JPH0436146A - Preparation of kefir-like fermented food - Google Patents

Abstract

PURPOSE:To prepare the subject product having excellent taste and flavor and preservable over a long period by fermenting a raw material consisting of animal milk, soya milk, etc., with lactobacillus and mixing the fermented liquid with a fermented and treated liquid produced by fermenting a sugar- containing liquid with yeast and removing the yeast from the product. CONSTITUTION:A raw material composed of animal milk, concentrated animal milk, soya milk, concentrated soya milk or their mixture (adjusted to a milk solids-not-fat content of 6-20wt.%) is subjected to alcoholic fermentation with a lactobacillus to obtain a fermented liquid. Separately, a sugar-containing liquid such as ultrafiltration liquid of fruit juice, milk whey, etc., (adjusted to a sugar content of 3-22wt.%) is fermented with yeast and the yeast is removed e.g. by filtration after the fermentation to obtain a fermented and treated liquid. The fermented liquid is mixed with the fermented and treated liquid and the mixture is optionally diluted with sterilized water and filled in a vessel to obtain the objective product. The concentrated animal milk and the concentrated soya milk can be produced by concentrating the raw milk with an ultrafiltration device.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for producing a kefir-like fermented product containing lactic acid, alcohol and carbon dioxide gas and having excellent long-term storage stability.

[Technical background and explanation of conventional technology]

Kefir is usually produced using a mixed grain called kefir grain;
A large number of microorganisms have been isolated [Japanese Journal of Dairy and Food Science (
Japanese Journal of Dairy
and Food 5science), Volume 36, No. 6
issue, page 236, 1987]. Lactic acid bacteria isolated and identified from kefir grains include Streptococcus, Leuconostoc, and Lactobacillus, and yeast include Candida and Satucharomyces.

When kefir is produced using kefir grains,
Lactic acid bacteria and yeast may survive in the kefir, and alcohol fermentation may proceed even after the kefir is filled into a container, producing alcohol and carbon dioxide gas, resulting in a significant change in flavor, expansion of the container due to carbon dioxide gas, and damage to the container. This causes liquid leakage, etc., and the period of commercial value is extremely short.
This was a major obstacle to the spread of kefir.

Various attempts have been made to produce kefir. For example, lactic acid fermentation is carried out using lactic acid bacteria that do not produce galactose, or alcoholic fermentation is carried out using lactose non-fermenting yeast until the sugar added to raw milk is substantially eliminated, and secondary alcohol is produced after filling the container. A method that does not cause fermentation (JP 1-317355), by fermenting raw milk containing citric acid or sodium citrate with Streptococcus diacetylactis, carbon dioxide gas is generated without using yeast, and the amount of kefir grains added is reduced. A method for stabilizing flavor and texture (Japanese Patent Publication No. 62-57289) has been disclosed.

However, in the former method, the flavor is insufficient because the types of lactic acid bacteria and yeast used for fermentation are limited, and the type and amount of sugar used is limited. In this method, there was a limit to the increase in shelf life by reducing the amount of kefir grains added.

As described above, all attempts to improve the shelf life of kefir using conventional methods have not been sufficient, and there has been no technical idea to perform lactic acid fermentation and alcohol fermentation separately.

The present inventors have conducted extensive research to improve the short shelf life of conventional kefir products, and by performing fermentation by lactic acid bacteria and fermentation by yeast using separate raw materials,
The present invention was completed based on the discovery that the above-mentioned disadvantages of conventional kefir products can be eliminated.

[Object of the invention and summary of the invention]

The object of the present invention is to provide a new method for producing kefir products.

Another object of the present invention is to provide a kefir product that has a similar flavor to conventional kefir products and can be stored for a long period of time.

Still another object of the present invention is to provide a kefir product that has a variety of flavors (for example, fruit juice flavor) different from conventional kefir products and can be stored for a long period of time.

The present invention produces yeast from a fermented liquid obtained by lactic acid fermentation of a raw material selected from the group consisting of animal milk, concentrated animal milk, soy milk, concentrated soy milk, and a mixture thereof, and a fermented liquid obtained by alcohol fermentation of a sugar-containing liquid with yeast. This is a method for producing a kefir-like fermented product, which is characterized by mixing the fermented liquid obtained by removing the fermented product.

[Detailed description of the invention]

The raw materials used in the present invention include raw milk such as cow's milk, Yamatehada, Tehada, horse's milk, skimmed milk obtained by defatting these, or animal milk such as reconstituted milk obtained by redissolving these powdered milk in water, and excluding these. Concentrated animal milk that has undergone treatments such as filtration and vacuum concentration, soy milk prepared from whole soybeans, powdered soybeans, isolated soy protein, etc., which are processed by ultrafiltration,
They are concentrated soymilk that has been subjected to a process such as vacuum concentration, and a mixture thereof, and both are prepared by known methods.

The solid content concentration of the raw material is usually limited to 6 to 20% (by weight) to determine the optimal concentration based on the physical properties and flavor of the desired product, or to perform fermentation efficiently. ,
(same below).

The sugar-containing liquid used in the present invention includes a filtrate obtained by ultrafiltering the above-mentioned raw materials (perminiite), fruit juice, whey, etc. In order to further promote fermentation by yeast, various sugars such as glucose are dissolved in these. Both can be prepared by known methods.

The sugar concentration of the sugar-containing liquid is usually adjusted to a range of 3 to 22%.

The lactic acid bacteria used in the lactic acid fermentation and the yeast used in the alcoholic fermentation are the above-mentioned known strains that are usually contained in kefir grains, and both are easily available strains.

Both lactic acid bacteria fermentation and alcohol fermentation are performed by known methods. For example, lactic acid fermentation involves sterilizing and cooling skim milk and using a pre-prepared lactic acid starter (e.g.
Streptococcus lactis, Streptococcus
Cremoris ζ 3% of one or more mixed starters such as Strebutococcus thermophilus, and 3% of Lactobacillus starter (for example, one or more of Lactobacillus acidophilus, Lactobacillus lactis, Lactobacillus kefianofaciens, etc.) A mixed starter of two or more types) is inoculated at 1% and fermented at 25 to 28°C for 20 hours to obtain fermented milk (pH about 4.4).

In addition, alcoholic fermentation requires 1% glucose and 5% sucrose.
The cheese whey containing C.
Ferment for 8 hours to obtain fermented liquid.

The alcoholic fermentation liquid is treated by a known method (for example, diatomaceous earth filtration, membrane filtration, centrifugation, etc.) to remove yeast contained in the fermentation liquid. Removal of yeast from this alcoholic fermentation liquid is a feature of the method of the present invention.

After removing yeast from the alcoholic fermentation liquid, both fermentation liquids may be mixed and diluted by adding sterilized water if necessary. The two fermentation liquors are mixed under aseptic conditions, and one of the fermentation liquors is stirred while the other fermentation liquor is added, but it is preferable to add the alcoholic fermentation liquor to the lactic acid fermentation liquor.

The mixed fermentation liquids are appropriately filled into containers to produce the final product. As is clear from the test examples below, this product can be stored for at least 14 days without any change in flavor or appearance when stored in cold temperatures, much longer than products manufactured by conventional methods. be.

The method of the present invention is carried out as described above.

Next, the present invention will be explained in detail by showing test examples.

(Test Example 1) In this test, the flavors of kefir produced by the method of the present invention and the conventional method were compared through a sensory test.

1) Preparation of sample A sample according to the method of the present invention (referred to as sample 1) was prepared by the same method as in Example 1. Samples by conventional method (
Control) was performed using a known method (Yuzo Anagama, “Nyakugaku J, 498
Page, Korin Shoin, 1975) was prepared as follows.

45 kg of skimmed milk, 0.2 kg of sucrose and 0.2 kg of glucose.
Add 3 kg, dissolve, sterilize at 90°C for 10 minutes,
Cool to 15°C and mix with commercially available kefir grains (Denmark).
(manufactured by Hansen) was added and fermented at 15°C for 10 hours while stirring every 2 hours, and then cooled to 5°C.
Each container was filled with 200 g.

In this test, each sample was subjected to the test immediately after production.

2) Test method A panel of 10 men and women conducted a 3-point discrimination test method and a 3-point preference test method between the control and each sample (“Applications of Stochastics to Chemistry and Biology, Vol. 3 J, 145 pages). , published by Nankodo,
(1963) was carried out at the same time. i.e. control and one for each sample.
Arrange the combinations of 2 of one and 1 of the other in a total of 3 arbitrarily (for example, control-sample 1-control, sample 1-control-sample 1), and The students were asked to identify the odd sample among the combinations, and their preference for the odd sample and other samples was tested at the same time. The number of subjects who correctly identified the odd samples was defined as the number of correct answers, and judgments were made based on the preferences of those who answered correctly.

3) Test results As a result of this test, there were 8 people who answered correctly and 12 people who answered incorrectly.
Since it became clear that there was no difference between those who answered correctly and those who answered incorrectly, a preference test was not conducted. This test result is
It shows that there is no difference between the samples made by the method of the invention and the control made by the conventional method.

(Test Example 2) In this test, samples after storage were compared by appearance and sensory tests.

1) Preparation of samples A sample prepared by the same method as in Example 1 (referred to as sample 1) and a sample prepared by the same conventional method as in Test Example 1 (referred to as control) were incubated at 15°C for 5 days. saved.

2) Test method Sample 1 and the control were tested for flavor by the same sensory test as in Test Example 1 every day. However, the appearance was observed with the naked eye, and if any abnormality was observed, a sensory test was not performed.

For the number of lactic acid bacteria, use a BCP-added plate count agar medium (manufactured by Eiken Chemical Co., Ltd.) at 37°C for 72 hours, and for the number of yeast bacteria, use a potato dextrose agar medium (manufactured by Eiken Chemical Co., Ltd.) at 25°C for 96 hours. Pour culture was performed for each, and the number of bacteria was measured using a conventional method.

3) Test results The results of this test were as shown in Table 1.

■Microbiological test The number of lactic acid bacteria in sample 1 was 2.6 after 3 days compared to that immediately after production.
It increased by 7 times, but in the control it increased by 3.27 times, which was not a big difference. The number of yeast in the control increased abnormally after 3 days to 15.5 times that immediately after production, and it was clear that this was the biggest cause of the loss of commercial value. On the other hand, all of the samples had yeast removed, so they had sufficient commercial value even after 5 days.

■Appearance The container was taken out from the refrigerator and its appearance was observed, and the presence or absence of engravings on the container was noted.Then, the container was opened and the contents were observed. After saving 2
No abnormalities were observed in either sample up until the 4th day, but after 3 days, cracks in the card due to gas generation were observed in the control, so the sensory test was discontinued after the 4th day. As described above, abnormalities were already observed in the control after 3 days of storage, but no abnormalities were observed in the appearance of all the samples until 5 days later.

■Flavor Test In a three-point comparison discrimination test, it was impossible to distinguish between the two samples until one day after storage, indicating that there was no difference between the two samples. However, after 2 days of storage, it was clearly possible to distinguish between the two samples (there was a clear difference between the two samples), and sample 1 was overwhelmingly preferred based on the preference test results. -All participants preferred sample 1.

As is clear from the above test results, the product manufactured by the method of the present invention (sample 1) has a longer shelf life than the product manufactured by the conventional method (control), and it has been found that the product does not lose its commercial value even when stored. did.

Next, the present invention will be explained in further detail by showing examples.

Example 1 10 kg of skim milk obtained by defatting raw milk was treated with an ultrafiltration device (manufactured by Loos-Boulin) and concentrated 1.8 times to obtain a total solid content of 10.3% (protein 4.8%). , lactose 4.5%
About 5.6 kg of concentrated milk with 1.0% ash content was prepared. Add 0.4 kg of sugar to this concentrated milk, dissolve it, and heat to 90°C.
The mixture was sterilized by heating for 10 minutes and cooled to 40°C. Next, 0.3 kg of mixed starter (0.2 kg of Streptococcus thermophilus starter).

Lactobacillus bulgaricus starter 0.1kg
) and cultured at 38°C for about 5 hours until the lactic acid acidity reached 0.
Approximately 6.0 kg of 8% fermented milk was obtained.

About 4.4 kg of the filtrate obtained by the ultrafiltration was added and dissolved in 0.6 kg of commercially available glucose (manufactured by Nippon Shiryo Co., Ltd.), and sterilized by heating at 90°C for 10 minutes. C
It was cooled to Next, 0.4 kg of mixed starter (0.2 kg each of Satucharomyces cerevisiae and Candida kefir starters) was inoculated, cultured at 30°C for about 20 hours, and then commercially available diatomite ± (manufactured by John Mulville's, USA) was inoculated. About 4.0 kg of filtrate was obtained.

Adding diatomaceous earth filtrate to the fermented milk while stirring,
Fill 200g of the mixture into containers and make kefir-like product 5.
Obtained 0 pieces.

The obtained kefir-like product was tested in the same manner as in Test Example 1, and the flavor was good, and it had a good flavor even after being stored at 4°C for 14 days.

Example 2 0.5 kg of skim milk was sterilized at 90°C for 10 minutes, and then sterilized at 40°C.
10 g of Lactobacillus helveticus was inoculated and cultured at 40°C for 20 hours to obtain fermented milk with a lactic acidity of 2.1%.

Separately, commercially available 5-fold concentrated grape juice (Concord variety, 60°Bx) was diluted 5-fold, glucose (manufactured by Wako Pure Chemical Industries, Ltd.) was added at a rate of 15%, and the mixture was uniformly dissolved and sterilized. , Satucharomyces cerevisiae (ATCC2373) was inoculated and cultured at 256C for 24 hours to obtain a preculture solution.

Next, 5 times glucose was added to 100 g of the 5 times concentrated grape juice.
0 g and 400 g of activated carbon-treated water were added to dissolve uniformly, sterilized at 80°C for 10 minutes, placed in a 1 liter fermenter equipped with a stirrer, and sterilely added 15 g of the pre-culture solution and stirred. The mixture was fermented for 48 hours at 30°C. After the fermentation was completed, the fermented liquid was centrifuged at 8000 rpm using a refrigerated centrifuge (manufactured by Tomy Seiko Co., Ltd.) to obtain about 500 g of a transparent alcoholic fermented liquid.

The fermented milk and alcoholic fermented liquid were mixed, and sterilized sugar solution (50% concentration>9 kg) was added and mixed uniformly.
0m+I! The mixture was filled into glass bottles to obtain 46 bottles of a concentrated kefir-like product (to be diluted 4 to 5 times for drinking).

After storing this product at 4°C for 21 days, it was tested in the same manner as Test Example 2, and as a result, it had sufficient commercial value.

〔Effect of the invention〕

The effects achieved by the present invention are as follows.

(1) A kefir-like fermented product with good flavor can be produced by the method of the present invention.

(2) By the method of the present invention, it is possible to produce a kefir-like fermented product that can retain good flavor for at least 14 days at cold temperatures.

(3) By the method of the present invention, kefir-like fermented products with various flavors including fermented liquids such as fruit juice can be produced.

Claims (1)

[Scope of Claims] 1) A fermented liquid obtained by fermenting a raw material selected from the group consisting of animal milk, concentrated animal milk, soy milk, concentrated soy milk, and a mixture thereof with lactic acid bacteria, and a sugar-containing liquid that is alcohol-fermented with yeast. A method for producing a kefir-like fermented product, which comprises mixing the fermented liquid with a fermented liquid obtained by removing yeast from the fermented liquid. 2) The production method according to claim 1, wherein the concentrated animal milk is a filtration residue obtained by concentrating animal milk by ultrafiltration. 3) The method according to claim 1, wherein the concentrated soymilk is a filtration residue obtained by concentrating soymilk by ultrafiltration. 4) The production method according to claim 1, wherein the sugar-containing liquid is an ultrafiltrate of fruit juice or animal milk. 5) The production method according to claim 1, wherein yeast is removed from the alcohol-fermented fermented liquor by filtration or centrifugation.