IT202100029855A1 - PROCEDURE FOR PRODUCING HYDROLYZED GELATIN - Google Patents

Description

Description of the industrial invention entitled:

?Process for producing hydrolyzed gelatine?

DESCRIPTION TEXT

Field of invention

Does the present description refer to processes for producing hydrolyzed gelatin solutions with a high degree of clarity? and purity.

Background of the invention

The enzymatic hydrolysis of gelatin for the production of hydrolyzed gelatin, commercially known as "collagen", generally occurs using a process carried out discontinuously (in batches). The process includes a phase in which a hydrolytic enzyme and gelatin are placed in contact for a period of time such as to allow the hydrolysis of the gelatin macromolecules. This procedure involves the use of a tank, placed under agitation, fed by a solution comprising gelatin in variable concentrations, from a few percentage points up to values of the order of 50%. The enzyme is added to this solution and, after a period of time that can even last a few hours, the hydrolysis reaction reaches a steady state and you can? consider concluded. The hydrolyzed gelatine present in the solution obtained has a significantly lower molecular weight compared to the origin and this manifests itself with a reduction in viscosity. of the solution. Once the enzymatic hydrolysis reaction is completed, the solution including hydrolyzed gelatin and the enzyme used for the hydrolytic reaction are sent to subsequent work phases foreseen in the production process. One of these phases includes the UHT sterilization of the product, the heat treatment of which allows to obtain not only the elimination of the bacterial load but also the denaturation of the enzyme (the enzyme loses its activity).

Consequently, the tank in which it is Enzymatic hydrolysis has been carried out. filled again with another gelatin solution and another enzyme in order to start a new production batch.

Summary of the invention

The purpose of the present description is to provide a simple and effective process for producing hydrolyzed gelatin with a high degree of purity.

According to the invention, the aforementioned object is achieved thanks to the object specifically referred to in the following claims, which are to be understood as forming an integral part of the present description.

One embodiment of the present disclosure provides a process for preparing hydrolyzed gelatin comprising the steps of:

i) provide a starting solution comprising gelatin,

ii) filtering said starting solution comprising gelatin through an ultrafiltration membrane to obtain a retentate fraction and a permeate fraction comprising a hydrolysed gelatin solution,

wherein the starting solution provided in step i) comprises at least one of hydrolyzed gelatin and non-hydrolyzed gelatin,

wherein when said solution provided in step i) comprises non-hydrolysed gelatin the process further comprises a step of adding to said starting solution provided in step i) at least one hydrolytic enzyme prior to step ii).

Does the hydrolysed gelatin solution obtained in phase ii) with the described procedure have a cloudiness? equal to or less than 5 NTU (Nephelometric Turbidity Unit). The hydrolyzed gelatin obtained with the described process has a molecular weight that can be between 50 Da and 50000 Da.

Brief description of the figures

The invention will be now described, by way of example only, with reference to the attached figures, in which:

- Figure 1 shows a diagram of a process known in the art for the production of hydrolysed gelatin;

- Figure 2 shows a diagram of an embodiment of the process covered by the present description in which a starting solution already comprising gelatin? hydrolysed? fed continuously with batch feed;

- Figure 3 shows a diagram of an embodiment of the process covered by the present description in which a starting solution comprising hydrolysed gelatin and non-hydrolysed gelatin? fed continuously with batch feed;

- Figure 4 shows a diagram of an embodiment of the process covered by the present description in which a starting solution comprising non-hydrolysed gelatin? fed continuously with batch feed;

- Figure 5 shows two samples compared: on the left, a hydrolyzed gelatin solution obtained according to an embodiment of the process covered by this description; on the right, a starting solution comprising gelatin not yet hydrolysed and with high turbidity? used in the process covered by this description;

- Figure 6 shows a further diagram of an embodiment of the process covered by this description in which tools and parts of a system are illustrated; FT: flow transmitter; Brix T: refractometer; TT: temperature transmitter; LT: level transmitter; HSL: very high level indicator; PT: pressure transmitter; CIP Tank: tank for washing the same with chemical products; UF: module containing the ultrafiltration membrane.

Detailed description of the invention

In the following description, numerous specific details are reported to allow a complete understanding of the embodiments. Can the embodiments be practiced without one or more? specific details, or with other processes, components, materials, etc. In other cases, well-known structures, materials, or operations are not shown or described in detail to avoid confusing aspects of the embodiments.

The reference throughout this description to ?a single embodiment? or ?an embodiment? indicates that a particular aspect, structure, or feature described with respect to the embodiment is ? included in at least one embodiment. So, the forms of expressions ?in only one embodiment? or ?in one embodiment? appearing at various points throughout this specification do not necessarily all refer to the same embodiment. Furthermore, the particular aspects, structures, or characteristics may be combined in any suitable way in one or more embodiments.

The headings provided herein are for convenience only and do not interpret the scope or meaning of any embodiment.

One embodiment of the present disclosure provides a process for preparing hydrolyzed gelatin comprising the steps of:

i) provide a starting solution comprising gelatin,

ii) filtering said starting solution through an ultrafiltration membrane to obtain a retentate fraction and a permeate fraction comprising a hydrolyzed gelatin solution,

wherein the starting solution provided in step i) comprises at least one of hydrolyzed gelatin and non-hydrolyzed gelatin, wherein when said starting solution comprises non-hydrolyzed gelatin the process comprises a step of adding to said starting solution at least one hydrolytic enzyme.

In one or more? embodiments, the process includes a step of separating said permeate comprising the, preferably consisting of, hydrolyzed gelatin solution and said retentate.

In one or more? forms of implementation, the procedure can? comprising a step iii) of concentrating the hydrolyzed gelatin solution obtained in the permeate and the step iv) of drying the hydrolyzed gelatin solution concentrated in step iii). Is hydrolysed gelatin like this? obtained? hydrolyzed gelatine that can? come in the form of a powder in which, preferably, the water content is equal to 5% or less.

The jelly? a natural polymer obtained by extraction in hot water, after partial acid or alkaline hydrolysis, of the collagen contained in animal connective tissues, preferably bovine, porcine and fish. Collagen can can also be obtained from fish bones, tendons and scales.

As anticipated in the previous sections, and as schematically illustrated in Figure 1, known processes for the production of hydrolysed gelatin (hydrolysed collagen, hereinafter simply ?hydrolysed gelatine?) are discontinuous (batch) processes, which involve the use of tanks for conducting the hydrolytic reaction of the gelatin, waiting for the period of time necessary to obtain hydrolyzed gelatin, draining the tank and restoring it, inactivating the enzyme.

The process covered by this description? a continuous process that involves the use of ultrafiltration membranes. In recent years, separation techniques using membranes have increased considerably. Membrane technology today? used on a large scale, for example for the production of drinking water from sea water, for the purification of industrial effluents, for the recovery of products in the food and pharmaceutical industries. Ultrafiltration membranes can have cut-offs (molecular cuts) such as to allow the separation of molecules with molecular weights even in the range between 500 Da and 100,000 Da. These membranes, therefore, have the capacity to retain, for example, colloidal particles, bacteria, proteins, polysaccharides and allow the permeation of sugars, amino acids, salts and water. In the food sector (Food & Beverage), the practical applications of ultrafiltration membranes are linked to the concentration and purification of macromolecules present in complex solutions made up of multiple substances, allowing the elimination of salts, sugars and any other low molecular weight compound from these solutions.

The process covered by this description allows to obtain high clarity hydrolysed gelatin solutions. thanks to the use of ultrafiltration membranes.

The described procedure can be conducted on i) starting solutions comprising gelatin already? hydrolysed, ii) starting solutions comprising gelatin not yet hydrolysed to which at least one hydrolytic enzyme is added, iii) starting solutions comprising both gelatin already hydrolysed gelatin is not yet hydrolysed to which at least one hydrolytic enzyme is added.

Does the ultrafiltration membrane allow you to retain ? in addition to the hydrolytic enzyme possibly added to the starting solution - any suspended particles present in the starting solution. Such particles, whose nature can? be protein and/or lipid, have dimensions greater than 0.1 ?m and therefore are not able to permeate the membrane, can allow to obtain a hydrolyzed gelatin solution with high clarity.

The procedure according to the embodiment illustrated in Figure 2? a process which includes a step of providing into a tank a starting solution comprising hydrolyzed gelatin. This hydrolyzed gelatin can have a molecular weight between 50 Da and 50,000 Da.

The procedure according to the embodiment illustrated in Figure 3? a process which includes a step of providing into a tank a starting solution comprising hydrolysed gelatin and non-hydrolysed gelatin to which at least one hydrolytic enzyme is added.

The procedure according to the embodiment illustrated in Figure 4, is a process which includes a step of providing into a tank a starting solution comprising only non-hydrolysed gelatin to which at least one hydrolytic enzyme is added.

In one or more? embodiments, the starting solution provided in step i) includes gelatin in a concentration between 2% and 50%.

This starting solution? a solution of gelatin (not hydrolysed or already hydrolysed) in water.

The procedure can comprising a step in which the solution provided in step i), comprising non-hydrolysed gelatin and/or hydrolysed gelatin, is heated to a temperature between 10?C and 80?C, preferably between 40?C and 55?C.

This solution is sent to an ultrafiltration membrane to be filtered obtaining a permeate and a retentate. For this purpose, a pump (for example illustrated in figures 2-4, 6) can? take the starting solution from the hydrolysis tank and feed it onto the ultrafiltration membrane.

The pressure difference (called transmembrane pressure, in English TMP, Trans-Membrane Pressure) or the pushing force applied upstream of the ultrafiltration membrane can be between 1 bar and 4 bar. This pressure difference between the two surfaces of the membrane allows the permeation of the hydrolyzed gelatin, which is sent to the subsequent planned work phases.

The pressure exerted by the solution to be filtered on the ultrafiltration membrane can be between 2 bar and 10 bar.

The molecular weight of gelatin macromolecules before hydrolysis can be included in the range between 50000 Da and 500000 Da.

The molecular cutting (cut-off) of the ultrafiltration membrane can? be between 500 Da and 50000 Da. This parameter allows us to obtain hydrolyzed gelatin in the permeate whose molecular weight can? be between 500 Da and 20000 Da.

The ultrafiltration membrane that can be used in the process can? be selected from the group consisting of polymeric spiral membranes, steel membranes, ceramic membranes, hollow fiber membranes.

The procedure can be conducted at a temperature between 10?C and 80?C, preferably between 45?C and 55?C.

In one or more? embodiments, the starting solution comprising gelatin sent to the ultrafiltration membrane can? present a concentration between 2 degrees brix and 45 degrees brix.

The starting solution comprising gelatin to be subjected to phase ii) of filtration through the ultrafiltration membrane can? present turbidity values? NTU (Nephelometric Turbidity Unit?) even higher than 500 NTU.

The starting solution can? include bovine, porcine and/or fish gelatine.

The hydrolyzed gelatin solution obtained with the described process (i.e. the permeate) can? present a concentration between 1 degree brix and 30 degrees brix.

In one or more? embodiments, the hydrolyzed gelatin solution obtained with the described process (i.e. the permeate) can? present a turbidity value? equal to or less than 5 NTU.

Can the solution? be a solution of hydrolyzed gelatin in water.

The hydrolyzed gelatin solution obtained with the described process can? include hydrolyzed gelatin in a concentration between 2% and 60%.

The hydrolyzed gelatin obtained with the described process can? include bovine, porcine and/or fish gelatine.

The hydrolyzed gelatin obtained with the described process can? have a molecular weight between 50 Da and 50,000 Da.

The hydrolyzed gelatin solution obtained with the described process can? be free of protein and/or lipid particles having dimensions greater than 0.1 ?m.

In one or more? embodiments, when the starting solution includes non-hydrolysed gelatin, the usable hydrolytic enzyme can be made up of proteases.

The hydrolytic enzyme can be used in a quantity? equal to or greater than 0.1%, preferably between 0.5% and 2.0% with respect to the weight of the non-hydrolysed gelatin (to be hydrolysed). In any case, the quantity? of enzyme to use? dependent on the activity? of the commercial formulation.

In one or more? forms of implementation, the permeate ? a solution of hydrolyzed gelatin while the retentate can? include suspended particles, gelatin not yet hydrolysed, enzyme.

The hydrolyzed gelatin obtained with the described process can be present in the form of powder. In this case the procedure can includes step iii) of concentrating the hydrolyzed gelatin solution obtained in the permeate and step iv) of drying the hydrolyzed gelatin solution concentrated in step iii).

The hydrolyzed gelatin solution obtained in the permeate can? be concentrated, for example, by thermal concentration or by a nano filtration system.

The concentrated gelatin solution can? be dried, for example, by spray drying.

An important aspect of the process described here derives from the obtaining of a permeate fraction substantially constituted by a hydrolyzed gelatin solution. In other words, when the solution subjected to the filtration step includes non-hydrolyzed gelatin to which? added at least one hydrolytic enzyme, the process allows to obtain hydrolyzed gelatin in the permeate without hydrolytic enzyme as it is totally retained in the retentate.

This aspect plays an important role both on the effectiveness of the process, which does not require subsequent inactivation phases and allows the separation of the enzyme from the hydrolysed gelatin obtained, and on the quality of the process. of the gelatin obtained as traces of hydrolytic enzyme in the final product could reduce its quality? organoleptic (taste and smell). Furthermore, the presence of the enzyme, even if denatured, in the final product could induce intolerance or allergy phenomena in sensitive subjects.

In a preferred embodiment, the retentate containing the enzyme, whose dimensions are such as not to allow its permeation through the membrane, can be reused to feed the hydrolysis tank.

The enzyme is continuously recirculated in the reaction environment and, consequently, is not It is necessary to integrate a new enzyme into the system to conduct the hydrolytic reaction. It is therefore clear that - compared to a batch process as described in the previous sections? the consumption of hydrolytic enzyme for carrying out the process is significantly reduced.

In the batch processes known in the art, the ratio between the hydrolytic enzyme used and the quantity of hydrolyzed gelatin? of the order of 5-10 kg of enzyme per 1000 kg of hydrolysed gelatin produced.

In the case of the procedure covered by this description, the relationship is of the order of 1-2 kg of enzyme per 1000 kg of hydrolyzed gelatine produced.

The process described here, compared to known processes, has the advantage of a lower consumption of hydrolytic enzyme.

Furthermore, the hydrolysis reaction is favored because by removing the hydrolysed gelatin produced from the reaction environment, the chemical balance of the hydrolysis reaction shifts towards the reaction products.

A further advantage brought by the procedure described? that once it reaches full capacity, the hourly quantity (kg/h) of hydrolysed gelatin removed from the plant will be able to be replaced with the same quantity? of fresh gelatin, in order to keep the volume constant inside the hydrolysis tank.

The ultrafiltration membrane that can be used in the process described also allows the suspended particles present in the starting solution to be retained. These particles, of such a size as not to permeate the membrane, can allow to obtain a hydrolyzed gelatin solution with high clarity. There? is evident from the image illustrated in Figure 5 where a hydrolysed gelatin solution obtained according to an embodiment of the process covered by this description (left) and a starting gelatin solution (not yet subjected to the filtration phase) are compared. . The hydrolyzed gelatin solution is decidedly clear and can present a cloudiness? also equal to 1 NTU, although the starting gelatin solution may have NTU values higher than 500.

Examples

The examples described below were carried out using an ultrafiltration system as schematized in Figure 6. In the following description with the expression ?supply solution? means the solution including gelatin indicated with the expression ?starting solution? in the terminology of the claims.

Example 1

The ultrafiltration membrane used has the following characteristics: manufacturer Koch; molecular cutting 7500 Dalton; surface area 5.6 m2.

In particular, 590 liters of a porcine gelatin solution (15% concentration in water) at a temperature of 53.2°C were introduced into the tank serving the ultrafiltration system. The solution including gelatin ? was fed to the ultrafiltration system, recirculating both the retentate and the permeate inside the tank kept under agitation.

At working time 00:25 (twenty-fifth minute) ? 1 liter of proteolytic enzyme (papain) was introduced and it was The concentration of the protein present in both the retentate and the permeate was periodically monitored.

At working time 00:35 ? a concentration of protein present in the permeate equal to 1.8% was detected.

The working conditions were kept constant until the working time 03:00 reaching a viscosity? of the feed solution of 1.58 cPs (the viscosity was measured at the reference concentration of 10%). The protein concentration in the permeate? resulted equal to 7.2%. The permeate? was then removed from the system and recovered in a dedicated tank for the following 4 hours. The system supply tank is not ? been replenished with further gelatin solution n? with water. At the end of the experiment the volume in the feed tank was reduced to 220 litres, the protein concentration in the feed solution was 21.6%, in the permeate 14.4%.

During the experiment? Has the clarity been measured? of the feed solution and the permeate. The results collected during the experiment are shown in the following table, in which in the "Notes" column, the row with the number 1 indicates the operating condition which involved the addition of 1 liter of enzyme, the row with the number 2 indicates permeate recovery.

Example 2

The ultrafiltration membrane used has the following characteristics: manufacturer Koch; molecular cutting 7500 Dalton, surface area 5.6 m2.

In particular, 300 liters of a starting solution of porcine gelatin (22.1% concentration in water) and a temperature of 50.0?C were introduced into the tank serving the ultrafiltration system. The gelatin solution? was fed to the ultrafiltration system, recirculating both the retentate and the permeate inside the tank kept under agitation.

At work time 00:10, 1.5 liters of proteolytic enzyme (papain) were introduced and ? The concentration of the protein present in both the retentate and the permeate was periodically monitored.

At working time 00:40 ? a concentration of protein present in the permeate equal to 11% was found and a viscosity? of the solution in supply of 1.79 mPa*s.

The working conditions were kept constant until the working time 01:10, reaching a viscosity? of the feed solution of 1.54 mPa*s (the viscosity was measured at the reference concentration of 10%). The protein concentration in the permeate? turned out to be equal to 15.0%.

The permeate? was then removed from the plant and recovered in a dedicated tank. The system supply tank is not ? been replenished with further gelatin solution n? with water until the working time 04:40, allowing the concentration of the protein solution to increase. At 05:00? Water was introduced into the tank in order to reach a concentration of the solution fed to the system of 21%. The system supply tank is not ? been replenished with further gelatin solution n? with water until the time of 07:40. From 08:00 to 09:40? Water was introduced into the tank in order to maintain the protein solution present at a constant volume of 100 litres. The concentration of this solution? decreased from 12.6% to 5.4%.

During the experiment? Has the clarity been measured? of the feed solution and the permeate.

The results collected during the experiment are shown in the following table, in which the number 1 indicates the addition of the hydrolytic enzyme, the number 2 indicates the recovery of the permeate, the number 3 indicates the addition of water in the feed tank until a concentration of 21% is reached, the number 4 indicates the addition of water to reach a volume of 100 liters in the supply tank.

Example 3

The ultrafiltration membrane used has the following characteristics: manufacturer Koch; molecular cutting 7500 Dalton, surface area 5.6 m2.

300 liters of a bovine gelatin solution (23.4% concentration in water) and a temperature of 44.6?C were introduced into the tank serving the ultrafiltration system. The jelly? was fed to the ultrafiltration system, recirculating both the retentate and the permeate inside the tank kept under agitation.

At work time 00:05, 0.9 liters of proteolytic enzyme (papain) were introduced and ? The concentration of the protein present in both the retentate and the permeate was periodically monitored.

At working time 00:30 ? a concentration of protein present in the permeate equal to 6.8% was detected and a viscosity? of the solution in supply of 1.82 mPa*s. The permeate? was then removed from the plant and recovered in a dedicated tank. The system supply tank is not ? been replenished with further gelatin solution n? with water until the working time 07:35, allowing the concentration of the protein solution to increase. At 07:35? Water was introduced into the tank in order to reach a concentration of the solution fed to the system of 29.7%. The system supply tank is not ? been replenished with further gelatin solution n? with water until the time of 09:05. At 09:05? Water was introduced into the tank in order to reach a concentration of the solution fed to the system equal to 19.8%. The system supply tank is not ? been replenished with further gelatin solution n? with water until the time of 10:50.

At the end of the experiment the volume in the feed tank had decreased to 100 litres, the protein concentration in the feed solution was 23.0%, in the permeate it was 9.0%. The volume of permeate collected was 260 litres. During the experiment? Has the clarity been measured? of the feed solution and the permeate. The results recorded during the experiment are shown in the following table, in which the number 1 indicates the addition of the hydrolytic enzyme, the number 2 indicates the recovery of the permeate, the number 3 indicates the addition of water in the feed tank until a concentration of 29.7% is reached, the number 4 indicates the addition of water to reach a protein concentration equal to

Example 4

The ultrafiltration membrane used has the following characteristics: manufacturer Koch; molecular cutting 3000 Dalton, surface 5.6 m2.

750 liters of a porcine gelatin solution (concentration 14.0% in water and temperature of 43.0?C) were introduced into the tank serving the ultrafiltration plant. The gelatin was fed to the ultrafiltration plant by recirculating both the retentate and the permeate inside the tank kept under agitation.

At working time 00:20 ? 1.0 liter of proteolytic enzyme was introduced and? The concentration of the protein present in both the retentate and the permeate was periodically monitored.

At work time 04:05 ? a concentration of protein present in the permeate of 3.6% was found and a viscosity? of the solution in supply of 1.80 mPa*s. The permeate? was then removed from the plant and recovered in a dedicated tank. The system supply tank? was replenished with water in order to maintain the protein concentration in the 14%-16% range until the working time 07:35, allowing the protein concentration of the solution to increase. At the working time 08:35 the volume in the feed tank was 600 liters, the protein concentration in the feed solution was 15.3%, in the permeate 3.6%.

During the experiment? Has the clarity been measured? of nutrition and permeate. The results collected during the experiment are shown in the following table, in which the number 1 indicates the addition of 1 liter of proteolytic enzyme, the number 2 indicates the recovery of the permeate and the addition of water in the feed tank in order to maintain the protein concentration at a value between 14% and 15%.

Example 5

The ultrafiltration membrane used has the following characteristics: manufacturer Koch; molecular cutting 10000 Dalton, surface 5.6 m2.

400 liters of a porcine gelatin solution (26.1% concentration in water) at a temperature of 46.9?C were introduced into the tank serving the ultrafiltration system. The jelly? was fed to the ultrafiltration system, recirculating both the retentate and the permeate inside the tank kept under agitation.

At 00:00 working time, 2.2 liters of proteolytic enzyme (papain) were introduced and ? The concentration of the protein present in both the retentate and the permeate was periodically monitored.

At working time 00:25 ? a concentration of protein present in the permeate equal to 8.1% was detected.

The permeate? was then removed from the plant and recovered in a dedicated tank. The system supply tank is not ? been replenished with further gelatin solution n? with water until the working time of 05:00, allowing the concentration of the protein solution to increase. At 05:00? Water was introduced into the tank in order to reach a concentration of the solution fed to the system equal to 20%. The system supply tank is not ? been replenished with further gelatin solution n? with water until the time of 05:20.

At the end of the experiment the volume in the feed tank had decreased to 90 litres, the protein concentration in the feed solution was equal to 23.4%, in the permeate equal to 15.8%. The volume of permeate collected was 430 litres.

During the experiment? Has the clarity been measured? of nutrition and permeate. The results collected during the experiment are shown in the following table, in which the number 1 indicates the addition of 2.2 liters of proteolytic enzyme, the number 2 the recovery of permeate, the number 3 indicates the addition of water to the feed tank to achieve a protein concentration of 20%.

Example 6

The ultrafiltration membrane used has the following characteristics: manufacturer Koch; molecular cutting 7500 Dalton, surface area 5.6 m2.

AND? a proteolytic enzyme (papain) was used, in a quantity? equal to 2 litres.

Below are the characteristics of the starting solution comprising gelatin subjected to ultrafiltration and of the gelatin solution obtained:

Starting solution

- Gelatine of porcine origin in solution with a concentration in the range of 15-25% in water

- Quantity? processed 1150 kg (expressed as dry) - Turbidity value? included in the range 20-410 NTU Gelatin solution obtained

- Quantity? produced 1110 kg (expressed as dry)

- Turbidity value? average: 2.0 NTU

- Viscosity? average 1.49 mPa*s

In particular, 950 liters of a porcine gelatin solution (concentration 14.4% in water) at a temperature of 43.2°C were introduced into the tank serving the ultrafiltration system. The jelly? was fed to the ultrafiltration system, recirculating both the retentate and the permeate inside the tank kept under agitation.

At 00:00 working time, 2 liters of proteolytic enzyme (papain) were introduced and ? The concentration of the protein present in both the retentate and the permeate was periodically monitored.

At working time 01:50 ? a concentration of protein present in the permeate equal to 6.8% was found while the viscosity? of the solution being fed? was found to be 1.49 mPa*s.

At working time 03:10 the permeate ? was removed from the plant and recovered in a dedicated tank.

From 03.10 to 100.45 the system supply tank is ? was reintegrated with gelatin solution with variable concentration in the 15-25% range and with water, in order to keep the volume and concentration of the protein solution contained constant.

At 100:45? the replenishment of the gelatin solution was interrupted and? water replenishment was maintained in order to maintain a constant value of the concentration of the protein solution contained in the system's supply tank.

At the end of the experiment the volume in the feed tank was reduced to 150 litres, the protein concentration in the feed solution was 14.4%, in the permeate 6.8%.

The volume of permeate collected was 11580 litres.

The quantity of gelatine (expressed as dry) processed? was 1150 kg, obtaining 1100 kg (expressed as dry) of hydrolysed gelatin and using 2 liters of proteolytic enzyme.

During the experiment? Has the clarity been measured? of nutrition and permeate. The results collected during the experiment are reported in the following table in which the number 1 indicates the addition of 2 liters of proteolytic enzyme, the number 2 indicates the start of the permeate recovery and the feeding of water and gelatin solution into the feeding tank of the system, the number 3 indicates the CIP (Clean In Place) washing of the system, the number 4 indicates the interruption of the introduction of gelatin into the feeding tank of the system and the introduction of water to maintain the protein concentration in the range 14%-17%.

The description of the present application provides a process for preparing hydrolyzed gelatin comprising the steps of:

i) provide a starting solution comprising gelatin,

ii) filtering said starting solution through an ultrafiltration membrane to obtain a retentate fraction and a permeate fraction comprising gelatin, wherein the starting solution comprising gelatin provided in step i) comprises at least one of hydrolysed gelatin and non-hydrolysed gelatin,

wherein when said starting solution provided in step i) comprises non-hydrolysed gelatin the process further comprises a step of adding to said solution at least one hydrolytic enzyme.

The procedure can furthermore comprise step iii) of concentrating the hydrolysed gelatin solution obtained in the permeate and step iv) of drying the hydrolysed gelatin solution concentrated in step iii).

In one or more? embodiments, the transmembrane pressure used in said phase ii) of filtering can? be between 1 bar and 4 bar. The molecular cutting (cutoff) of the ultrafiltration membrane can? be between 500 Da and 50000 Da. The ultrafiltration membrane can? be selected from the group consisting of polymeric spiral membranes, steel membranes, ceramic membranes, hollow fiber membranes. When the first solution comprises non-hydrolysed gelatin the process includes a step of adding at least one hydrolytic enzyme to said first solution. Furthermore, the procedure can be conducted at a temperature between 10?C and 80?C, preferably between 45?C and 55?C. The steps i) of providing and ii) of adding the hydrolytic enzyme can be carried out in a reaction tank. The starting solution provided in phase i) can? include gelatin in a concentration between 2% and 50%.

The disclosure further provides a hydrolyzed gelatin solution obtained with the described process. The hydrolyzed gelatin solution obtained with a described process can? present a cloudiness? equal to or less than 5 NTU. The gelatin obtained with the described process can? have a molecular weight between 50 Da and 50,000 Da.

Of course, while the principle of the invention remains the same, the formulation details and embodiments can vary widely as to what is? has been described and illustrated purely by way of example, without departing from the scope of the present invention.

Claims (10)

1. Procedure for preparing hydrolysed gelatine comprising the steps of: i) provide a starting solution comprising gelatin, ii) filtering said starting solution through an ultrafiltration membrane to obtain a retentate fraction and a permeate fraction, said permeate fraction comprising a hydrolyzed gelatin solution, wherein the starting solution provided in step i) comprises at least one of hydrolysed gelatin and non-hydrolysed gelatin, wherein when said starting solution provided in step i) comprises non-hydrolysed gelatin the process further comprises a step of adding to said starting solution at least one hydrolytic enzyme. 2. Process according to claim 1, wherein the transmembrane pressure used in said step ii) of filtering is ? between 1 bar and 4 bar. 3. Process according to claim 1 or claim 2, wherein the molecular cut-off of said ultrafiltration membrane is? between 500 Da and 50000 Da. 4. Process according to any of the preceding claims, wherein said ultrafiltration membrane is? selected from the group consisting of spiral polymer membranes, steel membranes, ceramic membranes, hollow fiber membranes. 5. Process according to any one of the preceding claims, wherein the hydrolytic enzyme comprises protease. 6. Process according to any of the preceding claims, wherein the process is? conducted at a temperature between 10?C and 80?C, preferably between 45?C and 55?C. 7. Process according to any one of the preceding claims, wherein the starting solution provided in step i) comprises gelatin in a concentration between 2% and 50%. 8. Process according to any one of the preceding claims, wherein the hydrolyzed gelatin solution obtained in step ii) has a cloudiness? equal to or less than 5 NTU. 9. Hydrolyzed gelatine obtained with a process according to any one of claims 1 to 8. 10. Hydrolyzed gelatin according to claim 9, wherein such gelatin has a molecular weight between 50 Da and 50000 Da.