JPS6322785B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing canned youth, and more particularly to a method for producing canned youth containing natural fruit juice that is prevented from browning. Natural fruit juices such as mandarin oranges, peaches, and apples (in the case of mandarin oranges, including canard, herein referred to as natural fruit juices) alone or mainly composed of natural fruit juice and water are conventionally produced at a temperature of approximately 80 to 95°C. After being heated and sterilized, the can is filled at the above temperature into a metal can made of painted tin, stain-free steel, or aluminum (alloy), leaving a head space, and the lid is immediately double-sealed to seal it. It had been.
Juice canned goods produced in this way by the usual method tend to brown over time, which is presumed to be due to the oxygen in the air remaining in the head space, especially when the concentration of natural fruit juice is high. It has been difficult to obtain canned youth products that are easy to use and have commercial value. The present invention has been made in view of the above-mentioned prior art, and an object of the present invention is to provide a method for producing canned youth containing natural fruit juice that is prevented from browning. In order to achieve the above object, the present invention has been developed by filling a metal can with juice heated to about 80 to 95°C containing 15% by weight or more of natural fruit juice, leaving a head space, and then immediately attaching the lid to the metal can. The headspace is locked with a slight gap at the top, and an inert gas is immediately blown into the headspace through the gap until the amount of residual oxygen in the headspace becomes substantially zero. After replacing the air with the inert gas and placing the lid on the metal can while continuing the blowing, immediately double-seal the lid to the metal can to seal the metal can. The present invention provides a method for producing canned youth products characterized by the following. The present invention will be explained below with reference to the drawings. The juice in the present invention is natural fruit juice from 15 to
100% by weight, preferably the rest consists of water, but if necessary, small amounts of additives such as acids,
There is no problem even if sugars, vitamins, coloring agents, etc. are added. The lower limit was set at 15% because of the first
This is because, as shown in the table, when the concentration of natural fruit juice is lower than 15%, even conventional methods do not cause browning to the extent that it becomes a commercial problem. The above-mentioned juice 1 (see Figure 2) is heated for a predetermined period of time at approximately 80 to 95°C (the optimum heating temperature varies depending on the pH of the juice, etc.) for sterilization, and then placed in a metal can 2 at the same temperature in a head space. All but part 3 is filled. The reason why the head space 3 is left is to prevent the juice from spilling out of the can during the filling process and the processing and transportation process until the lid is sealed by double seaming after filling. The height of 3 varies depending on the type of can, but is usually 8 to 12 mm.
That's about it. In the present invention, the air in the head space section 3 is replaced with an inert gas (for example, nitrogen gas, argon gas, etc. Nitrogen gas is particularly preferred from the viewpoint of economical efficiency and purity of gas that can be used commercially). It is important to reduce the residual oxygen in the head space 3 to substantially zero immediately after sealing. Vacuum sealing and steam replacement methods can be considered as methods to reduce residual oxygen in the head space, but in the former case, if the degree of vacuum is lowered, it is inevitable that some oxygen will remain, and therefore browning may occur. If high vacuum is applied in an attempt to completely remove oxygen, the body wall of the metal can is likely to dent, which creates an economical problem in that a relatively thick metal plate must be used. In the latter case, to prevent browning, replacing the can with sufficient air will increase the degree of vacuum inside the can (e.g. 50 to 60
cmHg) causes the same problem as the former. In the case of inert gas replacement, the above-mentioned problem of dented cans due to vacuuming inside the can does not occur. Replacement with inert gas can be performed, for example, in Figures 1 and 2.
This is done by the apparatus shown in the figure. Reference numeral 4 denotes a rotary transfer plate, which includes an upper disk 5 having a plurality (six in the figure) of pocket portions 5a each having a semicircular cross section;
It comprises a lower disk 7 in which a plurality (six in the figure) of liftable supports 6 are fitted. The rotary transfer plate 4 is configured to rotate intermittently in the direction of the arrow at predetermined timings by a drive mechanism (not shown), that is, to stop when the pocket portion 5a reaches the position shown in FIG. In Figure 1, A
is the charging station (where inert gas is also blown), B is the inert gas blowing station, and C is the inert gas blowing station.
is a tightening station, and D is a delivery station. A large number of inert gas blowing holes 8 are opened in the upper part of the pocket part 5a of the upper disk 5, extending almost parallel to the line connecting the center of the rotary transfer plate 4 and the center of the pocket part 5a, over almost the entire circumferential direction. are doing. The opening 8a has a substantially rectangular shape that is elongated in the height direction. A lid part 9 is provided at the top of the pocket part 5a.
The opening section 8a extends from the lower end of the mounting section 10 to slightly below the flange section 2a of the metal can 2, and air is blown into the inert gas from below the flange section 2a. It is designed to prevent you from getting caught in the accident. The blowing hole 8 is connected to a groove portion 11 that is spaced apart from each other for each pocket portion 5a. Outer circumference line 11a and inner circumference line 1 of each groove 11
1b are located on a common concentric circle. The upper part of the groove 11 corresponding to the feeding station A, the inert gas blowing station B, and the seaming station C is closed by a fixed shoe 12 having a flat lower surface, and the fixed shoe 12 is attached to a spring (not shown). Therefore, it is pressed against the upper surface of the periphery of the groove portion 11 to maintain sliding airtightness. Portions of the stationary shoe 12 corresponding to the downstream ends of the groove portions 11 at positions corresponding to the charging station A and the inert gas blowing station B (that is, the groove portions in a stopped state at each of the stations) are inert gas conduits, respectively. 13a and 13b, and the conduits 13a and 13b are connected to an inert gas supply source (for example, a nitrogen gas cylinder) not shown. A cam roller 14 is provided at the central lower end of the support 6, and the cam groove 15 becomes higher in the direction from the inert gas blowing station B to the seaming station C. Therefore, the metal can 2 is placed at the seaming station C. It rises as it approaches the seaming station C.
The flange portion 2a and the lid portion 9 are configured to come into contact with each other immediately before the groove portion 11 facing the metal can 2 in front of the metal can ends passing through the opening of the conduit 13b. Further, a flange portion 16 is provided at the lower part of the support body 6, and the lower surface of the flange portion 16 is pushed up by a plunger (not shown) at the seaming station C and placed on the metal can 2. The support body 6 is configured to rise to a position where the lid portion 9 faces a seaming roll of a seaming device (not shown). In the above apparatus, inert gas replacement and sealing are performed as follows. The metal can 2 filled with the juice 1 at about 80 to 95° C. leaving the head space 3 by a filling device (not shown) is immediately transferred to the pocket 5a stopped at the charging station A without cooling down below the above temperature. Transported and loaded. At the same time, the lid part 9 is also placed on the placing part 10 above the pocket part 5a by a transport mechanism (not shown). Furthermore, at the same time when the rotary transfer plate 4 almost stops after rotating in the direction of the arrow, the conduit 13a and the groove 11 located in the charging station A are connected (the conduit 13 is constantly supplied with inert gas). A substantially parallel flow of inert gas is blown through the holes 8 from the inside outward through the gap between the charged metal can 2 and the lid 9, covering the entire head space; At the same time, air and steam in the head space 3 are expelled. Furthermore, when the lid part 9 is placed above the metal can 2, inert gas is blown into the gap between the two, so that steam evaporated from the high-temperature juice 1 is absorbed into the curled part 9a of the lid part 9. There is no risk of water droplets condensing on the lower surface and impairing the sealing performance after double seaming. Next, the rotary transfer plate 4 rotates and the metal can 2 is transported to the inert gas blowing station B, while it is stopped at the station B, and also while it is transported to the seaming station C. The blowing will continue. When the metal can 2 approaches the seaming station C, the metal can 2 is raised by the cam action.
Then, just before reaching the seaming station C, the lid part 9 is placed on the flange part 2a of the metal can 2, and at the same time, the injection of inert gas into the metal can 2 ends (the injection ends). Since the lid portion 9 is also placed on the cover 9, there is virtually no air intrusion during the short period of time until the seaming is completed. At the same time as it stops at the seaming station C, the metal can 2 and the lid 9 placed thereon are moved together by a plunger (not shown).
It rises due to the action of , double seams are performed and sealed. Next, as the rotary transfer plate 4 rotates, the sample is transferred from the delivery station D to the next cooling device.
During the above-mentioned transportation, it is desirable to invert the sealed can in order to ensure the sterilization of bacteria on the lid 9 and in the inert gas blown into it. The gap between the metal can 2 and the lid 9 before being conveyed to the inert gas blowing station B and when it is stopped at the inert gas blowing station B is usually preferably about 6 to 15 mm. If it is narrower than about 6 mm, the inert gas will not be able to sufficiently spread into the head space 3, while if it is wider than about 15 mm, air from outside will easily enter, and in either case, it will not be possible to completely replace it with air. This is because it becomes difficult to do so. When using nitrogen as an inert gas, the purity of commercially available nitrogen gas is extremely high.
For example, it is 99.999%, so if the replacement is complete, the amount of residual oxygen in the head space 3 can be reduced to substantially zero. When the inert gas blowing pressure (gauge pressure) is about 0.2 to 0.5 Kg/cm ² and the blowing time is 0.05 seconds or more, it is usually possible to perform the substitution to reduce the above oxygen amount to substantially zero. Therefore, high-speed filling and therefore high-speed production of 1200 pieces per minute is possible. The method for manufacturing canned youth of the present invention is that after filling the can with browning-prone canned youth containing 15% by weight or more of natural fruit juice, air is removed from the head space until the amount of residual oxygen in the head space becomes substantially 0.
Since the canned food is replaced with an inert gas and immediately sealed, the amount of oxygen remaining in the head space of the can is virtually zero, and the browning phenomenon that is assumed to be caused by the oxygen remaining in the head space occurs. It has the effect of not being used. Further, the present invention provides a method for filling the metal can with the youth sterilized by heating it to about 80 to 95°C, and then immediately passing it through the gap between the lid and the metal can without cooling it below the above temperature. The active gas is blown into the head space (therefore, the inert gas replacement efficiency is high), the air in the head space is also replaced with inert gas, and the product is immediately double-sealed to make the process easier. It is simple, has a high complete replacement rate of inert gas, has excellent productivity, and has the advantage of being able to produce as high as 1,200 cans per minute. In addition, since the head space after sealing is at almost normal pressure (although the pressure is slightly reduced by cooling the product from about 80 to 95°C, i.e., it becomes slightly negative pressure), vacuum filling method or steam displacement filling method can be used. The risk of causing a concave can is relatively small (approximately 0.13
~0.18mm) Even if a body metal plate is used, it has the effect of being small. A specific example will be explained below. Specific example: Tin-plated steel plate with internal diameter of 52 mm, height of 133 mm, wall thickness of 0.15 mm, and internal volume of 265 c.c. (inner surface tin plating amount: 11.2 mm)
g/m ² ) and two types of internally coated cans (3-piece cans) made of stain-free steel (chromic acid electrolytically treated steel plate), which were heated and sterilized at 90°C with various concentrations of natural orange juice. The head space was filled leaving a height of 12 mm. Immediately after performing nitrogen gas replacement and water vapor replacement using the equipment shown in Figures 1 and 2, and without performing replacement as in the conventional method, the aluminum alloy lid (with internal coating) was used. Sealing was performed using the double seaming method. These canned goods were stored at room temperature, and the degree of browning was evaluated by visual observation over time. The evaluation was done with n=5 for each lot, and the evaluation points were 5 points for particularly noticeable browning, 4 points for very noticeable browning, 3 points for somewhat noticeable browning, and 2 points for slightly browning.
take the average value, taking one normal point,
A value of 2 or more was judged to be defective. The results are shown in Table 1. As is clear from Table 1, in the case of nitrogen substitution, browning is less likely to occur, especially when the concentration of natural fruit juice is 15% or more, compared to the cases of steam substitution and no substitution. In the case of steam displacement, most of the test cans had dents in their bodies, reducing their commercial value. In both cases, browning is less likely to occur in tin-plated steel cans than in tin-free steel cans, but this is presumed to be due to oxygen being consumed by eluted tin in the former case.
Therefore, it can be seen that the present invention is particularly effective when applied to stain-free steel cans.

【table】

【table】 [Brief explanation of the drawing]

FIG. 1 is a plan view of an example of an apparatus used to carry out the present invention, and FIG. 2 is a longitudinal sectional view taken along the line -- in FIG. 1...Juse, 2...Metal can, 3...Head space section, 9...Lid section.

Claims (1)

[Claims] 1. After filling a metal can with juice heated to approximately 80-95°C containing 15% or more of natural fruit juice, leaving a head space, immediately place the lid on top of the metal can with a slight gap. stopping and immediately blowing an inert gas into the headspace through the gap,
After replacing the air in the head space with the inert gas until the amount of residual oxygen in the head space becomes substantially 0, and placing the lid on the metal can while continuing the blowing, A method for producing a canned youth product, which comprises immediately double-sealing the lid to the metal can to seal the metal can.