ES2779058B2 - Procedure to obtain refined sugar syrup from raw sugar for its application in bottling plants of non-alcoholic sugary drinks and syrup thus obtained - Google Patents

Description

DESCRIPTION

PROCEDURE TO OBTAIN REFINED SUGAR SYRUP FROM RAW SUGAR FOR APPLICATION IN BOTTLING PLANTS

OF NON-ALCOHOLIC SUGARED BEVERAGES AND SYRUP SO OBTAINED

Field and background of the invention

The present invention refers to a process for obtaining a refined sugar syrup of the highest purity from raw sugar, that is, from natural brown sugar resulting from partially refining or not refining the juice of sugar cane, or beet sugar bowl, which makes it possible to obtain a colorless sugar syrup, free of foreign odors and impurities, which does not need subsequent treatment to be mixed with the rest of the ingredients used in the manufacture of sugary non-alcoholic beverages, with a resulting purity of between 99.7 and 99.9%.

More specifically, the invention provides a process for obtaining a refined sugar syrup from solid raw sugar, where the process can be integrated into an industrial plant for non-alcoholic sugary beverages in a simple way and at a low cost, not being necessary other treatments for its intended use in said plants. The refined sugar syrup obtained by means of the present process is also an object of the invention.

In the state of the art, plants for the manufacture and bottling of sugary non-alcoholic beverages are well known. To sweeten the beverages, these plants use a type of refined sugar with a degree of purity of 99.9%, which is purchased or acquired through the manufacturers that process this type of product.

However, this form of operation has various problems or drawbacks, for example when the manufacturing and bottling plant for this type of beverages is located in remote places or where access to refined sugar is difficult. In this case, the expenses due to the transportation of refined sugar from the manufacturer's or supplier's warehouse to the beverage production plant, increases by substantively the cost of final production of such beverages.

Another drawback is the existence of few manufacturers or suppliers of this sugar in the area where the production plant for these beverages is installed, which tends to increase the market price of refined sugar and, with it, the final cost of drinks.

There may also be the drawback that the sugar that can be accessed does not meet the regulatory, technical or health requirements necessary for its use in the manufacturing and bottling process of non-alcoholic sugary beverages, even though raw sugar is easily accessible. produced by the sugar mills that supply it to the refining plants.

The present invention solves these problems by providing a process for obtaining a refined sugar syrup from solid raw sugar that is easily integrated into the manufacturing and bottling plants of non-alcoholic sugary beverages, with which these bottling plants do not depend on of national or international regulations on the sugar trade or the existence of sugar refining plants in its vicinity. Furthermore, the process of the invention makes it possible to use as a sweetener for these beverages a refined sugar syrup obtained from a raw material such as solid raw sugar, the market price of which is much lower than that of refined sugar.

For example, European patent EP 0635 578 describes a process for refining raw sugar, in particular for refining brown sugar that comes from the sugar cane sugar industry, which comprises the steps of (a) melting raw sugar to obtain a raw sugar syrup, (b) carbonating or phosphating said raw sugar syrup and (c) tangentially microfiltering and / or tangentially ultrafiltering the raw sugar syrup that has been subjected to carbonation or phosphating. This process is completed with the following steps: (d) decolorization of the sugar syrup resulting from step (c) and (e) crystallization and / or demineralization of the sugar syrup resulting from step (d) using a flocculating agent .

Thus, starting from a solid raw sugar as raw material, which contains greater impurities than a refined sugar, the process object of this invention allows to obtain a high quality refined sugar syrup, free of coloring matters, metals and ashes, suitable for its use in the industry for the manufacture of non-alcoholic sugary beverages.

Detailed description of the invention

The process for obtaining a refined sugar syrup from solid raw sugar for its application in bottling plants for non-alcoholic sugary beverages of the present invention comprises the following stages:

a) Dissolution of solid raw sugar by hot recirculation until obtaining a syrup with a concentration of 62 - 64 Brix (62 - 64 g of sugar dissolved per 100 g of solution);

b) Addition of primary clot formation reagents that improve the physicochemical characteristics of the syrup during the dissolution stage;

c) Addition of a flocculating polymer and carbon dioxide, which positively modify the nature of the gas-liquid and solid-liquid interface, forming agglomerations of flocs that rise with the help of CO2 to the surface;

d) Stirring the obtained syrup mixture and clarifying it by flotation, in order to obtain a clean syrup at the bottom, where sludge and impurities rise to the surface and are compacted together thanks to the help of carbon dioxide;

e) Filtration of the clean syrup and elimination of non-floating sludge;

f) Discoloration of the syrup obtained by the ion exchange technique to counter flow;

g) Demoralization of the syrup using the reverse ionic exchange technique to remove conductometric ash and metals at a temperature of 60 ° C-40 ° C;

h) Deodorization of the syrup using counter flow adsorbent resins, i) Polishing of the syrup to provide a final finish with a degree of turbidity between 1 - 3 NTU, and

j) Cooling to room temperature for storage and later use.

Preferred embodiment of the invention

A preferred embodiment of the process for obtaining a refined sugar syrup from solid raw sugar for its application in bottling plants of non-alcoholic sugary drinks object of the present invention and whose raw material, raw sugar, is a raw material in a solid state, unlike refining factories that start from a raw material that is in a liquid state, which is the juice from the crushing and pressing of sugar cane or sugar beet.

In the present invention, the above difference is fundamental compared to refining industries, since these refining plants start from a raw material in liquid state to reach a final product in solid state, which is refined sugar, while in The present invention is based on a raw material in solid state, which is raw sugar, to obtain a final product in liquid state that is colorless sugar syrup of the highest purity, between 99.7 and 99.99% .

In a preferred embodiment, step a) of the process of the invention for dissolving solid raw sugar by hot recirculation until obtaining a syrup with a concentration of 62-64 Brix is carried out at a temperature of 75 ° C85 ° C, with the solid sugar preferably supplied through a Venturi feed system. To aid dissolution, the sugar is recirculated against a tank with the help of a pump and a vertical agitator that helps to dissolve and distribute the reagents used in subsequent stages b), c) and d).

Preferably, the primary clotting reagents used in step b) of the process of the invention are selected from calcium oxide, phosphoric acid and metal sulfate salts, such as aluminum sulfate, or polymerized coagulants, such as aluminum hydroxychloride. These clot-forming reagents are used in effective and adequate amounts for optimal coagulation, these amounts of clot-forming reagents will depend on the amount of raw sugar used in the process of the invention.

Preferably, as flocculant in step c) of the process of the invention, high molecular weight anionic polyacrylamide is used. As in the previous case, this flocculant is added at this stage of the process in an effective and adequate amount for optimal flocculation, said amount depending on the amount of raw sugar used in step a).

In this regard, coagulation refers to the formation of small gelatinous particles through the addition of the coagulant and the application of mixing energy, which destabilizes the suspended particles by neutralizing the charges of negatively charged colloids, while by flocculation is understood the agglomeration of the coagulated particles in flocs, larger.

Step d) of the present process consists in stirring the syrup mixture obtained and clarifying it by floating at rest. Thus, once the flocculating polymer has been added, rapid homogeneous stirring and subsequent rest are carried out so that the formation of sludge takes place, obtaining a clean syrup, this stage is called clarification since when the impurities are separated in the form from sludge to the surface the syrup clarifies; that is, the turbidity caused by insoluble materials contained in the syrup is eliminated. Once it is left to rest, the impurities rise to the surface and are compacted together thanks to the help of carbon dioxide. For this, it is important to control and distribute the bubbles correctly. CO2 in the entire surface area of the tank, so that the formed sludge rises to the surface and coalesces, forming a compact and stable layer.

In this regard, the use of a serpentine diffuser design with nozzles whose aperture is 0.2 to 0.6 mm arranged in the coil so as to form fine CO2 bubbles over the entire surface is preferred. This type of diffuser aerates the solution for a short time and the carbon dioxide interacts with the sludge formed. The effectiveness of this process step, in addition to being visualized in the formed layer of sludge, can be quantitatively measured with the turbidity, which drops from approximately 300-400 NTU to 3-9 NTU at this stage.

Another advantage of this injection system is that by having a compact layer of sludge, the syrup contained in this layer is lower than the layers formed in other processes where, when dispersed or swollen, the syrup loss is high.

Stage e) of filtration of the clean syrup and removal of non-floating sludge is preferably carried out with earth filters, since these filters allow a large flow of filtrate and better permeability. In order to retain this type of sludge, diatomaceous earths with a particle size distribution of between 10 and 20 microns are used. The sludge is retained in the lands and the clean syrup passes through the lands.

In stage f) of decolorization of the syrup by means of the counterflow ion exchange technique, the syrup, at a temperature between 75 ° C and 70 ° C, is passed from the tank where stages a) to e have been carried out. ) by a decolorizing train containing an anionic resin based on styrene and divinylbenzene.

In a preferred embodiment, the discolored syrup resulting from this step f) has a color less than or equal to 35 I.U. (ICUMSA units).

In this context, there are two important mechanisms in the fixation of sugar dyes to the strong anion of ion exchange resins: the ionic bond between the anionic dyes and the fixed charges of the resin and the hydrophobic interaction between the nonpolar parts of the resin. dye and styrene-divinylbenzene from the resin. Because Most syrup colorants are anionic (negatively charged) in nature, strong base anion resins are effective bleaches. Low molecular weight carboxylic acids and phenols are bound by chemical reaction and molecular interaction to resins. Large, high molecular weight organic acids can bind chemically and by interaction at various sites on the resin.

In the present process, an anionic resin based on styrene and divinylbenzene is selected that essentially maintains the pH of the syrup.

A fluidized bed technology is preferably applied here, which consists in that the resin bed is placed between two plates, one upper and one lower, of a tank, including the nozzle plates or specific diffusers to make an efficient distribution. Thus, the syrup passes through each column from the bottom up (counter flow) so that the resin flows to the top to the top plate, helping a good distribution.

In the present procedure, the decolorization can be done through several columns with anionic resin depending on the type of color of the starting product and the color of the syrup obtained before this decolorization step, as well as the desired color for the final product, related directly with the purity of the sugar in solution.

In step g) of demineralization of the syrup using the reverse ionic exchange technique to remove conductometric ash and metals, the syrup is passed through an anionic resin with a strong base (in OH- form) and subsequently through a column containing a high pK weak acid cationic resin. Preferably, the ash concentration in the syrup after this demineralization step ranges from 0.04% to 0.01%.

When the syrup passes through the strong base anion resin, all the salts go into their basic form, causing the pH of the syrup to rise to 9-10; later, when passing through the weak acid cationic column, it will exchange cations and neutralize the base, resulting in a slightly acidic pH of 3.5 - 4.5.

This type of specific demoralization has many advantages in the process of the invention, since it allows to reduce the concentration of amines produced in the product bleaching steps, stabilizing the pH at the outlet and giving the syrup a better appearance and shine.

Thus, this demineralization stage makes it possible to obtain a high quality syrup without chemically damaging the syrup. In this regard, since the syrup has a series of organic chemical compounds, during the demineralization process it can undergo an oxidation process due to the conditions of the demineralization process, which can cause a degradation that can be irreversible. To avoid this process generated by sudden changes in pH (when passing from one column to another), containing substances such as Fe and Cu in the syrup, and other compounds, a temperature reduction of between 60 ° C - 40 ° C is established. With this change in condition, it is ensured that the syrup in the demineralization process will not have any irreversible oxidation or degradation.

Once demineralized, in step h) the syrup is subjected to deodorization using counterflow adsorbent resins, in particular macroporous adsorbent resins. This type of resins retain odor and flavor-forming substances, such as amino flavors resulting from the passage of syrup through strong-based anionic resins, plastic and metallic flavors generated in the demineralization process, etc.

Stage i) of polishing the syrup to provide a final finish with a degree of turbidity between 1 - 3 NTU is preferably carried out using bag or cartridge filters, which in turn serve as a protective barrier that prevents possible leakage of the syrup. cleaning agent contained in these filters, which can re-dirty the syrup.

The process of the invention makes it possible to recover fresh water from all the previously described process stages, including sweetening, de-sweetening of ion exchange columns, especially by drying the sludge originated in stage d) of sugar clarification, for example using filters. rotary vacuum, which in turn facilitates the disposal of said sludge without causing cross contamination.

Preferably, this fresh water recovered from the stages of the process object of the invention is reused in stage a) of the process for the hot dissolution of the syrup, which generates a saving of 15-18% in the sugar used in the point starting point that is supplied to the facility day by day. In order to ensure the microbiological quality of this recovered water, before reintegrating it into the process of the invention, it can be subjected to a pasteurization process at 70 ° C - 80 ° C, in order to achieve a lower mold and yeast content. at 10 CFU / 10 g.

The refined sugar syrup obtained according to the procedure described above is also an object of the invention, this being a sugar syrup with a purity of 99.7% -99.99%, a turbidity of 1 - 3 NTU, a pH of 4 , 0 - 4.5, a color less than or equal to 35 IU (ICUMSA units), an ash content of 0.04 - 0.01% and a sediment content of less than 5 mg / kg.

In addition to the advantages described above, and those that will be evidenced by the person skilled in the art, the present invention also presents others, among which the following stand out:

• The plants or factories for the production of non-alcoholic sugary beverages that incorporate the process of the invention will not depend on regulations or fluctuations in the sugar market.

• Plants or factories that make non-alcoholic sugary beverages may use raw sugar and low-quality refined sugars as raw materials for their manufacturing.

• The quality of the final product is ensured and that it meets the required specifications regarding the amount of ashes, metals and color, which in turn guarantees the quality required for the beverages that incorporate it.

• In the process of the invention, carbon or pulverized activated carbon filters are not used to eliminate unwanted odors. To this In this regard, the use of activated carbon has serious disadvantages, for example the excessive use of carbon to eliminate uncharacteristic flavors and odors that come from the ion exchange treatment, possible contamination of the syrup with residual carbon, increase in the amount of residue or debris, dirt generated by coal dust.

Sludge disposal is made easy without causing cross contamination, helping to maintain a clean and safe production room.

It allows the regeneration of the resins used during the process.

The useful life of fresh water is lengthened, since it is possible to pasteurize it at a temperature that ensures the elimination of the microbial load and that at the same time does not cause caramelization.

No chemical bleaches are used in the process.

Claims (12)

1. Procedure for obtaining a refined sugar syrup from raw sugar for its application in bottling plants for non-alcoholic sugary beverages, comprising the following stages: a) Dissolution of solid raw sugar by hot recirculation until obtaining a syrup with a concentration of 62 - 64 Brix (62 - 64 g of sugar dissolved per 100 g of solution); b) Addition of primary clot formation reagents that improve the physicochemical characteristics of the syrup during the dissolution stage; c) Addition of a flocculating polymer and carbon dioxide, which positively modify the nature of the gas-liquid and solid-liquid interface, forming agglomerations of flocs that rise with the help of CO2 to the surface; d) Stirring the obtained syrup mixture and clarifying it by flotation, in order to obtain a clean syrup at the bottom, where sludge and impurities rise to the surface and are compacted together thanks to the help of carbon dioxide; e) Filtration of the clean syrup and elimination of non-floating sludge; f) Discoloration of the syrup obtained by the counterflow ion exchange technique; g) Demineralization of the syrup using the reverse ion exchange technique to remove conductometric ash and metals at a temperature of 60 ° C - 40 ° C; h) Deodorization of the syrup using counter flow adsorbent resins; i) Polishing of the syrup to provide a final finish with a degree of turbidity between 1 - 3 NTU; Y j) Cooling to room temperature for storage and later use. 2. Process for obtaining a refined sugar syrup from raw sugar according to claim 1, characterized in that step a) of the process is carried out at a temperature of 75 ° C - 85 ° C, supplying the solid sugar, preferably through a Venturi feeding system. 3. Process for obtaining a refined sugar syrup from raw sugar according to claim 1, characterized in that in step b) the primary clot-forming reagents are selected from calcium oxide, phosphoric acid and metal sulfate salts, or polymerized coagulants. 4. Process for obtaining a refined sugar syrup from raw sugar according to claim 1, characterized in that in step c) of the process, high molecular weight anionic polyacrylamide is used as flocculant. 5. Procedure for obtaining a refined sugar syrup from raw sugar according to claim 1, characterized in that in step d) a serpentine diffuser is used with nozzles whose opening is 0.2 to 0.6 mm arranged on the coil so that fine CO2 bubbles form over the entire surface. 6. Process for obtaining a refined sugar syrup from raw sugar according to claim 1, characterized in that step e) of the process is carried out with diatomaceous earth filters with a particle size distribution between 10 and 20 microns. 7. Process for obtaining a refined sugar syrup from raw sugar according to claim 1, characterized in that in step f) of the process the syrup, at a temperature between 75 ° C and 70 ° C, is passed from the tank where steps a) to e) have been carried out to a decolorization train containing an anionic resin based on styrene and divinylbenzene. 8. Process for obtaining a refined sugar syrup from raw sugar according to claim 1, characterized in that, in step g), the syrup is passed through an anionic resin with a strong base and subsequently through a column that contains a high pK weak acid cationic resin. 9. Process for obtaining a refined sugar syrup from raw sugar according to claim 1, characterized in that macroporous adsorbent resins are used in step h) of the process. 10. Process for obtaining a refined sugar syrup from raw sugar according to claim 1, characterized in that step i) of the process uses bag or cartridge filters. 11. Process for obtaining a refined sugar syrup from raw sugar according to any of the preceding claims, characterized in that the recovered fresh water is reused in step a) for the hot dissolution of the raw sugar after its pasteurization at 70 ° C - 80 ° C. 12. Refined sugar syrup obtained according to the process of any of claims 1 to 11, wherein the sugar syrup obtained has the following characteristics: purity 99.7% - 99.99%, turbidity 1-3 NTU, pH 4.0 -4.5, color less than or equal to 35 IU, ash content of 0.04 - 0.01%, sediment content less than 5 mg / kg and mold and yeast content less than 10 CFU / 10 g.