JPH07170965A - Method for deactivating enzyme of liquid food - Google Patents

Abstract

PURPOSE:To deactivate an enzyme without requiring its separation with a membrane or its heating at a high temperature by charging carbon dioxide liquid into an enzyme-containing liquid food in a micro-size. CONSTITUTION:This method for deactivating the enzyme of a liquid food comprises charging the enzyme-containing liquid food into a treating tank 13 comprising a pressure-resistant container, and subsequently charging carbon dioxide from a cylinder 1 into the treating tank through a filter 16. The carbon dioxide is charged into the liquid food in a supercritical state controlled with a pump 3, a heater 7, a treating tank heater 14 and a pressure-controlling valve 15 in a micro-size through a filter 16. The average diameter of the sieve opening of the filter is <=100mum, preferably <=20mum.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an enzyme deactivating method for liquid foods, and more particularly to an enzyme deactivating method which is excellent in deactivating efficiency, high in safety and free from quality deterioration. Is.

[0002]

Sake, which is a typical example of an enzyme-containing liquid food, is generally manufactured through the following steps. That is, the first step of obtaining fresh sake by squeezing and filtering after completion of fermentation,
The second step of heat-sterilizing and storing the sake at 60 to 65 ° C.
It is manufactured through the third step of blending the obtained raw liquor to determine the quality of the liquor (sweet or spicy) and adjusting the alcohol content to the standard, and the fourth step of sterilizing the adjusted liquor by heat sterilization again. In this way, sake is subjected to heat treatment twice in the above-mentioned second step and fourth step to undergo enzyme deactivation and sterilization.

By the way, the fresh flavor of sake is 2
Since the number of times of heat treatment markedly decreases, the demand for sake without heat treatment is rapidly increasing. However, freshly squeezed sake has a fresh taste and aroma, but its enzymatic activity is high, so the flavor is extremely likely to change. There is unprocessed fresh sake that has been distributed at low temperature as raw sake, but such sake is
Enzymes such as α-amylase, protease, carboxypeptidase and the like tend to cause deterioration in quality, and an increase in distribution cost for preventing the problem is a problem.

Therefore, in order to solve the above-mentioned problems, the enzyme in the raw sake has been conventionally removed by microfiltration or ultrafiltration, but it cannot be sufficiently removed. Moreover, the method using a film has a problem that the flavor component is lost because the scent component of sake is dissolved in the film and a certain taste component is removed.

Further, in order to maintain the stability of cloudy juice such as orange juice, it is necessary to inactivate pectinesterase (PE), but PE is a heat-stable enzyme, and its deactivation is against it. Generally, high temperature conditions (88-99 ° C or 1
Heat treatment at 20 ° C.) is required. However,
There is a problem that the flavor of fruit juice is deteriorated by the heat treatment under the high temperature condition as described above.

[0006]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above circumstances, and its object is to provide a novel liquid food which does not depend on membrane separation and which does not require high temperature heating at about 100 ° C. To provide a simple enzyme deactivation method.

[0007]

Means for Solving the Problems As a result of intensive studies to achieve the above-mentioned object, the inventors of the present invention, by contacting the enzyme-containing liquid food with carbon dioxide in a supercritical state,
We have found that it is possible to inactivate the enzyme. The present inventors, as a result of further studies based on such findings,
It was surprisingly found that the enzyme deactivation efficiency is significantly enhanced if a specific contact method is adopted.

The present invention has been completed based on the above findings, and the gist thereof is a liquid food containing carbon dioxide and an enzyme, which is supplied through a filter having an average diameter of 100 μm or less in a treatment tank and is in a supercritical state. And an enzyme inactivation method for liquid foods, which comprises contacting with.

The present invention will be described in detail below. Typical examples of the enzyme-containing liquid food to which the enzyme deactivating method of the present invention is applied include the above-mentioned sake. Other examples include fermented liquid foods such as beer and various fruit juices. The fruit juices are usually obtained from apples, grapes, various citrus fruits and the like as raw materials, but juices obtained from tomatoes and other vegetables may also be used.

In the present invention, carbon dioxide is used as a fluid in a supercritical state. In such a state, the pressure is 70
~ 400 atm, preferably 100-300 atm, particularly preferably 150-300 atm, temperature 30-70.
It can be achieved under the condition of ℃, preferably 30 to 50 ℃. Hereinafter, carbon dioxide in a supercritical state may be abbreviated as “carbon dioxide fluid”.

It is necessary that the liquid food and the carbon dioxide fluid be in sufficient contact. Therefore, in the present invention, it is necessary to supply the carbon dioxide fluid into the liquid food in a micro size. Specifically, in the treatment tank, carbon dioxide supplied through a filter having an average diameter of 100 μm or less and in a supercritical state is brought into contact with the enzyme-containing liquid food. The type of filter is not particularly limited, and for example, a sintered metal filter made of copper, bronze, stainless steel, nickel, monel metal, silver, platinum or the like is preferably used. In the present invention, the average diameter is 50
It is preferable to use a filter having a diameter of not more than μm, and it is particularly preferable to use a filter having an average diameter of not more than 20 μm. Generally, the average diameter of the filter can be reduced to a minimum of 1 μm.

The contact time between the liquid food and the carbon dioxide fluid varies depending on the type of the target food and the degree of deactivation of the target enzyme. For example, in the case of sake, it is usually 10 to 60 minutes, preferably about 20 to 30 minutes.
In the present invention, addition of an entrainer is not usually required, but if necessary, it may be used within a range of 5% or less with respect to the carbon dioxide fluid. In the case of a liquid food containing no alcohol component, ethyl alcohol is preferably used as the entrainer. The treatment with the carbon dioxide fluid may be a batch type or a continuous type.

After the contact treatment with the carbon dioxide fluid, the enzyme-inactivated liquid food is easily recovered by returning the treatment conditions to room temperature and pressure. The recovered liquid food is not impaired in flavor, and microorganisms such as lactic acid bacteria are sterilized, so that the quality does not deteriorate during storage.

Next, an example of the process of the present invention will be described with reference to the accompanying drawings. FIG. 1 is an explanatory diagram showing an example of the process of the present invention. In the process shown in FIG. 1, the entrainer container (2) is installed as needed, and the treatment tank (13) is composed of a pressure resistant container. The temperature and pressure in the treatment tank (13) are the same as those of the treatment tank warmer (14),
The pressure adjusting valve (15) can be adjusted to a constant level, and the filter (1) is installed at the bottom of the processing tank (13).
6) is installed. The temperature and pressure in the separation tank (17) are controlled by the separation tank warmer (18) and the pressure adjusting valve (1
It can be adjusted by 9).

First, carbon dioxide passes from the liquefied carbon dioxide gas cylinder (1) through the valve (9) and the filter (5).
(If it is gasified, it is cooled and liquefied by the cooler (6)) and supplied to the line mixer (8) via the warmer (7) and the check valve (10) by the pump (3). When an entrainer is used, it is supplied from the entrainer container (2) to the line mixer (8) via the check valve (11) by the pump (4) and mixed with carbon dioxide.

Next, carbon dioxide (and the entrainer)
Is supplied to the processing tank (13) containing the liquid food through the valve (12) and the filter (16). At this time, carbon dioxide is brought into a supercritical state by adjusting the pump (3), the warmer (7), the treatment tank warmer (14), and the pressure adjusting valve (15) to appropriate conditions. It is supplied into the processing tank (13). Moreover, it is supplied in a micro size by the filter (16). It is also possible to control so that the supercritical state is reached at the same time when it is supplied into the processing tank (13).

The carbon dioxide fluid contacted with the liquid food is
The supercritical state is released by being introduced into the separation tank (17) and operating the separation tank warmer (18) and the pressure adjusting valve (19). The gasified carbon dioxide is measured by the flowmeter (2
It is discharged to the outside of the system via 0). The valve (21)
Is preliminarily provided in order to discharge the carbon dioxide to the outside of the system halfway before being supplied to the treatment tank (13).

[0018]

EXAMPLES The present invention will be described in more detail with reference to test examples and examples, but the present invention is not limited to the following examples as long as the gist thereof is not exceeded.

Test Example 1 An enzyme test solution was contacted with a carbon dioxide fluid according to the process shown in FIG. As enzyme test solution, 20mg / 100ml
Using a glucoamylase aqueous solution adjusted to a concentration, a sintered metal (SUS316) having an average diameter of 10 μm is used as the filter (16) attached to the lower part of the treatment tank (13)
A filter was used. No entrainer was used.

First, 500 ml of the enzyme reagent solution was charged into the treatment tank (13), and the supply of carbon dioxide in the liquefied carbon dioxide gas cylinder (1) was started. Carbon dioxide passes through the valve (9) and the filter (5) and is liquefied by the cooler (6).
It is heated to 35 ° C. by the warmer (7), and is then pumped by the pump (3) into the processing tank (13) via the check valve (10), line mixer (8), valve (12) and filter (16). Supplied. Treatment tank warmer (14), pressure control valve (1
According to 5), the pressure in the processing tank (13) is 250 atm,
The temperature was maintained at 35 ° C. The supply rate of the carbon dioxide fluid to the treatment tank (13) was 10 NL / min, and the contact time between the enzyme reagent solution and the carbon dioxide fluid was 30 minutes.

Next, the enzyme test solution and the carbon dioxide fluid are introduced into the separation tank (17), and the separation tank warmer (18) and the pressure adjusting valve (19) are operated to separate the separation tank (17).
The supercritical state was released by returning the temperature and pressure of the carbon dioxide fluid inside to normal temperature and pressure. The gasified carbon dioxide was discharged to the outside of the system through the flow meter (20). In addition, in order to confirm the effect of the carbon dioxide fluid having a micro size, the same procedure as above was performed when the filter (16) was removed. The results are shown in Table 1, and the residual activity of the enzyme could be remarkably reduced by using the filter.

[0022]

[Table 1]

Test Example 2 As an enzyme reagent solution, carboxypeptidase (serine carboxypeptidase), lipase, glucoamylase,
20-100 mg / 100 m of each of the acidic proteases
An aqueous solution adjusted to 1 concentration was used. Then, the same operation as in Test Example 1 was performed except that the temperature of the carbon dioxide fluid supplied to the treatment tank (13) and the pressure and temperature in the treatment tank (13) were changed as shown in Tables 2 and 3. The enzyme reagent was contacted with a carbon dioxide fluid of microscopic size. The ratio (%) of the residual activity of the carbon dioxide fluid-treated solution to the untreated sample solution was compared, and the results are shown in Tables 2 and 3.

[0024]

[Table 2]

[0025]

[Table 3]

Example 1 As a liquid food, 500 ml of freshly squeezed sake was used and brought into contact with a carbon dioxide fluid of microscopic size under the same conditions as in Test Example 1. Residual enzyme activity of fresh sake after carbon dioxide fluid treatment (U / ml) and number of lactic acid bacteria after storage for 60 days (C
FU / ml liquor) is shown in Table 4. For comparison, an untreated product (Comparative Example 1) and a product heat-treated at 62 ° C. for 5 minutes (Comparative Example 2)
Table 4 also shows the residual enzyme activity of the. Further, as a result of a sensory test conducted by a specialized panelist on the new sake after the carbon dioxide fluid treatment, it had a good flavor close to that of unbrewed sake. On the other hand, the fresh sake after the heat treatment (Comparative Example 2) was inferior in flavor to the raw sake. The number of lactic acid bacteria was measured by a calibration curve method using the absorbance (wavelength 562 nm).

[0027]

[Table 4]

Further, the fresh sake in each of the above examples was stored for 60 days, and the change with time of lactic acid and acetic acid concentrations was measured. The results are shown in Table 5. As is clear from the results shown in Table 5, according to the enzyme inactivation method of the present invention, at the same time, the sterilization treatment of microorganisms such as lactic acid bacteria can be achieved, so that the concentrations of lactic acid and acetic acid do not increase.

[0029]

[Table 5]

Example 2 Commercially available American navel orange was squeezed with a hand presser to obtain fruit juice, and 500 ml of the fruit juice was used as a liquid food. Contacted with. The PE activity of the juice after the carbon dioxide fluid treatment was measured, and the residual activity (%) with respect to the untreated juice was calculated and shown in Table 6. In addition, as Comparative Example 3,
The same procedure was performed when the filter (16) was removed.

The above PE activity was measured according to the method described in Rouse A
It was performed according to the method of tkins (1955). That is, the enzyme activity was measured by using a 1 wt% pectin solution as a substrate solution, reacting with the enzyme at 30 ° C. for 30 minutes, and titrating the produced acid with a 0.02N sodium hydroxide aqueous solution. An automatic titrator manufactured by Metrohm Co. was used for the titration.

[0032]

[Table 6]

Example 3 Commercially available American Valencia orange was squeezed with a hand presser to obtain fruit juice, and 500 ml of the fruit juice was used as a liquid food. Then, the temperature of the carbon dioxide fluid supplied to the treatment tank (13) and the temperature in the treatment tank (13) are set to 45
The same procedure as in Test Example 1 was carried out except that the temperature was changed to 0 ° C. to carry out the contact treatment between the enzyme reagent solution and the carbon dioxide fluid of micro size. Further, as Comparative Example 4, the same operation as described above was performed when the filter (16) was removed. The residual activity (%) of PE was calculated in the same manner as in Example 2 and is shown in Table 7.

[0034]

[Table 7]

[0035]

INDUSTRIAL APPLICABILITY The enzyme deactivation method of the present invention described above is excellent in deactivation efficiency and highly safe because it uses carbon dioxide. Therefore, it is suitable as an enzyme deactivation method for liquid foods.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing an example of a process of the present invention.

[Explanation of symbols]

 1: Liquefied carbon dioxide cylinder 2: Entrainer container 6: Cooler 7: Warmer 8: Line mixer 13: Treatment tank 14: Treatment tank warmer 16: Filter 17: Separation tank 18: Separation tank warmer

Claims (3)

[Claims] 1. An average diameter of 100 μm in a processing tank.
A method for inactivating an enzyme of a liquid food, which comprises contacting carbon dioxide in a supercritical state, which is supplied through a filter of m or less, with an enzyme-containing liquid food. 2. The enzyme-containing liquid food is a raw sake.
The enzyme deactivation method described in 1. 3. The enzyme-containing liquid food is fruit juice.
The enzyme deactivation method described in 1.