HU194487B - Process for producing food-preparation suitable for feeding sicks of phenylketoneurea from protein hydrolysates - Google Patents

Abstract

Protein hydrolysates or meat- aroma concentrates are subjected to chromatography on a chromatographical column filled with a beta -cyclodextrin polymer to reduce their phenylalanine content.

Description

Applicability of the invention

SUMMARY OF THE INVENTION The present invention provides a process wherein the treatment with a cyclodextrin polymer reduces the phenylalanine content of protein hydrolyzates or optionally meat flavor concentrates.

Phenylalanine-deficient protein hydrolysates and products derived therefrom, e.g. meat flavor concentrates play a particularly important role in the protein supply of patients with phenylketonuria.

State of the art (Prior art procedures)

Several attempts have been made to reduce the amount of phenylalanine in protein hydrolysates.

Partridge, SM and RC Brinley (Biochem. X, 51, 628, 1951) removed phenylalanine and tyrosine from protein hydrolysates by ion exchange displacement chromatography (Zeo-Carb 215, DOWEX 2 and sulfonated polystyrene resin) 0.075 N sodium hydroxide and 0.15 N ammonia.

Campbell, P.N., S. Jacobs, and T.S. Work (Chem. And Ind., 117, 1975) have further developed the preparative ion exchange chromatography (Zeo-Karb 225 resin).

Celretti, P., G. Montesí, and N, Silipradi (Arch. Scienze Bioi., 554, 1957), were prepared to separate phenylalanine from the hydrolyzate on Amberlit-IRC-50 resin. The disadvantages of the processes for preparing phenylalanine-poor protein hydrolyzates are that they are very expensive and the taste of the products obtained is inadequate and unpleasant.

The unfavorable taste properties of phenylalanine-free protein hydrolyzates prepared by ion exchange chromatography are due to the process of hydrolysis. Ion exchange chromatography requires a salt-poor protein hydrolyzate, so that the hydrolysis is not with hydrochloric acid but with sulfuric acid, which can be easily removed from the system as the calcium salt.

It is also known that sulfuric acid hydrolysates have so-called "protein" hydrolysates. off-Flavor components are formed. (DE-PS 127-693; Prendesgast, K. Food Trade 44, 14-21. 1974)

GB-PS 1,091,637. The patent discloses that γ-cyclodextrin can be cross-linked with various bifunctional compounds (epi-chlorohydrin, dichlorohydrin, diepexibutane, diepexi-propyl ether) to form ß-cyclodextrin polymers.

O-cyclodextrin polymers are known to form cyclodextrin complexes with suitable compounds, e.g. with aromatic amino acids.

Wiedenhof (Starke, 21, 163, 1969) described that the complexing properties of β-cyclodextrin polymers serve as the basis for a new analytical chromatographic method, gel inclusion chromatography.

Zadon et al. (Starke, 31, 11, 1979) described an analytical procedure whereby phenylalanine, tryptophan and tyrosine were separated from each other and aliphatic amino acids simultaneously.

Known methods for separating aliphatic and aromatic amino acids have not yet been used for preparative purposes.

Object of the invention

Methods known hitherto, using cyclodextrin polymers, concern the analytical separation of aliphatic and aromatic amino acids from amino acid mixtures, and thus do not attempt to produce protein-poor protein hydrolysates. It is an object of the present invention to provide a process for the removal of phenylalanine from protein hydrolysates and their reaction products, which is commercially applicable.

Summary of the Invention

A long-standing challenge is to develop a method for removing phenylalanine from hydrolysates containing 10-30% total amino acids and 10-30% total amino acids and 10-30% common salt. The present invention is based on the surprising discovery that, under certain conditions, phenylalanine separation is also possible from such high concentrations of preparations.

The separation assumes conditions under which the? -Cyclodextrin polymer used has a high specific complexing activity against phenylalanine.

A large number of experiments have shown that the binding of phenylalanine and tyrosine on the? -Cyclodextrin polymer depends on the concentration of the two amino acids in the protein hydrolyzate.

For reducing the salt content of the hydrochloric protein hydrolyzates used or DDR-PS 127,693. German desalination or electrodialysis is suitable.

The amount of phenylalanine bound by 1 g of 6-cyclodextrin polymer depends on the diameter of the polymer-filled separation column, the height of the packing and the phenylalanine concentration of the solution to be treated, as well as the elution rate, pH and temperature.

It is important to recognize that the column separating power, i.e. the amount of phenylalanine absorbed by 1 g of polymer, increases with increasing concentrations of phenylalanine.

An essential feature of the process of the invention is to adjust the concentration ratios of the protein hydrate for treatment so that the amount of phenylalanine is between 0.5 g / l and 3 g / l, with an amino acid content of 10-30%, preferably 20%. The solids content should be 20-50%, preferably 40%. To 100 parts by weight of protein hydrolyzate is added 10-100 parts by weight of a cyclodextrin polymer.

The conditions required for the separation of phenylalanine, such as pH, temperature, column dimensions are conveniently selected as described. Details of the separations performed are given in Table I.

EXAMPLES A portion of the? -Cyclodextrin polymer (Hungarian Patent No. 177,419) was swollen in water and loaded onto a chromatographic column 70x2.5 cm. 100 parts of casein hydrolyzate (solids content 40%, amino acid content 20%, sodium salt content 20%, phenylalanine content 0.15%, pH 6) were applied to the gel bed. The dead volume from the column was discarded. By applying pressure and vacuum, the hydrolyzate can be completely pressed or sucked through the column. The solution draining from the column has the following composition:

solids content: 35% amino acid content: 17% common salt content: 18% phenylalanine content: 0.02%

This phenylalanine-poor hydrolyzate, when diluted to 1.5% saline, has a pleasant meaty taste.

The 6-cyclodextrin polymer used is prepared from a cyclodextrin and is reacted with a multi-reagent and is cross-linked with cyclodextrin and is prepared from Hungarian Patent No. 177,419).

/. spreadsheet

Complexation of cyclodextrin polymer-phenylalanine in aqueous medium as a function of phenylalanine concentration (pH 7, column diameter 16 mm)

The amount of 6-cyclodextrin polymer was 0.5 g

Column fill height 2 cm

Phenylalanine concentration (mg / 100 ml) Amount of phenylalanine applied (mg) The amount of phenylalanine bound Amount of phenylalanine bound by 1 g of cyclodextrin polymer (mg) mg % 50 15 mg (in 30 ml) 1.25 8.3 2.5 100 30 mg (in 30 ml) 1.70 5.7 3.5 150 45 mg (in 30 ml) 2.00 4.4 4.0

The amount of 6-cyclodextrin polymer is 1.0 g. The height of the column fill is 4 cm

50 15 mg (in 30 ml) 1.75 11.7 1.7 100 30 mg (in 30 ml) 2.95 9.8 3.0 150 45 mg (in 30 ml) 4.00 8.9 4.0 The amount of 6-cyclodextrin polymer was 2.0 g Column fill height 7 cm 50 15 mg (in 30 ml) 3.25 21.7 1.6 100 30 mg (in 30 ml) 4.70 15.7 2.4 150 45 mg (in 30 ml) 7.75 17.2 3.9

The amount of 6-cyclodextrin polymer was 3.0 g. The height of the column was 10 cm

50 15 mg (in 30 ml) 4.80 32.0 1.6 100 30 mg (in 30 ml) 7.00 23.3 2.3 150 45 mg (in 30 ml) 11.25 25.0 3.8

Claims (2)

Claims A process for the preparation of a nutritional formula from protein hydrolyzates for the nutrition of patients with phenylketonuria, characterized by reducing the phenylalanine content of the protein hydrolyzate, preferably casein hydrolyzate, by column chromatography on a beta-cyclodextrin polymer. The concentration of phenylalanine in the range 0.5-3.0 g / l: volume, 10-30% total amino acid content, passed through a column packed with 10-100 parts by weight of beta-cyclodextrin polymer per 100 parts by weight of protein hydrolyzate. 2. The process according to claim 1, wherein the protein hydrolyzate to be treated has a total amino acid content of 20% and a dry matter content of 40%. (no drawing)