A PROCEDURE FOR EXPLORATION OP RAW MATERIALS CONTAINING COLLAGEN IN ORDER TO PRODUCE GELATIN
Technical field The object of our invention is a procedure for the production of eating gelatin from raw materials containing collagen. More closely, there is some talk of an improved enzymatic procedure to produce gelatin, and by this method the gelatin can be produced more economically, cheaper, more easily and more quickly than up to now.
Background art
It is well known that the use of gelatin as a jellifying agent is most wide in the food industry, its demand is quite large therefore a whole range of procedures were developed.
The gelatin is produced primarily from materials containing collagen - namely from abattoir raw materials and by-products, from bones, tendons, hide, trimmings of mammalia or poultry, as well as from members of little value, e.g. from legs, claw, wing, neck or head. Certain parts of animals which contain little meat but their bone, tendon and hide content is very high can advantageously be used.
According to general producing method the materials containing collagen are heated and cooked in an aqueous solution, in a strongly basic solution or in a solution with high salt or enzyme content until a gelatinization is completed.
Our invention provides a procedure wherein gelatin is produced by means of enzymes, particularly
proteolytic enzymes acting in the neutral pH-interval
A whole range of experiments are known for processing of hides with enzymes. In the Hungarian patent specification No. 70,474 under the title "Processing of glue into products or similar substances" a procedure is reported in which hide wastes treated with caustic lye are subjected to the effect of pancreas enzymes or other enzymes which decompose protein. Since this early procedure one pays attention to both the preparation of enzymatic processes and to the enzymatic reaction, as well as to the selection of enzyme used. Different methods were developed for the enzymes acting in acidic, neutral or basic pH-interval. In such cases diverse final product quality was obtained depending on the variety of procedure. Parallel with these experiments proteolytic enzymes were produced from many microorganisms; of these the enzymes extracted from species Streptomyces and Bacillus were considered as effective ones.
In the Swiss patent No. 610,346 the same proteolytic enzyme complex obtained from Streptomyces fradiae is described which acts in both homogenous and heterogeneous medium. According to the Swiss method to the sufficient enzymatic activity a duration of 17 - 20 hours is necessary and the pH-values of 4 - 5 are the most advantageous.
In the well-known procedures the basic pretreating period is generally several weeks and according to Swiss patent the acidic pretreatment requires nearly one day. At the same time both the acidic and basic pretreatments go with surplus of agent demand (neutralization) consequently in the
final gelatin product the ion concentration is increased to a large extent. The removal of the surplus reagent is considered as a process which requires additional time, equipment and water consumption thus the economical efficiency of processes is decreased, on the other hand, the manufacturing period is lengthened.
The object of our invention is that a technology should be developed by which the disadvantages of procedures until now are eliminated and by which the gelatin can be produced really economically and quickly.
In the Hungarian patent No. 181,614 a procedure is given for a meatprotein-hydrolysate production which is suitable for human food and which is of meaty bone base. This invention is obtained with development and extension of abovementioned Hungarian patent.
Disclosure of invention
Our invention is based on the recognition that the abattoir by-products and/or raw materials (e.g. poultry legs, wings, neck, head, hide, bone or eventually pretreated hide or leg, claw, head and large-scale separated bone of mammalia) are precooked in water of 0.8 - 2.0 times quantity at the temperature between 70 °C and the boiling point of the mixture. The precooking time is 10 - 90 minutes depending on the type of animal by-products and/or raw materials to be processed. Our precooking procedure has a main part that the pH-adjusting is unnecessary as the pH-value of the mixture is adjusted by itself to 6.4 - 7.2 and this is an optimum for the precooking and for the following steps.
During precooking the abattoir by-products and/or raw materials become loose in their texture, and then a part of protein is denaturated.
After the precooking the mixture up to a temperature of 40 - 65, preferably 55 - 60 °C is cooled thereafter a protein decomposing enzyme is added to the mixture. This enzyme has an optimal effect in the pH 6.0 - 8.0 interval. With many neutral proteases different experiments were performed and suggested that the type of Colorase N (Röhm) is the most suitable. The concentration of proteolytic enzyme was adjusted in this mixture so that a value of 0.05 - 1.2 % should be obtained on the basis of the mass of animal by-products and/or raw materials. The digestive process was performed for a duration of 10 - 70 minutes. The digestion time is determined by the variety of used animal by-products and/or raw materials.
Starting from the explorated material prepared in above-mentioned way the gelatin can be cooked in one or more stage operation, and then the gelatin solution can be removed from the bones and other solid components by means of simple filtering, respectively. By the correct building of the boiling equipment the degreasing can be completed simultaneously.
The gelatin solution obtained in this way can be processed by the combination of well-known operations (filtration, ion release, sulphuring, gelation, drying, chopping) depending on the final product to be wanted.
Industrial applicability
The procedure according to our invention gives the following advantages:
- the exploration, the gelatin obtaining and preliminary purifying are simplyfied to a large extent, as well as the time demand is reduced up to a fraction compared to the conventional procedures;
- repeated chemical treatment is unnecessary thus the operation and water demand regarding to removal of surplus reagent are eliminated;
- by means of a simple method the carcass components and other solid substances can be removed;
- the degreasing operation can be coupled with the cooking of gelatin; - our procedure can be used for the process of abattoir by-products and/or raw materials containing collagen, and different technologies per species and per by-products or raw material types need not be elaborated; and - our procedure is suitable to process the different animal abattoir by-products and/or raw materials into gelatin simultaneously.
Modes of carrying out the invention Our procedure should be supported by the following examples:
Example 1 A material of poultry origin that contains some collagen is measured into a 1000 litres boiling-pan (e.g. leg, wing, neck, head, hide, etc.) thereafter 400 litres of water is added. Afterwards the mixture is precooked at a temperature of 82 ºC for a time of 30 minutes, and is cooled up to 55 °C. After cooling 0 2 % Rohm Bakterien-proteinase N is added and is
agitated for a time of 15 minutes. After exploration completed in this way the mixture is heated up to 85 ºC and in this point is maintained for a time of 195 minutes, thereafter the mixture containing solid components is separated, degreased, filtered and the gelatin is extracted by the well-known method.
Example 2 400 kg of mixed material containing collagen and of pig origin is measured into a 1000 litres boiling-pan (e.g. hide, claw, leg, head, etc.) and then 400 litres water is added. Afterwards the mixture is precooked for a time of 45 minutes and is cooled up to 60 °C. After cooling 0.4 % Colorase N is added and the whole mixture is agitated for a period of 30 minutes. After exploration completed in this way the mixture is heated up to 90 °C and at this point it is maintained for a time of 180 minutes, and then the mixture containing gelatin is separated from solid components. Afterwards the material is degreased, filtered and the gelatin is obtained by the above-mentioned method.
Example 3 400 kg of purified rabbit-hide, legs and heads is measured into a 1000 litres boiling-pan and 400 litres of water is poured. After this the mixture is precooked at 90 °C for a time of 50 minutes, and then is cooled up to 58 °C. After cooling 0.3 % neutral protease is added and the mixture is agitated for a time of 25 minutes. After the exploration by this way the mixture is heated up to 85 °C and at this point is maintained for a time of 210 minutes, thereafter the mixture containing gelatin is separated from solid components, is degreased, filtered, at last the gelatin is extracted by the well-known method.