JPH0530901A - Preparation of milk having low lactose content - Google Patents

Abstract

PURPOSE:To obtain cow's milk having low lactose content, suppressed sweetness and excellent taste and flavor by adjusting the milk solids-not-fat within a specific concentration range by the addition of defatted milk powder to fresh milk and treating the milk with a specific beta-galactosidase. CONSTITUTION:Fresn milk is mixed with defatted milk powder to adjust the milk solids-not-fat to 15-23% and treated with a BETA-galactosidase originated from Bacillus circulans at a low temperature (1-9 deg.C) to obtain the objective milk having low lactose content.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing milk having a low lactose content and suppressed sweetness.

[0002]

2. Description of the Related Art A large number of people have diarrhea or abdominal pain when drinking milk. Since this phenomenon is thought to be due to the indigestion of lactose contained in milk, milk was commercialized by treating milk with β-galactosidase and decomposing a considerable amount of lactose. Due to the glucose and galactose produced by the decomposition of the milk, there was a problem that the sweetness was excessive compared to ordinary milk.

In order to solve this problem, JP-A-2-303450 proposes a method for preparing milk having a reduced lactose content and suppressed sweetness. This method uses 25-45% concentrated reduced skim milk in β-
A method of treating with galactosidase, since high-concentration reduced skim milk is used, the milk obtained by β-galactosidase treatment has a normal flavor even if the purpose of reducing lactose content and suppressing sweetness is fulfilled. It had the drawback of being inferior to city milk. The temperature condition for the β-galactosidase treatment in this method is 45 ° C. according to the examples.
It was relatively hot.

[0004]

DISCLOSURE OF THE INVENTION The present invention provides a method for obtaining milk having a reduced lactose content and a reduced sweetness by treating with β-galactosidase. It is an object of the present invention to improve it to a level close to that of milk, and to allow treatment with β-galactosidase at a low temperature such that raw milk sent to the market milk production process retains it.

[0005]

[Means for Solving the Problems] The means adopted in the present invention for solving the above-mentioned problems are as follows. First, non-fat solids content is 15 to 23% by adding skim milk powder to raw milk. After that, it is characterized by treating with β-galactosidase derived from Bacillus circulans. Second, in the above method, treatment with β-galactosidase is performed at a low temperature of 1 to 9 ° C. It is characterized by.

[0006] In the above, the skim milk powder or the like added to raw milk is skim milk powder, whole skim milk powder, concentrated milk milk or the like.

[0007]

Since β-galactosidase derived from Bacillus circulans has a very high galactose transfer activity, even if milk having a non-fat solid content adjusted to a relatively low concentration of 15 to 23% is used as the milk to be treated. It is possible to obtain low-lactose milk with reduced sweetness by increasing the production rate of oligosaccharides and at the same time the production rate of monosaccharides. Since the non-fat solids have a relatively low concentration as described above, the adjusted milk containing a high proportion of raw milk can be used as the milk to be treated. Therefore, the flavor of the obtained low lactose milk is good.

Further, β-derived from Bacillus circulans
Since galactosidase has a high galactose transfer activity, it is intended to obtain milk with low lactose and low sweetness by treating milk having a low non-fat solid content as described above at a low concentration such as 1 to 9 ° C. Can be achieved.

[0009]

【Example】

(Example 1) Non-fat solid content was 1 by adding skim milk powder to raw milk
2 kg of 9.5% milk was prepared. After cooling to 4 to 5 ° C., β-galactosidase derived from Bacillus circulans was added at a rate of 2.5 units / g and reacted for 19 hours. Water and butter were added to this to adjust the non-fat solid content to 8.5% and the fat content to 3.5%, and then sterilization that also serves as inactivation of β-galactosidase for 5 minutes at 95 ° C. Then, homogenization was performed at 120 kg / cm ² to obtain milk with low lactose.

Example 2 2 kg of milk having a non-fat solid content of 22.5% was prepared by adding skim milk powder to raw milk. 4-5
After cooling to ℃, β- derived from Bacillus circulans
Add galactosidase at a rate of 3 units / g,
The reaction was carried out for 25 hours. Water and fresh cream were added to this to adjust the non-fat solid content to 9.0% and the fat content to 1.5%, and then sterilization which also serves to inactivate β-galactosidase as in Example 1. And homogenized to obtain low lactose milk.

The sugar composition of the milk obtained in the above examples is shown in Table 1.
Shown in. As shown in this table, these milks had a high oligosaccharide production rate and had a low sweetness in the sensory test.

[0012]

[Table 1]

[0013]

INDUSTRIAL APPLICABILITY The present invention uses β-galactosidase derived from Bacillus circulans, which has a very high galactose transfer activity, so that the non-fat solid content is lower than 25-45% of the above-mentioned reference. It is possible to use the treated milk in an amount of 15 to 23%, so that unlike the above-mentioned reference example in which the pure milk is exclusively used as the treated milk, a modified milk containing a high proportion of raw milk is prepared. Since it can be used as a milk to be treated, as a result, the flavor of the obtained low-lactose milk can be improved to a level close to that of city milk.

Further, according to the present invention, by using β-galactosidase derived from Bacillus circulans having a very high galactose transfer activity, the treatment temperature with this enzyme can be lowered to 1 to 9 ° C. The treatment with β-galactosidase can be performed at a low temperature held by raw milk sent to the market milk production process. Then, after the treatment, sterilization that also serves as inactivation of β-galactosidase can be performed in a normal sterilization step. Therefore, according to the present invention, it is possible to produce low-lactose milk in a normal market milk production process without newly setting special temperature conditions.

Claims (2)

[Claims] 1. Low-lactose characterized by being treated with Bacillus circulans-derived β-galactosidase after adjusting nonfat solid content to 15 to 23% by adding skim milk powder to raw milk. Milk manufacturing method. 2. Treatment with β-galactosidase 1
The method for producing low lactose milk according to claim 1, which is performed at a low temperature of 9 ° C.