JPS6244600B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for stabilizing fats and oils by heating the fats and oils together with starch and/or protein to 150°C or higher. In recent years, there has been a strong tendency to seek naturally occurring, harmless substances as antioxidants used to stabilize edible oils and fats. The present inventors also proceeded with research on stabilizing edible fats and oils using naturally occurring substances, and found that by heating fats and oils together with starch and/or protein to 150°C or higher, a remarkable stabilizing effect on fats and oils was expressed. I found out the truth. As an example, select soybean oil, rapeseed oil, lard, and palm oil, add 20% by weight each of potato starch, wheat gluten powder, and a mixture of equal amounts of potato starch and wheat gluten powder, and heat at 250℃ while stirring. The results of examining the stability of each oil obtained separately after heating for 30 minutes are the first results.
Shown in the table. All the fats and oils used here were deoxidized by conventional methods.
It is bleached and deodorized, and no antioxidants are added. The stability of these oils and fats was measured by AOM test.

[Table] As is clear from Table 1, starch and/or
Or fats and oils after adding protein and heating,
In both cases, the AOM time is significantly longer than that of the oil before heating, and therefore the stability is significantly increased. On the other hand, when only fats and oils are heated, the AOM stability is naturally extremely low. Such an effect can only be seen when fats and oils are heat-treated in the coexistence of starch and/or protein. Even if only starch and/or protein is heat-treated and then added to fats and oils, the No stabilizing effect appears at all. Such effects of the present invention were completely unknown until now, and are not only of technical significance but also of extremely high industrial applicability. Various factors that affect the effects of the present invention are explained below. (1) Starch and protein In the present invention, starch or protein is heat-treated with oil or fat, either alone or in a mixture of these in an appropriate ratio. As the starch used here, any of commonly available starches, ie, above-ground starches such as wheat starch and corn starch, and underground starches such as potato starch and sweet potato starch, can be used. It goes without saying that similar effects can be obtained by using other starches. In order to more fully exhibit the stabilizing effect of the fats and oils of the present invention, these starches are preferably sufficiently purified. Next, a wide range of proteins can be used, including plant proteins originating from soybeans, wheat, etc., and animal proteins originating from livestock meat, fish meat, etc. The above starch and protein may be used alone or in a mixture of both in an appropriate ratio. The stabilizing effect of fats and oils changes depending on the mixing ratio of starch and protein. However, no matter what ratio the two are mixed, the stabilizing effect on fats and oils is greater than when the treatment according to the present invention is not performed. An example of a change in the fat and oil stabilizing effect with respect to a change in the mixing ratio of starch and protein is shown in FIG. 1. In this example, the mixture ratio of wheat starch and isolated soy protein (95% protein) was changed in stages, and 20% of the mixture was added to soybean oil (500g).
% (weight) and heated at 250° C. for 30 minutes, the oil and fat were separated and their stability was measured by AOM test. FIG. 1 is a diagram showing the stabilizing effect of fats and oils (expressed in AOM time) with respect to changes in the mixing ratio of wheat starch to isolated soy protein. The vertical axis represents AOM time, unit (hour),
The horizontal axis shows the percentage of wheat starch in the mixture of isolated soy protein and wheat starch. Soybean oil not treated by the method of the present invention
Since the AOM stability is on line A, it is clear that the treatment according to the present invention has a stabilizing effect on fats and oils at all mixing ratios, including when starch and protein are used alone. As is clear from Figure 1, the stabilizing effect is particularly excellent when the mixing ratio of proteins is 50% or more. The results shown in FIG. 1 show the same tendency regardless of the type of starch or protein. Furthermore, the same applies when two or more types of starch and protein are combined. It has been confirmed that the effect of the method of the present invention is superior to that of mixing proteins and sugars and heating them with fats and oils. (2) Amounts of starch and protein added to fats and oils As a general rule, the stabilizing effect changes depending on the ratio of starch and/or protein added to fats and oils. That is, increasing the addition ratio increases the effect, and vice versa, the effect decreases. Furthermore, even if the addition ratio is the same, the effect is greater as the amount of fats and oils to be treated increases. The range of the addition ratio that provides the effects of the present invention is 0.002 to 9 parts of starch and/or protein to 1 part of fat or oil. (3) Conditions of heat treatment (1) Temperature The stability improvement effect begins to appear around 150°C, and a practically sufficient improvement effect is obtained at 160°C or higher. The higher the temperature, the greater the effect.
The upper limit temperature varies depending on whether heating is performed under normal pressure, in an open state, under reduced pressure, or in an inert gas environment, but heating in an open state
The temperature is around 300℃. (2) Time In general, increasing the length increases the effect, but unnecessarily increasing the length will not increase the effect. Depending on the heating temperature, a period of 300 minutes or less is usually selected, and this amount is also practical.
Of course, depending on the conditions, a longer time may be required. An example of heating time is adding starch and/or protein at 20% by weight to oil;
When heated to 250℃, the effect appears in 5 minutes or more. In addition, the same 20% starch and/or protein added to the oil was added under reduced pressure.
When heated to 160°C, the effect appears after heating for 3 hours or more. (3) Heating method Any conditions such as normal pressure, open state, reduced pressure, or inert gas flow can be adopted. Heating under reduced pressure or under an inert gas is more preferable in order to prevent deterioration of the fat and oil that may occur due to contact between the fat and oil and air (oxygen). Heating under reduced pressure and inert gas also has the effect of greatly reducing coloration and odor of heat-treated fats and oils. Stirring during heating is not necessarily necessary, but
In practice, stirring has the advantage that the heat treatment can be carried out quantitatively. In addition, after heat treatment, the oil and fat are generally separated.
Clarification etc. will be carried out. Of course, any known means such as a filtration method or a centrifugal separation method may be used for this purpose. In special cases, such clarification may not be performed and the insoluble components may be put into practical use in a state suspended in fats and oils. In addition, if the addition ratio of starch and/or protein to fats and oils is high (for example, when adding 9 parts to 1 part of fats and oils), in addition to separating the fats and oils by centrifuging the heated product as it is, Alternatively, a method may be adopted in which the entire heat-treated product is dispersed in unheated fats and oils that require stabilization, the fats and oils stabilized by the heat treatment are dissolved and transferred therein, and then the residue is separated and removed. can. In this case, by appropriately selecting the amount of the unheated product that requires stabilization relative to the heat-treated product, the stability of the resulting oil or fat can be improved to a desired degree. By appropriately selecting the processing conditions, the oils and fats obtained as described above and whose stability has been improved by the method of the present invention can be made into products with high stability that far exceeds that obtained using conventional synthetic antioxidants. can do. Furthermore, synthetic antioxidants are decomposed by heat when fats and oils are heated in frying, etc., and their effects gradually disappear. However, the oils and fats whose stability has been improved by the method of the present invention do not have this problem at all, and have extremely high heat resistance, and because they do not volatilize or decompose when heated, they also suppress oxidation during heating of the oils and fats. can do. Of course, the effect of stabilizing fats and oils by the method of the present invention also extends to products fried with fats and oils subjected to this treatment. The effect in this case can also be far superior to that of conventional synthetic antioxidants. It is also a great practical advantage of the method of the present invention that oils and fats treated by the method of the present invention can be blended with untreated oils and fats in appropriate proportions to obtain oil and fat products with excellent stability. In this case as well, it is possible to produce a product with far greater stability than conventional oils and fats using antioxidants. Of course, it is also possible to use it in combination with conventional antioxidants. The oils and fats stabilized by the method of the present invention are not limited to the above-mentioned soybean oil, rapeseed oil, lard, and palm oil, but also rice oil, corn oil, sunflower oil, cottonseed oil, safflower oil, coconut oil, and palm kernel oil. A wide range of animal and vegetable oils and fats including olive oil, cacao butter, beef tallow, mutton tallow, fish oil, and whale oil. Of course, it may be carried out at any stage of these crude oils, deoxidized oils, bleached oils, etc., and the same effect can be obtained with hydrogenated oils, fractionated oils, etc. In the present invention, in addition to the above-mentioned method, a method is employed in which the substances volatilized and generated when fats and oils are heat-treated in the coexistence of starch and/or protein are collected and added to fresh fats and oils that require stabilization. A similar stability improvement effect can be obtained. For example, in a flask there may be oil, starch and/or
Alternatively, if a protein is added and heated and the volatile products generated at that time are led to a cooler, the volatile products are condensed. When it is recovered and dissolved in fats and oils, its stability is significantly improved. Of course, the stability of the fats and oils remaining in the flask at this time has also been greatly improved. When such a condensate is used, the ratio of starch and/or protein to fat, heating conditions, and other conditions are all the same as those of the present invention described above. In addition, when collecting condensate, under normal pressure,
This may be carried out either under reduced pressure or under an inert gas stream, or the volatile matter may be directly introduced into the fat or oil and dissolved therein. It goes without saying that the effect of improving the stability of the fat or oil can be appropriately controlled by adjusting the ratio of the condensate added to the fat or oil. Example 1 A heat treatment was performed using a combination of the fats and oils shown in Table 2 (all containing no antioxidants), starch and/or protein, and the stabilizing effect of the fats and oils was examined. The conditions for heat treatment etc. are as follows. Fats and oils: 500g Starch and/or protein addition amount: 2nd
As shown in the table. Heat treatment: 250℃, 30℃ under open conditions while stirring at 400rpm
minutes. Stability test: AOM test was performed on the clear oil obtained by cooling to about 60°C after treatment and centrifugation. The results are shown in Table 2.

【table】

[Table] As is clear from the above, there are some differences depending on the type of fat, starch, protein, mixing ratio, etc., but in any case, the fat treated with the present invention is the same as the untreated one. A significant improvement in stability was observed. Example 2 When 1 part of each soybean salad oil treated according to the method of the present invention obtained in Example 1 was added and dissolved in 10 parts of untreated soybean salad oil and subjected to the AOM test, both
AOM stability improved to over 40 hours. Example 3 500ml of corn decolorizing oil was placed in a three-necked flask equipped with a stirring blade, a condenser (water-cooled type), and a thermometer.
Add 100 g of a mixture of equal amounts of wheat starch and isolated soy protein powder and stir the contents to 270 g.
Heated at ℃ for 2 hours. Volatile substances generated during heating were condensed and recovered in the condenser. When the AOM stability was measured by adding the entire amount of this condensate to 100 g of unheated soybean salad oil (AOM 16 hours), it was improved to 75 hours.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the stability effect of fats and oils (expressed in AOM time) with respect to changes in the mixing ratio of wheat starch to isolated soy protein. The vertical axis represents AOM time units (hours), and the horizontal axis represents the percentage of wheat starch in the mixture of isolated soy protein and wheat starch.

Claims (1)

[Claims] 1. A method for stabilizing fats and oils, which comprises heating fats and oils together with starch and/or protein to 150°C or higher. 2. A mixture of fats and oils and starch and/or protein obtained by heating fats and oils together with starch and/or protein to 150°C or higher, or a mixture of fats and oils separated from the mixture, is added to the fats and oils that require stabilization. A method for stabilizing fats and oils. 3. A method for stabilizing fats and oils, which comprises adding volatile substances generated during heating of fats and oils together with starch and/or protein to 150°C or higher to the fats and oils that require stabilization.