JPH09224570A - Edible oil using palmstearin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide safe and edible fat and oil by including palmstearin at a high ratio so as to prevent the generation of bulky crystals and lower its melting point. SOLUTION: Fat and oil obtained by blending 75 to 5% palmstearin and 25 to 95% liquid oil of <=30 deg.C melting point such as soybean oil, rapeseed oil, corn oil is ester-interchanged with a lipase having 1- and 3-site specificity. The origin of the lipase having 1- and 3-site specificity which is an enzyme does not matter but one originating from microorganism such as Rhyzopus delemar is preferable. A reforming method can correspond to either of a batch system or column system and a reacting condition can be applied with a normal oil and fat reforming condition by means of an enzyme. Thus obtained enzyme reformed oil is lowered in melting point less than the temp. of human beings to become edible oil and fat.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an edible oil containing palm stearin, which has a high melting point. It relates to edible oil modified by the action of a certain lipase.

[0002]

BACKGROUND OF THE INVENTION Palm stearin is a solid part obtained by melting palm oil, cooling while controlling the temperature to crystallize, and then filtering. On the other hand, the liquid part is usually called palm olein. Palm stearin typically has a melting point (AOCS test method Cc-25) 44-56.
° C, iodine value (AOCS test method Cd-25) 22-49
It has the physical properties of Since palm stearin has a melting point higher than human body temperature, it solidifies in the mouth and significantly deteriorates the texture. As a result, they are not used for food with a few exceptions, and most are raw materials for industrial use. On the other hand, recently, palm olein, which has physical properties similar to liquid oil, has been evaluated as an oil with good handling stability and good oxidative stability, and there is a tendency for its demand to increase, but palm stearin has limited applications due to the above reasons. As a result, the inventory is excessive in the producing countries. Therefore, application development of palm stearin is desired.

The frying oil accounts for a large proportion of fats and oils. The functions required for frying oil are not only the flavor of fats and oils, but also the stability against heating and the stability against oxidation at low temperatures (stability against autoxidation when the fried products are stored for a long period of time). ) Is required. Generally, the lower the content of highly unsaturated fatty acids (linoleic acid, linolenic acid, etc. in the case of vegetable oil) of fats and oils, the higher their stability. Since palm stearin has a very low content of these highly unsaturated fatty acids, it can be said that it has high stability. Partial hydrogenation is one of the well-known methods for processing fats and oils, and liquid oil is partially hydrogenated to reduce the content of highly unsaturated fatty acids to produce solid or semi-solid fats and oils. can do. By this means, general vegetable oils can also have improved stability. However, the partially hydrogenated fats and oils are heated for a long time (normal frying temperature of about 180 ° C).
Then, a peculiar flavor (usually called hydrogenated odor) is generated, and it cannot be used for foods that do not match this flavor. In addition, partial hydrogenation produces trans acids, which are rare in nature.

In recent years, with the progress of research on the nutritional aspect of fats and oils, the relationship between diseases such as adult diseases and fats and oils has been discussed. It has been proposed that trans-acid generated by partial hydrogenation is involved in adult diseases, especially heart disease, along with saturated fat.In Europe and the United States, the mainstream product development is to reduce trans-acid content. ing. From these points, it is considered that palm stearin has utility value as a natural solid fat that does not contain trans acid and has good oxidation stability.

Conventionally, when palm stearin is used for food, a method has been used in which it is blended with liquid oil, or chemically blended with liquid oil and then chemically transesterified. However, in order to obtain edible physical properties, in both cases, the composition of the liquid oil must be at least 50% or more. In addition, these methods have a problem that trisaturated triacylglycerols are present in the product and physical properties suitable for food cannot be obtained as described later. Further, not only palm stearin but also oil and fat derived from palm oil, when stored in a solid state, causes a problem of coarsening of crystals. If the crystals become coarse, the surface of the product becomes rough, cracks, etc., and the commercial value is significantly impaired. Therefore, the blending amount of the fats and oils derived from palm oil is limited. For example, in margarine, the blending ratio of palm oil is usually limited to 30% or less in order to prevent crystal coarsening.

[0006]

DISCLOSURE OF THE INVENTION In view of the above situation, the present inventors modified palm stearin for the purpose of expanding the application of palm stearin to edible foods, and did not cause the coarsening of crystals, and We have made intensive studies to develop a material with high melting point and stability.

The fats and oils are mainly composed of triacylglycerol (usually 90% or more). Triacylglycerol is an ester bond of one molecule of glycerin and three molecules of fatty acid, and the physical properties of fats and oils are greatly affected by the type and ratio of fatty acid, and the position of fatty acid bonded to glycerin. Generally, in natural fats and oils, it is highly possible that fatty acids with more unsaturated bonds are bound to the 2-position of glycerin, and fatty acids with less unsaturated bonds are bound to the 1- and 3-positions of glycerin. . By the way, palm oil has a high content ratio of saturated fatty acids, and palm stearin, which is a solid portion obtained by fractionating palm oil, has a higher content ratio of saturated fatty acids (usually 60% or more), and saturated fatty acids are contained in one molecule. It often contains 2 molecules (2 saturated triacylglycerol) or 3 molecules (3 saturated triacylglycerol). Due to the presence of these molecules, the melting point of palm stearin becomes high, and since many of them have similar molecular structures, problems of homogenization and coarsening of crystals occur.

[0008] As a means for solving these problems, it is general practice to blend an oil or fat having a low melting point (for example, liquid oil) or to chemically perform transesterification. However, palm stearin generally contains 10% or more of trisaturated triacylglycerol, and even if a small amount thereof is present, physical properties (particularly texture of a product using the same) are greatly affected. In the former method, this trisaturated triacylglycerol remains and cannot be a complete solution. Also, in the latter method, transesterification newly produces trisaturated triacylglycerol, which is not a complete solution.

Therefore, in order to modify palm stearin to be edible, it is important to reduce trisaturated triacylglycerol.
Palm stearin, which is a natural fat and oil, is likely to have unsaturated fatty acids bound to its 2-position, so unsaturated fatty acids at the 2-position can be modified without modification. Introducing is considered to be the best solution.

Based on the above idea, it was found that palm stearin can be modified to have edible physical properties by mixing palm stearin with a liquid oil and then applying a lipase having 1,3-position specificity. It was As a result,
It is possible to produce edible oils and fats containing palm stearin at a high ratio, which was not possible with conventional oils and fats blending methods and chemical transesterification methods. Further, this fat or oil becomes a solid oil containing no trans acid unless a partially hydrogenated fat is used in the blended oil, and it is possible to eliminate the nutritional anxiety of trans acid.

[0011]

According to the present invention, 75 to 5% of palm stearin and 25 to 25% of liquid oil having a melting point of 30 ° C. or less are used.
An edible oil obtained by transesterifying fats and oils mixed at a ratio of 95% with a lipase having 1,3-position specificity, and a shortening or margarine using the edible oil as a raw material.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
The palm stearin used in the present invention is generally produced by the above-mentioned method and has the above-mentioned physical properties. Next, the liquid oil used in the present invention only needs to have a melting point of 30 ° C. or lower, and examples thereof include soybean oil, rapeseed oil, corn oil, and the like, and palm olein and palm kernel oil that are semisolid at room temperature. Further, as a liquid oil having a melting point of 30 ° C. or lower,
Although it is possible to use a partially hydrogenated fat of vegetable oil, the present invention aims to obtain a solid fat having a low trans acid content by modifying palm stearin, and is therefore not so preferable. Two or more types may be blended depending on the physical properties of the oil or fat required for the liquid oil.

In the present invention, the blending ratio of the above fats and oils is
Although it can be set as appropriate in consideration of the application, it is usually appropriate to add palm stearin in a proportion of 75 to 5%, preferably 70 to 15%, and liquid oil 25 to 95%, preferably 30 to 85%. is there.

The enzyme used in the present invention, the lipase having 1,3-position specificity, may be of any origin. Preferably, it is derived from a microorganism, and examples thereof include those derived from Rhizopus delema r.

The reforming method may be either batch type or column type, but the latter method is industrially advantageous. There are no special points regarding the reaction conditions, and it is possible to deal with the conditions for modifying fats and oils with ordinary enzymes. In the examples described later, the reforming was carried out under the reaction conditions described in JP-A-4-65493. After the completion of the enzymatic reaction, the obtained modified oil and fat is refined by performing operations such as decolorization and deodorization in the same manner as ordinary oil and fat refinement. After purification, it can be used in the same manner as ordinary fats and oils.

[0016]

EXAMPLES Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited thereto. Example 1 40% purified Malaysian palm stearin (RBD palm stearin, melting point 53.5 ° C, iodine value 26.2)
And rapeseed white squeezing oil (manufactured by Ajinomoto Co., iodine value 117.
5) 60% was compounded. The melting point of this blended oil is 50.4 ° C.
And is higher than human body temperature, so if you eat this,
The fat and oil solidified in the mouth and was not suitable for food.

This blended oil was reformed under the conditions described in Example 1 of JP-A-4-65493. That is, cation exchange resin "WK-13" (Mitsubishi Kasei Co., Ltd.)
Manufactured) was dried at 120 ° C. under a reduced pressure of 30 mmHg for 4 hours to adjust the water content to about 1%. 1,3-position specific lipase derived from Rhizopus derema (manufactured by Amano Pharmaceutical Co., Ltd.),
Product name: "Lipase D") 26.6 g and soybean lecithin (manufactured by Ajinomoto Co., Inc.) 8 g are dissolved in 60 ml of water, and 1000 g of dried cation exchange resin "WK-1" is used as a carrier.
3 ”and stirred well for about 30 minutes to uniformly coat the surface of the carrier with lipase. This immobilized lipase contained about 6.1% water. As a reaction substrate, the above compounded oil was dried under reduced pressure to adjust the water content to 50 ppm. 300 g of immobilized lipase was packed in a glass column having an inner diameter of 10 cm and a length of 50 cm, and the whole column was kept warm at 60 ° C. The above blended oil is heated to 60 ° C and pumped at 5g / min.
Was quantitatively flown, and the enzyme reaction was continuously carried out at 60 ° C.
The reaction product that passed through the column was purified by decolorizing treatment using activated clay and deodorizing treatment by vacuum steam distillation according to a conventional method. The thus-obtained reformed oil had a melting point of 32.5 ° C., was a physical property that could be used as frying shortening, and was a melting point suitable for frying donuts, fried bread, and the like.

Example 2 Purified palm stearin from Malaysia (RBD palm stearin, melting point 53.5 ° C., iodine value 26.2) 35
%, Rapeseed white squeezing oil (manufactured by Ajinomoto Co., iodine value 117.
5) 35% and refined palm kernel oil from Malaysia (RBD
Palm kernel oil, melting point 27.5 ° C, iodine value 18.0) 30
%. The melting point of this compounded oil was 50.0 ° C. Next, this blended oil was modified with an enzyme in the same manner as in Example 1 to obtain a modified oil having a melting point of 29.3 ° C. The physical properties of the blended oil before modification and the enzyme modified oil are described in SFC (solid fat content, standard oil and fat analysis test method (edited by Japan Oil Chemists' Society)).
Was evaluated. The results are shown in Table 1.

[0019]

[Table 1]

As is clear from the table, the blended oil had a high melting point and the SFC at 37.8 ° C. also showed 18.9. this is,
It means that even at human body temperature, some of it does not melt and solid fat remains in the mouth. On the other hand, the enzyme-modified oil also had a low melting point, and SFC also showed an appropriate value as an oil and fat for margarine. That is, the SFC at 10.0 ° C is about 3
0, showing a value (hardness) sufficient to maintain shape retention at low temperature, and SFC at 33.3 ° C was 2.1, indicating that it has a good mouth-melting property near human body temperature. ing.

Next, this reformed oil was stored at 20 ° C., and the change with time of its crystal form was analyzed by X-ray diffraction. In general,
A crystalline form suitable as a fat and oil for margarine is said to be a β-prime type, and in the case of a β-type crystalline form, since the crystals become coarse, surface roughness and cracks occur, which is not suitable for a margarine fat and oil. It is said. As described above, palm oil and fats and oils derived from palm oil tend to have a β-type crystal form and are not suitable for fats and oils for margarine. The blended oil showed β-form as the crystal form immediately after solidification, but the enzyme-modified fats and oils showed β-prime form even after 2 weeks of storage, showing that they are suitable as margarine fats and oils. .

Example 3 Purified palm stearin (RBD palm stearin, melting point 53.0 ° C., iodine value 28.9) produced in Malaysia and corn oil (manufactured by Ajinomoto Co., iodine value 124.5, liquid oil). Blended in various compositions. Further, this blended oil was used for modification by an enzyme modification method using lipase or a chemical transesterification method. The enzyme modification was carried out under the same conditions as in Example 1, the chemical transesterification method was carried out by a conventional method using sodium methylate, and after the reaction was completed,
What was purified (decolorized, deodorized) was analyzed. The physical properties of the obtained various fats and oils were evaluated by melting point and SFC (solid fat content),
It is shown in Table 2 together with the physical properties of the compounded fats and oils before reforming. In addition,
In the table, the blending ratio of fats and oils is 75% palm stearin, 25% corn oil, 50% palm stearin, 50% corn oil, 25% palm stearin, 75% corn oil.
The following are shown respectively.

[0023]

[Table 2]

Example 4 Palm stearin 75% in Example 3 and corn oil 2
Donuts were fried using various types of fats and oils (blended fats, enzyme-modified fats, and chemically transesterified fats and oils) having a blending ratio of 5% as frying oil. The donuts were subjected to sensory evaluation (n = 15, blind test). The sensory evaluation panel is familiar with the sensory evaluation of fats and oils and foods. In addition, the production of donuts was carried out using commercially available donut mix flour (manufactured by Nippon Flour Milling Co., Ltd.,
The product name: Donut Mix CO2) was used, and the operation was performed according to the instructions attached to it. The results are shown in Table 3.

[0025]

[Table 3]

As is clear from the table, the donut produced by using the enzyme-modified fats and oils as frying oil was evaluated as the most delicious. This is the melting point of enzyme-modified fats and oils and SFC.
It is considered that the (solid fat content) was suitable for the texture of donuts.

[0027]

EFFECTS OF THE INVENTION According to the present invention, there is provided an edible oil or fat containing a large proportion of palm stearin, which is usually hardly used for food. This oil / fat does not contain trans acid (except when partially hydrogenated oil is used in the formulation) and is highly nutritionally safe. Further, it has good oxidative stability, and is suitable as a raw material oil for shortening and margarine mainly for frying.

Claims (2)

[Claims] 1. An oil and fat containing 75 to 5% of palm stearin and 25 to 95% of a liquid oil having a melting point of 30 ° C. or lower is obtained by transesterification with a lipase having 1,3-position specificity. Edible oil. 2. A shortening or margarine obtained from the edible oil according to claim 1.