JPS6338328B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a food material having a blood cholesterol level lowering effect. Conventionally, the production of peptides and amino acids by hydrolyzing proteins with enzymes has been carried out mainly in the food field. However, the purpose of these methods is to solubilize proteins by decomposing them with enzymes, or to reduce the molecular weight (molecular weight is several thousand or more) to make them suitable as food materials. There was no problem with the molecular weight of the product itself. As a result of researching the relationship between enzymatic degradation products of proteins and digestion and absorption, the present inventors found that (1) the average molecular weight should be lowered to 700 or less, preferably 500 or less, (2) peptides with a molecular weight of 700 or more should be (3) The content of free amino acids should be below 20% by weight. In other words, the low-molecular-weight peptide composition containing deipeptides and tripeptides as main components should reduce blood cholesterol levels. It was confirmed that it decreased. Furthermore, this composition: (1) has a different intestinal absorption capacity from proteins or amino acid mixtures with the same amino acid composition, has an increased total nitrogen absorption rate, and has low absorption antagonism between amino acids; (2) Improved nitrogen balance and becomes a highly efficient nitrogen source. (3) The rate of weight gain increases significantly. Many advantages as a food material, such as those mentioned above, were also confirmed. This is based on the tests that will be demonstrated in detail below.A diet with the same amino acid composition shown in the following table was prepared.

【table】

[Table] The nitrogen sources in the above table have the following composition. A...Egg white protein B...Peptide composition with an average molecular weight of 420 and 8% by weight of free amino acids C...Free amino acid mixture D...Peptide composition with an average molecular weight of 1400 and 2% by weight of free amino acids 10 animals each of these diets The results of 2 weeks of ad libitum ingestion of this product in Wistar rats were as shown in the table.

[Table] In the table above, Food efficiency refers to each weight.
It displays the ratio based on the value of Gain/Food intake. The following can be understood from this table. The food material () of the present invention has a significantly larger nitrogen retention amount (balance) than other materials, and as a result,
It was found that food efficiency was significantly increased and blood cholesterol levels were lowered despite weight gain. Furthermore, in order to consider the absorption of each amino acid, rather than the macroscopic consideration of nitrogen sources, 24
Nitrogen source samples (), (), (), and () used in the diet described above were forcefully injected into the stomachs of Wistar rats that had been fasted for a period of time using a tube, and blood was collected from the portal vein at regular intervals to obtain amino acids. The concentration was measured to determine the amount absorbed per hour. The results are shown in Table and Table. Note that the results are the average values of five rats each. The table shows the average absorption rate of each amino acid until the absorption amount reaches its peak value, and the table is a comparison table of the amino acid absorption patterns of the sample () with almost ideal amino acid composition and the above samples () to ().

[Table] As is clear from this table, the food material of the present invention () is not absorbed incompletely like egg white protein (), and the degree of mutual absorption antagonism between amino acids is greater than that of the amino acid mixture (). The initial yield rate is approximately 30% higher than that of conventional protein decomposition products.

[Table] Ideal amino acid pattern for amino acid absorption ()
It is desirable that it be close to . However, the table clearly shows that in egg white protein () and amino acid mixture (), the rate of separation from the ideal absorption pattern () is particularly large for Phe Tyr and His. It was confirmed that the food material (2) of the present invention has a pattern close to the ideal absorption pattern and achieves well-balanced absorption. The above facts are presumed to have a great influence on the metabolism of the absorbed amino acid itself or other amino acids. One of the evidences for this seems to be a decrease in cholesterol levels. As can be seen from the above test results, attention has not been focused on low-molecular-weight peptides that clearly have the effect of lowering blood cholesterol levels. Therefore, an object of the present invention is to provide a food material having a blood cholesterol level lowering effect. The present invention focuses on free amino acid content and molecular weight.
This is a food material that has a blood cholesterol level lowering effect and is mainly composed of a low molecular weight peptide composition with an average molecular weight of 700 or less, which is composed mainly of dipeptides and tripeptides with a peptide content of 700 or more and 20% or less. Furthermore, the food material preferably has a free amino acid content and a peptide content with a molecular weight of 700 or more at 10% or less. Furthermore, preferably, the food material has an average molecular weight of 500 or less. Conventionally, there has been no problem with low-molecular-weight peptides mainly composed of dipeptides and tripeptides, which have many advantages as described above, as concluded from the test results shown in the above tables. The present inventors attempted to produce such low-molecular-weight peptides from protein raw materials of arbitrary origin, and as a result, the following findings became clear (see table). (1) Among protein hydrolases, pepsin is the most soluble, but degradation with pepsin does not proceed easily once the molecular weight reaches a certain level, and it is extremely difficult to reduce the average molecular weight to less than 1000. Have difficulty. (2) The degrading power of neutral protease is weaker than that of acidic protease, and there is no enzyme other than pronase that can reduce the average molecular weight of the product to less than 1000. However, because it is a complex enzyme, the production of free amino acids is extremely large, and at the stage when the average molecular weight approaches 500, more than 50% is free amino acids. (3) Acidic protease has superior decomposition power, and morsin (Aspergillus originating from Fujisawa Pharmaceutical Co., Ltd.)
saitoi), Sanprose F (Hankyu Kyoei Bussan Origin)
Rhizopus chinensis) etc. are useful as they produce less free amino acids. (4) None of the currently known enzymes can be used alone to reduce the molecular weight to the desired level, and as a result of investigating various combinations of enzymatic decomposition reactions, we found that pepsin-morsin, pepsin-sanprose, morsin-morsin It has been confirmed that the enzyme combination of Samproda F is effective in reducing the molecular weight and free amino acid content sufficiently as desired. The method for producing the low-molecular-weight peptide composition constituting the main component of the food material of the present invention will be described below with reference to production examples. Production example: 50g of dried egg white (protein content 82wt%)
The mixture was dissolved in water, the pH was adjusted to 3 with hydrochloric acid, 1 g of Morsin and 1 g of Sunprose F were added, and the mixture was reacted at 40° C. for 24 hours while maintaining the pH at 3. After heating the post-reaction solution at 100℃ for 10 minutes to deactivate the enzyme,
The mixture was centrifuged at 3000 rpm (1500 G) for 10 minutes to remove insoluble matter, and the supernatant was freeze-dried. The yield of this product was 93.2% based on the starting protein, and the average molecular weight was 340. From the results of gel filtration of this product, it was possible to produce a blood cholesterol level lowering agent in which 88 wt% or more of the product had a molecular weight of 700 or less. In addition,
Discrimination below 700 cannot be performed by gel filtration.
The free amino acid content in the product was 8.5%. Production Example Under the same conditions as in Production Example except for the enzymes used, 1 g of Morsin was first added, and then 8 hours later, 1 g of Sunprose F was added and reacted for a further 10 hours, followed by the same treatment as in Production Example. The yield of the obtained product was 93.9%, the average molecular weight was 350, the free amino acid content was 8.1%, and from the gel filtration results, more than 90% of the molecular weight was
It was below 700. Production Example The same treatment as in Production Example was carried out under the same conditions as in Production Example except for the enzymes used, and 1 g of pepsin and 1 g of morsin were added at the same time. The yield of the obtained product was 96.1%, the average molecular weight was 510, the free amino acid content was 7.8%, and the gel filtration results showed that more than 86% had a molecular weight of 700 or less. Production example Under the same conditions as in the production example except for the enzyme used, first 1 g of pepsin was added, then after 6 hours, 1 g of morsin was added.
g was added and the reaction was continued for further 10 hours, followed by the same treatment as in the production example. The yield of the product obtained is 98.3
%, average molecular weight is 550, free amino acid content is 7.3%
According to the gel filtration results, more than 83% had a molecular weight of 700 or less. Production Example The same treatment as in the Example was carried out under the same conditions as in the Production Example except for the enzymes used, with the addition of 1 g of pepsin and 1 g of Sunprose F at the same time. The yield of the obtained product was 94%, the average molecular weight was 430, the free amino acid content was 8.7%, and the gel filtration results showed that more than 90% had a molecular weight of 700 or less. Production Example The same conditions as in Production Example were used except for the enzyme used. First, 1 g of pepsin was added, and after 6 hours, 1 g of Sunprose F was added and the reaction was continued for a further 10 hours, followed by the same treatment as in Production Example 1. The yield of the obtained product was 96%, the average molecular weight was 410, the free amino acid content was 9.2%, and the gel filtration results showed that more than 91% of the products had molecular weight.
It was below 700. Production example Under the same conditions as in Example 1 except for the enzyme used, first 0.25 g of pepsin was added, 3 hours later 1 g of morsin was added, and after 3 hours, 1 g of Sunprose F was added.
After reacting for 10 hours, the same treatment as in Example was performed. The yield of the product obtained was 95%, and the average molecular weight was
370, the free amino acid content was 11.3%, and gel filtration results showed that more than 93% had a molecular weight of 700 or less. The evaluation method of the products in the above examples is as follows. (1) Yield of product Nitrogen amount in product/nitrogen amount in raw materials x 100 Nitrogen analysis was based on the Kjeldahl analysis method. (2) Average molecular weight of product [average molecular weight of amino acids in raw protein] x [number of moles of amino groups in 1 g of product] / [number of moles of amino groups in complete hydrolyzate of 1 g of product] Quantification was performed using TNBS (Tri-Nitro-
Complete hydrolysis of the product was achieved by hydrolysis in 6N HCl at 110°C for 24 hours using the Benzen-Sulphonic acid method. (3) Quantification of free amino acids The product solution is treated with basic copper carbonate to form amino acids and peptides into copper complexes, which are adsorbed onto an anion exchange resin, and the free amino acids eluted with 0.05M boric acid buffer are automatically analyzed. It was quantified using an amino acid analyzer. However, since acidic amino acids were not liberated by the boric acid buffer, the product was directly subjected to an amino acid analyzer for quantification. Accurate quantification is possible because there is no influence of peptides at the separation position of acidic amino acids in an amino acid analyzer. (4) Gel filtration Use Sephadex G-10, which has the lowest molecular weight cutoff, to determine the ratio of peptides with a molecular weight of 700 or less. In the manufacturing example, the raw protein used is egg white, but is not limited to casein, soybean, wheat gluten, fish meal, chlorella, yeast protein, etc., as well as protein substances enriched with specific amino acids through plastein reaction. can also be used. The substrate concentration of the raw protein protein is preferably about 5 to 20 w/v%. This is because if it is less than 5%, it is not practical, and if it is more than 20%, it becomes too viscous. The amount of enzyme added should be at least 1wt%, preferably 2wt%, based on the substrate to achieve a degree of decomposition suitable for the purpose.
~5wt% is good. The reaction time depends on the substrate concentration, enzyme amount,
The reaction time is a function of the reaction temperature, etc., and is set at a time that allows a peptide composition that is not decomposed into amino acids to be obtained. The reaction temperature is determined depending on the optimum temperature of the enzyme used. The acid used may be a strong acid or a weak acid. For comparison, the table below shows a case where a protein is degraded by a combination of two or more proteases as in the production example of the present invention and a case where a single protease is used.

[Table] From the comparison between the production example and the table above, it is clear that according to the production example described above, various protein sources can be degraded in high yield to molecules with a molecular weight of 500 or less that mainly consist of the target dipeptide and tripeptide. Moreover, the main component of the food material of the present invention has a low free amino acid content of 10 wt% or less, which has little amino acid absorption antagonism, and a relatively high peptide content with a molecular weight of 700 or more, which is low at 20% or less. It can be easily understood that the low molecular weight peptide composition can be reliably produced.

Claims (1)

[Scope of Claims] 1. Blood whose main component is a low-molecular-weight peptide composition with an average molecular weight of 700 or less, the main components of which are dipeptides and tripeptides in which the content of free amino acids and the content of peptides with a molecular weight of 700 or more are 20% or less. A food material that has the effect of lowering intermediate cholesterol levels. 2 Claim 1 in which the content of free amino acids and the content of peptides with a molecular weight of 700 or more are 10% or less
Food ingredients listed in section. 3. The food material according to claim 1 or 2, which has an average molecular weight of 500 or less.