JPS585235B2 - Method for producing cottonseed salad oil - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing cottonseed salad oil from cottonseed oil with good yield and high cooling stability.

Cottonseed oil has long been popular as a high-quality edible oil because of its mild and excellent flavor and its richness in nutritionally useful linoleic acid.

However, cottonseed oil contains components with high melting points, which crystallize during storage, which not only impairs commercial value, but also causes the crystals to break the emulsion when used in emulsified foods such as dressings and mayonnaise. Cause.

Therefore, cottonseed oil is usually used as salad oil after the high melting point component, ie, cottonseed stearin, is separated and removed through a process called wintering.

The cooling stability of this salad oil varies depending on winter conditions, but it is required to obtain salad oil with as high cooling stability as possible at a high yield.

Generally, about 80% of salad oil is obtained by winterizing cottonseed oil, but if cottonseed stearin, which is a by-product of about 20%, can be effectively utilized, the added value of cottonseed oil as a whole can be increased.

Cottonseed stearin is usually a solid or semi-solid oil with a melting point of about 20°C, so it is used as a raw material for margarine and shortening, but if salad oil can be obtained from cottonseed stearin, it is economically advantageous. .

Various studies have been carried out with this intention in the past, such as methods for recovering liquid components attached to cottonseed stearin by melt fractionation of cottonseed stearin, and methods for directional transesterification of cottonseed stearin. Attempts have been made to obtain liquid oil by carrying out a reaction to increase the proportion of liquid components and then fractionating the liquid, but these methods have problems in terms of flowability, cost, yield of liquid oil, cooling stability, etc. This cannot be said to be satisfactory.

An object of the present invention is to effectively utilize cottonseed stearin in salad oil, thereby obtaining cottonseed salad oil with good yield and excellent cooling stability from cottonseed oil.

As a result of extensive research by the present inventor, the low melting point part obtained from cottonseed stearin by a specific method was blended into cottonseed oil,
It has been discovered that the above purpose can be achieved by wintering this.

The present invention was completed based on this knowledge, and involves indiscriminate transesterification of cottonseed stearin, which is a by-product when producing cottonseed salad oil from cottonseed oil, and converts this oil into 18
This is a method for producing cottonseed salad oil, which is characterized in that the low melting point portion is obtained by cooling to below .degree.

In the present invention, a random transesterification reaction is used as the transesterification reaction.

Directional transesterification improves reaction control, cost, and
Not only does it have problems with filtration, but it is also less effective in improving the cooling stability of cottonseed salad oil, so it cannot be used.

For fractionation after transesterification, a so-called dry method that does not use a solvent or a surfactant is preferable.

That is, completely melted fats and oils are cooled at a cooling rate of 10 to 40°C/hr while stirring the entire part uniformly to partially crystallize it, and after reaching a predetermined temperature, it is further stirred at the same temperature for an appropriate time as necessary. It is also possible to adopt a so-called wet method fractionation using a surfactant, which is a method in which the high melting point portion is separated and removed by filtering.

The cooling temperature during this separation must be below 18℃,
The amount of the low melting point part obtained by fractionation added to cottonseed oil was 10% (by weight).

The same shall apply below).

If the low melting point fraction obtained by fractionation at a temperature exceeding 18°C is blended with cottonseed oil and subjected to wintering, the yield of cottonseed salad oil will be lower than when it is not blended.

Furthermore, if more than 10% of the low melting point portion is blended into cottonseed oil, the yield of cottonseed salad oil will be lower than when it is not blended.

However, when the low-melting point fraction obtained at a fractionation temperature of 18°C or lower is blended with cottonseed oil at a rate of 10% or less, cottonseed salad oil can be obtained at a yield that is almost the same or slightly higher than when no cottonseed oil is blended. The cooling stability of salad oil is improved.

The lower limit of the fractionation temperature is preferably about 10°C from the viewpoint of ease of filtration operation, but wintering performed after blending the low melting point part with cottonseed oil, which is not a limiting condition of the present invention, is not a special condition.
General conditions used when producing cottonseed salata from cottonseed oil may be used.

That is, the melted oil and fat is allowed to slowly cool from room temperature to around 5° C. over a period of 2 to 3 days to several days, and after the crystals have grown sufficiently, it is filtered to obtain cottonseed salad oil.

In the present invention, the low melting point portion obtained from cottonseed stearin has a higher melting point than cottonseed oil.

Despite this, when koko is added to cottonseed oil for wintering, the yield of salad oil is almost the same as when it is not added, but it is slightly higher, and it also has the unique effect of improving the cooling stability of the salad oil.

This phenomenon is presumed to be due to the fact that the complexity of the triglyceride composition of the oil and fat increases due to the addition of the low melting point portion, which sterically inhibits the precipitation and growth of crystals.

According to the present invention, it was previously a by-product during the production of cottonseed salad oil.

Since a part of the seed stearin can be recovered and used for cottonseed salad oil, it not only increases the yield of salad oil from cottonseed oil, but also has the remarkable effect of improving the cooling stability of the cottonseed salata extract. It is.

Examples are shown below.

Example 1 Cottonseed stearin (melting point: 22°C) was subjected to a random transesterification reaction (melting point: 31°C) using 0.2% sodium methylate catalyst in a conventional manner.

After completely melting this fat and oil, it was cooled to a predetermined temperature by selecting several conditions while stirring at a cooling rate of 30 °C/hr from 55 °C, and partial crystallization was performed while stirring at the same temperature for 0 or 30 minutes. .

Thereafter, several types of low melting point parts were obtained by suction filtration using a glass filter kept at the same predetermined temperature.

These were blended in cottonseed oil in an amount of 0 to 15%, left in a refrigerator at room temperature to 5° C., and passed through a 30-diameter interfiltration to determine the yield of salad oil.

In addition, the yield of salad oil obtained in the winter of the blended oil was equal to or higher than that of the blended oil in the winter.
A cooling test at ℃ was conducted.

The classification results are shown in Table 1, and the winter yield of the low melting point blended oil and the cooling test results of the obtained salad oil are shown in Table 2.

As a result, when the low-melting point fraction obtained at a fractionation temperature of 20°C is blended with cottonseed oil, the yield of salad oil in the winter of the blended oil is considerably lower than that without blending, especially when the blending ratio is high. The amount of crystallization in winter increased, making winter filtration difficult.

When the low melting point fraction obtained at a fractionation temperature of 18°C or less is blended with cottonseed oil, the yield of salad oil in winter is the same or slightly improved compared to the case without blending, up to a blending ratio of 10%, and the obtained salad oil The cooling stability was also improved.

When the blending ratio was 15%, the yield of salad oil in winter decreased considerably.

Example 2 Cottonseed stearin (melting point: 25°C) was subjected to a random transesterification reaction (melting point: 36°C) using 0.2% sodium methylate catalyst in a conventional manner.

After completely melting this oil and fat, a low melting point portion was obtained by the same method as in Example 1 under several fractionation conditions.

These were blended in cottonseed oil in an amount of 0 to 15%, left in a refrigerator at room temperature to 5°C for 4 days, winter filtrated to obtain salad oil, and a cooling test at 0°C was conducted.

These results are shown in Table-3 and Table-4.

As a result, when the low melting point portion obtained at a fractionation temperature of 20° C. was blended with cottonseed oil, the yield of salad oil in the winter of the blended oil was considerably lower than the yield of salad oil when it was not blended.

The low melting point fraction obtained at a fractionation temperature of 18°C or lower was added to cottonseed oil by 1
When blended up to 0%, the yield of salad oil in winter was the same or slightly improved, and the cooling stability of the obtained salad oil was significantly improved.

Although the cooling stability of the obtained salad oil was high even when the blending ratio of the low melting point portion was 15%, the yield of the salad oil was decreased.

Claims (1)

[Claims] 1 Perform indiscriminate transesterification on cottonseed stearin, which is a by-product when producing cottonseed salad oil from cottonseed oil, and cool this oil to 18°C or lower to obtain a low melting point portion, which is blended with cottonseed oil at 10% by weight or less. A method for producing cottonseed salad oil, which comprises drying and wintering.