Organic compounds -- part of the class 532-570 series – Organic compounds – Fatty compounds having an acid moiety which contains the...
Reexamination Certificate
2000-03-30
2001-07-24
Carr, Deborah D. (Department: 1621)
Organic compounds -- part of the class 532-570 series
Organic compounds
Fatty compounds having an acid moiety which contains the...
C554S206000, C554S211000
Reexamination Certificate
active
06265595
ABSTRACT:
TECHNICAL FIELD
The present invention relates to a method of solvent fractionation of a fat. More specifically, it relates to a novel solvent fractionation method characterized in that a fat dissolved in a solvent is rapidly cooled in a pre-cooling device prior to crystallization such that the fat comes just close to crystallization or a blockade of the pre-cooling device does not occur, and the fat is then crystallized in a crystallizer in an efficient manner, for example, within a shorter period of time, with better quality, or with a larger amount to be treated.
BACKGROUND ART
Many methods for fractionating components of a feedstock fat are known, including methods of dry fractionation and methods of solvent fractionation. The steps of the methods of dry fractionation, which do not use any solvent, are relatively simple. However, the methods have drawbacks concerning the low purity of the fat component of interest or the difficulty in operating the fractionation steps. The methods of solvent fractionation advantageously overcome the above-mentioned drawbacks of the methods of dry fractionation, but have other drawbacks such as a long operation time due to an increased cooling load resulting from a high concentration of a fat dissolved in a solvent.
JP-B 38-917, for example, describes a method of solvent fractionation-crystallization of a fat comprising treating a fat in a rapid heat exchanger. This method is different from the method of the present invention in that the pre-cooling is performed below the crystallization temperature. Although the method of the publication is not defined by the yield of crystals based on the total amount of the fat at the crystallization temperature of the feedstock fat, the yield of around 8% described in Examples of the publication is quite different from that of 20% or higher obtained by the method of the present invention. The ratio of the total cooling load to the load for removing heat of crystallization in a crystallizer obtained by the method of the publication is 1, which is different from that obtained by the method of the present invention. The method of the publication is also different from the method of the present invention in that the method is not defined by the temperature of a refrigerant used in the crystallization.
When a feedstock fat which yields 20% or higher of crystals based on the total amount of the fat at the crystallization temperature is crystallized according to the method described in JP-B 38-917, deposition of crystals occurred before the temperature reached the crystallization temperature even if a rapid cooling was applied. Introduction of the feedstock fat in such a state into a crystallizer resulted in deposition of unnecessary components as constituents of crystals. Accordingly, a product with the objective quality was not obtained. These results are construed as follows. If a feedstock fat which yields 20% or higher of crystals is crystallized, a step of crystal growth should be usually performed slowly in order to avoid the formation of crystals before reaching the crystallization temperature. However, the step was performed rapidly. As a result, the incorporation of unnecessary components etc. occurred, which resulted in a failure in obtaining a product with the objective quality.
DISCLOSURE OF INVENTION
The present inventors have studied intensively in order to solve the problems listed in Background Art. As a result, it has been found that a high fat concentration can be attained, that the temperature of a refrigerant can be raised, and the operation time can be shortened in a method of solvent fractionation of a fat. Thus, the present invention has been completed. Therefore, the object of the present invention is to provide an efficient method of production in which the crystallization time in a crystallizer is shortened, the yield of crystals is increased and the like.
The method of solvent fractionation of fat of the present invention is characterized in that a feedstock fat dissolved in a solvent is rapidly cooled to a temperature higher by 1 to 20° C. than the crystallization temperature used in a crystallizer in the step prior to introduction of the feedstock fat into the crystallizer.
BEST MODE FOR CARRYING OUT THE INVENTION
In the method of the present invention, steps immediately prior to the crystallization in crystallization procedure is performed while cooling in a cooling device set up in the step prior to the crystallization. This method is particularly effective when a feedstock fat which yields 20% or higher of crystals at the crystallization temperature is used. On the other hand, practically, a yield which is too high, for example 80% or higher, may make the method less operative. In the cooling step, because it is required to cool the fat to a temperature which is higher than the crystallization temperature and as close to the crystallization temperature as possible in order to avoid crystallization at the outlet of the cooling device, the fat is rapidly cooled to a temperature higher by 1 to 20° C. than the crystallization temperature.
Specifically, it is required to set the cooling temperature such that the total cooling load in the crystallizer is in the range of 1.5 times to twice its load for removing heat of crystallization, although it correlates with the pre-cooling temperature. When the total cooling load is below 1.5 times its load for removing heat of crystallization, deposition of crystals may occur upon cooling, which may make it difficult to obtain a product with the objective quality due to the blockade of the cooling device or deposition of unnecessary components upon crystallization. When the total cooling load is above twice its load for removing heat of crystallization, the cooling load in the crystallizer becomes too large to expect an efficient operation of the crystallizer.
The crystal portion of the fat obtained by the method of the present invention can be utilized for foodstuffs and other non-foodstuffs. For example, it can be utilized as a fat for chocolate. Similarly, the liquid portion of the fat can be utilized for foodstuffs and other non-foodstuffs. For example, it can be used as a fat for fried food, or as a fat for margarine after hydrogenating the liquid portion of the fat.
Now the elements constituting the present invention are described hereinbelow.
The type of the solvent is not specifically limited as long as it dissolves a vegetable oil, an animal oil or any feedstock fat containing it. The typical examples of the solvent practically used include hexane, acetone, methyl ethyl ketone, and any mixture thereof. A solvent suitable for the object is preferably selected at each time of performance.
The feedstock fat is not specifically limited as long as it is a vegetable oil, an animal oil or a mixture thereof. The typical examples of the feedstock fat practically used include one which contains much of intermediate melting point fraction. Palm olein, palm oil, palm kernel oil and the like are desirable.
The range of the concentration of the feedstock fat dissolved in the solvent is not specifically limited. Practically, it is desirable to make the concentration as high as possible in order to increase the amount to be treated. Alternatively, the concentration of the fat is preferably selected at each time of performance so as not to interfere with the operation by the blockade of the pre-cooling device or, in particular, of the crystallizer after crystallization.
The pre-cooling device may be any heat exchanger. Preferably, it may be a device which can cool the fat to just close to crystallization while allowing the fat to continuously run in a flow of the fat. The device is desirably equipped with a device having a heating function in order to completely dissolve the crystals depositing in the heat exchanger and in the pipe between the outlet of the heat exchanger and the inlet of the subsequent crystallizer.
The pre-cooling temperature may be any temperature which is higher by 1 to 20° C., preferably by 5 to 15° C., most preferably by 8 to 12°
Kajiyama Tokisane
Kuwabara Yuji
Taniguchi Atsushi
Yoneda Shin
Carr Deborah D.
Fuji Oil Company Limited
Wenderoth , Lind & Ponack, L.L.P.
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