JP3056930B2 - Retort sterilization method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for retort sterilizing packaged foods (packages to be sterilized) such as canned foods, retort pouched foods, and plastic molded container-packed foods. It relates to a combined retort sterilization method.

[0002]

2. Description of the Related Art In general, steam sterilization and hot water sterilization are known as methods for retort sterilizing packaged foods such as canned foods, retort pouched foods, and foods packed in plastic molded containers. However, these sterilization methods (1) tend to cause poor degassing or flow stagnation (non-uniform flow) around the material to be sterilized in the retort, so that the temperature during sterilization varies, resulting in quality deterioration. And (2) equipment costs are high. Therefore, recently, a so-called shower-type sterilization method which has no problem and has a simple structure is used.

[0003]

However, in the conventional shower-type sterilization method, the running cost at the time of heat sterilization increases. The present invention solves the above problems by reducing uneven heating due to poor degassing at the time of temperature rise up to the sterilization set temperature, reducing contact unevenness of the heat medium, and reducing running costs during sterilization. It is an object of the present invention to provide a retort sterilization method that can be performed.

[0004]

According to the present invention, there is provided a method for retort sterilizing a package to be sterilized in a retort main body, wherein the temperature in the retort main body reaches a set sterilization temperature. Until then, hot water is showered down from above to heat the package to be sterilized, and after achieving the sterilization set temperature, steam is jetted to sterilize the package to be sterilized.

[0005]

Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 1, a shower-type retort sterilizer A for carrying out the present invention has a substantially cylindrical retort body 1 (having a pot radius of 1 m) extending in a horizontal direction and an upper part of an inner wall of the retort body 1. A hot water introduction unit 2 that is attached and introduces hot water as a heating medium and a multi-stage detachably laminated substantially middle portion in the retort main body 1 are subjected to sterilization of canned food, retort pouch food, plastic molded foodstuffs, and the like. A tray 3 for accommodating a package (not shown); shower forming means 4 for showering hot water introduced from the hot water introduction unit 2 onto the package to be sterilized; and steam to the package to be sterilized. The steam blow-off pipes 20, 21 and 22 are provided for ejecting water. The hot water introduction part 2 is a tube extending substantially in the horizontal direction, and has a large number of holes uniformly formed on the lower surface. The hot water introduction part 2 is connected to a hot water supply pipe 5 outside the retort main body 1 at an upper central portion thereof. Shower forming means 4
Is composed of a first water pressure adjustment shelf 6 and a second water pressure adjustment shelf 7 both made of stainless steel and having a large number of holes, and is disposed between the hot water introduction section 2 and the tray 3.

[0006] The steam blow-out pipe 20 has a blow-out nozzle (not shown) for blowing out steam from below to above.
Each of the nozzles 1 and 22 has a jet nozzle (not shown) for jetting steam from both sides to the center. Steam outlet pipes 20, 21, 22
Are connected to the steam supply pipe 23, respectively. 24 is a steam supply valve. A water supply section 8 a is provided in a lower portion of the retort main body 1, and water is supplied to the water supply section 8 a via a water supply pipe 8. The water supply pipe 8 and the hot water supply pipe 5 are connected via a directional control valve (not shown), and water supplied to the water supply unit 8a by switching the directional control valve is supplied to the hot water supply pipe 5 by a pump (not shown). And heated by a heating device to hot water of a predetermined temperature. Retort body 1
A pressurizing pipe 13 is connected to the upper part of the
a and the air compressor 14b pressurizes the inside of the retort main body 1. Next, the operation of the embodiment of the present invention will be described. First, water is supplied from a water supply device to a water supply section 8a in the retort main body 1 through a water supply pipe 8 at a water level of 20%.
Supply water up to about cm. Next, the supplied water is pumped by a pump, and the water is heated to a predetermined sterilization set temperature (about 120 ° C.) by a heating device. The heated hot water is introduced into the hot water introduction unit 2 through the hot water supply pipe 5,
It passes through the first hydraulic pressure adjustment shelf 6 and the second hydraulic pressure adjustment shelf 7 from the hole of the hot water introduction unit 2. The hot water that has fallen from the hole of the second hydraulic pressure adjustment shelf 7 is
The product to be sterilized is stored in the tray 3 in a shower. Precipitation by hot water is about 360 l / min.

[0007] The hot water that has precipitated on the package to be sterilized returns to the water supply section 8a in the retort main body 1, and then is again supplied to the water supply pipe 8,
Circulated through the hot water supply pipe 5. In the shower heating step , the temperature inside the retort main body 1 is set at a sterilization set temperature (about 120 ° C.).
C.) (10 minutes). After the sterilization set temperature is reached, the shower-type heating is stopped, and instead the steam supply pipe 24 is opened, and steam is ejected from the steam blow-out pipes 20, 21, 22 via the steam supply pipe 23. Sterilize the package to be sterilized (15 minutes). After the above steps, the sterilization step is completed. FIG. 3 shows that a retort pouch can be prepared according to the present invention by combining shower type sterilization and steam type sterilization.
It is a graph which shows the temperature change in the front end part in a 21st stage tray, and the front end part in a 2nd stage tray at the time of storing in a tray of a stage, and sterilizing. On the other hand, FIG.
Shows the temperature change at the front end of the 21st tray and at the front end of the 2nd tray when the retort pouch is stored in a 22-stage tray and sterilized using only the conventional steam sterilizer. It is a graph shown with time.

As is clear from the comparison between the graphs of FIGS. 3 and 4, according to the present invention, when the temperature inside the retort main body 1 rises to the sterilization set temperature, shower-type heating is performed. , Compared to the case where only steam sterilization is performed,
The temperature difference between the stages is small, and more uniform and stable heating can be performed. Further, after the temperature in the retort main body 1 reaches the sterilization set temperature, steam-type sterilization is performed, so that steam consumption during sterilization can be reduced by 50% as compared with the case where only shower-type sterilization is performed, The running cost can be reduced accordingly. While the preferred embodiment of the present invention has been described above, various changes may be made to the embodiment disclosed within the scope of the technical matters described in the claims without departing from the scope or spirit of the invention. Obviously you can do that. Therefore, sterilization setting temperature, sterilization time, etc.
It should be appropriately changed depending on various conditions such as the type and amount of the package to be sterilized.

[0009]

According to the present invention, when the temperature in the retort main body rises to the sterilization set temperature, the shower type is used.
Since heating is performed, the temperature difference between the stages is smaller than in the case where only steam-type sterilization is performed, and more uniform and stable heating can be performed. In addition, after the temperature in the retort body reaches the sterilization set temperature, steam-type sterilization is performed, so that the steam consumption at the time of sterilization can be reduced by 50% compared to the case where only shower-type sterilization is performed. The running cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a front sectional view schematically showing an apparatus for practicing the present invention.

FIG. 2 is a side sectional view schematically showing an apparatus for practicing the present invention.

FIG. 3 is a graph showing, with time, the temperature change at the front end of the 21st tray and at the front end of the second tray when the retort pouch is stored in a 22-stage tray and sterilized according to the present invention. It is.

FIG. 4 is a graph showing changes in temperature at the front end of the 21st tray and at the front end of the second tray when the retort pouch is stored in a 22-stage tray and sterilized by a conventional steam sterilizer. It is a graph shown typically.

[Explanation of symbols]

 A ... retort sterilizer 1 ... retort main body 2 ... hot water introduction part 3 ... tray 4 ... shower forming means 5 ... hot water supply pipe 6 ... first water pressure adjustment shelf 7 ... second water pressure adjustment shelf 8 ... water supply pipe 20, 21 , 22 ... Steam supply pipe 23 ... Steam supply pipe 24 ... Steam supply valve

Continuation of the front page (56) References JP-A-61-260863 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) A23L 3/00-3/24

Claims (1)

(57) [Claims] 1. A method for retort sterilizing a package to be sterilized in a retort main body, wherein hot water is dropped from above in a shower form from the top until the temperature in the retort main body reaches a set sterilization temperature. A method of sterilizing a retort, comprising heating an object to reach a sterilization set temperature, and then ejecting steam to sterilize the package to be sterilized.