GB1561663A

GB1561663A - Protection of food additives

Info

Publication number: GB1561663A
Application number: GB40817/76A
Authority: GB
Original assignee: F Hoffmann La Roche AG
Current assignee: F Hoffmann La Roche AG
Priority date: 1975-10-02
Filing date: 1976-10-01
Publication date: 1980-02-27
Also published as: DK445476A; JPS5244250A; NO763366L; LU75910A1; FR2345944B1; SE7610930L; DE2643624A1; BE846843A; CH613609A5; FR2345944A1; NZ182168A; NL7610882A; MC1107A1; AU1810076A

Description

(54) THE PROTECTION OF FOOD ADDITIVES (71) We, F. HoFFMANN-LA ROCHE & Co., AKTIENGESELLSCHAFT, a Swiss Company of 124184 Grenzacherstrasse, Basle, Switzerland, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: The present invention relates to the protection of food additives. More particularly, the invention is concerned with a process for the manufacture of stable and protected food additives. The invention is also concerned with such stabilised and protected food additives and with the use of proteins of ultra-filtered milk for the stabilisation and protection of food additives.

Although not being limited thereto, the present process is of particular application in the treatment of products such as food colorants, water-soluble and fat-soluble vitamins, and mineral salts for complementing the food of humans and of animals.

In order to obviate the changes in the composition and in the appearance of foods brought about by industrial treatment, the use of food additives is becoming increasingly frequent.

However, the addition of such additivcs poses serious technological problems since they are often sensitive, unstable, insoluble or immiscible in or with the media to which they are to be added. They are also sometimes aggressive towards the components of the latter. It is thus necessary to attempt to protect them efficiently in order to enable them to be handled more easily in industrial technology and in order to guarantee the organoleptic and nutritional-technical properties of the end products.

This notion of protection must be seen from two different angles: a) certain additives are very unstable in the pure crystalline state, which makes them entirely unusable in this form from a technological point of view.

This inherent degradability of the molecules is principally due to factors such as temperature, light and oxidation. The carotenoids may be mentioned here by way of example.

In the pure state, carotenoids exist in the form of red-brown to violet coloured crystals. They are insoluble in water and have a fairly high melting point They are soluble in certain organic solvents, but are sparingly soluble in fats. They are also very sensitive, especially to light, and decompose readily. Accordingly, they require very delicate handling.

The industrial use of carotenoids thus poses a problem of incorporation, in particular in food where the aqueous phase predominates.

b) To the aforementioned inherent instability of the molecules are also to be added the detrimental interactions with certain elements of the medium with which they are admixed, which give rise to losses during the processing.

The temperature, humidity, pH, oxidis- ing or reducing action of the medium and the interaction with other micro-elements which catalyse the decomposition (e.g. enzymes, heavy metals etc) are other parameters which influence the stability of the additives. To this it is also necessary to add the storage conditions (e.g. temperature, humidity, duration, light, packing etc) which vary considerably according to the nature of the end product.

Although all of the factors mentioned earlier work separately, they more often work simultaneously and a synergism of the effects can result, which increases the speed of decomposition of the molecules.

The food industry, in turn, desires to use stable products which guarantee a practical management. In the majority of cases, it is necessary to have available preparations which are easy to handle, which are miscible in the dry state and which are dispersible or soluble in liquids.

In order to achieve these results, two conditions must be determined, namely: a) The inherent properties of the additive used. The inherent properties of an additive used are often unsuitable for the intended use; for example its solubility is zero or insufficient. This is the case, for example, for fat-soluble vitamins in aqueous media, and also for carmine of cochineal in an acid medium.

Furthermore, the incompatibility one with another of several substances which are to be used in a mixture is often encountered. A known example of this is the total instability of vitamin C in the presence of iron or of copper.

b) Since the physical and chemical characteristics of food are very varied, it is necessary! to find dissimilar and standardised use-forms of the additives so that they can be incorporated in media of a very varying nature.

Furthermore, since these substances are often used in low concentrations, they must be diluted in order to guarantee a homogeneous distribution in the mass into which they are incorporated.

The problem to be resolved thus consists in finding a process according to which it is possible to protect and to stabilise food additives, and therewith to facilitate their use, in order to obviate the disadvantages mentioned hereinbefore. This problem has now been solved according to the present invention, in the scope of which it has been found that proteins of ultra-filtered milk are especially suitable to fulfil the aforementioned conditions.

The process provided bv the present invention, namely the process for the manufacture of stable and protected food additives, comprises fixing these food additives on or enveloping them with proteins of ultra-filtered milk.

The aforementioned proteins are known and are obtained by ultrafiltration from milk (preferably cows milk) and of products derived therefrom. They can be used alone or in association with other natural polymers used as foods such as starches, dextrins and their derivatives, pectins, alginates, and carrageenins.

These proteins on the one hand guarantee the fixing or enveloping of the food additives in that they guarantee an efficient protection and on the other hand have technological properties which facilitate their use to a maximum.

In the scope of the present invention the term "fixing" will be understood to mean the binding by a substance of a certain number of molecules of ligands; this resulting by physico-chemical interactions of different types between the two substances (bond of different energy).

The phenomenon of enveloping is purely mechanical in nature. Since the biological macromolecules have a cross-linked and porous structure, they can take up in their framework one or more substantially smaller molecules and thus protect them against the action of the surrounding medium.

When a substance is thus protected by fixing or enveloping, its inherent properties are masked and the individual properties of the carrier prevail. It is then sufficient to consider only the properties of this carrier in the technological processing.

In the process provided by the present invention the originality of the use of milk proteins stems from their properties, which are derived from their structure and which enable them to play the double role of fixing and enveloping.

The fixing of a body on a protein can be carried out according to various procedures, the results being additive. It is a function: -of the primary structure, i.e. the linkage of the amino acids forming the protein; -of the secondary structure, which expresses the existence of hydrogen bonds and which confers the helical structure to the protein chains; -of the tertiary structure which results from the twisting of the protein chains already arranged in the secondary structure.

This twisting is caused by covalent bonds (e.g. disulphide bridges and prolyl residues which connect the chains) and, above all, by bonds of lower energy, such as hydrogen bonds, hydrophobic bonds and polar bonds.

When a foreign molecule comes into contact with a protein it can bond itself thereto by high energy-containing covalent bonds. This process is irreversible and modifies the primary structure. The foreign molecule can, however, also bond to the protein by means of bonds of lower energy, these being of two types: (a) The foreign molecule occupies fixing sites on the protein which are still free.

(b) There is competition between the foreign molecule and another ligand which already ocupies a site: the additive taking the place of the ligand since the bonds formed between it and the protein have more energy than those which previously existed at this site.

Whatever the method of fixing, the secondary and tertiary structures of the protein are modified.

The tertiary structure of the protein determines its spatial configuration. The majority of proteins have a spherical form which can be likened to a ball of wool.

Small molecules of ligands can readily slip between the chains in order to fix themselves in certain sites; this being all the more read ily when, in the moist state, this structure is still swollen and partially uncoiled. When it is subsequently dried, the ball contracts and the molecules, which have entered the structure but have still not fixed themselves to a site, are imprisoned; i.e. they become enveloped.

Protein solutions have an emulsifying effect which enables the use of emulsifying agents to be avoided or limited during the manufacture.

Milk is an excellent, abundant and cheap source of proteins.

Recent progress in milk technology, as a result of ultra-filtration methods, makes it possible to obtain protein concentrates which are of varied kinds but of constant quality and nature and which are, moreover, precisely defined.

This makes it possible to start from fresh products which are not denatured since they have in no way been subjected to any preliminary treatment (the ultrafiltration is not a denaturing), so that the reactivity of the proteins is guaranteed to remain at a maximum.

In spite of the complexity of its composition, milk and its derivatives have the advantage of being neutral and only slightly aggressive towards substances which are to be protected; this reducing the loss during the manufacture. On the other hand, such a carrier has the advantage that it can later be introduced into a wide variety of foods without modifying the characteristics thereof.

Milk technology is, meanwhile, wellknown and involves no problems. Accordingly, it can be readily made use of. This presents the possibility of starting from the same basic material, namely milk, to obtain products having various technological properties but having an identical form, i.e.

powders which have the advantage that they can be readily used independently of the various molecules which are fixed or enveloped.

Ultrafiltration enables two categories of products to be obtained, one containing the total proteins of milk and the other containing the proteins of lactoserum, at chosen and known concentrations.

This primary material can subsequently be modified to provide other kinds of material such as caseinates, comprecipitates, demineralised lactoserums and acid proteins.

The use with other macromolecules of a different kind (e.g. pectins, algines, carrageenins or sugar) enables the technological properties of the thus-prepared carrier to be further modified.

There is thus obtained, according to desire, for example, a carrier which can or cannot be coagulated by rennin, which is soluble at a given pH, which is of known viscosity in the moist state, but which, however, has the advantage that it is always the same in the dry state.

After introduction of the food additive to the protein carrier under optimum conditions at which the protection is achieved, the entire mixture is then dried.

Amongs the different drying methods used in the milk industry, atomisation is the method which causes the least degradation not only for the proteins but also for the sensitive molecules added. However, it will be understood that other methods which do not bring about a denaturing of the proteins can also be used.

The process used is a function of the molecule to be protected; it takes into account the properties thereof in order to thus guarantee the least degrading operating conditions. The carrier is accordingly chosen as a function of the inherent properties of the additives and of the technological quality required.

Depending on whether it is water-soluble or fat-soluble substance, the food additive is dissolved or emulsified in a concentrated solution of the carrier.

Thus, for example, in a process starting from a water-soluble or water-dispersible additive, the carrier solution is initially heated to a temperature between about 20"C and about GOOC, preferably between about 300C and about 50"C and especialy between about 400C and about 45"C, following which any additional ingredients such as dextrins, pectins, alginates, carrageenins, starches, sugar and antioxidants are added.

The substance to be protected is then added in an amount of about 1% to about 10% by weight based on the total weight of the solution or dispersion, then dissolved or dispersed and the solution or dispersion then homogenised and dried in a known manner.

It will be understood that the amount of substance to be protected is a function of the solubility in an aqueous medium. Thus, for example, vitamin C is preferably used in an amount of 2% to 8% by weight, vitamin B1 is preferably used in an amount of 3% to 5% by weight and vitamin B2 is preferably used in an amount of 1.5 to 8% by weight.

In a process starting from a flat-soluble additive, the carrier solution is likewise initially heated to a temperature between about 20"C and about 600C, preferably between about 300C and about 50"C and especially between about 400C and about 45"C, and any additional ingredients, such as those mentioned earlier, and emulsifiers are added. The food additive is then added in an oil solution in an amount of about 0.1% to about 2% by weight based on the total weight of the solution, and the mixture is then homogenised under pressure and subsequently dried by atomisation in a known manner. It will be understood that the amount of substance to be protected is a function of the solubility in an oil medium.

Thus, for example, P-carotene can be used in an amount of O.1C/o to 0.6% by weight and especially in an amount of about 0.3% by weight.

There are thus obtained powders in which the content of food additive can vary considerably as a function of the physicochemical properties of the additives used with respect to the capacity of the carrier to envelope or fix them.

The following Examples illustrate the present invention (percentages are by weight): EXAMPLE 1 Firing of riboflavin on the proteins of lactoserum The ingredients used are the sodium salt of riboflavin 51-phosphate in pure crystalline condition and a fraction of the ultrafiltration of lactoserum having about 10% of dry matter, the composition of which is as follows: Total amount of nitrogen-con taining material . 7.00% Lactose 1.70% Ash ... 0.36% Fat . 0-50to Water .. 90.44% The protein solution (100 litres) is heated to about 400-450C.

The sodium salt of riboflavin 5'-phosphate is added in an amount which corresponds to a content of 25% in the dry end product (i.e. 3.333 kg) and is dissolved by stirring the medium with a homogeniser, care being taken that no air penetrates into the concentrate.

The solution obtained is immediately dried by spray-drying. There is obtained a fine powder having a yellow colour and containing about 23% of riboflavin.

The percentage of riboflavin recovered is about 92%.

EXAMPLE 2 Protectiot of P-carotene by the proteins of lactoserwn The ingredients used are as follows: - a 2.1% supersaturated oily solution of R-carotene stabilised with 0.8% of dl-ag- tocopherol.

- a fraction of the ultrafiltration of lactoserum containing 24.02% of dry extract having the following composition: Total amount of nitrogen-con taining material ...... ... 14.90% Lactose ... ... 7.44% Ash . . ...... 0.94% Fat . ... 0.74% Water ... 75.98% The protein solution (32 kg to 24.02% of dry extract) is heated to about 4 45 C.

To this solution is added 0.124% of sodium ascorbate as an antioxidant. 1.7 kg of the supersaturated oily solution of - carotene are coarsely dispersed in the concentrate at room temperature. The resulting mixture is then homogenised under a pressure of 350 bars. The emulsion thus obtained is immediately dried by spray-drying.

The product obtained is a fine yellow powder which contains 0.37% of P-carotene.

100% of the amount added is recovered.

WHAT WE CLAIM IS:- 1. A process for the manufacture of stable and protected food additives, which process comprises fixing (as herein defined) these food additives on or enveloping them with proteins of ultrafiltered milk.

2. A process according to claim 1, wherein fixing or enveloping is carried out by solution, dispersion or emulsion of the food additives in a solution of proteins of ultrafiltered milk and drying the solution, dispersion or emulsion obtained.

3. A process according to claim 2, wherein the drying is carried out by atomisation.

4. A process according to claim 1, claim 2 or claim 3, wherein a carrotenoid or a water-soluble or fat-soluble vitamin is used as the food additive.

5. A process for the manufacture of stable and protected food additives, substantially as hereinbefore described with reference to Example 1 or Example 2.

6. Stable and protected food additives which are fixed on or enveloped with proteins of ultrafiltered milk.

7. Food additives according to claim 6, wherein the additive is a water-soluble or fat-soluble vitamin or a carotenoid.

8. A method for the stabilisation and protection of food additives, wherein proteins of ultrafiltered milk are used as a stabilising and protecting carrier.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. subsequently dried by atomisation in a known manner. It will be understood that the amount of substance to be protected is a function of the solubility in an oil medium. Thus, for example, P-carotene can be used in an amount of O.1C/o to 0.6% by weight and especially in an amount of about 0.3% by weight. There are thus obtained powders in which the content of food additive can vary considerably as a function of the physicochemical properties of the additives used with respect to the capacity of the carrier to envelope or fix them. The following Examples illustrate the present invention (percentages are by weight): EXAMPLE 1 Firing of riboflavin on the proteins of lactoserum The ingredients used are the sodium salt of riboflavin 51-phosphate in pure crystalline condition and a fraction of the ultrafiltration of lactoserum having about 10% of dry matter, the composition of which is as follows: Total amount of nitrogen-con taining material . 7.00% Lactose 1.70% Ash ... 0.36% Fat . 0-50to Water .. 90.44% The protein solution (100 litres) is heated to about 400-450C. The sodium salt of riboflavin 5'-phosphate is added in an amount which corresponds to a content of 25% in the dry end product (i.e. 3.333 kg) and is dissolved by stirring the medium with a homogeniser, care being taken that no air penetrates into the concentrate. The solution obtained is immediately dried by spray-drying. There is obtained a fine powder having a yellow colour and containing about 23% of riboflavin. The percentage of riboflavin recovered is about 92%. EXAMPLE 2 Protectiot of P-carotene by the proteins of lactoserwn The ingredients used are as follows: - a 2.1% supersaturated oily solution of R-carotene stabilised with 0.8% of dl-ag- tocopherol. - a fraction of the ultrafiltration of lactoserum containing 24.02% of dry extract having the following composition: Total amount of nitrogen-con taining material ...... ... 14.90% Lactose ... ... 7.44% Ash . . ...... 0.94% Fat . ... 0.74% Water ... 75.98% The protein solution (32 kg to 24.02% of dry extract) is heated to about 4û 45 C. To this solution is added 0.124% of sodium ascorbate as an antioxidant. 1.7 kg of the supersaturated oily solution of ss- carotene are coarsely dispersed in the concentrate at room temperature. The resulting mixture is then homogenised under a pressure of 350 bars. The emulsion thus obtained is immediately dried by spray-drying. The product obtained is a fine yellow powder which contains 0.37% of P-carotene. 100% of the amount added is recovered. WHAT WE CLAIM IS:-

1. A process for the manufacture of stable and protected food additives, which process comprises fixing (as herein defined) these food additives on or enveloping them with proteins of ultrafiltered milk.