JPH02154661A - Removal of dregs of heated soy sauce - Google Patents

Abstract

PURPOSE:To immediately remove dregs in high recovery ratio without settling dregs of heated soy sauce in a tank by removing dregs of heated soy sauce using a dynamic membrane comprising porous ceramic as a supporting material. CONSTITUTION:Unrefined soy sauce is squeezed to give raw soy sauce, which is heated to give heated soy sauce. The heated soy sauce in a high-temperature state after heating is filtered by using a self suppression type dynamic membrane comprising porous ceramic having <=1mum, preferably <=0.8mum average particle diameter under <=0.4MPa, preferably <=0.2MPa filter pressure.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a lees removal method for removing lees from pasteurized soy sauce and refining soy sauce.

(Prior art) As shown in Figure 7A, the current general manufacturing process for soy sauce is to heat raw soy sauce obtained by pressing various methods to make pasteurized soy sauce, and store this pasteurized soy sauce in a tank. The soy sauce is allowed to stand still, and the oxygen and proteins deactivated and denatured by pasteurization are allowed to aggregate and settle as lees at the bottom of the tank, and the supernatant soy sauce is filtered through diatomaceous earth to become a product.

In such a conventional method, about 10% of pasteurized soy sauce is removed as lees, but a large amount of soy sauce still remains in the lees, which is disadvantageous in terms of product yield.

Therefore, a method shown in FIG. 7B has been proposed as an improved method of the conventional method. In this method, the lees that have settled at the bottom of the tank are filtered again through a polymer membrane, the soy sauce in the lees is recovered, and this recovered amount is added to the supernatant soy sauce and filtered through diatomaceous earth, increasing the product yield to around 98%. This is a way to increase it.

(Problems to be Solved by the Invention) In all of the conventional methods described above, products are obtained through diatomaceous earth filtration, but diatomaceous earth filtration cannot completely remove fine sludge and heat-resistant spores of bacteria. Diatomaceous earth containing soy sauce after use has become a problem as industrial waste.

Furthermore, even when using polymer membranes to increase product yield, polymer membranes have disadvantages in terms of chemical resistance (cleanability) and heat resistance, especially hollow fibers that are widely used as polymer membranes. With this type, as the viscosity of the retentate increases, the difference between the population pressure of the membrane module and the outlet pressure becomes large, and there is a risk that the membrane may be destroyed.

(Means for Solving the Problems) In order to solve the above problems, the present invention provides a method for immediately filtering pasteurized soy sauce using a self-blocking dynamic membrane using porous ceramic as a support, without allowing the pasteurized soy sauce to settle in a tank. and especially to improve membrane permeation flux? 8! The temperature, the pore size of the porous ceramic support, and the filtration pressure were set within predetermined ranges.

(Function) Fresh fried soy sauce is pasteurized, and the pasteurized soy sauce heated to about 80 m is directly passed through a porous ceramic support. Then, the polymer components to be separated, mainly proteins, form a dynamic membrane on the ceramic surface of the porous membrane, and the capacitance increases by 9.
It is separated into about 7-98% soy sauce and 2-3% high viscosity lees.

(Example) Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a schematic diagram of a racking device, in which the left side shows the device used for carrying out the method of the present invention, and the right side shows the device used in a comparative example, with the tank being shared.

The racking device stores pasteurized soy sauce 2 in a tank 1 and is equipped with a temperature controller 3, and the pasteurized soy sauce 2 in the tank 1 is supplied to a membrane module 5.6 by a pump 4, and the retained liquid that has not passed through the membrane is removed. Tank again! A pressure gauge 7 is provided at the inlet and outlet of the membrane module 5.6, and a pressure regulating valve 8 is provided downstream of the outlet of the membrane module 5.6. Here, the membrane modules 5 used for carrying out the method of the present invention were arranged in series and housed a porous ceramic support membrane therein, and the membrane module 6 used for the comparative example housed a polymer membrane.

In the present invention, pasteurized soy sauce is separated into soy sauce and lees using the above-mentioned device as shown in Fig. 2, using a filter A membrane. The following describes experimental results comparing various operating conditions when using a dynamic membrane, when using a polymer membrane, and when using a dynamic membrane.

[Comparison of ceramic membrane and polymer membrane] Comparison of ceramic membrane and polymer membrane is based on capacity reduction rate RF,
The relationship between the membrane permeation flux and the viscosity η was investigated, and the results are shown in FIG. 3. The preparation of the sample liquid, the type of membrane, the operating conditions, and the operating method are as follows.

Imitation uW 22'' Ll Honjozo Koikuchi Namaage Soy Sauce at 65℃ for 2 hours and then at 85℃ for 1 hour.
Uses pasteurized lees cloudy soy sauce that has been heated for a while.

Type of membrane Invention (self-blocking dynamic membrane): Pore diameter of multitubular module support made of alumina-silica is 0.2 μm and 0.5 μm Comparative example (polymer membrane): Hollow fiber membrane made of borisulfone Operating conditions Invention Filtration Pressure crab 0.2MPa Membrane surface linear velocity: 2m-5- Temperature/30℃ Comparative example Filtration pressure crab 0.1MPa Membrane surface linear velocity: Initially 1 ts-5-' RF4 0.75a-5-' RF25 0.03m-5-' Temperature = 30°C Here, the reason why the filtration pressure and membrane surface linear velocity of the comparative example were made lower than those of the method of the present invention is that as the RF increases, the polymer membrane
This is because the difference between the inlet pressure and outlet pressure of the module becomes large and there is a risk of destruction.

Operating method The operating method is the same for both the method of the present invention and the comparative example, specifically 20
Retained liquid 41 obtained by treating fl test liquid to RF5 while measuring the membrane permeation flux, and retained liquid 18n obtained by processing 90J2 test liquid to RF5 to make 22Il.
The membrane permeation flux from RF5 to RF50 of the retentate at °C was measured.

As is clear from FIG. 3, according to the method of the present invention using a self-blocking dynamic membrane, the change in the membrane permeation flux is small from the beginning of the filtration process, and the viscosity of the retentate is particularly large after RF1o. Even when the temperature increases, the membrane permeation flux does not change significantly and remains stable.

In the comparative example using a polymer membrane, the membrane permeation flux was large at the beginning of the filtration process, but as the viscosity of the retentate increased, the membrane permeation flux suddenly decreased.

As described above, according to the method of the present invention, from RFIO to RF45
Since the membrane permeation flux hardly changes, pasteurized soy sauce can be filtered with a higher recovery rate than diatomaceous earth filtration.On the other hand, when using a polymer membrane, diatomaceous earth filtration must be combined to increase the recovery rate. It won't happen. Therefore, according to the method of the present invention, the process can be simplified. According to the method of the present invention, the turbidity of the retentate increased from 0.86 to 18.01, but
The turbidity of the permeate was maintained at 2% or less of the retentate.

[It has been found that the self-blocking dynamic membrane is advantageous when the filtration temperature of pasteurized soy sauce is higher than 0. Furthermore, the relationship between the filtration temperature of pasteurized soy sauce and the membrane permeation flux when a self-blocking dynamic membrane is used is The results of the experiment conducted are shown in Figure 4. The operating conditions except for the preparation of the sample solution, the type of membrane, and the temperature were the same as those of the method of the present invention described above, and the temperature was set at 20.4%.
The tests were carried out at various temperatures of 0°C, 60.80°C.

As is clear from FIG. 4, the membrane permeation flux increases linearly as the temperature increases, and at 80°C, the membrane permeation flux is about three times that at 20°C. In particular, when using a self-blocking dynamic membrane, it has better heat resistance than a polymer membrane, so it is possible to process pasteurized soy sauce (80-85°C) immediately after pasteurization, and it is also possible to process it in this way. This increases the membrane permeation flux and reduces processing time.

[Pore size of porous ceramic support and operating pressure] When filtrating solutions containing polymeric substances, using a membrane with a large pore size will cause clogging, which will greatly reduce the membrane permeation flux, and using a membrane with a small pore size will cause the membrane to clog. Since the resistance of the membrane becomes large and a high membrane permeation flux cannot be obtained, the pore diameter and operating pressure were varied and the results are shown in FIG. The preparation of the sample solution was the same as described above, and the type of membrane and operating conditions were as follows.

Each tube module is made of membrane type alumina/silica, and the pore size is 0.
2μm, 0.5μm, 0.8μrn,
1.0μm.

1.5μm Operating conditions Filtration pressure Crab 0. IMPa, 0.2MPa, OJM
Pa, 0.4 MPa Membrane surface linear velocity: 2 m-3-' Temperature: 30°C As is clear from Figure 5, the pore diameter (average pore diameter) is 1.0 μ
When using a ceramic support of m and 1.5 μm,
The critical flux is approximately 0.1 MPa, and its value is 0.2 μ.
m, only 60% of the critical flux of the dynamic membrane with 0.5 μm and 0.8 μl ceramic supports. This is thought to be because the size of the sludge is about 0.8 to 1.2 μm, which causes clogging in ceramic supports with pore diameters of 1.0 μm or more. Therefore, the pore diameter of the ceramic support used for racking pasteurized soy sauce is 0.8 μm.
The following are preferred.

Further, the operating pressure reaches its maximum value around 0.2 MPa, and as the pressure increases, clogging tends to occur.

Therefore, the operating pressure is 0.4 MPa or less, especially 0.2 M
It is preferable to set it to Pa or less.

[Membrane surface linear velocity] As the membrane surface linear velocity increases, the shear force at the membrane surface increases, the mass transfer conditions near the membrane surface improve, and the membrane permeation flux is thought to increase. It is shown in FIG.

As is clear from FIG. 6, there is a proportional relationship between the membrane surface linear velocity and the membrane permeation rate.

(Effects of the Invention) As explained above, according to the present invention, by using a dynamic membrane with porous ceramic as a support to remove the lees from pasteurized soy sauce, the conventional method of standing still in a tank and diatomaceous earth filtration can be avoided. It can be omitted, and a product yield equivalent to or higher than that obtained when using a polymer membrane can be expected.

By filtering the pasteurized soy sauce immediately after pasteurization and by adjusting the pore size and operating pressure of the ceramic support membrane to appropriate values, it is possible to further improve the yield.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of the racking equipment, Fig. 2 is a process diagram of the method of the present invention, and Fig. 3 is a diagram showing the capacity reduction rate and membrane permeation flow of a dynamic membrane using porous ceramic as a support and a polymer membrane. A graph comparing the relationship between flux and viscosity, Figure 4 is a graph showing the relationship between filtration temperature of pasteurized soy sauce and membrane permeation flux, and Figure 5 is a graph comparing the relationship between flux and viscosity.
The figure is a graph showing the relationship between the pore diameter and operating pressure of the ceramic support membrane and the membrane permeation flux. Figure 6 is a graph showing the relationship between the membrane surface linear velocity and the membrane permeation flux. Figure 7 A and B are graphs showing the relationship between the membrane surface linear velocity and the membrane permeation flux. It is a figure which shows the process of a conventional method. In addition, in the drawing, 1 is the tank, 2 is pasteurized soy sauce, 4 is the pump,
5 and 6 are membrane modules. Patent applicant: Ministry of Agriculture, Forestry and Fisheries Food Research Institute Agent: Patent attorney Yo Shimoda - Ind.

Claims (3)

[Claims] (1) Raw soy sauce obtained by pressing moromi is heated to make pasteurized soy sauce, and this pasteurized soy sauce is filtered using a self-blocking dynamic membrane with porous ceramic as a support to separate soy sauce and lees. A method for straining pasteurized soy sauce, which is characterized by separating the soy sauce. (2) The method for straining the pasteurized soy sauce according to claim 1, wherein the filtration of the pasteurized soy sauce is carried out when the pasteurized soy sauce is in a high temperature state after pasteurization. (3) The method for straining pasteurized soy sauce according to claim 1, wherein the ceramic support has an average pore diameter of 1 μm or less, and the filtration pressure is 0.4 MPa (megapascal) or less.