JPH0151978B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing unripened soft cheese that can be stored for a long period of time without using synthetic preservatives. More particularly, the present invention relates to a method for producing unripened soft cheese that can be pasteurized at high temperatures and stored for long periods of time without the addition of any stabilizers. In general, cream cheese, New York cheese, quark, and the like are collectively referred to as non-ripened soft cheeses because they have a high moisture content and a soft structure. Soft cheese has a significantly higher moisture content than regular cheese aged at 50-80% moisture, which has a moisture content of 35-40%, but it also has a soft texture.
Due to its delicious taste, it has become a popular food in recent years. Non-ripened soft cheese is generally made by heat-sterilizing milky raw materials, adding various lactic acid bacteria starters and fermenting them for 5 to 20 hours, adjusting the pH to 4.5 to 5.0, stirring and heating the resulting curd, and filtering the whey. It is manufactured by separating and cooling the card. However, there is almost no further aging, and the fruit is immediately marketed and consumed. For this reason, the water remains at 50 to 80% and is hardly lost, making it extremely susceptible to corrosion and water separation. Conventionally, in order to improve the shelf life of soft cheese, the resulting cheese stock solution or curd was heat sterilized, but the proteins in soft cheese are easily denatured, and if complete heat sterilization was attempted, protein denaturation would occur. This resulted in syneresis and deterioration of taste. Therefore, stabilizers such as pectin and guar gum were added to stabilize the protein before heat sterilization. The present inventors conducted research in search of a method for producing high-quality unripened soft cheese that can be stored for a long period of time without using any bactericidal agents or stabilizers.As a result, the inventors found that fermentation using lactic acid bacteria has a pH of approximately 3.7 to 4.3. It is most effective to prevent thermal denaturation of proteins, and Lactobacillus bulgaricus is effective as the lactic acid bacteria, and a mixture of Lactobacillus bulgaricus and Streptococcus thermophilus is more preferable. I found out something. The present invention involves adding a Lactobacillus bulgaricus culture to milk raw materials, fermenting them, and reducing the pH to approximately
3.7 to 4.3 and then heat sterilization, the present invention is a method for producing non-ripened soft cheese that can be stored for a long period of time, and the present invention is a method for producing non-ripened soft cheese that can be stored for a long time, and is characterized in that it is characterized in that the milky raw material is cultured with Lactobacillus bulgaricus and Streptococcus thermophilus. This is a method for producing non-ripened soft cheese that can be stored for a long period of time. The feature of the present invention is that the milk raw material is
bulgaricus or Lactobacillus bulgaricus and Streptococcus thermophilus to adjust the pH to about 3.7 to 4.3. Conventional fermentation of non-aged soft cheese has a pH of only 4.5 to 5.0, so the fermentation of the present invention at a pH of 3.7 to 4.3 results in a considerably acidic fermentation, and the sourness at the end of fermentation is strong, compared to the conventional fermentation. The acidity is considerably higher than the pH of 4.5 to 5.0. However, this high acidity appears to have protected the protein from denaturing even after subsequent high-temperature sterilization. In conventional non-aged soft cheese, the fermentation pH is 4.5.
Since the value is only ~5.0, sterilization can at most
Processing at 62℃ for 2 minutes will cause protein denaturation, so higher heating is not possible, and sterilization will be insufficient, and the product will only last 1 minute even if refrigerated.
The best-before period was about 3 weeks. On the other hand, in the non-ripened soft cheese according to the present invention, the pH of fermentation is 3.7 to 4.3, so
Sterilization is possible at 100°C, preferably 70 to 85°C. For example, sterilization at 72°C for 2 minutes can reduce the number of residual bacteria to zero, and if refrigerated, it can be stored for a long time. Further, according to the method of the present invention, since the protein is stable even after high temperature sterilization, the product will not become water separated even after long-term storage, and its commercial value will not be reduced. Milk raw materials in the present invention include whole milk, skim milk, skim-enriched whole milk, reconstituted milk, and the like. These milky raw materials are sterilized by being held at 90°C for 5 minutes, for example, and then cooled to about 20 to 45°C. Separately, when using Lactobacillus bulgaricus together with Streptococcus thermophilus,
A starter can be prepared by culturing each in sterilized skim milk for 24 hours at 30°C and adding them at the same time, or by inoculating a mixture of both in sterilized skim milk and culturing at 30°C for 24 hours. Starter is 0.5-5.0% based on milk raw materials.
degree is added. At this time, if a slightly hard unripened soft cheese is to be produced, it is advisable to add a small amount of rennet. Fermentation is carried out at 20-45°C (preferably 42°C) for 5-40°C.
The fermentation is carried out for 20 hours and stopped at any time as long as the pH of the fermentation liquid is between 3.7 and 4.3. After fermentation is complete, the curd is stirred, fluid cheese is used as a stock solution, and sterilized at 70°C or higher, for example 72°C, for about 2 minutes. It may be sterilized after commercialization without being sterilized here. The sterilization temperature is about 70-100℃, 70
If the temperature is below 100°C, residual bacteria will be seen, which is undesirable, and if it exceeds 100°C, protein denaturation will begin to occur, which is undesirable. In addition, the sterilization time is 70
About 3 minutes at 100°C is sufficient, and as the temperature rises, the time can be shortened; at 100°C, heating for a very short period of time will accomplish the purpose of sterilization. The sterilized cheese stock solution is obtained by separating the whey by filtering through a cloth or centrifuging, collecting curd, and cooling the curd to obtain a product. It is also possible to sterilize the card after making it into a card. By the method of the present invention, it is possible to produce non-ripened soft cheeses such as cream cheese, New York cheese, quark, etc. without using any synthetic preservatives or stabilizers, and it is possible to produce non-ripened soft cheeses that can be stored for a long time. This makes it possible to obtain matured soft cheese. Next, test examples and examples of the present invention will be shown. Test example 1 Test bacteria A Lactobacillus bulgaricus out8163 B Streptococcus thermophilus
out8162 C Streptococcus lactis out8161 D Streptococcus cremoris out8164 Starter production: Three sterilized skim milks were inoculated with bacteria A alone, a mixture of bacteria A and B, and a mixture of bacteria C and D, and the mixture was incubated at 30°C. The cells were cultured for 20 hours and used as starters. Test method: 2 ml of each starter was added to 3 flasks containing 100 ml of skim milk sterilized at 90℃ for 5 minutes, and the fermentation temperature was the optimum fermentation temperature for each bacteria.
In the case of a mixture of bacteria A and B, at 42°C, bacteria C and D
The mixed bacteria were cultured at 22°C for 20 hours, during which time the pH was measured every 2 hours. The results are shown in FIG. Here a is A
Bacteria, b indicates a mixed bacteria of A bacteria and B bacteria, and c indicates a mixed bacteria of C bacteria and D bacteria. From this figure, when using bacteria A and a mixture of bacteria A and B, the PH quickly drops and the PH
The pH drops to 3.7 to 3.8, but it can be seen that those using a mixture of bacteria C and D, which are generally used in the production of non-ripened soft cheeses, usually drop to 4.5. Test Example 2 When adding the starter, 0.3 mg of rennet was added and no addition was made in exactly the same manner as in Test 1.
PH was measured 16 hours later. As shown in the table below, the results showed that there was no change in the progress of acidity.

[Table] Test Example 3 Each soft cheese was produced using the three starters of Test Example 1, each was heated at 40 to 110°C for 2 minutes, the samples were stored at 15°C for 10 days, and a thermal stability test was conducted. I went. The results are shown in FIG. Here, 1 indicates that syneresis and aggregation are severe and the product quality is unsuitable, 2 indicates that syneresis and aggregation occur slightly and there are some problems, and 3 indicates that syneresis and aggregation do not occur and the product quality is unsuitable. It shows that it is preferable. From FIG. 2, it can be seen that the mixture of bacteria A and B exhibits the most preferable thermal stability, and the bacteria A alone exhibits preferable thermal stability. On the other hand, C used for general unripe soft cheese
It can be seen that the mixture of bacteria and D bacteria loses thermal stability when heated above 62°C. Test Example 4 In Test Example 3, the number of lactic acid bacteria and pH in the cheese stock solution after 16 hours of fermentation were measured, and then each product was heated at 62℃2.
The number of lactic acid bacteria was measured after heating for 1 minute and after heating at 82°C for 2 minutes. The results are shown in the table below.

[Table] From this table and Figure 2, it can be seen that in the method of the present invention, 82
Although it is completely sterilized at ℃ and the quality is stabilized, C bacteria, which is used in general unripe soft cheese,
Those caused by a mixture of D bacteria are 62, which is the limit for stable quality.
It can be seen that 3.2 x 10 ³ viable bacteria still remain after sterilization for 2 minutes at ℃. Example 1 Lactobacillus bulgaricus out8163 was inoculated into sterilized skim milk, and cultured statically at 30°C for 24 hours to obtain a starter. Add 200 ml of the resulting starter to whole milk and add 42
The cells were incubated statically at ℃ for 20 hours. The culture was stirred and made into a cheese stock solution. The pH of the cheese stock solution was 3.8. This cheese stock solution was heat sterilized at 72°C for 2 minutes.
Whey was removed from the pasteurized cheese stock solution using a centrifuge to obtain curd 2. Divide the cards into individual pieces and wrap them at 15℃ for 24 hours.
Even after leaving it for a long time, it was not altered by viable bacteria, and no separation of whey was observed. Example 2 A mixture of Lactobacillus bulgaricus out8163 and Streptococcus thermophilus out8162 was inoculated into sterilized skim milk, and statically cultured at 30°C for 24 hours to obtain a starter. 200 ml of the obtained starter was added to reduced milk 10, and the mixture was statically cultured at 42°C for 20 hours. The culture was stirred and made into a cheese stock solution. The pH of the cheese stock solution was 3.75. This cheese stock solution was heat sterilized at 75°C for 2 minutes. The whey was removed from this cheese stock solution through a cloth to obtain curd 3.3. The resulting curd was packaged in 200 ml portions and sterilized again at 80°C for 1 minute. Even when the obtained product was left at 15°C for 24 days, there was no deterioration due to live bacteria and no separation of whey.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the PH measured by culturing each test bacteria in Test Example 1, and FIG. 2 is a diagram comparing the stability of each product in Test Example 3. a... Bacterium A alone, b... Bacterium A and B mixed bacteria, c
...C bacteria, D bacteria mixed bacteria, 1... Area where syneresis and aggregation are severe, 2... Area where syneresis and aggregation occur slightly, 3...
...A part without syneresis or coagulation.

Claims (1)

[Claims] 1. A non-ripened soft cheese that can be stored for a long time, characterized by adding a culture of Lactobacillus bulgaricus to a milky raw material, fermenting it, adjusting the pH to about 3.7 to 4.3, and then heat-sterilizing it. manufacturing method. 2. The method according to claim 1, wherein the heat sterilization is performed at a heating temperature of 70 to 100°C. 3. A non-ripened soft cheese that can be stored for a long time, which is characterized by adding cultures of Lactobacillus bulgaricus and Streptococcus thermophilus to milky raw materials, fermenting the mixture, adjusting the pH to 3.7 to 4.3, and then heat-sterilizing it. Manufacturing method. 4. The method according to claim 3, wherein the heat sterilization is performed at a heating temperature of 70 to 100°C.