JP3386255B2 - Whey preparation and method for producing the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a whey preparation and a method for producing the whey, more specifically, a whey preparation having a reduced threonine content by removing a heat-aggregating protein from a raw whey and a whey preparation thereof. Manufacturing method

[0002]

2. Description of the Related Art Whey protein is used as a protein material for various nutritional compositions because of its excellent nutritional value and protein utilization efficiency. Whey protein is usually used in these infant formulas, taking advantage of the fact that it contains a large amount of essential amino acids, especially cystine, which is highly essential in infants. When used in a modified milk powder, whey as it is has a high ratio of minerals and lactose to the protein, and therefore, a material prepared by adjusting these excess components is usually used as a material. As a component adjusting method, generally, treatments such as electrodialysis, ultrafiltration, or lactose crystallization removal are often performed alone or in combination. According to these treatment methods in which the economic loss of the protein is suppressed as much as possible, a whey protein material having the same protein composition as the raw whey is prepared with almost no selective loss of the polymer protein component. In the development of infant formula as a milk substitute, milk whey protein has been used to enhance whey protein so that the ratio of casein to whey protein is close to that of human milk. Alternatively, a peptide composition obtained by enzymatically degrading whey protein is being used as a protein material for a reduced allergen-modified milk powder.

[0003]

However, even if the whey protein is enhanced by using the milk whey protein as described above and the ratio of casein to whey protein in the formula is close to that of breast milk, the whey protein is Since milk and human milk are significantly different in composition, it is unavoidable that some essential amino acids are insufficient or deficient in terms of the amino acid composition that is an important index of protein nutrition. Among them, the plasma threonine concentration of artificially fed infants is 1.5 times that of breast-fed infants.
2.5 times when fed with whey protein decomposed milk
There are also reports that the price will almost double (Lin Marie Janus, Mary Francis Piciano, Terry F.
Hatch (Lynn Marie Janas, Mary Frances Picciano, T
erry F. Hatch: Pediatrics 75 (4) 775-784 (1985)) and J. Rigo, A. Bellrose, J. Center (J.Rigo,
A. Verloes, J. Senterre: The Journal of Pediatrics, 1
15 (5) 752-755 (1989))).

[0004] Despite concerns about the effects of excess threonine, methods for reducing the threonine content of milk powder and its whey protein material have not yet been investigated. Therefore, the present invention aims to provide a method for producing a whey preparation having a reduced threonine content. It is also an object of the present invention to provide a whey preparation with a reduced threonine content.

[0005]

Means for Solving the Problems As a result of intensive studies, the present inventors have conducted a heat treatment on a raw material whey to remove a protein having a low heat stability as an aggregated protein or an acid-insolubilized protein. The present inventors have succeeded in efficiently reducing the threonine content therein and completed the present invention. That is, in the present invention, the raw whey is heat-treated at a temperature of 70 ° C. or higher at a pH of 4.6 ± 0.1 under the condition that 15% or more and 40% or less of the total protein is insolubilized, and the resulting aggregated protein is removed. The present invention provides a method for producing a whey preparation having a reduced threonine content in the amino acid composition. The present invention also provides a whey preparation produced by the above method and having a reduced threonine content in the amino acid composition.

The present invention will be described in detail below. In the present invention, first, the raw material whey is heat-treated at a temperature of 70 ° C. or higher. By this treatment, a protein having a high threonine content and a low thermal stability is aggregated.

As the raw material whey, cheese whey, milk whey, rennet whey, acid whey, whey protein concentrate, separated whey protein and the like can be used, among which cheese whey and rennet whey are preferred. .
The raw whey may be in any form such as liquid, gel, powder and cake. The heating may be carried out under conditions such that 15% or more and 40% or less of the total protein in the raw whey is insolubilized at pH 4.6 ± 0.1. Specifically, the raw material whey is heated to 70 ° C. or higher, preferably 70 to 95 ° C.
It is good to heat for seconds to 15 minutes, preferably 15 seconds to 5 minutes.
When the heat treatment temperature is 70 ° C. or lower, it is difficult to effectively induce the irreversible denaturation of the target protein, and there is a problem that the aggregate formation is insufficient. Also, the heat treatment time is 5
If the time is less than or equal to 2 seconds, it will be difficult to obtain sufficient aggregate formation, and if it is more than 30 minutes, there will be a problem that excessive denaturation of the protein and aggregation formation which are not intended will be caused. The pH of the raw material whey may be adjusted to 5 to 10 prior to the heat treatment. By adjusting the pH of the raw material whey in this manner, it is possible to obtain the effect that the targeted denaturation of the protein can be advanced in preference to other proteins.

Next, the aggregated protein produced by the above heat treatment is removed. It is advisable to cool the heat-treated whey before removing the aggregated proteins. Although any method may be used to remove the aggregated protein, for example, a membrane filter may be used. As the membrane filter, an ultrafiltration membrane having a molecular weight cutoff of 80,000 daltons or more and a microfiltration membrane having a pore diameter of 0.01 to 1 μm can be used. Among them, an ultrafiltration membrane having a molecular weight cutoff of 200,000 to 500,000 daltons and a pore diameter of 0.01 A microfiltration membrane of 0.5 μm is preferred. The removal operation of the aggregated protein using a membrane filter as described above, in order to enhance the recovery rate of the target low threonine protein, the concentrated solution obtained by filtering using a certain membrane filter, water Is added so that the concentration of the concentrated solution becomes 1/2 or less, and then filtration may be performed again using the same membrane filter.

Alternatively, the aggregated protein may be removed by adding an acid to the aggregated protein produced by the heat treatment to remove the precipitate produced by centrifugation. The acid may be added in such an amount that the isoelectric point of the aggregated protein is reached, generally pH 4 to 5, preferably pH 4.5 to 4.7.
It is advisable to add an acid so that As the acid, hydrochloric acid,
Citric acid, lactic acid and the like can be used, and among these, hydrochloric acid and citric acid are preferable. Since the addition of such an acid causes isoelectric precipitation, the precipitate thus produced can be removed by centrifugation to remove the aggregated protein. Centrifugation is 5000-10,000 xg, 10-90
It may be performed continuously for 2 seconds, preferably 8000 to 10000 ×
It is good to carry out continuously for 20 to 60 seconds. It is advisable to adjust the pH of the resulting supernatant to 5-8 after removing the precipitate generated by the addition of the acid by centrifugation. Furthermore, this supernatant may be filtered using the membrane filter as described above. By combining such filtration operations, the effect of further concentrating and desalting the low threonine protein can be obtained.

As described above, the threonine content in whey can be reduced, and as a result, the threonine content in the amino acid composition of whey is 5 to 7% by weight,
A whey preparation is obtained which is preferably 5-6% by weight. The whey preparation of the present invention is suitable as a protein material such as infant formula, low allergen milk, nutritional food, and functional food. That is, the above whey preparation, infant formula, low allergen milk, to balance the amino acid composition of nutritional foods and functional foods, to be used as a protein material for eliminating excess or deficiency of intake. You can

[0011]

EXAMPLES The present invention will be specifically described below with reference to examples, but the scope of the present invention is not limited to these examples. Unless otherwise stated, all percentages represent weight percentages.

[Example 1] HTST (High Temperature) at 78 ° C for 45 seconds was added to 200 kg of Gouda cheese whey liquid having a pH of 6.4.
Short time) After heat treatment, it was cooled to 50 ° C. and treated with an ultrafiltration membrane (DGR, type GR30PP) having a molecular weight cutoff of 200,000 daltons. 40 times concentrated 5 times
Water (kg) was added, and the mixture was further treated with the same ultrafiltration membrane and concentrated 4 times (concentrate I). The total permeated liquid (220 kg) thus obtained was subjected to an ultrafiltration membrane having a molecular weight cut off of 20,000 daltons (DDS, type G).
It was concentrated 6 times with R61PP) to obtain 36 kg of concentrated liquid (concentrated liquid II).

Denatured protein rate of HTST heated whey (pH
The percentage of insolubilized protein in 4.6) was measured by the Kjeldahl method and was 38.2%. In addition, the starting whey and the essential amino acid compositions of the concentrates I and II were hydrolyzed with 6N iron-free hydrochloric acid, and then an automatic amino acid analyzer (JEOL,
JCL-200A). The results are shown in Table 1. As can be seen from Table 1, the ratio of threonine to the total essential amino acid composition was 7.51% in the raw material whey, whereas it was 5.97% in the concentrate II, which was 21% lower.

[0014]

[Table 1]                   Table 1. Essential amino acid composition of whey preparations                               Raw material whey concentrate I concentrate II           amino acid%           Isoleucine 6.17 4.28 6.00           Leucine 10.09 11.02 11.93           Lysine 9.00 8.51 9.95           Methionine 2.22 1.73 2.13           Cystine 2.18 3.33 3.58           Phenylalanine 3.41 3.80 3.47           Tyrosine 3.11 4.45 3.56           Threonine 7.51 7.07 5.97           Tryptophan 1.99 1.98 2.23           Valine 6.18 6.53 5.62           Histidine 2.00 2.29 1.96           Other 46.14 45.01 43.59           Total 100.00 100.00 100.00

Example 2 200 kg of rennet cheese whey liquid having a pH of 5.8 was subjected to HTST heat treatment at 75 ° C. for 20 seconds, cooled to 30 ° C., and adjusted to pH 4.6 with hydrochloric acid.
After preliminary cleaning treatment with a clarifier, insoluble matter was removed with a continuous centrifuge (Alfa Laval Co., LAPX202). The operating conditions were a centrifugal force of 8200 × g and a separation time of 20 seconds. After adjusting the pH of the supernatant to 6.5 with potassium hydroxide, an ultrafiltration membrane (DDS with a cut-off molecular weight of 20,000 Daltons) was used.
(Type GR61PP), to obtain 34 kg of 5-fold concentrated solution.
The modified protein rate of the HTST heated whey was 15.6%.
Table 2 shows the essential amino acid compositions of the starting material whey, the insoluble matter and the concentrated solution. As can be seen from Table 2, the ratio of threonine in the total essential amino acid composition was 7.36% in the starting material whey, whereas it was 5.54% in the concentrated liquid, which was a decrease of 24.7%.

[0016]

[Table 2]                   Table 2. Essential amino acid composition of whey preparations                               Raw material whey acid insoluble matter concentrate           amino acid%           Isoleucine 6.18 3.04 6.76           Leucine 10.08 9.41 10.21           Lysine 9.00 7.36 9.30           Methionine 2.18 1.03 2.40           Cystine 2.18 3.61 1.91           Phenylalanine 3.45 4.22 3.31           Tyrosine 3.17 5.10 2.82           Threonine 7.49 8.68 5.54           Tryptophan 1.91 2.01 1.89           Valine 6.17 7.53 5.92           Histidine 1.95 2.53 1.85           Other 46.24 45.48 48.10           Total 100.00 100.00 100.00

[Example 3] 200 kg of Gouda cheese whey liquid having a pH of 6.4 was subjected to HTST heat treatment at 70 ° C for 120 seconds, then cooled to 50 ° C, and a membrane filter having a pore size of 0.2 µm (NIF5205). Processed in.
When it was concentrated 8 times, 25 kg of water was added, and it was concentrated 2 times with the same membrane filter (concentrated solution I). 200 kg of the total permeated liquid obtained was concentrated 5 times with an ultrafiltration membrane (type GR61PP, DDS, Inc.) having a molecular weight cut off of 20,000 daltons to give 40 kg.
To obtain a concentrated liquid (concentrated liquid II).

The modified protein rate of HTST heated whey is 31.4
%Met. Also, starting whey, concentrates I and II
The essential amino acid composition of is shown in Table 3. As can be seen from Table 3, the ratio of threonine to the total essential amino acid composition is
The starting material whey was 7.49%, whereas the concentrate II
Was 6.01%, a decrease of 20%.

[0019]

[Table 3]                   Table 3. Essential amino acid composition of whey preparations                               Raw material whey concentrate I concentrate II           amino acid%           Isoleucine 5.98 4.62 6.00           Leucine 9.60 11.47 11.93           Lysine 9.11 8.83 9.95           Methionine 2.16 1.92 2.13           Cystine 2.32 3.25 3.58           Phenylalanine 3.44 3.67 3.47           Tyrosine 3.04 4.27 3.56           Threonine 7.49 7.82 6.01           Tryptophan 1.95 1.97 2.23           Valine 6.06 6.24 5.62           Histidine 1.96 2.14 1.96           Other 46.89 43.80 43.55           Total 100.00 100.00 100.00

[0020]

EFFECT OF THE INVENTION According to the method of the present invention, a whey preparation can be produced on an industrial scale, inexpensively and efficiently by a simple treatment, in which the excess threonine content in the raw whey is reduced to an appropriate level. be able to. Such a whey preparation is suitable as a protein material for infant formula, low allergen milk, nutritional foods, functional foods and the like.

Front Page Continuation (72) Inventor Yu Kuwata 1-21-3 Sakaemachi, Higashimurayama City, Tokyo Meiji Dairy Co., Ltd., Institute of Nutrition Science (56) Reference JP-A-5-236883 (JP, A) -507312 (JP, A) (58) Fields surveyed (Int.Cl. ⁷ , DB name) A23C 21/00 A23C 9/14-9/15 A23J 3/08

Claims (8)

(57) [Claims] 1. A raw material whey is heat-treated at a temperature of 70 ° C. or higher for 5 seconds to 15 minutes to obtain a total protein content of 15 at pH 4.6 ± 0.1.
% And 40% or less are insolubilized, and the resulting aggregated protein is removed, and a method for producing a whey preparation having a reduced threonine content in the amino acid composition. 2. The method according to claim 1, wherein the raw material whey is at least one selected from the group consisting of cheese whey, milk whey, rennet whey, acid whey, whey protein concentrate and isolated whey protein. 3. The method according to claim 1, wherein the aggregated protein is removed by using a membrane filter. 4. The method according to claim 3, wherein the membrane filter is an ultrafiltration membrane. 5. The membrane filter has a pore size of 0.01 to 0.5.
The method according to claim 3, which is a microfiltration membrane having a thickness of μm. 6. The method according to claim 1, wherein the aggregated protein is removed by removing the precipitate formed by adding an acid to the aggregated protein by centrifugation. 7. The method according to claim 1, wherein the content of threonine in the amino acid composition of the obtained whey preparation is 5 to 6.5% by weight. 8. A whey preparation produced by the method according to any one of claims 1 to 7 and having a reduced threonine content in the amino acid composition.