JP3065328B2 - Methods for disinfecting and homogenizing dairy products - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a method for producing dairy products, and more particularly to a method for selectively removing only fungi and contaminants from milk and / or dairy products. The present invention relates to a method for obtaining a sterilized and homogenized dairy product.

In other words, the present invention relates to a new method for sterilizing or homogenizing dairy products which contains all the components of the raw material and which has not undergone any denaturation or quality deterioration.

The term "milk and dairy products" used herein includes not only milk and dairy products specified by ministerial ordinances such as milk but also synthetic or similar products thereof.

(Conventional technology and problems) Conventionally, milk and dairy products are almost always subjected to heat-induced germs, but when subjected to heat sterilization, changes in flavor are generally unavoidable (edited by Yoshito Sakurai) "Comprehensive Food Encyclopedia (New Edition)", Tokyo Dobunshoin, pages 305-307 (Showa 46-
3-15)).

So, in order to avoid such deterioration of flavor and quality,
For example, even if raw milk is forcibly filtered, only the concentrated milk portion having a high fat content is separated into skim milk (that is, only skim milk removed by filtration is obtained), and all components of the raw milk are removed. It cannot be disinfected without damage.

That is, it was impossible to filter milk and milk products by the conventional technique.

(Means for Solving the Problems) In view of the state of the art, the present invention has been made for the purpose of developing a method of sterilizing milk and all components of dairy products without separating or denaturing the components. Things.

As a result of various studies to achieve the above objectives, it was determined that the conventional heat sterilization method could not maintain the original natural ingredients and flavor and texture of dairy products. We paid our attention to the filtration method that had been considered possible.

Therefore, as a result of diligent research on the filtration method using a membrane, it was found that by selecting the membrane, selecting the temperature and pressure conditions, it was completely unexpected, or rather impossible at all with the conventional technical level, that the raw milk completely Discovered the phenomenon of transmission. Based on the discovery of this new phenomenon, a very useful new finding has been obtained that it is also possible to remove bacteria by controlling the pore diameter of the membrane under the condition of permeation.

The present invention has been completed based on such a new finding and as a result of further detailed studies, and uses a membrane to selectively permeate all components other than milk, bacteria of dairy products and contaminants. And a method for producing a dairy product characterized by simultaneously obtaining a sterilized filtrate and a homogenized filtrate.

Milk in the present invention, as the membrane used to filter dairy products, any type of membrane can be used as long as it is a membrane used for the separation and purification of substances and acting as a partition having selectivity. , An ultrafiltration membrane, a semipermeable membrane, a reverse osmosis membrane, a microfiltration membrane, and the like are appropriately used.

As described above, as the membrane, any of an organic polymer membrane and an inorganic membrane can be used. However, since the permeation of raw milk requires a relatively high pressure, when using an organic polymer membrane, it is necessary to pay attention to the pressure resistance. . In general, the strength of an organic polymer film is low at high temperatures, and many of them have heat resistance of about 100 to 150 ° C. In contrast, inorganic membranes have heat resistance of about 600 to 1300 ° C, are easy to sterilize with steam, and can be easily baked at about 500 ° C even when the amount of permeation decreases due to contamination. There is an advantage that it can be recovered.

As the form of the film, a plate, a sheet, a roll, a hollow fiber, a tubular shape, or another shape can be appropriately used. These shapes can be combined, or different types of films can be used in combination.

In practicing the present invention, as a result of test research, it was found that there was a minimum pressure at which the whole amount of milk permeated depending on the type of membrane and the pore size, and it is necessary to perform filtration at a pressure higher than that pressure. The minimum value at which the total amount occurs is determined by factors such as the membrane thickness, pore diameter, and flow rate, and by factors such as fat percentage and fat globule diameter before permeation, and is expressed by the following formula based on experimental results.

P = ad ¹² P: Minimum permeation pressure (kg / cm ² ) d: Average fat globule diameter (μm, before permeation) a: Constant that changes depending on the type of membrane, fat percentage, etc. Therefore, be forewarned before membrane overload The minimum permeation pressure can also be reduced by homogenizing milk and dairy products to reduce the average fat globule diameter.

Further, at the time of membrane filtration, if the fat is melted by heating it to a temperature equal to or higher than the melting point of milk fat, the treatment of the present invention is further smoothly performed. When fats and oils of fat globules in milk are solid, particles larger than the pore size of the membrane cannot pass through the membrane even under pressurized conditions, so it was difficult to permeate the whole amount. Since milk fat is in a liquid state, particles larger than the pore size of the membrane can be deformed and pass through, and the whole amount of permeation is possible here.

Furthermore, since the large fat globules become finer as they pass through the membrane, homogenization and sterilization can be performed in a single step by completely selecting the pore size of the membrane.
The functions of the homogenization treatment and the eradication treatment are essentially different from each other, and it has never been considered in the art to carry out both treatments at once.

By carrying out membrane filtration in this way, not only the whole amount of milk and dairy products can be permeated but also bacteria can be removed, heating can be minimized, and a natural flavor and nutrient that has never existed before This made it possible to obtain a product that was excellent in terms of quality, and it was also possible to perform homogenization. In addition, the present invention is very characteristic in that these processes can be performed in one step, that is, simultaneously, and the above-described pressurizing process further increases these effects. Thus, according to the invention, all types of mammalian milk and / or dairy products can be processed.

In addition, to remove bacteria and contaminants, and within the range that can remove bacteria and homogenize the liquid, partial permeation of milk and dairy products, leaving a certain amount of all or some of the components, The present invention can also be implemented.

Hereinafter, the present invention will be described in more detail with reference to Test Examples and Examples.

Test Example 1 Raw milk with a fat percentage of 3.8% and not homogenized
While varying the temperature, the solution was passed through a porous membrane having a pore size having the following constant conditions, and tested for the permeation flow rate, the fat percentage of the filtrate, and the flavor of the obtained dairy product, and the results in Table 1 were obtained. Was.

As the membrane, a porous glass membrane having an average pore diameter of 0.4 μm and a pressure of 1 kg / cm ² and a water permeation amount of 2.0 m ³ / m ² · hr was used.

As can be seen from Table 1 showing the relationship between the temperature of raw milk and the permeability of the membrane, the permeation flow rate began to increase from 25 ° C., the temperature at which the solid fat number of milk fat suddenly decreased, and the permeation of fat globules increased. There is an increase in the percentage of fat, which is a measure.

Test Example 2 Using the raw milk of Test Example 1 and the porous glass membrane, while varying the pore diameter of the membrane, the relationship between the pore diameter of the membrane, the particle diameter of the fat globules after permeation, and the degree of sterilization was tested. 2 were obtained. The test was performed at 40 ° C.

As is clear from the results in Table 2 which summarizes the relationship between the pore diameter of the membrane, the degree of sterilization, and the average particle diameter of the fat globules after permeation, the effect of sterilization is high up to a pore diameter of about 0.6 μm. Recognize.

However, in Table 2 above, each symbol of the sterilization state and the permeation state means the following.

Bactericidal state A: Sterilized state B: Corresponds to sterilization at 62 to 65 ° C for 30 minutes C: Many bacteria pass through Permeable state ○: Flows more than 1.0m ³ / m ² · hr △: Permeates, but 1.0m ³ / m ² -Less than hr x: Almost no permeation Test Example 3 Porous glass used in Test Example 1 while heating to 40 ° C using raw milk from which the fat percentage was 3.8%, and from which contaminants were removed and homogenized The relationship between the minimum permeation pressure when milk and milk fat of milk products permeate through the membrane after passing through the membrane and the particle size of fat globules before permeation were tested, and the results in Table 3 were obtained.

From the results in Table 3 that summarizes the relationship between the pore diameter and the change in the minimum permeation pressure due to the difference in the particle diameter of the fat globules before permeation, when the average pore diameter r changes to 0.2 μm, 0.3 μm, 0.5 μm, The minimum permeation pressure P kg / cm ² is P = 21.2d ¹² (r = 0.2 μm) P = 16.0d ¹² (r = 0.3 μm) P = 10.4d ¹² (r = 0.5 μm) d: average particle diameter (μm, (Before transmission).

The coefficient varies depending on the fat percentage, temperature, and the like, in addition to the particle diameter.

Example 1 Raw milk 1 kept at 40 ° C. for 20 minutes was prepared with an average pore diameter of 0.4 μm.
In using a porous glass membrane of permeation amount of water during the pressure 1.0 kg / cm ² is 2.0m ³ / m ² · hr, and filtered at a pressure 30kg / cm ^2, the filtrate 0.
Got 7 The obtained filtrate did not contain bacteria, and the average particle size was 2.2 μm. In order to sterilize raw milk to make it aseptic, high-temperature heating at 145 ° C for several seconds is usually required.However, the filtered milk has very little change in flavor and flavor due to heating compared to high-temperature sterilization, and has a flavor similar to raw milk. Was confirmed.

Example 2 In the same manner as in Example 1, raw milk was obtained by using a porous glass membrane having an average pore diameter of 0.7 μm and a water permeation rate of 3.0 m ³ / m ² · hr at a pressure of 1.0 kg / cm at a pressure of 30 kg / cm ^2. Filtration through cm ² gave 0.7 filtrate. The obtained filtrate contained only about 1 × 10 ² bacteria / ml. At 62-65 ° C to get the same level of sterilization
Heating for 30 minutes was required.

It was confirmed that the filtered milk had very little change in flavor and flavor due to heating compared to high-temperature sterilization, and had a flavor similar to raw milk.

In these examples, the porous glass film is
An MGP filter manufactured by Ise Chemical Co., Ltd. was used.

(Effects of the Invention) According to the present invention, not only milk that has been impossible until now, but the whole amount of milk and milk products can be permeated for the first time, sterilization and homogenization can be performed simultaneously, A very good effect is achieved.

In addition, the resulting product is not treated at high temperatures for sterilization as in the past, so the original flavor and nutritional components of the raw material are not impaired, and since it is homogenized, it is delicious and easy to drink It was.

Claims (4)

(57) [Claims] Claims 1. Milk and / or milk product having an average pore size of 0.6 µm
In the following, using a membrane having no pores larger than 0.7 μm, 25
By filtering at a temperature higher than or equal to ℃ and a pressure higher than the minimum permeation pressure determined by the following formula, all components other than bacteria and contaminants of milk and / or dairy products can be selectively permeated and homogenized together with the bacteria removal A method for producing dairy products, characterized by obtaining a filtrate. P = ad ¹² , where P: minimum permeation pressure (kg / cm ² ) d: average fat globule diameter (μm, before permeation) a: constant that changes depending on the type of membrane, fat percentage, etc. 2. The method according to claim 1, wherein the membrane is an inorganic porous membrane. 3. The method according to claim 2, wherein the inorganic porous film is a porous glass film. 4. The method for producing a dairy product according to claim 1, wherein the milk and / or the dairy product is subjected to filtration after being homogenized in advance.