RU2786668C2 - Food oil refining - Google Patents

Abstract

FIELD: fat and oil industry.

SUBSTANCE: method for increasing the quality of food oils or fats includes following stages: a) supply of food oil through equipment for oil refining under vacuum, and addition of distillate substance to an oil flow in such a way that oil comes into contact with distillate substance, and reduction in a content of hydroperoxides and/or volatile substances in oil, and b) collection of refined food oil after the stage a). Moreover, refining equipment includes a stripper with a nozzle and no more than one plate for oil collection, while the stripper is characterized by a specific load by oil from 0.5 to 4.0 kg/m²·h. The stripper has the ratio of height to diameter from 0.1 to 10. The use of refining equipment including the stripper with a nozzle and no more than one plate for oil collection is described, wherein the stripper is characterized by a specific load by oil from 0.5 to 4.0 kg/m²·h, and it has the ratio of height to diameter from 0.1 to 10, for decomposition of products of oxidation of triglycerides, diglycerides, monoglycerides, and/or fatty acids.

EFFECT: invention allows for reduction in a content of hydroperoxides and volatile substances in oil.

12 cl, 3 tbl, 8 ex

Description

Cross reference to related applications

The present application claims priority from European Patent Application No. 18157904.6 filed February 21, 2018 entitled "Edible Oil Refining", European Patent Application No. 18184132.1 filed July 18, 2018 entitled "Edible Oil Refining" and the European Patent No. 18187287.0, filed August 03, 2018, entitled "Edible Oil Refining", the contents of which are incorporated herein by reference in their entirety.

Scope of the invention

A refining process using a stripper packed column to improve the quality of edible oils.

Prerequisites for the creation of the invention

Crude oils, as extracted from their original source, are often unsuitable for human consumption due to the high concentrations of impurities present, which can be toxic or can impart an undesirable color, odor or taste. Therefore, crude oils are usually refined before use. The refining process, as a rule, consists of the following main stages: degumming and/or alkaline refining, bleaching and deodorization. The oil obtained after the completion of the refining process (referred to as neutralized bleached deodorized (NBD) oil or refined bleached deodorized (RBD) oil) is generally considered suitable for human consumption, and therefore can be used in the manufacture of a number of foods and beverages.

In the deodorization process, the oil is heated to elevated temperatures and held at the elevated temperature for a long residence time sufficient to break down the flavor precursors and coloring constituents, and to remove volatile impurities and unwanted substances from the oil under the action of vacuum and steam passed through the oil.

At present, there are many different types of continuous deodorizers, batch deodorizers, and the like on the market. It is common knowledge that deodorizer plates for retention and long holding times are needed to improve the quality of oils.

However, there is a need to improve the method of refining oils or fats.

Such a method is proposed in the present invention.

Statement of the Invention

The present invention relates to a method for improving the quality of edible oils or fats, and such a method includes the following steps:

a) feeding edible oil through vacuum oil refining equipment and adding a stripping agent to the oil stream so that the oil comes into contact with the stripping agent and reducing hydroperoxides and/or volatiles in the oil, and

b) collection of refined edible oil after step a),

at the same time, the refining equipment includes a stripping column with a packing and no more than one oil collection tray.

Furthermore, it relates to the use of refining equipment comprising a packed stripper and not more than one oil collection tray to decompose, decompose or break down the oxidation products of triglycerides, diglycerides, monoglycerides and/or fatty acids.

Detailed description

The present invention relates to a method for improving the quality of edible oils or fats, and such a method includes the following steps:

a) feeding edible oil through vacuum oil refining equipment and adding a stripping agent to the oil stream so that the oil comes into contact with the stripping agent and reducing hydroperoxides and/or volatiles in the oil, and

b) collection of refined edible oil after step a),

at the same time, the refining equipment includes a stripping column with a packing and no more than one oil collection tray.

The present invention relates to a method for improving the taste and flavor properties of edible oils or fats, and such a method includes the following steps:

a) feeding edible oil through vacuum oil refining equipment and adding a stripping agent to the oil stream so that the oil comes into contact with the stripping agent and reducing hydroperoxides and/or volatiles in the oil, and

b) collection of refined edible oil after step a),

at the same time, the refining equipment includes a stripping column with a packing and no more than one oil collection tray.

The present invention relates to a process for producing flavorless edible oils or fats, and such process includes the following steps:

a) feeding edible oil through vacuum oil refining equipment and adding a stripping agent to the oil stream so that the oil comes into contact with the stripping agent and reducing hydroperoxides and/or volatiles in the oil, and

b) collection of refined edible oil after step a),

at the same time, the refining equipment includes a stripping column with a packing and no more than one oil collection tray.

The present invention relates to a method for reducing the content of hydroperoxides and/or off-flavours in edible oils or fats, and such method includes the following steps:

a) feeding edible oil through vacuum oil refining equipment and adding a stripping agent to the oil stream so that the oil comes into contact with the stripping agent and reducing hydroperoxides and/or volatiles in the oil, and

b) collection of refined edible oil after step a),

while the refining equipment includes a stripping column and no more than one oil collection tray.

The term “refining equipment consisting of a packed stripper and no more than one oil collecting tray” indicates that the refining capability of the refining equipment is ensured by using a stripper and no more than one oil collecting tray. It should be understood that valves, pumps, heat exchangers, and the like will be required to operate the refining equipment. A flow heater may be used upstream of the stripping column.

The term "not more than one" oil collection dish means a range covering "up to one" collection dish, and thus also includes the absence of a collection dish.

In one aspect of the present invention, in which there is one collection plate, it is designed to collect oil dripping from the nozzle under the action of gravity, and makes it available to pumps that pump oil. No processes and/or quality changes are carried out in the collection dish. The sole purpose of the collection plate is to collect and/or accumulate oil for retention purposes. There are no chemical and/or physical changes in the quality of the oil in the collection dish. Refining equipment without a collection plate may also be used. In the absence of a collection plate, the oil will bypass the collection stage and will be directly fed to the refining equipment of stage a). The oil is cooled by using a heat exchanger. There is no need to mix oil with cooling oil.

Stage b) includes the collection of refined oil, and at this stage the oil from stage a) is obtained.

The refining equipment of step a) in the present invention does not include holding trays. In standard deodorizer equipment known in the art, whether batch, continuous or semi-continuous deodorizer equipment, there are always holding plates, holding vessels or compartments, also referred to as sections. Batch, continuous, or semi-continuous deodorizers consist of these various compartments, holding plates. In each plate, the oil is kept for a certain time at a high temperature, and steam is introduced into the oil. In order to change the physical and chemical properties of the oil, which is achieved by moving the oil from one tray to the next tray, a long oil retention time is required. Components such as, but not limited to, colors, flavors, and/or flavor precursors are decomposed into volatile decomposition products, which are then removed by steam passing through the oil in the retention trays. To obtain oils of acceptable or good quality, a long retention time (exposure) is required. However, this long exposure time at high temperatures is known to lead to the formation of additional undesirable industrial contaminants such as chloropropanol esters (3-MCPD esters), glycidyl esters, trans fatty acids, and the like. In addition, the components present in the oil that favorably affect the oil's oxidation resistance can be degraded, and the content of these components, such as tocopherols, tocotrienols, and the like, can be significantly reduced. This is, among other things, a good reason to avoid long holding times at high temperatures.

Moreover, these holding plates can increase the complexity of deodorizers known in the art and thus lead to high investment costs. The retention plates hold large volumes of oil inside the equipment. Keeping such large volumes of oil at high temperatures for long periods of time can also result in significant energy costs. The transition from one edible oil to another can be difficult, and the risk of mixing them further increases.

The refining equipment, consisting of a packed stripper and one oil collecting tray, or no such trays, used in the process of the present invention is free from the previously described disadvantages. It is also characterized, among other things, by the simplicity of the equipment, low investment costs and ease of operation, as well as the ability to provide high productivity (due to, for example, short holding times and low risk of intermixing).

The stripping agent is steam or any other stripping gas such as nitrogen gas. Preferably, steam is used as the stripping agent.

The stripping agent is fed into the oil flow in co-current or counter-current. The stripping agent is preferably fed countercurrently into the oil stream. In one aspect of the process of the present invention, in which a stripping agent is fed countercurrently into the oil stream, such a stripping agent is introduced at or near the bottom of the stripping column.

The equipment can be operated at absolute pressures below 8 mbar, 0.1 to 8 mbar, 0.5 to 7 mbar, 1 to 6 mbar, 1.5 to 5 mbar, 2 to 4 mbar.

The present invention relates to a process in which the refining equipment is operated at a temperature of 170 to 240°C, 180 to 230°C, 190°C to 225°C, 195°C to 220°C, 197°C up to 215°C, 198°C to 210°C, 170°C to 215°C, 170°C to 205°C.

The packing may be irregular packing or structured packing. Preferably the packing is structured packing.

The term "structured packing" is well known in the art and refers to a range of specially designed materials for use in absorption and distillation columns. Structured packings typically consist of thin, corrugated metal plates arranged to allow fluids to flow in complex contours through the column and thus create a large surface area that can enhance interaction between oil and stripper.

The packing in the equipment of the present invention has a specific surface area of 100 to 750 m²/m³, from 100 to 500 m²/m³, from 150 to 400 m²/m³, from 150 to 300 m²/m³, from 200 to 250 m²/m³.

It should be understood that the method of the present invention is suitable for improving the quality of edible oils. Quality includes improvement in taste and flavor properties, reduction in off-flavour substances such as aldehydes, i.e. secondary oxidation products. In another aspect of the present invention, this includes the reduction of primary oxidation products such as hydroperoxides (measured by peroxide value using the AOCS Cd 8b-90 method). This also increases the resistance of edible oils to oxidation.

It has surprisingly been found that refining equipment comprising a packed stripper and no more than one oil collection tray is suitable for improving the quality of edible oils and for reducing hydroperoxides and/or volatiles in the oil.

It is now known that a deodorizer with multiple holding plates is needed to produce a good quality edible oil with hydroperoxides and/or volatiles removed and/or no strong flavor. The present invention shows that deodorizer retention trays are not needed and refining equipment, which includes a packed stripper and no more than one oil recovery tray, produces good to superior quality edible oils.

In one aspect of the present invention, a packed stripper provides a specific oil load of 0.5 to 10.0 kg/m ² h packing surface, 0.5 to 4.0 kg/m ² h packing surface, 0.5 up to 3.5 kg/m ² h nozzle surface, from 0.6 to 3.4 kg/m ² h, from 0.7 to 3.3 kg/m ² h, from 0.8 to 3.2 kg/ m ² h, from 0.9 to 3.1 kg/m ² h, from 1.0 to 3.0 kg/m ² h, from 1.5 to 2.8 kg/m ² h, from 2.0 up to 2.5 kg/m ² h, preferably from 1.0 to 3.0 kg/m ² h. An oil load of 1.6, 2.2, 2.3, 2.4 or 2 can also be used, 5 kg/m ² h nozzle surface.

Unexpectedly, it was found that the reduction of the specific load on the oil has a positive effect on the results. The specific oil load (expressed in kg/m ² h of packing surface) is affected by flow rate and packing surface area, which in turn determines the relationship between packing specific surface area and packing volume. Among other factors, the efficiency and/or profitability of the industrial refining process affects the consumption. The inventors have found that increasing the area of the nozzle, in particular, will improve the quality of refined oils. The specific oil load may be at least one of the parameters for determining the efficiency of the process.

The height to diameter ratio of the stripping column is 0.1 to 10, 0.5 to 5, 1 to 4.9, 1.4 to 4.7, 1.4 to 4.5, 1.5 to 4.4, from 1.5 to 4.3, from 1.5 to 4.2, from 1.6 to 4.0, from 1.6 to 3.0, from 1.7 to 2.8. Similarly, height to diameter ratios of 1.2, 1.3, 1.8, 1.9, 2.0, 2.1, 2.5, 3.5, 3.6, 3.7, 4.1. In an alternative embodiment, height to diameter ratios of 6, 7, 8, and 9 may be used.

The ratio of height to diameter has been found to be between 0.1 and 10, provided that the height is not 1 meter for a diameter of 200 mm.

In one aspect of the present invention, the edible oil is heated prior to being fed through an oil refining facility. Heating can be carried out using techniques known to those skilled in the art. The oil may be heated by countercurrent heating or by passing through a flow heating system or the like.

In a further aspect of the invention, the present method includes a preheating step prior to step a).

In a further aspect of the invention, the present method allows the use of a short dwell time. In particular, the total residence time in the refining equipment, which includes no more than one collection plate and provides for preheating (using a flow heater) of edible oil before supplying edible oil through the refining equipment, is not more than 20 minutes, from 1 to 18 minutes, 5 to 16 minutes, 10 to 14 minutes. Similarly, the total exposure times can be 4.6, 6.0, 6.1, 7.3, 7.4, 7.5 and 8.6 minutes. More specifically, the method of the present invention makes it possible to obtain a residence time in the stripper bed from 1 to 10 minutes, from 1 to 9 minutes, from 2 to 8 minutes, from 3 to 7 minutes, from 4 to 6 minutes, from 1 to 5 minutes, 1 to 3 minutes. Similarly, dwell times can be 3.2, 3.5 or 4.7 minutes.

The present invention shows that if it is planned to operate at temperatures below 215°C, below 210°C, below 205°C, from 180°C to 200°C, in order to be able to obtain refined oils of acceptable or good quality, oil refining equipment should include a stripping column with a packing and a specific oil load of 0.5 to 4.0 kg/m ² h of the packing surface.

Low oil loading (expressed in kg/m ² h of packing surface) is possible, for example from 0.5 to 4.0 kg/m ² h, and this allows suitable short dwell times to be used. It should be understood that the holding time depends on the type of packing, oil loading and column dimensions. The dwell time can be increased or decreased by changing one or more of these parameters. Deodorizers known in the art require longer dwell times due to the use of holding plates.

The edible oils can be of any type, derived from any source, or of any origin. Oil may refer to vegetable oils or fats, animal oils or fats, fish oils, microbial oils or algal oils, preferably edible oils. Oils may be derived, for example, from one or more vegetable and/or animal sources and may include oils and/or fats of the same origin or consisting of a mixture of two or more oils and/or fats from different sources or with different characteristics. They can be obtained from standard oils or from specialty oils such as low 3-MCPD (3-monochloropropane-1,2-diol) ester oils, low GE oils (GE = glycidyl esters), modified or unmodified oils and/or fats (i.e. from oils in their natural state or oils that have undergone chemical or enzymatic modification, hydrogenation or fractionation), and the like. Preferably they are derived from vegetable oils or mixtures of vegetable oils. Examples of suitable vegetable oils include: soybean oil, corn oil, cottonseed oil, linseed oil, olive oil, palm oil, palm kernel oil, coconut oil, peanut oil, rapeseed oil, safflower oil, sunflower oil, sesame oil, rice bran oil , low acid rapeseed oil, babassu oil, palm seed oil, takum oil, kufei oil and any fractions or derivatives thereof.

Palm oil encompasses palm oil as well as palm oil fractions such as stearic and oleic fractions (both single and double fractionation as well as middle palm oil fractions) and mixtures of palm oil and/or fractions thereof.

In one aspect of the present invention, the edible oil is a vegetable oil. Vegetable liquid oils are selected from the group consisting of cottonseed, corn, peanut, flaxseed, olive, rapeseed, canola, sesame, safflower, soybean, sunflower, their respective varieties with medium or high oleic acid content, or any variety with a high content of unsaturated fatty acids compared to the original seed variety and a mixture of two or more of them. These varieties with a high content of unsaturated fatty acids can be obtained through natural selection or genetic modification (GMO). Preferably, the vegetable oil is selected from the group consisting of corn, rapeseed, canola, soybean, sunflower, their respective high oleic acid varieties, and a mixture of two or more of these. High oleic acid grades contain at least 40%, at least 50%, at least 60%, at least 70%, preferably at least 80% oleic acid relative to the fatty acid profile. The vegetable oil is preferably selected from the group consisting of rapeseed oil, canola oil, soybean oil, sunflower oil and a mixture of two or more of these.

In a further aspect of the present invention, the vegetable oil is rapeseed oil, sunflower oil, or combinations thereof. In yet another aspect of the present invention, the vegetable oil is rapeseed oil or canola oil.

In another aspect of the present invention, the edible oil is selected from palm oil, a palm oil based material, oil of any palm species with a modified fatty acid composition from the original palm species, and combinations thereof, wherein the palm oil material refers to a palm oil that has been fractionated, hydrogenated, chemically interesterified, enzymatically interesterified, or processed by a combination of one or more of these processes. The term "palm species" refers to any palm species with an altered fatty acid composition compared to the original palm species, such as a high oleic acid palm species obtained by natural selection or genetic modification (GMO). Preferably, the palm-based material is fractionated palm oil and fractions thereof, such as fractions of stearin and olein (both singly and doubly fractionated), middle fractions of palm oil, and blends of palm oil and/or fractions thereof. Preferably, the palm-based material is fractionated palm oil, fractions thereof, and combinations thereof. In yet another aspect of the present invention, the vegetable oil is selected from palm oil, palm oil fraction, or combinations thereof.

In addition, an edible oil, preferably vegetable oil, is a crude oil, bleached oil, RBD oil, NBD oil, or any further refined and/or processed RBD/NBD oil, which essentially refers to the refining process applied to oils prior to being fed into equipment. RBD stands for Refined Bleached and Deodorized Oil and corresponds to conventional physically refined oil. NBD stands for Neutralized Bleached Deodorized Oil and corresponds to chemically refined oil. Processing includes, without limitation, fractionation, chemical or enzymatic interesterification, and hydrogenation. Preferably, the quality of the oil entering step a) of the process is such that the content of free fatty acids is not more than 0.2%, not more than 0.15%, preferably not more than 0.1%, more preferably not more than 0, 07%, not more than 0.06% (as measured in accordance with the AOCS Ca 5a-40 method). In one aspect of the present invention, the edible oil in step a) of the process is processed using one or more refining steps.

In a specific aspect of the present invention, the edible oil of step a) is a lightly colored oil that has not yet been deodorized. A slightly colored oil is an oil whose color is characterized by max 4R on the red Lovibond scale, more preferably max 3.5R, most preferably max 3R, max 2.5R, max 2R and max 40Y on the yellow Lovibond scale, more preferably max 35Y, most preferably max 30Y , max 25Y, max 20Y (as measured in a 5¼" glass measuring cell in accordance with AOCS Method Cc13e-92). A typical example of such an oil is soybean oil, peanut oil, sunflower oil, high oleic acid sunflower oil, palm kernel oil, coconut oil, cottonseed oil, linseed oil, and mixtures of two or more of these.

In another specific aspect of the present invention, the edible oil of step a) is a colored oil that has not yet been deodorized, and the harvested refined edible oil from step b) is a colored refined oil. Typical examples of such oils are, without limitation, red palm, red palm oleic, algal oils, and mixtures thereof.

In another aspect of the invention, the edible oil of step a) has undergone one or more refining steps, such edible oil is preferably a refined, bleached and deodorized oil (RBD or NBD).

The method of the present invention improves, restores the quality of RBD or NBD oil. RBD or NBD oil that is of reduced quality (also categorized as "aged oil"), eg due to long transportation, long storage, can be recovered by the method of the present invention. The present invention shows that by feeding such aged refined, bleached and deodorized oil through a refining facility comprising a packed stripper and no more than one oil collection tray, hydroperoxides and volatiles can be reduced. This ensures short residence times (as noted above), and the quality of the oil thus obtained is in the range from good to excellent, especially in terms of taste and resistance to oxidation. In one aspect of the present invention, the RBD or NBD oil is palm oil.

Indeed, most of the off-taste substances in fats and oils are formed by the reaction of oxygen with unsaturated fatty acids, which are part of triacylglycerols or polar lipids. When unsaturated lipids react with oxygen, hydroperoxides (also called primary oxidation products) are formed. Such hydroperoxides are generally very unstable and decompose to form a wide variety of volatile flavor compounds such as aldehydes and ketones (also known as secondary oxidation products). Said aldehydes are potent off-flavours and are often the cause of undesirable tastes and/or odors in fats and oils.

The method of the present invention includes a plant that produces oxidation-resistant oils with a peroxide value of < 1 meq/kg, < 0.5 meq/kg, or even < 0.1 meq/kg, as well as without a pronounced taste and characteristic index of a refined oil. oxidative stability (OSI). Alternatively, the process of the present invention produces oils with a peroxide value (PV) that is at least 40%, at least 50%, at least 60%, at least 70%, at least 80% , at least 85%, at least 90%, at least 95%, at least 99% less than the PV of the aged oil.

In one aspect of the present invention, the method utilizes oil refining equipment and further includes the step of heating the oil through the refining equipment, such as using a flow heater. Without being tied to any scientific explanation, it can be noted that primary oxidation products, such as hydroperoxides, can partially decompose during the heating step. Complete decomposition of the hydroperoxides may be started or continued in the stripper of the refining equipment used in the process of the present invention.

It has been noted that oils with an acceptable peroxide value may still have unacceptable taste and flavor properties. The method of the present invention improves the taste and flavor properties of edible oils with an acceptable peroxide value by removing volatile substances such as aldehydes and ketones.

The lack of strong flavor (= absence of off-flavour substances) can be further quantified by measuring the amount of strong flavor aldehydes. The specific aldehydes obtained depend on the type of oil in which they are formed. Without wishing to be bound by any theory, the location and number of unsaturations in the fatty acids that make up triglycerides can determine the type of aldehyde that is typically formed as a product of the oxidation of a particular oil. Non-limiting examples of aldehydes that are likely to form as typical oxidation products of oleic acid-rich oils (such as palm oil) include hexanal and nonanal. Exemplary oxidation products of oils rich in linoleic acid (such as sunflower oil) are, without limitation, hexanal and 2-nonenal. Typical oxidation products of oils rich in linolenic acid (such as rapeseed oil) are, without limitation, propanal and 2,4-heptadienal.

Moreover, the use of the present invention makes it possible to obtain an oil with minimal loss of desirable constituents. The method of the present invention produces good to excellent quality oil in terms of nutritional quality and chemical quality. Undesirable contaminants are absent, and the content of desirable constituents is kept as high as possible.

It has surprisingly been found that, using the process of the present invention, the decomposition, decomposition, or breakdown of the oxidation products on the stripper column of the refining equipment occurs at a much higher rate, and usually at significantly lower temperatures, than conventional continuous (or batch, or semi-continuous) deodorizers. with deodorizer plates for holding.

Typically, running this process at a maximum temperature of 230°C, a maximum temperature of 220°C, a maximum temperature of 215°C, a maximum temperature of 205°C, a maximum temperature of 200°C and a shorter retention time in a packed stripper, e.g. 8 minutes, allows you to get the oil of the required quality in terms of oxidation resistance, odor and taste. A standard continuous (or batch or semi-continuous) deodorizer is typically operated at higher temperatures and requires a hold time greater than twice the stated time. By operating at temperatures below refining temperatures in conventional deodorization systems (eg below 240° C.), the present process avoids the formation of undesirable products and process contaminants such as trans fatty acids, chloropropanol compounds and glycidyl esters.

The method of the present invention makes it possible to reduce the peroxide values of vegetable oils or fats. This decrease is very significant. The peroxide value (=PV) of the edible oils at the start of the process was 0.30 to 10 meq/kg, 0.30 to 7 meq/kg, 0.30 to 5 meq/kg. Aged RBD oil typically has a PV value greater than 4 meq/kg. PV decreases to peroxide value below 0.9 meq/kg, below 0.5 meq/kg, below 0.4 meq/kg, below 0.3 meq/kg, below 0.2 meq/kg, below 0.1 meq /kg, below 0.075 meq/kg. Or PV is reduced by at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 85%, at least 90 %, at least 95%, at least 99% compared to the PV of aged RBD oil.

The method of the present invention makes it possible to reduce the content of off-flavour compounds.

In one specific aspect, the present invention provides a method for improving the quality of edible oils or fats, wherein the method includes the following steps:

a) feeding edible oil under vacuum at a temperature of from 190°C to 235°C through an oil refining equipment containing a stripper column with a packing and a height to diameter ratio of from 0.1 to 10, and adding a stripping agent to the oil stream in such a way, so that the oil comes into contact with the stripper and the reduction of hydroperoxides and/or volatiles in the oil, and

b) collection of refined edible oil,

where edible oil is a vegetable liquid oil.

In one specific aspect, the present invention provides a method for improving the quality of edible oils or fats, wherein the method includes the following steps:

a) supply of edible oil under vacuum at a temperature of from 190°C to 235°C through an oil refining equipment containing a stripping column with a packing and a specific oil load of 0.5 to 10.0 kg/m ² h of the packing surface and the ratio height to diameter from 0.1 to 10, and adding a stripping agent to the oil stream so that the oil comes into contact with the stripping agent, and reducing the content of hydroperoxides and/or volatiles in the oil, and

b) collection of refined edible oil,

where edible oil is a vegetable liquid oil.

In a further aspect of the present invention, wherein the edible oil is a vegetable liquid oil, the oil refining equipment uses an oil specific load of 0.5 to 9.0 kg/m ² h of packing surface, of 0.5 to 8.0 kg/ ^m2 h, 0.5 to 7.0 kg/ ^m2 h, 0.5 to 6.5 kg/ ^m2 h, 0.5 to 6.0 kg/ ^m2 h, from 0 .5 to 5.0 kg/m ² h of nozzle surface.

In one specific aspect, the present invention provides a method for improving the quality of edible oils or fats, wherein the method includes the following steps:

a) supply of edible oil under vacuum at a temperature of from 190°C to 215°C through an oil refining equipment containing a stripping column with a packing and an oil specific load of 4.1 to 10.0 kg/m ² h of the packing surface and the ratio height to diameter from 0.1 to 10, and adding a stripping agent to the oil stream so that the oil comes into contact with the stripping agent, and reducing the content of hydroperoxides and/or volatiles in the oil, and

b) collection of refined edible oil,

where edible oil is a vegetable liquid oil.

It has been shown that a method for improving the quality of vegetable liquid oil uses refining equipment consisting of no more than one collection tray and a stripping column, and the quality is further improved at a lower temperature of 170°C to 225°C when using a stripping column with nozzle and specific oil load from 0.5 to 4.0 kg / m ² h of nozzle surface,

and with a ratio of height to diameter from 0.1 to 10.

In a further aspect of the present invention, in which the edible oil is a vegetable liquid oil, the oil refining equipment uses an oil specific load of 4.1 to 9.0 kg/m ² h of packing surface, of 4.1 to 8.0 kg/ ^m2h , 4.1 to 7.0 kg/m2h, 4.1 to 6.5 kg/ ^m2h , 4.1 to 6.0 kg/m2h, 4.1 to 5 .0 kg/m ² h of the nozzle surface.

In one specific aspect, the present invention provides a method for improving the quality of edible oils or fats, wherein the method includes the following steps:

a) supply of edible oil under vacuum at temperatures from 170°C to 215°C, from 170°C to 210°C, from 170°C to 205°C, from 180°C to 200°C through the oil refining equipment, containing a stripping column with a packing and an oil specific load of 0.5 to 4.0 kg/m ² h of the packing surface and a height to diameter ratio of 0.1 to 10, and adding a stripping agent to the oil stream so that the oil enters in contact with the stripping agent, and reducing the content of hydroperoxides and/or volatiles in the oil, and

b) collection of refined edible oil,

where the edible oil is palm oil.

In one aspect of the present invention, a packed stripping column has an oil specific load of 0.5 to 4.0 kg/m ² h, 0.5 to 3.5 kg/m ² h of packing surface, 0.6 to 3 .4 kg / m ² h, from 0.7 to 3.3 kg / m ² h, from 0.8 to 3.2 kg / m ² h, from 0.9 to 3.1 kg / m ² h, 1.0 to 3.0 kg/m ² h, 1.5 to 2.8 kg/m ² h, 2.0 to 2.5 kg/m ² h, preferably 1.0 to 3, 0 kg/m ² h. Specific oil loading of 1.6, 2.2, 2.3, 2.4 or 2.5 kg/m ² h of nozzle surface can also be used.

In one specific aspect, the present invention provides a method for improving the quality of edible oils or fats, wherein the method includes the following steps:

feeding palm oil RBD under vacuum at 170°C to 215°C, 170°C to 210°C, 170°C to 205°C, 180°C to 200°C through oil refining equipment containing a stripping column with a packing and an oil specific load of 0.5 to 4.0 kg/m ² h of the packing surface and a height to diameter ratio of 0.1 to 10, and adding a stripping agent to the oil stream so that the oil enters the contact with the stripper, and removal of hydroperoxides and/or volatiles in the oil, and

Collection of refined palm oil.

Deodorization is a well known process. It includes the stripping of volatile components, the removal of off-flavours, and the thermal decomposition of undesirable components.

Deodorization typically takes place in a deodorizer, and the deodorizer may have several configurations, such as horizontal vessels, vertical tray-type deodorizers, and a combination with packed columns. It is known that at least one deodorizer holding plate is needed to decompose hydroperoxides and remove off-flavours, and retention times are typically between 30-60 minutes and up to 4 hours.

It has been found that in the process of the present invention, primary oxidation products are decomposed and secondary oxidation products formed are removed as volatiles, usually at a low deodorization temperature. This requires only short retention times in the stripper column or a short total holding time, i.e. the retention time in the stripper column, taking into account the preheating stage. Feeding through refining equipment, including a stripper with a packing and not more than one oil collection tray, and involving heating before feeding edible oil through the refining equipment, requires a total residence time in the equipment of not more than 20 minutes, from 1 to 18 minutes , 5 to 16 minutes, 10 to 14 minutes. Similarly, the total exposure times can be 4.6, 6.0, 6.1, 7.3, 7.4, 7.5 and 8.6 minutes. The quality of the collected deodorized oil ranges from good to excellent, in particular in terms of high oxidation resistance, color, neutral odor and taste.

Moreover, the present invention relates to the use of refining equipment, consisting of a packed stripper and no more than one oil collection tray, to reduce the content of hydroperoxides and/or volatiles in edible oils.

The use of the present invention makes it possible to reduce peroxide values in edible oils or fats. This decrease is very significant. The peroxide value (=PV) of the edible oils at the start of the process was 0.10 to 10 meq/kg, 0.30 to 7 meq/kg, 0.30 to 5 meq/kg.

Typically, the PV of aged RBD oil is over 4 meq/kg. PV decreases to peroxide value below 0.9 meq/kg, below 0.5 meq/kg, below 0.4 meq/kg, below 0.3 meq/kg, below 0.2 meq/kg, below 0.1 meq /kg, below 0.075 meq/kg. Or PV is reduced by at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 85%, at least 90 %, at least 95%, at least 99%. The present invention makes it possible to significantly reduce the content of volatile substances such as aldehydes and ketones, preferably to a level below the LQF (limit of quantitation).

The resulting edible oils are tasteless (= free of off-taste substances), which can be quantified by measuring the content of aldehydes with pronounced flavoring properties.

The present invention relates to the use of a refining equipment consisting of a packed stripper and not more than one oil collecting tray to improve the quality of edible oils. The quality of the oil is associated with the absence of hydroperoxides and/or volatile substances and/or the absence of substances with an unpleasant odor or taste in the oil. The use of refining equipment, which includes a stripping column with a packing and no more than one oil collection tray, makes it possible to obtain edible oils without a pronounced taste.

The present invention relates to the use of refining equipment comprising a packed stripper and not more than one oil collecting tray to produce an edible oil with an overall flavor score of at least 7, 8 or 9 according to the AOCS Cg 2- 83 (with 10 being the best score for flavor and 1 being the worst score).

It is known in the prior art to produce good quality edible oils in batch, continuous, or semi-continuous deodorizers, at least one deodorizer holding plate must be used. It has been shown in the present invention that the use of refining equipment consisting of a packed stripper and no more than one oil collecting tray produces oils of the same good or better quality as oils obtained in a batch, continuous or semi-continuous deodorizer with at least one deodorizer plate for holding.

It additionally refers to operating conditions under which the stripping column contains a packing providing a specific oil load of 0.5 to 4.0 kg/m ² h of the packing surface. In addition, it refers to an application in which the stripper column has a height to diameter ratio of 0.1 to 10.

It refers to the use of a packed stripping column with an oil specific load of 0.5 to 4.0 kg/m ² h of packing surface and a height to diameter ratio of 0.1 to 10 to improve the flavor and flavor properties of edible oils, provided that the height is not 1 meter and the diameter is not 200 millimeters.

The present invention relates to the use of equipment for oil refining, including a stripping column with a packing and a specific oil load of 0.5 to 4.0 kg/m ² h of the packing surface, and also with a height to diameter ratio of 0.1 to 10 to improve the quality of edible oils, to remove hydroperoxides and/or volatiles from edible oils, and/or to improve the odor and taste of the oil.

The advantages of the present invention include but are not limited to:

- After applying the method of the present invention, the improvement in the quality of RBD palm oil was demonstrated even at temperatures below 200°C. The value of PV decreases. Improved OSI. Refined palm oil reduces the content of volatile substances such as nonanal. When using an oil refining equipment including a stripping column with a packing and an oil specific load of 0.5 to 4.0 kg/m ² h of packing surface and a height to diameter ratio of 0.1 to 10, the taste is preferably in range from good to excellent.

- If it is planned to operate at temperatures below 205°C or from 180°C to 200°C, and in order to obtain refined oils of acceptable to good quality, the oil refining equipment contains a stripper column with a packing and an oil specific load of 0.5 to 4.0 kg/m ² h

- The application of the method of the present invention to aged low-colored RBD oils or colored oils that are collected as refined colored oils leads to an improvement in their quality. The corresponding PV value is reduced and a good taste score is achieved.

- Application of the method of the present invention to RBD vegetable liquid oils, preferably RBD rapeseed oil, leads to an improvement in their quality. When using oil refining equipment, which includes a stripping column with a packing and a specific oil load of 0.5 to 10.0 kg/m ² of the packing surface and a height to diameter ratio of 0.1 to 10, the corresponding PV value decreases . Taste ranges from good to excellent.

The present invention is illustrated by the following non-limiting examples.

Analytical Methods

The oils were tasted and evaluated for their gustatory qualities (taste). A flavor score was obtained according to the AOCS Cg 2-83 method, where a flavor score of 10 is excellent and a flavor score of 1 is worst.

Peroxide value (PV) was measured according to the AOCS Cd 8b-90 method.

The Oxidation Stability Index (OSI) was measured according to the AOCS Cd12b-92 method.

Off-flavour aldehydes were analyzed by headspace dynamic sampling after aldehyde separation using a combination of 2D gas chromatograph and time-of-flight mass spectrometer (2DGC-TOFMS), and a quantification for each aldehyde was obtained from the calibration curves.

Examples

The RBD oils were stored for several days at 55° C. and exposed to air until the PV increased above 4 meq/kg to simulate accelerated oil aging.

The aged oils were processed in a refining facility containing a flow heater, a stripper column with packing of the dimensions shown in the tables below, and one collection tray.

The tables below show the refining conditions.

The quality of the oil after treatment with the method of the present invention was evaluated by measuring PV, taste, OSI and analysis of off-flavour aldehydes.

Example 1-3

The laboratory refining equipment is equipped with a stripper and one collection tray, see table 1 for approximate dimensions of the laboratory stripper.

Table 1

Example 1 Example 2 Example 3 Oil type Rapeseed oil RBD Rapeseed oil RBD Rapeseed oil RBD aged oil •PV
• Hexanal
• (e,z)-2,4-Heptadienal 4.1 meq/kg
117.35 billion
329.70 billion 4.1 meq/kg
117.35 billion
329.70 billion 4.1 meq/kg
117.35 billion
329.70 billion Stripping column • Height (H)
• Diameter (D)
• H/D ratio
• Nozzle area
• Nozzle volume
• Specific packing area 0.922
250 ^m2 / ^m3 0.922
250 ^m2 / ^m3 0.922
250 ^m2 / ^m3 Process conditions • Temperature
• Consumption
• Pressure
• Bubble steam 19 kg/h
2.6 mbar
1.0 wt%/h 19 kg/h
2.6 mbar
1.0 wt%/h 25 kg/h
2.6 mbar
1.0 wt%/h Specific oil load
Cumulative hold time (including heating time in flow heater) 6.3 kg/m ² h
6.0 min 6.3 kg/m ² h
6.1 min 8.3 kg/m ² h
4.6 min Processed oil (after the method of the present invention) •PV
• % reduction (PV)
• Taste
• Hexanal
• (e,z)-2,4-Heptadienal 0 meq/kg
100%
eight
< 10 bn.
< 20 bn. 0.4 meq/kg
90%
7
< 10 bn.
< 20 bn. 0.8 meq/kg
80%
7
< 10 bn.
27.54 billion

It has been shown that at lower temperatures (which were chosen to avoid the formation of unwanted compounds and the breakdown of beneficial minor compounds in the oil), the absence of such holding plates results in a deterioration in the taste of the refined oil and a significant deterioration in the PV value.

Example 4-6

The laboratory stripper used in Examples 4-6 consisted of a stripper and one collection tray. Approximate dimensions of the laboratory column are given in Table 2.

It has been demonstrated that the quality of RBD rapeseed oil improved after being treated with the method of the present invention at a temperature of about 200-210°C. The value of PV decreases. Taste ranges from good to excellent.

table 2

Example 4 Example 5 Example 6 Oil type Rapeseed oil RBD Rapeseed oil RBD Rapeseed oil RBD aged oil •PV
• Hexanal
• (e,z)-2,4-Heptadienal 4.3 meq/kg
< 10 bn.
41.89 billion 4.3 meq/kg
< 10 bn.
41.89 billion 4.3 meq/kg
< 10 bn.
41.89 billion Stripping column • Height
• Diameter
• Height/diameter ratio
• Nozzle area
• Nozzle volume
• Specific packing area 2.766
250 ^m2 / ^m3 2.766
250 ^m2 / ^m3 2.766
250 ^m2 / ^m3 Process conditions • Temperature
• Consumption
• Pressure
• Bubble steam 22 kg/h
2.6 mbar
1.0 wt%/h 19 kg/h
2.6 mbar
1.0 wt%/h 22 kg/h
2.5 mbar
1.0 wt%/h Specific oil load
Cumulative hold time (including heating time in flow heater) 2.4 kg/m ² h
7.4 min 2.1 kg/m ² h
8.6 min 2.4 kg/m ² h
7.3 min Processed oil (after the method of the present invention) •PV
• % reduction (PV)
• Taste
• Hexanal
• (e,z)-2,4-Heptadienal 0.3 meq/kg
93%
7
< 10 bn.
< 20 bn. 0.2 meq/kg
95%
eight
< 10 bn.
< 20 bn. 0.0 meq/kg
100%
7
< 10 bn.
< 20 bn.

Example 7-8

It has been shown that the quality of RBD palm oil improved after being treated with the method of the present invention, even at temperatures below 200°C. The value of PV decreases. Improved OSI. The content of volatile substances, such as nonanal, has decreased. When using equipment for oil refining, including a stripping column with a packing and a specific oil load of 0.5 to 4.0 kg/m ² h of packing surface and a height to diameter ratio of 0.1 to 10, the taste was in the range from good to excellent.

Table 3

Example 7
In accordance with the invention Comparative Example 8 Oil type Palm oil RBD Palm oil RBD aged oil •PV
• Nonanal 4.7 meq/kg
136.7 billion 5.8 meq/kg
180.9 billion Stripping column • Height
• Diameter
• Height/diameter ratio
• Nozzle area
• Nozzle volume
• Specific packing area 2.766
250 ^m2 / ^m3 0.922
250 ^m2 / ^m3 Process conditions • Temperature
• Consumption
• Pressure
• Bubble steam 15 kg/h
2.7 mbar
1.1 wt%/h 19.1 kg/h
2.5 mbar
1.0 wt%/h Specific oil load
Cumulative hold time (including heating time in flow heater) 1.6 kg/m ² h
7.5 min 6.3 kg/m ² h
6.1 min Processed oil (after the method of the present invention) •PV
• % reduction (PV)
• Taste
• OSI (at 120°C)
• Nonanal 0.1 meq/kg
98%
7.5
13.7 h
< 25 bn. 4 meq/kg
31%
3.8
12.5 h
67.2 billion

Claims (17)

1. A method for improving the quality of edible oils or fats, which includes the following steps: a) feeding edible oil through vacuum oil refining equipment and adding a stripping agent to the oil stream so that the oil comes into contact with the stripping agent and reducing hydroperoxides and/or volatiles in the oil, and b) collection of refined edible oil after step a), wherein the refining equipment includes a packed stripper and no more than one oil collection tray, and while the stripping column is characterized by a specific oil load from 0.5 to 4.0 kg/m ² ⋅h, wherein the stripping column has a height to diameter ratio of 0.1 to 10. 2. The method according to claim 1, wherein in step a) the edible oil is fed through the oil refining equipment at a temperature of 170 to 240°C or 170 to 215°C. 3. The method of claim 1 or 2, wherein the edible oil is heated prior to being fed through the oil refining equipment. 4. The method according to any one of paragraphs. 1-3, in which the edible oil is fed through the refining equipment and includes heating before supplying the edible oil through the refining equipment with a total holding time of not more than 20 minutes. 5. The method according to any one of paragraphs. 1-4, wherein the edible oil in step a) has a peroxide value of 0.30 to 10 meq/kg. 6. The method according to any one of paragraphs. 1-5, wherein the edible oil in step a) is processed through one or more refining steps. 7. The method according to any one of paragraphs. 1-6, wherein the edible oil is a refined, bleached and deodorized oil. 8. The method according to any one of paragraphs. 1-6, in which the edible oil has not undergone a deodorization step. 9. The method according to any one of paragraphs. 1-8, in which the equipment is operated at an absolute pressure of 1 to 8 mbar, 1.5 to 6 mbar, 2 to 4 mbar. 10. The use of refining equipment, which includes a stripping column with a packing and not more than one oil collection tray, and the stripping column is characterized by a specific oil load from 0.5 to 4.0 kg/m ² ⋅h and has a height to diameter from 0.1 to 10, for the decomposition of the products of oxidation of triglycerides, diglycerides, monoglycerides and/or fatty acids. 11. The use according to claim 10, which reduces or removes hydroperoxides and/or volatiles from edible oils. 12. The use according to claim 10 or 11, in which there is a decrease in the peroxide values of edible oils or fats.