"EXTRACTION PROCESS OF HYDROLYZED COLLAGEN AND OF CHROME/COLLAGEN COMPLEX FROM CHROME TANNED LEATHER RESIDUES"

This patent of invention regards an Ex- traction Process of Hydrolyzed Collagen and of Chrome/Collagen Complex from Chrome Tanned Leather Residues, with the practical result of obtaining hydrolyzed collagen to be applied in the food, pharmaceutical, cosmetic, animal food, glue and adhesive manufacturing, photographic material, fertilizers, plastic, rubber, leather, chemical products for the tanning industry and various segments of the chemical industries, while additionally a paste of chrome/collagen complex is obtained, which, at its turn applies in a variety of segments of the chemical industry.

The technical state recognizes proteins like amino acid polymers, which are abundantly found in all living sells, making up three fourths of the dry weight of the animal tissues.

Some proteins have a structural function

(skin, hair, muscle fibers, for example) where there also exists a second type of proteins, which are characterized by their catalytic function (enzymes) in the reactions that occur in living systems, and such reaction are vital to maintain a living organism.

Other proteins present a regulating (hormones) and other functions and complementarily participate actively in immunology mechanisms for defense of the organisms (antibodies).

There is an estimation of the existence of about 5 million different proteins in human beings, each of them performing an important function in the organism. Other species of superior animals also have a high quantity of different proteins. The different species have different proteins. In some cases vary for each individual.

Proteins are composed of OC-amino acids, interconnected by peptide bonds. They are amphoteric double ions that migrate in an electric field and have characteristic isoelectric spots. Even though the main chain may consist of relatively stable amide bonds, the proteins are reac-

tive and have a rather specific behavior. This reactivity is associated with the active groups free of side chains, like the lysine amino groups, the arginine guanide groups or the cysteine sulphydryl groups. Many proteins contain a variety of peptide chains, interconnected by cross-links. The bisulfate links between cysteines can connect two chains or two parts of the same chain.

The partial hydrolysis of the proteins provides minor polyamides while total hydrolysis produces free amino acids.

The molecular weight of the proteins varies from 6,000, for insulin, to 41 ,000 for a protein of the mosaic tobacco virus. The polyamides with a molecular weight that is lower than 5,000 are called polypeptides. Bigger proteins are highly organized complexes with many identical sub-units, each having a molecular weight of 17,500, associated by non- covalent interactions.

Few proteins that have a molecular weight that is higher than 100,000 are made up of only on continuous polypeptide. The natural polypeptides are capable of performing their biological functions due to specifically arranged amino acid sequences and their well-defined spatial arrangement.

The amphoterous characteristic of Leather, or more precisely, of Collagen (leather protein) leads to the consideration that leather is compared to a battery with negative and positive terminals. Leather if, thus defined to one and the others to the other. Collagen is constituted of a variety of types of amino acids, characterized by the nature of the side chain that is free for reactions. The collagen amino acids are classified in accordance with the nature of the Radicals (R) as being non-polar, with hy- droxyl groups, with acid groups or respective amide groups with basic groups.

In quantitative terms, we have the following composition of natural collagen expressed in number of amino acids per 1 ,000 amino acids: - Non-polar: 642.6 (-H, -CH ₃ , etc.);

- Hydroxylic: 151.7 (-OH);

- Acids and amide: 120.0 (-COOH / - CONH ₂ );

- Basic: 84.4 (-NH ₂ ).

Of the 120 residues corresponding to acid and amide groups, 44 residues remain respective the derived amides and its corresponding acids. The presence of acid and basic ionizable groups is of great usefulness. This characterizes the skin as an amphoterous substance because if we ionize the acid groups, it reacts with the basics and if the basic groups are ionized, the reaction will occur with the acids. The ionization of acid or basic groups is determined by the pH of the medium. In very acid solutions the carboxylic groups are in their non-dissociated form NH ₃ ⁺ -PrOt- COOH and the total load is strongly positive. On the contrary, in a basic medium the carboxylic groups are dissociated NH ₂ -PrOt-COO ^" and the total load is negative. There is, however, a pH value for which the global load of the skin in balance with the medium is nil (NH ₃ ⁺ -PrOt-COO ^" ) this is the ISOELECTRIC SPOT (IS).

Partial collagen or protein hydrolysis yields minor polyamides, that is hydrolyzed collagen. The total hydrolysis produces free amino acids.

The molecular weight of the proteins var- ies from 6,000 for insulin to 41 ,000 for the tobacco mosaic virus. Polyamides of molecular weight that is lower than 5,000 are called polypeptides. The major proteins are highly organized complexes where many identical sub-units, each with a molecular weight of 17,500, are associated by non-covalent interactions.

Few proteins that have molecular weight higher than 100,000 are constituted by only one continuous polypeptide. Natural polypeptides are capable of performing their biological functions due to the specifically arranged sequences of amino acids and their well-determined spatial organization.

To obtain total and complete comprehen- sion of the EXTRACTION PROCESS OF HYDROLYZED COLLAGEN AND OF CHROME/COLLAGEN COMPLEX FROM CHROME TANNED LEATHER RESIDUES" in question and object of this invention patent, a set of block diagrams is attached to this report, to which reference is made as follows:

Figure 1 is a graphical representation of the necessary steps to obtain hydrolyzed collagen.

Figure 2 is a schematic representation of the steps necessary to obtain the chrome/collagen complex. Figure 3 is a schematic representation of the block diagram of the steps necessary to obtain the resulting liquid residue.

The following description must be read and interpreted in relation with the figures 1 , 2 and 3 that were presented and highly schematic, where the extraction process of hydrolyzed collagen and of the chrome/collagen complex of tanned leather residues now claimed can be better understood by obtaining three products where: the first product is called hydrolyzed collagen (A); the second product is called chrome/collagen complex (B) and a final product defined by the resulting liquid residue (C).

The hydrolyzed collagen product (A) is constituted by the prime material based on the extraction of some residues, among which the residue of chrome tanned leather can be named.

The hydrolyzed collagen presents a pH that varies from 5,5 to 6.0 with a proportion of chrome oxide that varies between 1.8 and 2.0 ppm (on a dry basis), which can be used in the food, pharmaceuti- cal, cosmetic, animal food, glue, adhesive, photographic, fertilizer, plastic and rubber industries and in various segments of the chemical industries.

The procedure defined for the extraction of hydrolyzed collagen is based on a first step that is called the mixing of the first enzyme (A1), where the chrome tanned leather residues are placed in de- vices, over which 15 % of the JOANA FELIX-1 H Enzyme and 120% of water is added; after this the mixture is stirred with rotating movement of the device for a period of twelve hours, where a digestive process occurs until a digested collagen paste is obtained.

The following step, called the mixing of the second enzyme (A2), consists of the transfer of the resulting digested paste to a stirring tank where 7% of the JOANA FELIX-2H enzyme is added, after which the paste is stirred for one hour after which a step, called resting of the paste (A3), in which the resulting paste is left to rest for a period of fifteen hours.

At the end of the resting period a step starts that is called the hydrolysis of the collagen (A4), where 70 to 75% of the yellow liquid collagen is extracted, which is then filtered, evaporated to form a yellow viscous liquid, the viscous liquid hydrolyzed collagen (A5). This way collagen is obtained in the range of 35 to 37% of viscous liquid hydrolyzed collagen (A5) at a pH that varies from 5.5 to 6.0. This viscous liquid hydrolyzed collagen (A5) has a proportion of hydrolyzed collagen that varies from 50 to 55% and a proportion of chrome oxide that varies from 1.7 to 1.9 ppm (on a dry basis), being as an alternative form it may be prepared in concentrations from 10 to 90%.

The condition that is reached above permits that the viscous liquid hydrolyzed collagen (A5) be used as such, that is, used as viscous liquid (A6), or alternately a step of drying of the hydrolyzed collagen (A7) can be applied, which results in a yellow solid end product (A8). In relation to the chrome/collagen complex

(B), it is also extracted from some residues, like the residues of chrome tanned leather residues, under which condition the byproduct presents a pH that varies from 5.0 to 5.5, with a chrome oxide proportion that varies from 5.0 to 6.0% and with a proportion of hydrolyzed collagen that varies from 10 to 15%, which can be useful in various segments of chemical industries.

The processing defined for the extraction of the chrome/collagen complex (B) is based on a step following the obtaining of viscous liquid hydrolyzed collagen (A5) and can be called the step of preparation of the chrome/collagen complex (B1) where, after the extraction of the hy- drolyzed collagen (A5) 5% of the JOANA FELIX-1C is added over the resulting paste of viscous liquid hydrolyzed collagen (A5), which is stored in the stirring tank.

Then a step starts that is called the first rest (B2), in which this mixture remains in a resting state for a period of four hours, after which the mixture is filtered to a resting repository, starting a step that is called the second rest (B3) where the resulting paste rests for twenty-four hours, after which the extraction step of the chrome/collagen complex (B4) starts, from which the green chrome/collagen (B5) paste is obtained, aside from

the resulting residue (B9).

The green paste chrome/collagen complex

(B5) is obtained in the range of 35 to 40% of the green paste chrome/collagen complex at a pH that varies between 5.0 and 5.5, with a proportion of viscous liquid hydrolyzed collagen (A5) that varies from 10 to 15%, beside having a 5.0 to 6.0% proportion of chrome oxide. Its index of baseness is in the range of 45 to 47%.

The condition above allows for the green paste chrome/collagen complex (B5) to be used as such, that is, used as green paste (B6) or, alternately, a drying step of the chrome/collagen complex (B7) can be applied, which yields a green solid (B8) as end product.

Finally the resulting liquid residue (C), presents as raw material the resulting residue (B9) of the extraction of the chrome/collagen complex (B4), in such a way that the latter present a pH that varies from 5.0 to 5.5% and with a chrome oxide proportion that varies from 1.0 to 1.5% and with a collagen proportion that varies from 1.0 to 1.4% of viscous liquid hydrolyzed collagen (A5), this resulting liquid is reused in the digestion step of the chrome tanned leather residues.

At its turn, the process for obtaining the resulting liquid residue product (C), occurs from a first step of obtaining the resulting residue (C1), where the obtaining of the resulting residue (B9) of the extraction of the chrome/collagen complex (B4), after which a step follows of residue separation (C2) where a residue is obtained which is reused in the digestion step of the residues (C3), more specifically, the digestion of the chrome tanned leather residues, resulting in yellow liquid residue (C4).

The residue obtained (C4) presents a physical characteristic in the range of 13 to 20% of yellow liquid residue, which has a 1.0 to 1.4% proportion of hydrolyzed collagen and a 1.0 to 1.5% chrome oxide proportion. From all that has been described and illustrated, it can be seen that this regards a new process in obtaining hydrolyzed collagen and chrome/collagen complex which completely complies with the norms that regulate the Invention Patent in the light of the Industrial Property

Law, and therefore deserving respective privileges when regarding what has been exposed and its consequences.