Heat sterilized high protein compositions with hydrolyzed protein from a continuous process with at least one endopeptidase

Abstract

The present invention is directed to a heat sterilized composition comprising: a protein source in an amount of 5 to 20% by weight of the composition, said protein source comprising hydrolyzed protein; wherein the protein source has been treated in a continuous process with at least one endopeptidase, typically for a finite length of time. Furthermore, the invention concerns a heat sterilized high protein composition having low viscosity and being devoid of bitterness, comprising hydrolyzed heat sensitive protein source having a degree of protein hydrolysis in NPN/TN of 20 to 50% and at least one heat inactivated endopeptidase. The present invention is furthermore directed to a continuous process for preparing a heat sterilized composition which comprises a protein source containing hydrolyzed protein, the process comprising the following steps: (i) Providing an aqueous solution of a protein source; (ii) Performing a continuous hydrolysis step wherein the aqueous solution of a protein source is treated with at least one endopeptidase by heating at 40 to 90 C. and for a finite length of time of 2 to 20 minutes; (iii) heat inactivation of the endopeptidase. The invention also concerns a method of controlling viscosity and preventing bitter taste of a heat sterilized high protein composition, the method comprising providing an aqueous solution of a protein source and continuously hydrolyzing the aqueous solution of a protein source with at least one endopeptidase prior to heat inactivation of the said endopeptidase. Finally, the invention concerns the use of hydrolyzed protein prepared in a continuous process as described herein by treatment with at least one endopeptidase for a finite length of time, for preparing a heat sterilized composition and/or for controlling the viscosity of a liquid composition, wherein the composition comprises 5 to 20 weight % total protein. The invention also concerns medical uses and treatments applying or using the inventive heat sterilized composition.

Claims

1. A process for preparing a heat sterilized liquid composition which comprises a protein source containing hydrolyzed protein, the process comprising the following steps: (i) providing an aqueous solution of a protein source; (ii) performing a continuous hydrolysis step wherein the aqueous solution of the protein source is treated with at least one endopeptidase by heating at 40 to 90 C. for a finite length of time selected from a period of 2 to 20 minutes; and (iii) heat inactivation of the at least one endopeptidase to obtain the heat sterilized liquid composition, the protein source being 5 to 20% by weight of the heat sterilized liquid composition, the heat sterilized liquid composition having a viscosity below 875 mPa s at 20 C./100 s.sup.1, and the protein source comprising hydrolyzed protein having a degree of protein hydrolysis in Non-protein nitrogen/Total nitrogen (NPN/TN) of 20 to 50%.

2. The process according to claim 1, wherein steps (i) and (ii) are performed at a pH of 6 to 11.

3. The process according to claim 1, wherein step (iii) heat inactivation of the at least one endopeptidase is performed at above 70 C.

4. The process according to claim 1, wherein following steps (i) to (iii) the heat sterilized liquid composition is obtained comprising the protein source in an amount of 5 to 20% by weight of the heat sterilized liquid composition, the heat sterilized liquid composition having a viscosity below 200 mPa s at 20 C./100 s.sup.1.

5. The process according to claim 1, wherein following steps (i) to (iii) the heat sterilized liquid composition is dried to form a powder.

6. The process according to claim 5, wherein the heat sterilized liquid composition is dried to form the powder by spray drying.

Description

FIGURES

(1) The following Figure is intended to illustrate the invention further. It is not intended to limit the subject matter of the invention thereto.

(2) FIG. 1: Shows a schematic for the process as described herein. As one can see, the inventive process preferably employs a protein source, typically in form of a solution, wherein the endopeptidase is added to said protein source, preferably as a solution. The obtained mixture is then typically preheated to 40 to 90 C. and hydrolysis may then be carried out at 40 to 90 C. in for instance a holding tube for a finite length of time selected from a period of 2 to 20 minutes. Following hydrolysis, the enzyme is inactivated and then typically cooled to provide a heat sterilised composition comprising the thus obtained hydrolysate.

(3) FIG. 2: Shows a schematic for a typical batch process for protein hydrolysis of the prior art. As one can see from the RHS rectangle (with broken line), there is little impact on the range of extent or degree of hydrolysis at the end of reaction as the protein is extensively hydrolysed.

(4) This is in stark contrast to the LHS rectangle (with solid line), which shows a big impact in the range of the degree of hydrolysis for a partial hydrolysis, which ranges in a degree or extent of hydrolysis from about 20 to 75%.

(5) FIG. 3: Shows a schematic of the inventive process whereby the protein source is treated in a continuous process with at least one endopeptidase. The RHS rectangle (with broken line) is for comparative purposes and shows little impact if the hydrolysis is allowed to go to completioni.e. when a finite length of time is not appliedproviding an extensively hydrolysed protein not falling under the scope of the present invention.

(6) In stark contrast, as shown by LHS rectangle (with solid line) when as per the inventive process a finite length of time is employed selected from a period of 2 to 20 minutes, there is little impact in the range of the extent or degree of hydrolysis for a partial hydrolysis of the protein source. In this illustration, the extent or degree of hydrolysis ranges from about 35 to 45%.

EXAMPLES

(7) The following examples are intended to illustrate the invention further. They are not intended to limit the subject matter of the invention thereto.

Example 1: Exemplary Continuous Process for Preparing a Heat Sterilized Composition from Whey Protein ConcentrateModerate Temperature

(8) A whey protein source containing

(9) TABLE-US-00001 Ingredient % by weight Water 72 Dry matter 28 Whey Protein concentrate.sup.1 20 Notes: .sup.1% NPN/TN = 11.1; % amino N/TN TNBS method 3.5
was adjusted to pH 7.4 at 60 C. with a potassium hydroxide solution, followed by 10 minutes hydration time to obtain an aqueous solution. To said aqueous solution was added an endopeptidase solution of alcalase 2.4 L in 3% by weight based on the whey protein source. Said mixture was then preheated to 55 C. using a plate heat exchanger for about 30 seconds, followed by hydrolysis in a holding tube for 15 minutes at 55 C. Enzyme inactivation was then directly carried out on this mixture by heating at 95 C. for 10 seconds. The obtained hydrolysate was then cooled to 4 C.

(10) The obtained liquid composition was without any taste/bitterness and had a % NPN/TN of 40.4. Furthermore this had a viscosity of below 600 mPa s at 20 C./100 s.sup.1 determined using a rotational viscosity meter using a cone/plate geometry.

Example 2: Exemplary Continuous Process for Preparing a Heat Sterilized Composition from Whey Protein ConcentrateModerate Temperature

(11) A whey protein source containing

(12) TABLE-US-00002 Ingredient % by weight Water 72 Dry matter 28 Whey Protein concentrate.sup.1 8 Notes: .sup.1% NPN/TN = 11.1; % amino N/TN TNBS method 3.5
was adjusted to pH 7.4 at 60 C. with a potassium hydroxide solution, followed by 10 minutes hydration time to obtain an aqueous solution. To said aqueous solution was added an endopeptidase solution of alcalase 2.4 L in 3% by weight based on the whey protein source. Said mixture was then preheated to 55 C. using a plate heat exchanger for about 30 seconds, followed by hydrolysis in a holding tube for 15 minutes at 55 C. Enzyme inactivation was then directly carried out on this mixture by heating at 95 C. for 10 seconds. The obtained hydrolysate was then cooled to 4 C.

(13) The obtained liquid composition was without any taste/bitterness and had a % NPN/TN of 40.4. Furthermore this had a viscosity of below 800 mPa s at 20 C./100 s.sup.1 and below 320 mPa s at 70 C./100 s.sup.1 determined using a rotational viscosity meter using a cone/plate geometry.

Example 3: Exemplary Continuous Process for Preparing a Heat Sterilized Composition from Whey Protein ConcentrateHigh Temperature

(14) A whey protein source containing

(15) TABLE-US-00003 Ingredient % by weight Water 72 Dry matter 28 Whey Protein concentrate.sup.1 8 Notes: .sup.1% NPN/TN = 11.1; % amino N/TN TNBS method = 3.5
was adjusted to pH 7.4 at 60 C. with a potassium hydroxide solution, followed by 10 minutes hydration time to obtain an aqueous solution. To said aqueous solution was added an endopeptidase solution of alcalase 2.4 L in 1% by weight based on the whey protein source. Said mixture was then preheated to 78 C. using a plate heat exchanger for about 30 seconds, followed by hydrolysis in a holding tube for 5 minutes at 78 C. Enzyme inactivation was then directly carried out on this mixture by heating at 95 C. for 10 seconds. The obtained hydrolysate was then cooled to 4 C.

(16) The obtained liquid composition was without any taste/bitterness and had a % NPN/TN of 38.6. Furthermore, this had a viscosity of below 205 mPa s at 20 C./100 s.sup.1 and below 80 mPa s at 70 C./100 s.sup.1 determined using a rotational viscosity meter using a cone/plate geometry.

Example 4: Exemplary Continuous Process for Preparing a Heat Sterilized Composition from Casein: Whey (30:70)Moderate Temperature

(17) An aqueous protein source containing:

(18) TABLE-US-00004 Ingredient % by weight casein:whey (30:70).sup.1 8 Notes: .sup.1% NPN/TN = 11.1; % amino N/TN TNBS method = 3.5
was adjusted to pH 7.4 at 60 C. with a potassium hydroxide solution, followed by 10 minutes hydration time to obtain an aqueous solution. To said aqueous solution was added an endopeptidase solution of alcalase 2.4 L in 3% by weight based on the protein source. Said mixture was then preheated to 55 C. using a plate heat exchanger for about 30 seconds, followed by hydrolysis in a holding tube for 5 minutes at 55 C. Enzyme inactivation was then directly carried out on this mixture by heating at 95 C. for 10 seconds. The obtained hydrolysate was then cooled to 4 C.

(19) The obtained liquid composition was without any taste/bitterness and had a % NPN/TN of 39.0. Furthermore this had a viscosity of below 200 mPa s at 20 C./100 s.sup.1 determined using a rotational viscosity meter using a cone/plate geometry.

Example 5: Exemplary Continuous Process for Preparing a Heat Sterilized Composition from Soy Protein Isolate/Curd

(20) A soy protein source containing

(21) TABLE-US-00005 Ingredient % by weight Water 87 to 90 Dry matter of which: 10-13 Soy protein isolate/curd.sup.1 60 Fat 33% Ashes on TS 3% Notes: .sup.1% amino N/TN TNBS method = 3

(22) Several trials 4a to 4d were then conducted following the protocol of example 1 and example 2 with the following modificationsthe pH was adjusted to pH 6.8 to pH 8 at 60 C. with a potassium hydroxide solution to obtain an aqueous solution, the pre-heating step was at 68-70 C. for about 30 seconds and hydrolysis was conducted at 68-70 C. for 15 to 20 minutes along with the following further modifications:

(23) TABLE-US-00006 Ref Endopeptidase solution Enzyme inactivation 4a Alcalase 2.4 L 0.05% on 120 C. for 5 seconds solids 4b 0.1% Alcalase 2.4 L based 120 C. for 5 seconds on protein 4c Alcalase 2.4 L 0.2% on 140 C. for 40 seconds solids 4d 0.33% Alcalase 2.4 L 140 C. for 40 seconds based on protein

(24) In all of trials 4a to 4d a liquid composition was provided having a viscosity of below 200 mPa s at 20 C./100 s.sup.1 determined using a rotational viscosity meter using a cone/plate geometry.

(25) Furthermore, for all of 4a to 4d the liquid composition was without any bitter taste having an % amino N/TN TNBS method of around 6%.

Example 6: Comparison of Typical Batch Process with the Inventive Process Conducted at 55 C.

(26) To compare a typical batch hydrolysis process with the inventive continuous process the following trials were conducted. In all cases the input protein source had a % NPN/TN=11.1; % amino N/TN TNBS method=3.5.

(27) Trial 5aThe whey protein source of example 2 was subjected to a batch hydrolysis process at 55 C. for 2 hours at pH 7.4, by pH adjustment with potassium hydroxide solution.

(28) Trial 5b was subjected to the inventive continuous hydrolysis process at 55 C. under the conditions as described for example 2

(29) Trial 5c was subjected to the inventive continuous hydrolysis process at 55 C. under the conditions as described for example 4.

(30) TABLE-US-00007 Ref Time Protein Source (8%) % NPN/TN Taste 5a 2 hours Whey protein concentrate) 57 Very (batch) bitter 5b 15 minutes Whey protein concentrate 40.4 Not (continuous) bitter 5c 5 minutes Whey protein concentrate 39 Not (continuous) 30:70 casein:whey bitter

(31) As one can see, a typical batch hydrolysis process (5a) provided a product which was very bitter in taste. In contrast, the inventive continuous hydrolysis process as outlined in trials 5b and 5c provided products which were not bitter in taste.