JP4766270B2 - Method for preventing the occurrence of filmy aggregates in beverages containing milk components in plastic containers - Google Patents

Description

  The present invention relates to a method for preventing the formation of film-like aggregates in a beverage containing a plastic container milk component such as a coffee beverage containing plastic container milk. In particular, it is an object to prevent the formation of film-like aggregates that are generated when the beverage is sterilized by retort, and to efficiently produce a plastic container-packed milk component-containing beverage.

  In general, when milk component-containing beverages such as coffee beverages containing milk are heated and heated, milk fat content is separated, and film-like aggregates are generated on the surface due to protein aggregation due to changes in the emulsified state of milk components. It has been known. In order to prevent the occurrence of this film-like aggregate, the occurrence of the film-like aggregate is usually prevented by heating and heating while stirring the milk component-containing beverage.

  On the other hand, in recent years, the demand for plastic container-packed beverages such as cup shapes has increased due to lighter containers, better portability, and better storage of contents. There are many products on the market filled with ingredient-containing beverages in plastic containers.

In order to distribute plastic containers and beverages containing milk components such as coffee beverages containing plastic containers and milk at room temperature distribution and heating, perform retort sterilization to sterilize heat-resistant bacteria in the beverages. is required. However, in retort sterilization, by heating the contents containing milk components, (1) separation of milk fat, (2) protein aggregation accompanying changes in the emulsified state of milk components, and (3) the headspace surface of the container In some cases, a change in appearance or the generation of a foreign substance is observed, such as the formation of a yuba-like film-like agglomerate formed in the part. As a result, not only the appearance of the contents is poor, but also when the beverage is drunk, the throat is bad and the commercial value is lowered, and in some cases, it becomes a fatal defect.

  In order to prevent the occurrence of such defects, contrivances have been made to prevent protein aggregation due to separation of milk fat after sterilization and emulsification stability by changing the prescription of contents and processing conditions during preparation. On the other hand, regarding the prevention of the formation of film-like aggregates, there is no significant effect by changing the prescription or changing the conditions during preparation, and it is necessary to forcibly stir the contents during sterilization. As a method of stirring the contents, a hot water rotary sterilization method may be used. For example, Patent Document 1 discloses a method for producing canned products of sauces containing fats and oils and milk components. In order to prevent separation, partial denaturation and aggregation of milk proteins, a method is disclosed in which canned sauces are sterilized by heating while rotating until the product temperature reaches 110 to 115 ° C., and then statically sterilized by heating. .

  However, the invention of Patent Document 1 is an invention relating to a retort sterilization method for a product in which contents are packed in a relatively rigid metal can, and the hot water rotary sterilization method is applied to a beverage containing a plastic container filled milk component. Acceleration due to rotation is excessively applied to a plastic container that is less rigid than a metal can, resulting in deformation of the container, which may impair the commercial value of the product. In this case, the normal sterilization shelf provided in the existing retort sterilizer cannot be used to prevent the container from colliding or falling due to rotation, and each container is fixed so that it does not move. For example, in the case of a plastic cup container, a special sterilization shelf for fixing the cup by receiving it at the flange portion is required. If this special sterilization shelf is used, a special sterilization shelf must be prepared for each container shape and size, which is expensive, so the running cost of the apparatus may increase, and it is not generally used. In addition, when placing on the sterilization shelf, the interval between the containers must be large, so the number of cups accommodated in the retort sterilizer is reduced to about 2/3 compared to the stationary sterilization, and the production efficiency is significantly reduced. It will be.

  On the other hand, Patent Documents 2 and 3 previously filed by the applicant of the present application are a multi-stage sterilization shelf in which a flexible package such as a bag-like container is retort sterilized with efficient heat transfer without causing container deformation. Discloses a retort sterilizer in which a flexible package is laid down and a sterilization shelf is slid horizontally.

Such a sliding retort sterilizer is less likely to be deformed because the flexible package is slid only in the horizontal direction compared to a rotary retort sterilizer, and the sterilization shelf does not require a special sterilization shelf and is expensive. However, the contents of the invention disclosed in Patent Documents 2 and 3 are based on the subject of laying a flexible package filled with the contents on a sterilization shelf for retort sterilization. For example, there is no disclosure of heat retort sterilization of containers having relatively low rigidity, such as plastic cup containers and plastic bottles, and in particular in such containers the contents are agitated by stirring or the like. There is no suggestion of preventing the generation of things. For this reason, there was room for improvement in these respects.
JP-A-8-294376 Japanese Patent Publication No.58-2666 Japanese Patent Application No. 2006-190138

  The present invention has been considered in view of the above-mentioned problems in the production of plastic container-packed milk component-containing beverages, and can be used with existing retort sterilizers. Without deteriorating the appearance characteristics of the product such as container deformation, it is possible to prevent separation of milk fat and aggregation of proteins accompanying changes in the emulsified state of milk components, and to form on the headspace surface of the container An object of the present invention is to provide a method for preventing the formation of film-like aggregates for producing a beverage containing a milk component containing plastic containers with high production efficiency, which can effectively prevent the formation of yuba-like film-like aggregates. is there.

  In order to achieve the above-mentioned object, the present inventors have conducted intensive research and experiments. As a result, beverages containing milk components in plastic containers are loaded on an existing sterilization shelf of a steam or hot water shower type retort sterilizer and sterilized. When the sterilization shelf is slid back and forth or left and right particularly preferably with a sliding acceleration within a limited range, surprisingly, separation of milk fat and aggregation of milk component proteins can be prevented. In addition, it was discovered that the formation of film-like aggregates formed on the surface portion of the head space of the container can be effectively prevented, and the present invention has been achieved.

  That is, the method for preventing the occurrence of film-like aggregates in the plastic container-packed milk component-containing beverage of the present invention that achieves the object of the present invention described above is performed when the plastic container-packed milk component-containing beverage is sterilized with a retort sterilizer. The plastic container filled with the dairy ingredient-containing beverage is slid in the horizontal direction, and particularly preferably, the sterilization shelf loaded with the dairy ingredient-containing beverage is slid back and forth or left and right. is there.

  In a preferred embodiment of the present invention, the sliding acceleration of the sterilization shelf is 0.2G to 25G.

  In another preferred embodiment of the present invention, the sterilization shelf slides at a frequency of 5 times / minute to 90 times / minute.

  According to the present invention, a special sterilization shelf is not required as in the conventional rotary sterilization method, and since an existing sterilization shelf can be used, without reducing the number of containers accommodated in the retort sterilizer, Therefore, the production efficiency is not lowered and the running cost is not increased. The retort equipment can be remodeled into a sliding retort sterilizer only by partially remodeling the existing retort sterilizer, and can be applied to most existing steam and hot water shower retorts.

  According to a preferred embodiment of the present invention, the separation of milk fat and milk protein and the formation of film-like aggregates are prevented while the deformation of the plastic container is prevented by limiting the sliding acceleration of the sterilization shelf to 0.2 G to 25 G. Can be completely prevented.

  According to another preferred embodiment of the present invention, the milk fat / milk protein is similarly prevented from deformation of the plastic container by limiting the number of sliding times of the sterilization shelf to 5 times / minute to 90 times / minute. Separation and formation of membrane aggregates can be completely prevented.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
The present invention is applied to the production of a plastic container-packed milk component-containing beverage. The milk component-containing beverage is preferably applied to beverages such as coffee with milk, tea with milk, milk, soup and the like having a viscosity of 1 to 100 mPa · s.

  Examples of the plastic container include molded containers such as cups and bottles made of a simple substance or a laminate of a synthetic resin such as polypropylene, PET, and nylon. As the laminated material, a material including EVOH or an oxygen absorbing layer as an intermediate layer is preferable from the viewpoint of storage stability of the contents.

  When sterilizing with a retort sterilizer, the contents surface is forcibly agitated by sliding the sterilization shelf loaded with beverages containing milk-packed ingredients horizontally, back and forth or left and right until the drainage process. It is possible to prevent the formation of a film-like aggregate.

  Although the sliding conditions of the sterilization shelf vary depending on the beverage contents, the number of sliding is set in the range of 5 times / minute to 90 times / minute. If the number of sliding times is less than 5 times / minute, the stationary state of the contents becomes long, and fat / milk protein separation and film-like aggregates are likely to occur, and the number of sliding times is more than 90 times / minute. If it is too much, the movement of the container becomes intense, and the container may be deformed or toppled. A more preferable range is 10 times / minute to 90 times / minute.

  About the acceleration at the time of sliding, it sets to the acceleration of 0.2G-25G. When the acceleration is lower than 0.2G, the contents are not sufficiently stirred, and fat / milk protein separation and film-like aggregates are likely to be formed. When the acceleration exceeds 25G, the movement of the container due to sliding changes. The size of the container may increase, causing the container to fall over in the sterilizer or to collide with the container, causing deformation of the container. A more preferable acceleration range is 0.4G to 25G, and a most preferable acceleration range is 1G to 25G.

1 and 2 are cross-sectional views showing an example of an apparatus for carrying out the method of the present invention.
FIG. 1 shows a sterilization shelf sliding mechanism by an air cylinder system.
In FIG. 1, A1 is a retort main body, and A2 is a support base such as a rail. A movable table A4 is mounted on the support table A2 via a wheel A3, and a sterilization shelf (tray) A5 in which a large number of container-packed milk component-containing beverages are arranged and stored is loaded in multiple stages on the movable table A4. .

  A6 is an air cylinder, and A7 is a fixed base for fixing the air cylinder A6. The other end of the air cylinder A6 is connected to a drive shaft A8 protruding from the movable base A4 via a seal mechanism A9 of the retort body A1. .

  If the air cylinder A7 is driven at the time of driving, the movable table A4 will reciprocate back and forth, and the packaged beverage accommodated in the movable table A4 slides back and forth to stir the filling.

  FIG. 2 shows a sterilization shelf sliding mechanism using a crank system. 2, the same components as those in FIG. 1 are denoted by the same reference numerals as those in FIG.

  2, A10 is a motor, and A11 is a crank mechanism driven by the motor A10. When the motor A10 is driven during driving, the movable base A4 reciprocates back and forth by the crank mechanism A11. The filled beverage slides back and forth and the filling is stirred.

  As a beverage containing a plastic container milk component (A) coffee containing milk and (B) milk, the sliding conditions of the sterilization shelf are changed in various ways to separate milk fat content, milk protein agglomeration and film-like agglomerates. The prevention effect was investigated.

1. Test conditions As a plastic container, a plastic cup having a material structure PP, adhesive layer, EVOH, adhesive layer, oxygen absorbing layer, PP, a side wall thickness of about 0.4 mm, an outer diameter of 75 mm, a height of 80 mm, and a full capacity of 215 ml is used. used. A material having a total thickness of 0.08 mm in a multilayer film configuration made of PET, nylon, aluminum, and PP was used as a lid.

  As the coffee with milk, a coffee extract, milk, sugar, and a pH adjuster (bicarbonate) were blended, homogenized and emulsified. UHT pasteurized milk was used as the milk.

The filling / sealing conditions and retort sterilization conditions for each beverage are as follows.
(1) Filling and sealing conditions Filling amount 180g
Filling temperature around 50 ° C Deoxygenation condition Nitrogen gas · 10 NL / min Sealing condition 190 ° C, 1.5 seconds, 0.4 MPa
(2) Retort sterilization conditions Heat medium Hot water shower Sterilization conditions Sterilization temperature 121 ° C 35 minutes (CUT
15 minutes, CDT 15 minutes) (F ₀ value 30 under these conditions)

  Sliding was performed by intermittently driving the sterilization shelf of the retort sterilizer with an air cylinder or a crank.

The evaluation items are as follows.
(1) Changes in appearance of actual contents Presence or absence of separation of milk fat content
Presence or absence of milk protein separation
Presence or absence of formation of film-like aggregates (2) Deformation of container Depression of cup flange and trunk

2. Test results (1) Influence of the number of sliding times Tables 1 and 2 show the appearance evaluation results of the contents after sterilization when the number of sliding times is changed and retort sterilization is performed.

  From Tables 1 and 2, film-like aggregates were produced when sterilized by standing, but no film-like aggregates were observed when sterilized while sliding. Further, in any sliding sterilization test, container deformation such as dents did not occur.

(2) Effect of Stroke Table 3 and Table 4 show the appearance evaluation results of the contents after sterilization when retort sterilization is performed by changing the stroke.

  From Tables 3 and 4, it can be seen that changing the sliding stroke does not affect the appearance of the contents and the deformation of the container.

(3) Influence of acceleration 3-1. Air Cylinder System Tables 5 and 6 show the appearance evaluation results of the contents after sterilization when retort sterilization is performed by changing the sliding acceleration in the air cylinder system.

  Regarding the change in the acceleration of sliding with the air cylinder method, if the acceleration was too low, the contents could not be forcibly stirred, so separation of milk fat and milk protein and formation of filmy aggregates were observed. On the other hand, increasing the acceleration almost eliminated these phenomena and showed good quality characteristics of the contents. However, when the acceleration was too high, container deformation was observed during sterilization due to intense movement of the container. It can be seen from Tables 5 and 6 that the optimum acceleration range is 1G to 25G.

3-2. Crank system Table 7 shows a conversion table of sliding conditions and acceleration in the crank system. In the case of the crank system, the acceleration is determined by changing the number of sliding times and the stroke.

  Tables 8 and 9 show the appearance evaluation results of the contents after sterilization when retort sterilization is performed by changing the sliding acceleration in the Table 7 crank system, and Table 10 shows the results of the degree of container deformation.

From Tables 8 and 9, the effect of preventing the formation of film-like agglomerates similar to the air cylinder method was recognized also in the crank method. It can be seen that the appropriate acceleration is about 0.2 or more. Further, since the acceleration of this method is lower than that of the air cylinder method, it can be seen that the container does not deform under any sliding condition as shown in Table 10.

(4) Influence on pH and color tone of contents by sliding sterilization Tables 11 and 12 show the pH and color tone of contents by sliding sterilization.

  From Tables 11 and 12, no change in pH and color tone due to the difference in the number of sliding was observed for any of the contents.

It is sectional drawing which shows an example of the apparatus for enforcing the method of this invention. It is sectional drawing which shows the other example of the apparatus for enforcing the method of this invention.

Explanation of symbols

A1 Retort body A2 Support base A3 Wheel A4 Movable base A5 Sterilization shelf A6 Air cylinder A7 Fixed base A8 Drive shaft A9 Seal mechanism A10 Motor A11 Crank mechanism

Claims (2)

Sterilizing shelves loaded with the plastic container filled with dairy ingredients containing beverage when sterilizing plastic containers Tsumechichi component containing beverage made of synthetic resin cup retort sterilizer horizontally slid in the crank system, the acceleration less than 0.2 G 1G sliding, the occurrence of film-like agglomerates in a plastic container Tsumechichi component-containing beverage, wherein 45 times / min to 90 times / min and a to Rukoto the number of the slide How to prevent. When sterilizing a plastic container-packed milk component-containing beverage comprising a synthetic resin cup with a retort sterilizer, the sterilization shelf loaded with the plastic container filled with the milk component-containing beverage is slid horizontally by an air cylinder method, A method for preventing the formation of film-like aggregates in a beverage containing a plastic container-packed milk component, wherein the sliding acceleration is 1 G to 30 G, and the sliding frequency is 5 times / minute to 20 times / minute. .

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