WO2006034708A1

WO2006034708A1 - Process for the preparation of highly concentrated and stable carbohydrate

Info

Publication number: WO2006034708A1
Application number: PCT/DK2005/000604
Authority: WO
Inventors: Nielsen Christian Fogtmann
Original assignee: Danifo A/S
Priority date: 2004-09-28
Filing date: 2005-09-24
Publication date: 2006-04-06

Abstract

The present invention relates to a method for the preparation of a highly concentrated carbohydrate solution comprising the steps of i) heating an aqueous mixture of the carbohydrate in a concentration of at least 75% w/w with an acidic reacting agent and an agent with surface-active properties to a temperature of from 80 to 90 °C to obtain a first carbohydrate solution, ii) cooling the thus obtained first carbohydrate solution to room temperature i.e. a temperature of from 15 to 25 °C, iii) repeating step i) and ii) at least two times with a time interval of up to 24 hours to obtain a carbohydrate solution having a carbohydrate concentration of at least 75% w/w such as from 75 to 85% w/w and being stable with respect to precipitation as noted by visual inspection for at least 6 months such as, e.g., for at least 8 month, for at least 10 months or for at least 12 months when stored at room temperature.

Description

Process for the preparation of highly concentrated and stable carbohydrate solution

Field of the invention The present invention relates to a novel process to prepare a highly concentrated stable carbohydrate solution and to the stable carbohydrate solution. The process involves the use of an acidic reacting agent and an agent with surface-active properties. A highly concentrated carbohydrate solution is together with the acid reacting agent and the agent with surface-active properties heated to a temperature of from 80 to 90 ⁰C and specific cycles of heating/cooling are employed.

Background of the invention

The prior art has generally disclosed methods of adding granulated sugar to hot water for converting the granulated sugar into a liquid sugar product having a desired brix of concentration, which may be around 65°Brix at the highest level. Normally, such systems merely relied upon a continuous agitation of the sugar and hot water until the sugar was completely dissolved. In utilizing these types of systems it was normally necessary that the liquefaction process be carried out in a batch manner due to the extreme length of time required for completely dissolving the sugar.

Due to the increased utilization of liquid sugar, and particularly liquefied sugar having a higher concentration over 65°Brix, it has been of interest to improve the procedure, which can be done by adding an agent with surface tension properties, which improve the solubility of sugar crystals and further by adding very small amount of acid, which at the same time releases all or almost all air developed under the process.

Accordingly, it is the object of this invention to provide a continuous or batch-wise process for forming liquid sugar starting from fine or extra fine granulated sugar and resulting in a solution having higher than 65°Brix.

More particularly, the present invention is directed to a continuous or batch-wise process for forming liquid sugar having a desired brix starting from granular sugar by metering granulated sugar and water together in predetermined ratios to form a substantially uniform solution. Description of the invention

Basically, the present invention is directed to stable carbohydrate solutions and a method of continuously or batch-wise forming the liquid sugar/carbohydrates solutions having a desired brix_of 75° Brix or higher starting from granular sugar/carbohydrates, hot water, containing an agent with surface-active properties and an acidic reacting agent. The ingredients are mixed in predetermined ratios to continuously form a substantially uniform solution.

Accordingly, in one aspect the invention relates to a method for the preparation of a highly concentrated carbohydrate solution comprising the steps of i) heating an aqueous mixture of the carbohydrate in a concentration of at least 75% w/w with an acidic reacting agent and an agent with surface-active properties to a temperature of from 80 to 90 ⁰C to obtain a first carbohydrate solution,

ii) cooling the thus obtained first carbohydrate solution to room temperature i.e. a temperature of from 15 to 25 ⁰C,

iii) repeating step i) and ii) at least two times with a time interval of up to 24 hours to obtain a carbohydrate solution having a carbohydrate concentration of at least 75% w/w such as from 75 to 85% w/w and being stable with respect to precipitation as noted by visual inspection for at least 6 months such as, e.g., for at least 8 month, for at least 10 months or for at least 12 months when stored at room temperature.

The carbohydrate may be any carbohydrate that is suitable to obtain as a highly concentrated and stable solution such as, e.g. monosaccharides, disaccharides, oligosaccharides or polysaccharides. In specific embodiments of the invention the carbohydrate is selected from sucrose or glucose or derivates thereof.

The acid reacting agent used in a method according to the invention has generally a function of expelling air produced during the process. The acidic reacting agent may be a natural or synthetic agent selected from the group consisting of malic acid and other acids capable of adjusting pH to below 6.0 such as, e.g., ascorbic acid, hydrochloric acid, citric acid, phosphoric, tartaric acid etc. and salts thereof acceptable according to European regulation. In order to remove air produced during the process, the process may comprise de- aeration either during the whole process or at suitable steps (e.g. the heating and/or cooling step). Accordingly, in one embodiment the method according to the invention further comprises de-aeration during one or more steps resulting in that 80-90% of the air in the carbohydrate solution developed under the process is removed.

In specific embodiments, continuously mixing and de-aeration in warm condition take place in a predetermined time and cooling. The treatment may be repeated 2-3 times depending of the concentration (65-99°Brix, such as, e.g., 65, 70, 75, 80, 85, 90, 95 or 99° Brix). During this treatment the present inventors have found that the solubility of the carbohydrate will increase.

The agent with surface-active properties imparts improved solubility to the system. In a specific embodiment the agent is lecithin. The agent with surface-active properties such as, e.g., lecithin is normally employed in the form of a 10% w/w aqueous solution, cf. the Examples herein.

In general, the agent with surface-active properties is a natural product, such as a lecithin or a synthetic product. It is a non-ionic, anionic or cationic agent and it is non- toxic. Examples of agents with surface-active properties are:

Lecithin, hydroxylated lecithin, refined phospholipids, poly-oxy-ethylene sorbitan fatty esters, sorbitan esters of fatty acids, propylene glycol mono-laurate and mono-stearate, glycerol mono-stearate and mono-oleate, safflower mono-glycerides, poly-oxy-ethylene nonyl phenol adducts, di-ethylene glycol mono-laurate and mono-oleate, poly-ethylene glycol mono- and di-laurates, stearates and oleates, poly-oxy-ethylene ethers, di- ethanol-amides of coconut oil fatty acids, lauric acid or stearic acid, phosphatidyl choline mono- and di-glycerides, inositol phosphatides, cepalin fractions, sodium stearoyl-2-lactylate, di-octyl sodium sulfo-succinate and di-acetyl sodium sulfo- succinate etc. and mixtures thereof.

Furthermore, the agent with surface-active properties is derived from sources such as soybeans and is an approved food additive or helping-agent.

In a specific embodiment, the agent with surface-active properties is used in the form of a solution obtained by i) mixing the agents with surface-active properties with hot water, ii) heating to 80 ⁰C iii) cooling to 20 ⁰C and repeating steps ii) and iii) two times with a time interval of up to 24 hours to obtain the solution containing the agent with surface active properties.

In a preferred embodiment, the method according to the invention is as follows: Sucrose is the carbohydrate, malic acid is the acidic reacting agent and lecithin is the agent with surface-active properties and the concentration ranges of the individual components in the obtained solution are as follows: sucrose: 75-99% w/w such as, e.g., 75-95% w/w, 75-90% w/w, 75-85% w/w,

80-90% w/w, 80-85% w/w or 75-80% w/w malic acid: 0.01-0.5% w/w such as, e.g., 0.03-0.05% w/w lecithin: 0.05-0.5% w/w such as, e.g., 0.05-0.15% w/w

In another embodiment, the method according to the invention is as follows: Sucrose is the carbohydrate, malic acid is the acidic reacting agent and lecithin is the agent with surface-active properties and the concentration ranges of the individual components in the obtained solution are as follows: sucrose: 75-99% w/w such as, e.g., 75-95% w/w, 75-90% w/w, 75-85% w/w, 80-90% w/w, 80-85% w/w or 75-80% w/w malic acid: 0.1-5% w/w such as, e.g., 0.3-0.5% w/w lecithin: 0.5-5% w/w such as, e.g., 0.5-1.5% w/w

In another aspect, the invention relates to a concentrated carbohydrate solution having a carbohydrate concentration of at least 75%> w/w and further comprising: i) an acidic reacting agent, and ii) an agent with surface-active properties; wherein the solution is stable with respect to crystallization as noted by visual inspection for at least 6 months such as, e.g . , for at least 8 months, for at least 10 months or for at least 12 months when stored at room temperature. The concentrated carbohydrate solution may be prepared as described in a method according to the invention. The individual components of the concentrated carbohydrate solution are as described in connection with the description of the method above.

In the concentrated carbohydrate solution, the concentration of the acidic reacting agent is preferably in a range of from 0.01 % to 0.5% w/w, and even more preferably in a range of from 0.03% to 0.05% w/w. Furthermore, the concentration of the agent with surface-active properties is preferably in a range of from 0.05% to 0.5% w/w and even more preferably in a range of from 0.05% to 0.15% w/w.

In a preferred embodiment, the invention relates to a concentrated carbohydrate solution having a carbohydrate concentration of at least 75% w/w and further comprising: i) an acidic reacting agent in a concentration range of from 0.03% to 0.05% w/w, and ii) an agent with surface-active properties in a concentration range of from 0.05 to 0.15% w/w; wherein the solution is stable with respect to crystallization as noted by visual inspection for at least 6 months such as, e.g., for at least 8 months, for at least 10 months or for at least 12 months when stored at room temperature.

Furthermore, in a preferred embodiment of the concentrated carbohydrate solution the carbohydrate is sucrose, the acidic reacting agent is malic acid, and the agent with surface-active properties is lecithin.

In another embodiment, the invention relates to a concentrated carbohydrate solution having a carbohydrate concentration of at least 75% w/w and further comprising: i) an acidic reacting agent in a concentration range of from 0.1% to 5% w/w such as, e.g., from 0.3 to 0.5% w/w, and ii) an agent with surface-active properties in a concentration range of from 0.5 to 5% w/w such as, e.g., from 0.5 to 1.5% w/w; wherein the solution is stable with respect to crystallization as noted by visual inspection for at least 6 months such as, e.g., for at least 8 months,, for at least 10 months or for at least 12 months when stored at room temperature.

The invention is illustrated in the following non-limiting examples. Examples

Example 1

Preparation of a solution of an anti-crystallization agent Lecithin 10O g

Distilled water ad 1000 g

Lecithin is mixed with warm distilled water and heated to 80 ⁰C for 1 hour. Then the solution is allowed to cool to room temperature. The mixture is left to next day. Next day the procedure is repeated and again the following day. Finally the solution is kept at 10 ⁰C until use.

Example 2

Preparation of a highly concentrated solution of sucrose (75°Brix) Solutions having the following constitution were prepared:

Constitution Solution A Solution B Solution C

Pure refined sugar 750.0 g 750.0 g 750.0 g

Malic acid, 10% 3.O g 5.O g

Lecithin 10%² 10.0 g 10.0 g 10.0 g

Distilled water, hot 237.0 g 235.0 g 240.0 g

² prepared as described in Example 1

After mixing, the solutions were treated three times by heating/cooling at 80°C/20°C for three consecutive days. It is important that the manufacturing process starts with dissolution of lecithin in warm water and then, adding to sugar and the other ingredients subsequently.

The solutions were stored at room temperature to evaluate the stability of the solutions (i.e. whether a crystallization of sugar crystals occurred during time). As a control was used the following solution:

Control:

Pure refined sugar 750.0 g

Distilled water, hot 250.0 g Example 3

Preparation of a highly concentrated solution of sucrose (80°Brix)

Solutions having the following constitution were prepared:

Constitution Solution A Solution B Solution C

Pure refined sugar 800.0 g 800.0 g 80O.O g

Malic acid, 10% 3.O g 5.O g

Lecithin 10%² 10.0 g 10.0 g 10.O

Distilled water, hot 187.O g 185.O g 190.O g ² prepared as described in Example 1

After mixing (cf. Example 2 above), the solutions were treated tree times by heating/cooling at 80°C/20°C for three consecutive days.

Control: Pure refined sugar 800.0 g

Distilled water, hot 200.0 g

The control solution was prepared in the same manner as described above.

Result of stability study

Control: After 6 days few crystals were formed. The crystal grew slowly.

Samples marked C (i.e. without acid): After 1-2 month crystals were formed (having a smooth structure). The crystals grew slowly.

Samples A and B: After 11 months still no visible crystallization.

Claims

1. A method for the preparation of a highly concentrated carbohydrate solution comprising the steps of i) heating an aqueous mixture of the carbohydrate in a concentration of at least 75% w/w with an acidic reacting agent and an agent with surface-active properties to a temperature of from 80 to 90 ⁰C to obtain a first carbohydrate solution,

2. A method according to claim 1 , wherein the agent with surface-active properties is used in the form of a solution obtained by i) mixing the agents with surface-active properties with hot water, ii) heating to 80 ⁰C, iii) cooling to 20 ⁰C, and repeating steps ii) and iii) two times with a time interval of up to 24 hours to obtain the solution containing the agent with surface active properties.

3. A method according to claim 1 or 2, wherein the carbohydrate is sucrose or glucose or derivates thereof.

4. A method according to any of the preceding claims, wherein the acidic reacting agent is a natural or synthetic agent selected from the group consisting of malic acid and other acids capable of adjusting pH to below 6.0 such as, e.g., ascorbic acid, hydrochloric acid, citric acid, phosphoric, tartaric acid etc. and salts thereof.

5. A method according to any of the preceding claims, wherein the agent with surface- active properties is lecithin. 6. A method according to any of the preceding claims further comprising de-aeration during one or more steps resulting in that 80-90% of the air in the carbohydrate solution developed under the process is removed.

7. A method according to any of the preceding claims, wherein the agent with su rface- active properties such as, e.g., lecithin, is employed in the form of a 10% w/w aq ueous solution.

8. A method according to any of the preceding claims, wherein the agent with su rface- active properties is a natural product, such as a lecithin or a synthetic product.

9. A method according to any of the preceding claims, wherein the agent with su rface- active properties is a non-ionic, anionic or cationic agent and it is non-toxic.

10. A method according to any of the preceding claims, wherein the agent with s urface- active properties is selected from the group consisting of

Lecithin, hydroxylated lecithin, refined phospholipids, poly-oxy-ethylene sorbitan fatty esters, sorbitan esters of fatty acids, propylene glycol mono-laurate and mono-stearate, glycerol mono-stearate and mono-oleate, safflower mono-glycerides, poly-oxy-ethylene nonyl phenol adducts, di-ethylene glycol mono-laurate and mono-oleate, poly-ethylene glycol mono- and di-laurates, stearates and oleates, poly-oxy-ethylene ethers, dϊ- ethanol-amides of coconut oil fatty acids, lauric acid or stearic acid, phosphatidyl choline mono- and di-glycerides, inositol phosphatides, cepalin fractions, sodium stearoyl-2-lactylate, di-octyl sodium sulfo-succinate and di-acetyl sodium sulfo- succinate, and mixtures thereof.

11. A method according to any of the preceding claims, wherein the agent with surface- active properties is derived from sources such as soybeans and is an approved food additive or helping-agent.

12. A method according to any of the preceding claims, wherein sucrose is the carbohydrate, malic acid is the acidic reacting agent and lecithin is the agent with surface-active properties and the concentration ranges of the individual components in the obtained solution are as follows: sucrose: 75-99% w/w such as, e.g., 75-80% w/w malic acid: 0.01-0.5% w/w such as, e.g., 0.03-0.05% w/w lecithin: 0.05-0.5% w/w such as, e.g., 0.05-0.15% w/w

13. A concentrated carbohydrate solution having a carbohydrate concentration of at least 75% w/w and further comprising: i) an acidic reacting agent, and ii) an agent with surface-active properties; wherein the solution is stable with respect to crystallization as noted by visual inspection for at least 6 months such as, e.g., for at least 8 months, for at least 10 months or for at least 12 months when stored at room temperature.

14. A concentrated carbohydrate solution according to claim 13, wherein the concentration of the acidic reacting agent is in a range of from 0.01 % to 0.5% w/w.

15. A concentrated carbohydrate solution according to claim 13, wherein the concentration of the acidic reacting agent is in a range of from 0.03% to 0.05% w/w.

16. A concentrated carbohydrate solution according to any of claims 13-15, wherein the concentration of the agent with surface-active properties is in a range of from 0.05% to 0.5% w/w.

17. A concentrated carbohydrate solution according to any of claims 13-15, wherein the concentration of the agent with surface-active properties is in a range of from 0.05% to 0.15% w/w.

18. A concentrated carbohydrate solution according to claim 13, wherein the concentration of the acidic reacting agent is in a range of from 0.03% to 0.05% w/w and the concentration of the agent with surface-active properties is in a range of from 0.05% to 0.15% w/w.

20. A concentrated carbohydrate solution according to any of claims 13-18, wherein the carbohydrate is sucrose, the acidic reacting agent is malic acid, and the agent with surface-active properties is lecithin.