JPH10262549A - Lactose-hydrolyzed and skimmed milk and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lactose-hydrolyzed and skimmed milk that is excellent in taste and coloring effect and can be served to the patient with lactose intolerance and its production. SOLUTION: Lactase is added to skimmed milk or an aqueous solution of skimmed powdery milk to hydrolyze at least 80% of the lactose included in the skimmed milk or the skimmed powdery milk. Then, the lactase is deactivated, the treated milk or solution is concentrated, spray-dried and the resultant powdery lactose-hydrolyzed skimmed milk is heat-treated to produce the objective lactose-hydrolyzed and skimmed milk having the following physical and chemical properties: a) whey protein index: <=1.0; b) L 70-95, a 0-5, b 14-22 according to the color-difference meter, and c) the rate of hydrolysis of lactose: at least 80%.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention uses skim milk or skim milk powder as a starting material and hydrolyzes at least 80% (by weight, hereinafter the same unless otherwise specified) of lactose contained in skim milk or skim milk powder. Concentrate the decomposed decomposed product, spray drying, heat-treated lactose-decomposed skim milk powder obtained and relates to a method for producing the same,
Lactose-decomposed skim milk powder has a unique flavor and can be used as a new food material, especially for bakery products and confectionery products such as chocolate, and most of the lactose in skim milk or skim milk powder is hydrolyzed, resulting in lactose content. It is a product that is well tolerated by lactose intolerant patients due to its low level.

[0002]

BACKGROUND OF THE INVENTION Skim milk powder and skim milk are mainly used as raw materials for bakery products, but conventional skim milk powder and skim milk have not been satisfactory in flavor.

On the other hand, lactose contained in raw milk, which is a raw material of powdered milk, is hydrolyzed with lactase obtained from yeast, and lactose is decomposed into monosaccharides of galactose and glucose to enhance sweetness. It is known to produce lactose-hydrolyzed powdered milk (JP-A-54-84066).
In addition, lactose contained in liquid dairy products such as skim milk is enzymatically decomposed by lactase in a non-mobilized form to produce dairy products that are well tolerated by lactose intolerant patients with reduced lactose content. The technology is also known (Japanese Patent Laid-Open No. 47-1666)
No. 3).

[0004] However, these prior arts have the following disadvantages.

[0005]

The lactose-hydrolyzed milk powder produced by hydrolyzing lactose contained in raw milk or skim milk has a poor flavor and is colored when used in bakery products and confectionery products. There was a problem that the effect was small.

[0006] In view of the above prior art, the present inventors hydrolyze lactose contained in skim milk or skim milk powder with an enzyme, deactivate the lactose-degrading enzyme, concentrate, and spray-dry. It has been found that by treating the obtained powdery lactose-decomposed skim milk in a powdered state under predetermined heating conditions, the flavor can be enhanced and lactose-decomposed skim milk having an excellent coloring effect can be obtained.

[0007] An object of the present invention is to provide a lactose-decomposed skim milk which is excellent in flavor and coloring effect and which solves the conventional disadvantages, and a new method capable of producing the above-mentioned lactose-decomposed skim milk.

[0008]

Means for Solving the Problems A first invention of the present invention for solving the above-mentioned problems comprises the following physicochemical properties of a) to c): a) a whey protein index of 1.0 or less; b ) L value by color difference meter is 70 to 95, a value is 0
5, and the b value is 14 to 22; c) the lactose hydrolysis rate is at least 80%;
Lactose-decomposed skim milk characterized by having:

[0009] A second invention of the present invention for solving the above-mentioned problems is to add lactose-degrading enzyme to an aqueous solution of skim milk or skim milk powder, and to provide at least 80% (by weight) of lactose contained in skim milk or skim milk powder. ), After which the lactose-degrading enzyme is inactivated, concentrated, and spray-dried. The resulting powdery lactose-degraded skim milk powder has a whey protein index of 1.0 or less and is measured by a colorimeter. L value is 70 to 95, a value is 0
A method for producing lactose-decomposed skim milk characterized by performing a heat treatment in the range of 5 to 5, and the b value is in the range of 14 to 22.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail, but first, the second invention of the present invention will be described in order to facilitate understanding of the present invention.

[0011] The starting material used in the method for producing lactose-decomposed skim milk powder of the present invention may be a commercial product, and skim milk produced by defatting whole milk, which is dried and powdered by a spray dryer or the like. It is skim milk powder. When skim milk powder is used as a starting material, it is used as an aqueous solution, but its concentration is preferably about 10%. In addition, in order to remove spores from the whole milk protein used as a starting material, it is desirable that the solution is previously subjected to filtration and bacterium treatment such as microfiltration.

A commercially available lactose-degrading enzyme (eg, lactase, β-galactosidase, etc.) is added to the aqueous solution of skim milk or skim milk powder, and at least 80% of the lactose contained in skim milk or skim milk milk is added in a conventional manner. Is hydrolyzed. Usually, 200 to 300 Gu (lack of labeling will be described later), preferably 250 to 280 Gu, of lactose-degrading enzyme is added to 1 g of lactose contained in skim milk or skim milk powder, and the mixture is added at 40 to 45 ° C. Desirably 42 to 4
At a temperature of 4 ° C. for 1 to 2.5 hours, preferably 1.5 to
Hold for 2.0 hours to perform hydrolysis. The resulting solution is then heated to 70-85 ° C for 1-5 minutes to deactivate the lactose-degrading enzymes.

The obtained solution is concentrated to a solid concentration of about 40% using a vacuum concentrator or the like, and the concentrated liquid is spray-dried to obtain a powdered lactose-decomposed skim milk.

The obtained powdery lactose-decomposed skimmed milk powder is dried at 80 to 150 ° C. for 10 to 300 minutes, preferably at 98 to 150 ° C. by using a dryer such as a cylindrical dryer, a fluidized dryer and an oven, and a heater. Heat treatment at 110 ° C. for 30 to 180 minutes,
A final product having a whey protein index of 1.0 or less, and a heat treatment with an L value of 70 to 95, an a value of 0 to 5, and a b value of 14 to 22 by a colorimeter is obtained.

The lactose-decomposed skim milk powder obtained by the above-mentioned production method has the following physicochemical properties a) to c), as is apparent from the examples described later. a) The whey protein index is 1.0 or less. b) L value by color difference meter is 70 to 95, a value is 0
5 and b value are 14-22. c) Lactose hydrolysis rate is at least 80%.

As shown in the above a) to c), the lactose-decomposed skim milk of the present invention is compared with skim milk or skim milk,
Since at least 80% of lactose contained in skim milk or skim milk powder is hydrolyzed, it is well tolerated by lactose intolerant patients and has a whey protein index of 1.0 or less under dry conditions. , L value by color difference meter is 70-
95, the a value is from 0 to 5, and the b value is heat-treated in the range of 14 to 22, compared to skim milk powder and lactose hydrolyzed milk powder, is excellent in flavor and coloring effect,
Lactose-decomposed skim milk having such good properties.

The lactose-decomposed skim milk powder of the present invention can be used for foods such as bakery products and confectionery such as chocolate, like ordinary skim milk powder and skim milk.

In the present invention, the whey protein index (hereinafter sometimes abbreviated as WPNI) is an index indicating the degree of heating of milk protein, and a specific measuring method will be described later. The L value obtained by the color difference meter indicates lightness, and a
And the b value indicates the degree of red and yellow, respectively, and represents the degree of coloring, indicates that the L value and the b value are small and the a value is large, the baking color is better, the heating degree of the skim milk powder and It is an index for monitoring the baking color of a bakery product using the skim milk powder, and a specific measuring method will be described later.

Next, the present invention will be described in detail with reference to test examples.
In the present invention, the following test method was adopted.

(1) Lactose Degrading Enzyme Activity Measuring Method and Labeling Method The lactose degrading enzyme label is the enzyme activity measured by the following method.

About 1 g of lactose-degrading enzyme is precisely weighed and a small amount of 1
0 ^-3 MMnCl containing ₂ 0.1MKH ₂ PO ₄ -NaO
Dissolve in H buffer (pH 6.5) and add 100 ml with purified water
And mix well and dilute 1 ml to a further 100 ml.

A test tube held in constant temperature water at 37 ° C.
l of a substrate solution (100 mg of 2-nitrophenyl-β-D-galactopyranoside dissolved in 100 ml of the buffer) and 1 ml of the buffer, and after several minutes, 1 ml of the enzyme solution, Mix well. After exactly one minute, the reaction is stopped by adding 4 ml of 0.2 M Na ₂ CO ₃ . In addition, the solution which performed said operation without adding a substrate solution is used as a control.

The absorbance at 420 mμ of the yellow reaction solution is measured using a 1 cm cell with respect to the control solution. From the obtained absorbance, the activity (Gu /
g) is calculated.

Gu / g = [E (OD) × 10 (min)] /
[1 (min) × w (g)] (where E is the absorbance at 420 mμ and w is the weight of lactose-degrading enzyme contained in 1 ml.) Here, 1 Gu / g is the above-mentioned condition. 1.0 for 10 minutes
Represents the amount of enzyme that increases the absorbance of

(2) Method for measuring lactose hydrolysis rate The lactose hydrolysis rate was determined by the enzyme method [Official Methods
Of Analysis of the Association of Official Analytical Chemists (Official
Methods of Analysis of the Association of Officia
l AnalyticalChemists), 14th edition, page 284,
Association of Official Analytical C
hemists, Inc.), 1984].

(3) Measurement method of whey protein index (WPNI) The whey protein index was determined by the method of Harland and Ashworth (edited by The Pharmaceutical Society of Japan, “Daily Product Test Methods and Comments”, 1st edition, Pages 31-32, Kanehara Publishing Co., Ltd., March 20, 1984).

(4) Test Method of Color Degree The color degree of the sample was measured for L, a and b values using a color difference meter (manufactured by Minolta Camera Co., Ltd.) according to the instruction manual attached to the apparatus.

(5) Flavor test method Samples were dissolved in distilled water, and 100 ml of a 10% strength aqueous solution was used as a sensory test by a panel of 20 men and women from 20 to 40 years old. Good taste (0 points), good taste (1 point), bad taste (2 points)
Points) and poor flavor (3 points). Based on the average of the evaluation points, less than 0.5 points are good, 0.5 points or more and less than 1.5 points are slightly good, and 1.5 points or more. A score of less than 2.5 was judged as poor, and a score of 2.5 or more and less than 3.0 was judged as bad.

(6) Baking color test method for bakery products A sample is dissolved in distilled water to prepare a 10% strength aqueous solution of 70 ml of a sample solution, 150 g of commercially available flour, and salt-free butter 40
g, 7 g of baking powder as a material, a method of making plain corn (Yoko Arimoto, "My Life Series No. 315, Special Edition, Easy Bread without Yeast Fermentation", page 7, Graph Co., Ltd. Company, 19
1994), and baked in an oven at 200 ° C. for 13 minutes to produce plain scones. Next, the burnt color of the plain cone was measured using a color difference meter (manufactured by Minolta Camera Co., Ltd.) according to the same method as the above-mentioned coloring degree test method, and according to the instruction manual attached to the apparatus, L, a and b.
The value was measured.

(7) Acceptability test for lactose intolerant patients Lactose intolerant ages 20 to 40 using 100 ml of a sample solution prepared by dissolving a sample in distilled water and preparing a 10% aqueous solution. 1 day after drinking the sample solution by 10 volunteers, and evaluated as normal stool (0 points) and loose stool (1 point). From the average of the evaluation points, more than the majority of 10 volunteers The sample having a score of 0.4 or less at which the sample had normal stool was judged to be a sample acceptable for use by lactose intolerant patients.

When testing different samples, the same volunteers were given a 5-day rest period, and after confirming that all of them recovered to normal stool, the same test was performed.

Test Example 1 This test was conducted to show that the lactose-decomposed skim milk powder of the present invention is superior to conventional skim milk powder and lactose hydrolyzed milk powder.

(1) Preparation of Test Samples The following three types of samples were prepared. Sample 1: untreated skim milk powder (lactose 50%, manufactured by Morinaga Milk Industry Co., Ltd.) Sample 2: skim milk powder (lactose 50%, manufactured by Morinaga Milk Industry Co., Ltd.) in the same manner as in Example 1 except that the heat treatment was not performed. ) 10 kg was dissolved in 90 kg of distilled water, 100 kg of a 10% strength aqueous solution was prepared, sterilized by heating at 72 ° C for 40 seconds with an HTST sterilizer (manufactured by Hisaka Seisakusho), and a commercially available lactase (GODO- manufactured by Godo Shusei Co., Ltd.). (YNL) 35 g, and the mixture was hydrolyzed by keeping at 43 ° C. for 2 hours.
Lactase was inactivated by heating at 5 ° C. for 5 minutes. The hydrolysis ratio of lactose in the obtained solution was 100%. Then
The obtained solution was solidified by using a vacuum concentrator to obtain a solid content of 40%.
And then spray-dried to obtain a powdered lactose-decomposed skim milk powder (so-called conventional lactose hydrolyzed milk powder) Sample 3: Lactose-decomposed skim milk powder prepared by the same method as in Example 1 of the present invention

(2) Test method Lactose hydrolysis rate, whey protein index (WPN) of each sample
I), the degree of coloration, flavor, baking color of bakery products using each sample, and whether or not lactose intolerance is acceptable for use by patients.
All were measured and tested according to the test method described above.

(3) Test Results The results of this test are as shown in Table 1. As is clear from Table 1, lactose-decomposed skim milk powder of the present invention (sample 3)
Is superior to conventional skim milk powder (Sample 1) in all of its flavor, roasting color of bakery products and that it can be used by lactose intolerant patients, and the conventional lactose hydrolyzed milk powder (Sample 2) ), It was confirmed that the bakery product was superior in flavor and baking color.

The tests were conducted by changing the type of lactose-degrading enzyme and the raw material (skim milk powder or skim milk), and almost the same results were obtained.

[0037]

[Table 1]

Test Example 2 In this test, the appropriate lactose content of lactose-decomposed skim milk was determined by using the flavor of lactose-decomposed skim milk, the roasting color of bakery products using the same, and whether lactose intolerance was acceptable for use by patients. Performed to determine the hydrolysis rate.

(1) Preparation of Test Sample As shown in Table 2, the lactose hydrolysis reaction was carried out while measuring the decomposition rate over time, and the decomposition rates were 50%, 70%, and 80%.
%, 90% and 100%, the lactose in the skim milk solution was decomposed, concentrated, spray dried and heated in the same manner as in Example 1, except that lactase was inactivated and stopped. By processing, five kinds of lactose-decomposed skim milk powder samples having a whey protein index of 0.2 and an L value of 83, an a value of 1.0, and a b value of 20 by a colorimeter were prepared. .

(2) Test method Lactose hydrolysis rate, whey protein index (WPN) of each sample
I), the degree of coloration, flavor, baking color of bakery products using each sample, and whether or not lactose intolerance is acceptable for use by patients.
All were measured and tested according to the test method described above.

(3) Test Results The results of this test are as shown in Table 2. As is evident from Table 2, in order to produce lactose-degraded skim milk powder which is excellent in all of flavor, coloring effect of bakery products and lactose intolerance patients, the lactose hydrolysis rate must be at least 80%. It turned out to be necessary.

The tests were conducted by changing the type of lactose-degrading enzyme and the raw material (skim milk powder or skim milk), and almost the same results were obtained.

[0043]

[Table 2]

Test Example 3 In this test, appropriate heat treatment conditions (whey protein index, degree of coloration) of lactose-decomposed skim milk powder are examined by using the flavor of lactose-decomposed skim milk powder and the baking color of a bakery product using the same as an index. Went for.

(1) Preparation of test sample As shown in Table 3, lactose in skim milk solution was decomposed, concentrated and spray-dried in the same manner as in Example 1 except that the heat treatment time was changed. Then, by heat treatment, seven kinds of lactose-degraded skim milk powder samples having a lactose hydrolysis rate of 100% were prepared.

(2) Test method Lactose hydrolysis rate of each sample, whey protein index (WPN)
I), the degree of coloring, the flavor, and the baked color of the bakery product using each sample were all measured and tested according to the above-described test methods.

(3) Test Results The results of this test are as shown in Table 3. As is clear from Table 3, in order to produce lactose-decomposed skim milk powder which is excellent in flavor and coloring effect of bakery products, powdered lactose-decomposed skim milk powder has a whey protein index of 1.0 or less, and L value by color difference meter is 70
It was found that the heat treatment had to be carried out in the range of ~ 95, a value of 0-5 and b value of 14-22.

The test was conducted by changing the lactose-degrading enzyme, the type of raw material (skim milk powder or skim milk), and the hydrolysis ratio of lactose to 80%, and almost the same results were obtained.

[0049]

[Table 3]

From the above Test Examples 2 and 3, in order to produce lactose-decomposed skim milk powder which is excellent in all of flavor, coloring effect and lactose intolerance, it is necessary to prepare skim milk powder or skim milk powder. The lactose hydrolysis rate in the milk is set to at least 80%, and the powdered lactose-decomposed skim milk obtained after the lactose decomposition treatment has a whey protein index of 1.0 or less and an L value measured by a colorimeter. Is 70 ~
It has been found that it is important to perform the heat treatment in the range of 95, a value of 0 to 5 and b value of 14 to 22.

Next, the present invention will be described in more detail by way of examples, but the present invention is not limited to the following examples.

[0052]

【Example】

Example 1 10 kg of commercially available skim milk powder (lactose 50%, manufactured by Morinaga Milk Industry Co., Ltd.)
Is dissolved in 90 kg of distilled water and 100% aqueous solution of 10% concentration is dissolved.
The weight was adjusted, and sterilized by heating at 72 ° C. for 40 seconds using an HTST sterilizer (Hisaka Seisakusho), 35 g of a commercially available lactase (GODO-YNL), and 43 ° C.
For 2 hours to hydrolyze, and then heated at 75 ° C. for 5 minutes to inactivate lactase. The hydrolysis ratio of lactose in the obtained solution was 100%. Next, the obtained solution was concentrated to a solid content ratio of 40% using a vacuum concentrator and spray-dried to obtain about 8 kg of powdery lactose-decomposed skim milk. 5 kg of the obtained powdery lactose-decomposed skim milk powder is
Using a cylindrical dryer, heat treatment was performed at 100 ° C. for 120 minutes to obtain about 4 kg of lactose-decomposed skim milk powder.

The obtained lactose-decomposed skim milk powder has a whey protein index of 0.2 and an L value of 8 using a colorimeter.
3, the a value was 1.0 and the b value was 20, the hydrolysis ratio of lactose was 100%, and the flavor and coloring effect were excellent.

Example 2 71.1 kg of commercially available skim milk (lactose 5%, manufactured by Morinaga Milk Industry Co., Ltd.)
, Microfiltration (manufactured by Nippon Millipore)
After removing the spores by filtration, 19.5 g of a commercially available lactase (manufactured by Godo Shusei Co., Ltd., GODO-YNL) was added, and the mixture was hydrolyzed by keeping it at 43 ° C. for 1.5 hours. Lactase was inactivated by heating at 5 ° C. for 5 minutes. The decomposition rate of lactose in the resulting solution was 89%. Then
The obtained solution was solidified by using a vacuum concentrator to obtain a solid content of 40%.
And then spray-dried to obtain about 6 kg of lactose-decomposed skim milk powder.

5 kg of the obtained powdery lactose-decomposed skim milk powder
Was subjected to heat treatment at 98 ° C. for 90 minutes using a fluidized drier to obtain about 4 kg of lactose-decomposed skim milk powder.

The resulting lactose-decomposed skim milk powder has a whey protein index of 0.5 and an L value of 9 using a colorimeter.
0, a value was 0.5, and b value was 16, the hydrolysis rate of lactose was 89%, and the flavor and coloring effect were excellent.

Example 3 1 kg of commercially available skim milk powder (lactose 50%, manufactured by Morinaga Milk Industry Co., Ltd.) was dissolved in 9 kg of distilled water, 10 kg of a 10% aqueous solution was prepared, and 75 kg was prepared using an HTST sterilizer (manufactured by Hisaka Seisakusho). ° C
And heat-sterilize for 60 seconds, add 7.0 g of a commercially available lactase (manufactured by Godo Shusei Co., Ltd., GKDK-YNL), and add
The mixture was hydrolyzed by holding for a time, and then heated at 80 ° C. for 2 minutes to inactivate lactase. The decomposition rate of the obtained solution was 9
7%. Next, the obtained solution was concentrated to a solid content ratio of 40% using a vacuum concentrator and spray-dried to obtain about 700 g of powdery lactose-decomposed skim milk.

The obtained powdery lactose-decomposed skim milk powder 500
g, using an oven and stirring appropriately, at 150 ° C.
For 10 minutes to obtain about 400 g of lactose-decomposed skim milk powder.

The obtained lactose-decomposed skim milk powder has a whey protein index of 0.1 and an L value of 8 using a colorimeter.
0, the a value was 2.0, and the b value was 21, the lactose hydrolysis rate was 97%, and the flavor and coloring effect were excellent.

[0060]

As described in detail above, the effects obtained by the lactose-decomposed skim milk powder of the present invention and the method for producing the same are as follows. 1) Since lactose-decomposed skim milk has both good properties such as excellent flavor and coloring effect, it can be suitably used as a raw material for bakery products and the like. 2) Lactose-decomposed skim milk powder is useful as a new food material that is well tolerated by lactose intolerant patients because of its reduced lactose content.

Claims (2)

[Claims] 1. The following physicochemical properties of a) to c): a) the whey protein index is 1.0 or less; b) the L value measured by a colorimeter is 70 to 95;
5, and b value is 14-22, c) Lactose hydrolysis rate is at least 80% (weight), lactose-decomposed skim milk powder. 2. A lactose-degrading enzyme is added to an aqueous solution of skim milk or skim milk to hydrolyze at least 80% (by weight) of lactose contained in skim milk or skim milk, and then the lactose-degrading enzyme is lost. Activated, concentrated, and spray-dried, the resulting powdered lactose-decomposed skim milk powder is obtained with a whey protein index of 1.
0 or less, and the L value measured by a colorimeter is 70 to 9
5. A method for producing lactose-decomposed skim milk characterized by heating to a value of 0 to 5 and a value of 14 to 22.