JPH04183376A - Heat sterilizing method - Google Patents

Abstract

PURPOSE:To eliminate residence of solid article in a pipe and uniformly and sufficiently sterilize solid article by subjecting a material to be sterilized consisting of a solid article having 5-20mm diameter and liquid having a specific viscosity to heat sterilization while transferring through the pipe. CONSTITUTION:A material 1 to be sterilized consists of a solid article and liquid and the solid article is preferably food having 5-20 mm diameter. The liquid has >=2000cp viscosity. The material 1 to be sterilized is charged from a hopper 2 provided in a pipe 4 end part and continuously transferred through the pipe 4. It is necessary to successively provide a microwave heater 6 and holding part 7 in the circumference of a pipe 4, because the material to be sterilized is sufficiently subjected to heat sterilization. A preliminary heater 5 is preferably arranged before a microwave heater 6, because the solid article and liquid are uniformly subjected to heat sterilization. The microwave heater 6 sterilizes the material to be sterilized by irradiating microwave from outside of pipe and utilizing generation of heat of the material 1 itself.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to a method for sterilizing an object consisting of a mixture of solid and liquid by irradiating it with microwaves while continuously transporting the object through a pipe. .

(Prior Art) A method of sterilizing a liquid object by irradiating it with microwaves while continuously transporting it through a pipe is known.
Utility Model Publication No. 63-5513, JP-A-62-11756
It is described in Publication No. 1, Japanese Unexamined Patent Publication No. 111870/1983, and the like.

These methods transport the material to be sterilized through the pipe.
First, it is heated to a high temperature by irradiation with microwaves, then maintained at high temperature for the time required for sterilization in an insulated holding section, and finally cooled and removed.

In principle, this sterilization method is heat sterilization, and in order to obtain a sufficient sterilization effect, it is necessary to transfer the material through a pipe for 5 minutes or more.

(Problem to be Solved by the Invention) However, when the object to be sterilized contains solids in addition to liquids, there is a problem that the solids settle and stagnate while being transferred through the pipe for 5 minutes or more. there were.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a method for uniformly and sufficiently sterilizing objects to be sterilized, including both solids and liquids, by transporting them through a pipe without the solids remaining therein.

(Means for Solving the Problems) In order to solve this object, the present invention provides a method for sequentially disposing objects to be sterilized around a vibrator while continuously transporting objects to be sterilized consisting of solids and liquids having a diameter of 5 to 20 mm through a pipe. Provided is a heat sterilization method in which the liquid is sterilized by heat using a microwave heating device and a holding part in an adiabatic state, characterized in that the liquid is 2000 cp or more of clay.

(The object to be sterilized (1) according to the detailed description of the invention consists of a solid substance and a liquid.

The solid material is preferably a food product, and usually has a size of 5 to 20 mm. For example, diced meat, green peas, corn kernels, carolft, potatoes, etc. can be used.

Further, as the liquid, soups with various seasonings, white sauce, etc. can be used.

Such a liquid needs to have a viscosity of 2000 cp or more, preferably 5000 cp or more. 2000
This is because if the viscosity is lower than cp, solids may not be transferred and may remain in the pipe. Also 10m in diameter
Table 1 shows an experimental example of the sedimentation rate of green peas of 1.5 mm, cubed carlofts of 10 mm in diameter, and corn grains of 10 mm in diameter.

Table 1 As shown in Figure 1, the object to be sterilized (1) is introduced through the sieve (2) provided at the end of the pipe (4) and continuously passed through the vibrator [4] by the pump (3). can be transferred.

In order to sufficiently heat and sterilize the object to be sterilized (1), the pipe (4
), it is necessary to sequentially provide a microwave heating device (6) and a holding part (7). In addition, in order to uniformly heat and sterilize solids and liquids, it is desirable to arrange a preheating device (5) in front of the microwave heating device (6).

It is preferable that the preheating device (5) uses a heat exchange method. 20. In heating by a heat exchange method, liquids are more easily heated than solids and reach a higher temperature.

The microwave heating device (6) heats the preheated liquid and solid material to the temperature required for sterilization. The solids are heated to a lower temperature than the liquid by the pre-sterilizer (5), but because of the high heating efficiency of microwaves, the solids rise in temperature at a higher rate than the liquid, and the temperature of the holding part (7) increases. At the inlet, the solid and liquid reach approximately the same temperature.

The preheating device (5) may be configured by, for example, providing a large-diameter pipe around the pipe (4) and passing heated steam or hot water through it.
In terms of thermal efficiency, it is preferable that the heat medium such as heated steam or hot water be passed in the opposite direction to the direction of transfer of the object to be sterilized, that is, from the microwave sterilizer (6) side toward the entrance of the pipe.

Such a heat medium depends on the type of the object to be sterilized (1), but
The temperature of ~100°C is preferable, and the heat exchange time is 160°C.
A good guideline is 200 seconds.

The microwave heating device (6) sterilizes the object (1) by irradiating it with microwaves from outside the pipe and utilizing the heat generated by the object (1) itself. Temperature of liquid or viscous substance is 120~
It is sufficient to irradiate at a temperature of 140°C. However, even if the temperature of the solid material is taken as a standard, both of them reach approximately the same temperature. Generally, it is sufficient to irradiate microwaves of 2.45 Hz with an output of 1.3 Kw for 30 to 90 seconds.

The holding part (7) holds the object to be sterilized (1) which has reached a high temperature.
) is maintained at high temperature for the time required for sterilization.

The pipe (4) may be provided by being covered with a heat insulating material. A holding time of 10 to 120 seconds is sufficient.

As shown in FIG. 1, it is desirable that the object to be sterilized (1) heated and sterilized in the holding section (7) is taken out after passing through the cooling section (8). This is to prevent liquid or viscous material heated to 120° C. or higher from being suddenly discharged to normal pressure and expanding. Cooling usually requires 100 to 300 seconds.

(Example) Using various solids and the apparatus shown in FIG. 1, the retention loss rate of the solids was measured according to the viscosity of the liquid.

The time it took to transfer through the pipe was approximately 8 minutes (180 seconds of preheating, 60 seconds of microwave heating, 60 seconds of holding, and 180 seconds of cooling), and the liquid and solids were uniformly and sufficiently sterilized in all cases.

Solid material Example 1 Cone example 2 with a diameter of approximately 10 mm
Green peas with a diameter of about 10 m, Example 3 of m green peas Example 4 of 10 mm square carrots Example 5 of 15 mm square cut beef cubes The results of retention loss rate of 10 mm square beef cubes are shown in FIG. In addition, the retention loss rate is a value expressed as (weight of solids input - weight of solids discharged) / (weight of solids input), and the results for both solids are within the range shown by NWA. Included.

(Effects) As described above, according to the present invention, it is possible to uniformly heat and sterilize a mixture of solids and liquid by transferring it through a pipe without sedimentation of the solids.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing the apparatus according to the present invention, and FIG. 2 is a graph showing the retention loss rate in the example. (1) -1--Object to be sterilized (2) -Hopper (
3) --- Pump (4) --- Pipe (5) --- One-piece heating device (6,) --- Microwave heating device

Claims (1)

[Claims] (1) Heating to sterilize objects consisting of solids and liquids with a diameter of 5 to 20 mm while continuously transferring them through the pipe using a microwave heating device and an adiabatic holding section installed around the pipe. A heat sterilization method characterized in that the liquid has a viscosity of 2000 cp or more.