trend of acid value, color and polar compounds and the oil absorption rate of food in the frying process, and the frying index △ AV, &lttttranslation = delta "&gttdelta &ltt/t &gttr, △ polar compounds and the oil absorption rate can be reduced by 10-30%, so that the oil fume generation, the oil color deepening and the generation amount of harmful substance polar compounds in the frying process can be slowed down, the oil absorption rate of the fried food can be effectively reduced, more food can be fried by the same amount of oil, the using frequency of frying is increased, and under the condition that the same amount of fried food is ingested, the human body can reduce the intake of oil and fat, reduce the intake of harmful substances and is beneficial to health.

EXAMPLE III

The oils and fats of examples 1 to 26 and comparative examples 1 to 28 were stored in 900ml PET bottles in a shelf room at 25 ℃ at room temperature, and examined for indices AV, PV and color R at a shelf life of 18 months.

Among them, the results of examples 1 to 3 and comparative examples 1 to 3 are shown in Table 15.

Watch 15

The shelf life performance of some of the examples and comparative examples is shown in Table 15, e.g., comparative example 2 is a low temperature alkali refining, and compared to example 2, although the initial AV, PV and color are slightly lower than those of example 2, it fails to meet the requirements of △ AV (24 h). ltoreq.0.04 mgKOH/g, △ PV (9 h). ltoreq.5.5 mmol/kg, △ R (6 h). ltoreq.0.7, and the increase in AV, PV and color after 18 months of shelf life is greater than that of example 2, showing a more pronounced tendency to increase, i.e., the shelf life stability is less than that of example 2. examples 1, 3 also show better shelf life stability.

Claims

1. A moderate alkali refining method for grease is characterized by comprising the following steps:

(1) acid pretreatment, namely adding a degumming medium into the degummed oil with the oil temperature of 70-90 ℃, and uniformly mixing at 70-90 ℃, wherein the degumming medium is acid;

(2) alkali treatment: dividing alkali liquor into at least two parts, and sequentially adding the parts to the mixture subjected to acid pretreatment obtained in the step (1) at intervals of 5-15 minutes, wherein the amount of each part of alkali liquor is the same or different;

the concentration of the alkali liquor in the step (2) is 5-10%;

in the step (2), the super-alkali amount is 0-15%;

the oil temperature in the step (2) is 70-90 ℃;

adding the alkali liquor into the mixture obtained in the step (1) by two or three times; and

and finally, adding alkali liquor for 5-15 minutes, and then removing soap, washing and drying.

2. The method of claim I, wherein the method has one or more of the following features:

in the step (1), the acid is phosphoric acid and/or citric acid;

in the step (1), the addition amount of the acid is 100-600ppm based on the weight of the degummed oil;

in the step (1), the oil temperature is kept at 70-90 ℃ for 30-90 minutes;

the concentration of the alkali liquor in the step (2) is 6-8%;

in the step (2), the super-alkali amount is 0-10%;

the oil temperature in the step (2) is 80-85 ℃.

3. A method for processing fats and oils, which comprises the method for alkali-refining fats and oils according to any one of claims 1 to 2, and one or more steps selected from degumming, dewaxing, decoloring and deodorizing.

4. The mild grease processing method according to claim 3,

the degumming is hydration degumming, the hydration degumming comprises the step of degumming by using hot water at 70-90 ℃, the using amount of the hot water at 70-90 ℃ is 1-5% of the weight of the oil, the temperature of the crude oil is 70-90 ℃, and the stirring time is 15-60 minutes;

the decolorization is moderate decolorization; the decolorizing temperature is 100-110 ℃; the consumption of the decolorizing medium is 0.5-3.0 percent based on the weight of the oil; the decolorizing medium is selected from clay, activated carbon, attapulgite and any combination thereof, and/or

The deodorization is moderate deodorization; the deodorization temperature is 190 ℃ and 240 ℃; deodorizing for 30-120 min; the vacuum degree is less than or equal to 10 torr; deodorizing by steam stripping, wherein the stripping amount is 0.5-2%; and/or

The dewaxing is moderate dewaxing; the dewaxing comprises the steps of cooling the neutralized oil obtained by alkali refining to 10-15 ℃, adding a dewaxing assistant, stirring uniformly, continuously cooling to 5-8 ℃, keeping for 6-15 hours, and filtering to obtain the dewaxed oil.

5. The mild grease processing method according to claim 4, wherein,

the decolorization is two-stage decolorization, wherein the first-stage decolorization comprises the step of enabling oil with the oil temperature of 100-110 ℃ to pass through a filter filled with a decolorization medium for pre-decolorization; the second-stage decolorization is carried out in a decolorization tank for 30 minutes to 1 hour, and the dosage of a decolorization medium is 0.5 to 1.5 percent of the weight of the oil; and/or

Deodorizing by adopting a double-tower deodorization technology, wherein the sequence of the double towers is a plate tower and a packed tower, wherein the decolorized oil with the temperature of 195 plus 215 ℃ is conveyed to the plate tower, and steam stripping is carried out for 30-100 minutes under the conditions of the vacuum degree less than or equal to 10 torr and the stripping amount of 0.5-2.0%; then the oil flowing out by the plate culture is heated to 220-235 ℃, is conveyed to a packed tower, and is subjected to steam stripping for 5-20 minutes under the conditions of the vacuum degree less than or equal to 10 torr and the stripping amount of 0.5-2.0 percent.

6. The mild processing method of fats and oils according to claim 4 or 5, wherein the decolorizing medium is a combination of clay and attapulgite at a weight ratio of 1:2 to 2:1, and/or

The dewaxing assistant is perlite or diatomite and the dosage of the dewaxing assistant is 0.5 to 1.5 percent of the weight of the oil.

7. The moderate processing method of grease as claimed in claim 4, wherein the deodorization temperature is 200-230 ℃; deodorizing for 30-105 min; the vacuum degree is less than or equal to 5 torr; the stripping amount is 1-1.5%.

8. A moderately processed fat or oil, wherein the moderately processed fat or oil has a trans-fatty acid content of 0.3% or less, △ AV (24h) or less, 0.04mgKOH/g or less, △ PV (9h) or less, 5.5mmol/kg or less, △ R (6h) or less, and FFA or less, 0.1% or less, based on the total amount of the moderately processed fat or oil, and wherein the moderately processed fat or oil has a vitamin E content of at least 90% by weight and a sterol content of at least 90% by weight, based on the sterol content of the crude oil, of at least 90% by weight, based on the weight of the crude oil used to prepare the moderately processed fat or oil;

the moderately processed fat or oil is produced by the moderately processing method for fat or oil according to any one of claims 3 to 7.

9. The moderately processed fat of claim 8, wherein said moderately processed fat is selected from the group consisting of moderately processed soybean oil, rapeseed oil, corn oil, sunflower oil, and rice oil.

10. A blend oil containing the moderately processed oil and fat of claim 8 or 9, wherein the blend oil has a trans fatty acid content of 0.3% or less, △ AV (24h) or less, 0.04mgKOH/g or less, △ PV (9h) or less, 5.5mmol/kg or less, and △ R (6h) or less, 0.7 or less, based on the total amount of the blend oil, the blend oil has a saturated fatty acid content of 8-16%, an omega-6 unsaturated fatty acid content of 40-47%, and an omega-3 unsaturated fatty acid content of 4-13%, based on the total amount of the blend oil, the blend oil contains at least 90% of the moderately processed oil and fat of claim 8 or 9, and the rest of the blend oil is one or more of peanut oil, sesame oil, linseed oil, and safflower oil.

11. The blend oil of claim 10 comprising 0.1-5% linseed oil and/or safflower oil, 0.1-5% peanut oil, and/or 0.1-5% sesame oil.

12. A blended oil containing 100% of the moderately processed fat or oil according to claim 8 or 9, based on the total amount of the blended oil.

13. The blend oil of claim 10, wherein the blend oil is:

the blend oil contains 15-60% of moderately processed soybean oil, 15-30% of moderately processed rapeseed oil, 1-20% of moderately processed corn oil, 10-40% of moderately processed sunflower oil and 1-15% of moderately processed rice oil based on the total weight of the blend oil.

14. A process for producing a blend oil, which comprises producing a moderately processed fat by the moderately processing method for a fat according to any one of claims 3 to 7, and producing a blend oil using the moderately processed fat.