JPS63309138A - Liquid yoghurt containing bacteria of genus bifidobacterium - Google Patents

Abstract

PURPOSE:To obtain a liquid yoghurt, containing bacteria of the genus Bifidobacterium and having good flavor and excellent stability of quality, by containing a citrate and keeping pH at a specific value. CONSTITUTION:A citrate, e.g. sodium citrate or potassium citrate, in 0.2-20mM concentration is added to a liquid yoghurt, containing bacteria of the genus Bifidobacterium and prepared by a conventional method and pH is adjusted to >=4.4, preferably 4.4-4.7.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a liquid yogurt containing Bifidobacterium that has excellent quality stability.

[Conventional technology]

Liquid yoghurt (so-called drink yoghurt), which is made by homogenizing lactic acid fermentation of animal milk and adding syrup and flavorings, has reached its limit as a beverage that can be drunk directly from the container or, at best, through a straw. It has a similar high viscosity. Since the viscosity has a great effect on the mouthfeel and downing of the drink, it is desirable that it is not only strictly controlled during production, but also stable after production.

In general, it is considered appropriate for liquid yogurt to have a viscosity of 150 (!I) or less; anything with a higher viscosity is difficult to swallow;
It is similar to the type of yogurt eaten with a spoon.

The viscosity of liquid yogurt and its stability are determined by the culture conditions during yogurt production, the processing method of the culture, the pH of the product, additives, storage conditions, etc. Above all, pH is closely related to the viscosity of liquid yogurt; the higher the pH, the more unstable the viscosity becomes, and tends to increase over time. leads to separation. Therefore, in order to prevent the viscosity from increasing to an undesirable range during storage, the pH during production of liquid yogurt is usually adjusted to 4.4 or less, and at most 4.5.

However, from the perspective of product flavor, a pI of less than 4.4 is by no means optimal;
．． At a pH of 5 or higher, it becomes extremely mellow and palatable.

The need to keep the pH of liquid yoghurt within a low range is also a major obstacle when attempting to produce liquid yoghurt containing viable Bifidobacterium bacteria, which has great health benefits. In other words, as is well known, Bifidobacterium generally has poor acid resistance;
．． In a low pH range of less than 4, most of the bacteria will die in a short period of time, so when the survivability of this bacteria is considered, the desirable product pH is in a higher range.

In this way, conventional liquid yogurt is a low-pH product that emphasizes the stability of physical properties such as viscosity at the expense of some flavor, and therefore, it is almost impossible for such products to contain Bifidobacterium. It made no sense and was not implemented.

[Problem that the invention seeks to solve]

The purpose of the present invention is to solve the above-mentioned problems regarding the stability of the quality of liquid yogurt, and to provide a liquid yogurt containing Bifidobacterium that has good flavor and excellent quality stability. be.

[Means for solving problems]

The liquid yogurt provided by the present invention has a concentration of 0.2 to 20
It is characterized by containing mM citrate and having a pH of 4.4 or higher.

As the citrate used in the present invention, sodium salt, potassium salt, ammonium salt, etc. of citric acid are preferable, and double salts having citric acid and other acids as acid groups, such as sodium succinate iron citrate (C112 (COONa
)C(0■) (COONa)CHi (COONa)
:] ,・((OOCCH2CH2COO)Fe) 3
・2, 5H20 can also be used.

Although the mechanism of action of the citrate contained in the liquid yogurt of the present invention is not yet clear, the non-fat milk solids content is about 8.
It has the effect of suppressing the increase in viscosity that tends to occur when the pH of liquid yogurt of 0 to 12.0% is high, and therefore,
It is possible to set the pH to a high range of 4.4 or higher without fear of increasing viscosity over time.

The citrate concentration should be 0.2mM for full effectiveness.
However, if the concentration exceeds 2On+M, the saltiness, bitterness, metallic taste, etc. will become confusing, so it is preferable not to add more than necessary.
A particularly preferred citrate concentration is about 10 nM or less (note that when a double salt such as sodium iron succinate citrate is used, the molar concentration of the citrate is determined only by the citric acid moiety in the double salt). , and calculate it by converting it into citrate.)

When producing the liquid yogurt of the present invention, citrate is added at any stage after the fermentation of animal milk using Bifidobacterium (or using this in combination with lactic acid bacteria) until the product is filled into containers. It can be added alone or after making a mixed solution with other additives such as sweeteners.
When using Bifidobacterium and lactic acid bacteria together,
The culture may be carried out by mixing the two cultures or may be carried out separately. No special consideration is required for culture conditions and culture treatment methods, except for the final pH of the culture to be 4.4 or higher. Needless to say, the viscosity of the product is preferably 150 cp or less (particularly preferably about 100 cp or less) as the viscosity of liquid yogurt.

[Action/Effect]

The liquid yogurt of the present invention has a high pH of 4.4 or more,
Since it has a mild flavor with little acidity, it can be enjoyed by everyone from infants to the elderly. Furthermore, by containing Bifidobacterium, it has better health effects than liquid yogurt containing only lactic acid bacteria, but the high pH also allows Bifidobacterium to survive.

The liquid yogurt of the present invention has a feature based on the high pH as described above, but the increase in viscosity that tends to occur when the pH is high is suppressed by the addition of citrate, which is normally expected. It maintains stable drinkability without significant increase in viscosity during the shelf life.

〔Example〕

The present invention will be explained below with reference to Examples.

Example 1 Reconstituted milk with non-fat milk solids content of 12.3% and milk fat content of 1.5% was sterilized, and 0.5% of Streptococcus thermophilus starter and Bifidobacterium breve starter were added to this. 0.5%, each inoculated, 37
The cells were cultured at ℃ for 24 hours. The obtained culture solution with a pH of 4.5 was homogenized at 50 kg/am2, and then syrup containing citrate was added to obtain a mixture with a non-fat milk solid content of 8.2%, a milk fat content of 1.0%, and a syrup containing citrate dissolved therein. Sugar concentration 5%, citrate concentration 2mM
, a liquid yogurt with a pH of 4.5 was obtained.

A test was conducted in which the liquid yogurt obtained as described above was stored at 10° C. for 15 days with various changes in citrate or without the addition of citrate. Table 1 shows the change in viscosity in that case.
Shown below. Note that the pH change during the test period was negligible.

Table 1 Change in viscosity [Cp] (double salt: sodium iron citrate succinate) Example 2 A panel of 10 people evaluated four types of samples in which citrate was added to the culture solution produced and homogenized in Example 1. A sensory evaluation of taste was conducted, and the results shown in Table 2 were obtained.

Table 2 Sensory evaluation Double salt: Sodium iron citrate succinate (Concentration is citrate equivalent value) Rating = 2 Delicious 1 Slightly delicious 0 Neither -1 Somewhat tasteless -2 bad

Claims (2)

[Claims] (1) Contains citrate at a concentration of 0.2-20mM and has a pH
A liquid yoghurt containing Bifidobacterium, characterized in that the ratio is 4.4 or more. (2) pH is 4.4 to 4.7 Claim 1
Liquid yogurt as described in section.