CA2067785A1

CA2067785A1 - Low-calorie drink and process and apparatus for production thereof

Info

Publication number: CA2067785A1
Application number: CA 2067785
Authority: CA
Inventors: Walter Gresch
Original assignee: Individual
Current assignee: Bucher Guyer AG
Priority date: 1990-08-22
Filing date: 1991-08-14
Publication date: 1992-02-23
Also published as: WO1992003066A1; EP0496849A1; CH681847A5

Abstract

The reduced-calorie beverage of the invention is made of sweet fruit juices of vegetable products, especially grapes, berries and other fruits. The raw juice is first selectively de-sugared by the physical removal of sugar in contact with the fruit juice, whereupon enough water is added and/or removed so that the water content again approximates to that of the original fruit juice. In the ideal case, enough low-calorie sweetener is then added to the de-sugared juice to give the same degree of sweetness as at the outset. The pre-separation process removes various components from the raw juice before de-sugaring which are replaced thereafter.
This gives a reduced-calorie beverage which has much the same flavour, sweetness, components and colour as the natural fruit juice.

Description

( 20~7785 Docket No. 2818 LOW-CALORIE DRINKAND PROCESS AND APPARATUS FOR PRODUCTION THEREOF

The invention relates to the composition as well as a prbcess and a unit for the production of a low-calorie, nonalcoholic drink, especially fruit juice made from sweet juices from vegetable products, especially fruit, grapes, berries and other fruits, which contains low-calorie, especially artificial sweetener.
Drinks of this type are known, which consist of 50% pure fruit juice, which is diluted with water and sweetened with artificial sweetener. Also, in the known nectar or diet drinks, the addition of sugar is completely or partially substituted by artificial sweetener. Low-calorie fruit juices generally consist of fruit juices diluted with water, to which, in addition ro other additives, artificial sweetener, is added instead of sugar.
Disadvantageous in the production of these drinks is that with the dilution of the fruit juice with water, also all components of the fruit juice are diluted with water. By subsequent sweetening, only the sweetness is brought to the desired value. Other additives, to attain, e.g., the original taste quality, are possible only within very modest limits and are greatly limited, moreover, by the food law. The juices produced in this way therefore have a weak and unnatural effect.
Individual processes for desugarizing drinks are known in the art. For an economical large-scale production with automatic ~-and continuous operating conditions, these known processes do not : :- . .. . , - . . ...

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yet correspond to the set requirements. Above all, not too many other valuable components should be lost with the desugarization, nor should foreign substances develop and change the nature of the drink. Moreover, for food law reasons, the desugarization processes are greatly restricted.
Processes are also known (CH-PS 668 887, CH-PS 632 137), in which the sugar in fruit juice is directly converted by biotechnological, especially fermentative processes, and the reaction products are removed if possible before the addition of artificial sugar. In this way, numerous volatile and nonvolatile reaction by-prGducts always result, which can be removed only partially from the fruit juice. In particular, it is practically impossible to remove sufficiently the nonvolatile by-products that have developed. ~-Although with the help of these known processes, an easily digestible, nonalcoholic drink can be produced, which can be approved under the food laws, the drinks have lost their original typical nature.
The object of the invention is to provide, with the help of an economical production process, a low-calorie drink of the initially mentioned type, which after the desugarization of the raw juice comes as close as possible sensorially to the natural fruit juice relative to taste, components, color and sweetness.
According to the invention, this object is achieved in that the drink consists of the components indicated in claim 1.
Embodiments of the invention as well as the process and the unit : .- , - - -, - . ~ .- . . . - .
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(~ 2~77~5 for production of the drink according to the invention are to be gathered from the other claims.
The invention and especially a suitable production process for it is explained in more detail in the following description and the drawing which represents several embodiments. There are shown in fig. 1 a diagrammatic representation of a unit for performing the process, fig. 2 the unit according to fig. 1 with a desugarization unit consisting of a combined membrane process and fig. 3 the unit according to fig. 1 with a desugarization unit consisting of a pure nanofiltration process.
As fig. 1 of the drawing shows, the raw juice is fed by a pipe 1 to a desugarization unit 2. As raw juice, any juice containing sugar, raw or processed, can be used. Especially, for -~
example, concentrated juices, concentrated and rediluted juices, cloudy and clarified juices, as well as dearomatized and depectinized juices, are also suitable. Unless fresh juice is processed, it is mostly advantageous, because of the better efficiency, to feed the juice in concentrated form to desugarization unit 2. By using dearomatized juices, problems relative to losses of flavor can be easily avoided.
Depending on the desugarization process but also for logistical reasons, it can be sensible to use concentrates of desugarized fruit juice. Further, it is possible to use several fruit juices mixed as an initial product.

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( . . , In desugarization unit 2, the raw juice is partially or totally desugarized in a selective manner, if in direct contact with the fruit juice, by removal of the sugar. For taste and partially also for legal reasons, only physical desugarization processes are used for the sugar removal, if there is a direct contact with the juice to be desugarized. Thus, the original nature of the fruit juice is maintained. Selective desugarization is generally understood to mean that the sugar is removed from the raw juice as much as possible only in the form of an aqueous sugar solution. Since this is not 100% feasible in practice, a departure from the ideal has to be tolerated. The discharge of the sugar solution from desugarization unit 2 for further use takes place by a pipe 3.
To replace at least partially the water also removed in the desugarization, diluting water is, if necessary, added by a pipe 4 to the juice passing through. In this connection, drinking water can preferably be used. In the desugarization, lost, dissolved mineral substances can advantageously be at least partially replaced by the addition of suitable mineral water.
The addition of diluting water can be necessary, especially if, for economic reasons, an insufficiently selective desugarization process is used, which removes the sugar in sufficiently concentrated, aqueous and dissolved form. But the addition of diluting water in the course of the process can also take place before or after the process. An addition before or in the course of the process when using membrane processes for the ,, , .. - ' - , '. ., ` 20~7~
desugarization has a favorable effect on the desugarization efficiency, or on the economic efficiency of the process.
But with regard to a relatively high desugarization performance or economic efficiency, it is also possible that the fruit juice loses too many important taste-determining components, especially in deliberate use of diafiltration to increase output. In such cases, it is advisable to remove water from the fruit juice after the desugarization, e.g., by known concentrating processes, evaporation, reverse osmosis, pervaporation, membrane distillation, etc.
In ideal cases, enough diluting water should be added to and/or enough water should be removed from the desugarized juice, so that the water content of the finished drin~ again corresponds approximately to the original fruit juice.
~ fter the desugarization, it is useful to analyze and/or to measure the juice as to its content of various components. But in practice, it is too expensive to analyze the desugarized juice for all important components. For the sake of simplicity, therefore, only one or more so-called conductances are determined in the product at hand to determine the quality of the desugarlzation or the similarity with a natural fruit juice. In this connection, an analysis of important sums of components, e.g., the nitrifiable total acid, the sugarfree extract content, etc., is involved. In general, it involves those analyses that can be performed automatically and as in-line as possible, e.g., by automatic analyzers. It is therefore required that one or more conductances in the desugarization of the fruit juice are : . ~.... . . .

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reduced by no more than 50~ of the original absolute content. In fruit juice mixtures, this should be the case at least in one of the fruit juices used. Relative to usual drinks, conductances, which vary by about + 50% from natural juice, are still of great interest, e.g., -50% and more for high quality nectars and +25%
and more for additions to other drinks, to desserts, especially low-calorie desserts, etc. In the embodiment according to fig.
1, a measuring point 6 for determining, e.g., by automatic analysis, at least one conductance is placed in a pipe 5, by which the desugarized juice is removed from the desugarization unit. Because of this measure, the typical nature of the fruit juice used in the new drink, can, together with this process, also be determined very well in the course of the desugarization or water removal after the desugarization, e.g., while adding water within the limits of the losses.
With the help of the determined conductance or a combination of conductances, the ~uantitative, if necessary and desired addition of diluting water or the necessary removal of water can be determined or controlled or adjusted. For this purpose, for the example of an addition of water, a control line 7 leads from the measuring point to a control valve 8, which is placed in pipe 4 for the supply of diluting water. Depending on the situation, because of experience, also simple direct measurements (e.g., refractive index) can be used possibly connected with a correlation factor as a conductance to determine the amount of diluting water. An analogous adjustment can also be used for a 2~5778~
possible removal of water after the desugarization to determine the concentrating performance.
The supply of diluting water according to the concentrating process and a subsequent concentration can also be performed in batches or continuously especially in smaller outputs independently of the desugarization process. But to determine the amount of diluting water, or the amount of water to be removed, a start is also made here with the idea to simplify the above-defined conductance.
After the passage of desugarization unit 2 or at the latest indirectly or directly after completed desugarization of low-calorie sweetener as an at least partial substitute for the removed sugar, the desugarized juice is fed by a pipe 9, which empties into pipe 5 after measuring point 6. Enough sweetener is preferably fed so that the juice has at least partially the sweetness which the fruit juice or the fruit juices have before the desugarization. As low-calorie sweetener, preferably artificial, highly intensive sweeteners are used, whose caloric content can be practically negligible. But for certain cases, especially purely dietetic uses, also complete or partial fructose, whose sweetening power is greater than the removed saccharose or glucose, can be added. Moreover, generally a sweetener is preferably selected which tastes like natural sugar and is at least partially added to the desugarized juice. As preferred artificial sweeteners, aspartame and similar sweeteners or its derivatives are used. Aspartame also exhibits very attractive health features and consists of a natural protein : : .
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compound. This sweetener has a very high health safety value, which is important for a health drink.
In pipe 9, by which the desugarized juice is removed from desugarization unit 2, another measuring point 10 for determining the sugar content of the desugarized juice is placed in front of measuring point 6 for the-conductance. A control line 11 leads from measuring point 10 to a control valve 12, which is placed in -pipe 9 for the addition of sweetener. In this way, the amount of the addition of low-calorie sweetener can be adjusted automatically because of the determination of the sugar content, or an analog of it (e.g., refractive index) after the desugarization in a simple manner because of the known sweetening power of the low-calorie sweetener to be added. To take into consideration the sweetening power of the sugar types contained in the fruit juice, a correction by a correlation factor, which is typical for the desugarization unit, is generally also necessary.
After the desugarization the desugarized juice preferably can also be fed still other additives by a pipe 13 (fig. 1). In principle, all additives possible according to food laws can be considered. In this connection, components, which were removed or lost in the desugarization or in earlier process steps, such as, e.g., flavor, pectin, acids, e.g., citric acid, are especially useful. These additives can be both foreign additives and fruit-specific additives. The addition of pectin and additives having similar effects is appropriate, i.a., to impart the original full-bodiedness again to the fruit juice. The . :

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amounts of these additives can be derived partially also from the conductance determination and can be suitably adjusted. For this purpose, a control line 14 leads from measuring point 6 for the conductance to a contro' valve 15, which is placed in pipe 13 for the addition of the remaining additives. (Fig. 1).
It can also be advantageous to subject the raw juice before the desugarization to one or more preliminary separating processes. For this purpose, the raw juice is fed according to fig. 1 by a pipe 16 to a preliminary separating device 17. If juices are not used as raw juice, the usual processes for, e.g., dearomatization, depectinization, etc. are included among the above. In certain cases, it is advisable to remove certain components deliberately before the desugarization and again to add the latter after the desugarization. According to fig. 1, the separated components are brought out by a pipe 18 from preliminary separating device 17 and again returned to pipe 5 after desugarization unit 2. The addition of the preseparated components in the juice takes place preferably at least before measuring point 6, so that in the conductance determination, the recycled components are jointly taken into consideration. By these measures, it is avoided that said components are lost in the desugarization. In this way, e.g., membrane processes can be used which can make possible the partial separation. A
separation of a polar or electrically charged connection, especially a deacidification, is preferably performed by electrodialysis and/or ionically plugged diffusion membranes, , .

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which make possible a suitable separation and a simple recycling to desugarized juice.
In preliminary separating device 17, a separation of higher-molecular compounds can also take place as sugar by reverse osmosis, which also makes possible a simple recycling of the higher-molecular components in the juice.
Further, it is useful in juices, which are not already dearomatized, e.g., fresh juice, to dearomatize the latter in -preliminary separating device 17 and to add again the specific flavor by pipe 18 after the desugarization. In this way, practically no losses of flavor result.
In fig. 2 of the drawing, another embodiment of the invention is represented simplified and without the usual circulations of the membrane process. In this embodiment, the selective removal of the sugar from the raw juice is performed in direct contact with the fruit juice with the help of a dialysis unit 19 and a nanofiltration 21 placed in permeate circulation 20 of dialysis unit 19. Nanofiltration 21, which removes the sugar ~-from permeate circulation 20, i.e. no longer in direct contact with the fruit juice, is in the intermediate area of ultrafiltration and reverse osmosis. By suitable selection of the separating border or nanofiltration, it can be achieved that of the three most important types of sugar, fructose, glucose and saccharose, the sugar with the highest molecular weight, i.e., saccharose, is preferably retained and removed. Since saccharose as compared with fructose has substantially less sweetening power -and more calories, this is in the interest of the objective. The 11 2~7~

desugarized juice is removed as a retentate of dialysis unit 21 by pipe 5 and treated in the same way as in the unit according to fig. 1. The retentate of nanofiltration 19 is concentrated with sugar, and the permeate exhibits 1 to 4 Bx, e.g., in a retentate input of ~ 12 Bx and more. The retentate drawn off as aqueous, sugary solution, which is, e.g., a partial stream from the retentate circulation of the nanofiltration, can be concentrated, e.g., as in all physical processes in a concentrating device 22 and can be fed separately for use e.g. as natural, fructose- and glucose-rich sweetener (liquid-fruit juice-sugar), which substantially improves the overall economic efficiency.
In using greatly sugar-selective membrane processes, especially sugar-selective, pressure-driven membrane processes instead of pure dialysis, a back-diffusion from the permeate side to the retentate side is greatly reduced, and thus also nonphysical desugarization processes are used here in a few cases on the permeate side, which catabolize the sugar e.g.
fermentatively, for example, according to CH-PS 668 887, up to the carbon dioxide/water step.
Fig. 3 of the drawing shows the integration of a pure nanofiltration 21 as a desugarization process in the overall process. Since in the known, pure nanofiltration, substantially more is removed from the fruit juice, relative to the unit according to fig. 2, a substantially larger expense is necessary in the preliminary separation of the components from the raw juice. Molecules, which are larger than sugar molecules, at least should be removed selectively concentrated before the . .

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desugarization. ~his can preferably take place also with the help of a sugar-selective (concentration of sugar in the retentate) nanofiltration 23 or other membrane processes as part of the physical separating processes. Further, the flavoring ~;
substances should be removed definitely from the raw juice and added again after the desugarization with fur~her additions in the same way as in the unit according to fig. 1.
As other positive measures that are part of the preliminary separation for improving the quality, the removal of a wide spectrum of polar electrically charged molecules can be, e.g., ~y electrodialysis or other membrane processes as well as their recycling after the desugarization in the juice.
Because of the preliminary separation according to the invention, especially by nanofiltration 23 according to fig. 3, despite arrangement of nanofiltration 21 in the direct juice stream, it is still possible to attain acceptable color values with the end product. By exclusive use of nanofiltration without preliminary separation, almost all color would be removed from the juice.
Another possibility to use a nanofiltration directly for the --~
desugarization consists in feeding the retentate of the nanofiltration to another sugar-separating process, which removes relatively little color (e.g., ion exclusion process) and in adding the desugarized juice from the second desugarization -process to the permeate of the nanofiltration. Relative to the use of nanofiltration only, the other values are improved in this way in addition to better color values.

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To improve the selectivity of the retention of acids and bases, especially of important acids in the juice to be desugarized, generally also ionic, especially plugged membranes can be used in the membrane processes used in the process according to the invention. As a result, the membrane can be superimposed analogously to the electrodialysis in addition also with an electric field.
It is especially important in the desugarization of citrus fruits that above all the loss of citric or ascorbic acid is relatively small. But both these acids have a molecular weight similar to monosaccharide sugar components of the juice (fructose, glucose). Therefore, special measures are necessary to retain these acids in the juice to be desugarized. The use of ionic, especially plugged membranes, as they are used especial~y in ionic dialysis, connected with a separating border and compressive load capacity required for this object, offers a possible solution of the problem. ~-To implement this measure, with the overall process according to fig. 2 for dialysis unit 19 or the sugar-selective, pressure-operated membrane processes alternatively possible at this point, a cationic, plugged membrane is used, which substantially blocks the passage of acids.
The process according to the invention is suitable also for production of cloudy, low-sugar juices. To improve the fouling behavior of the desugarization process or to attain higher outputs and service lives, it is also possible, both for clear and cloudy end products, to start from clear juices, e.g., .... ~,,, .~.. .. , . .,, .. ." ........... . ......... .... ...
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clarified by ultrafiltration or microfiltration, and to add clouding substances to the juice after the desugarization according to known processes. In this way, for cloudy end products, especially retentate made from an ultrafiltration or microfiltration of the present or other juices can be used. In the production of clear, low-alcohol juices, the juice should be clarified preferably for said reasons at least before the desugarization.
The operating method to perform the process according to the invention can be selected both batchwise and continuously, depending on the amounts to be processed. The unit can be driven cold or hot, depending on qualitative and economic requirements.
A preferred drink composition according to the invention is characterized in that the drink is similar to a natural fruit juice because of the main components (desugarized fruit juice, possibly diluting water, low-calorie sweetener) and other additives except in the content of natural sugar (saccharose, fructose, glucose). However, this drink exhibits preferably at least 25~ fewer calories because of the substitution of natural sugar by low-calorie sugar. Despite the substitution of fruit-specific sugar preferably by aspartame, such a juice is hardly distinguishable from natural juice. But because of the low caloric content, this juice is very valuable and appealing for health reasons not only for the diabetics (light fruit juice).

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Claims

1. Low-calorie, nonalcoholic drink, especially fruit juice made from sweet juices from vegetable products, especially fruit, grapes, berries and other fruits, which contains low-calorie, especially artificial sweetener, characterized in that the drink consists of at least the following components:
a) one or more fruit juices, which are desugarized by sugar removal, partially or completely in a selective manner, if in direct contact with the fruit juice, b) enough diluting water and, if necessary, that the water optionally removed in the desugarization of the fruit juice is at least partially replaced again, c) enough low-calorie, especially artificial sweetener, that the drink at least partially has the sweetness of the fruit juice or the fruit juices before the desugarization.

2. Low-calorie drink according to claim 1, wherein in a possible loss of important substances during the desugarization, the latter are again concentrated by subsequent removal of water from the fruit juice.

3. Low-calorie drink according to claim 1 or 2, wherein if in direct contact with the fruit juice, only physical desugarization processes are used.

4. Low-calorie drink according to one of claims 1 to 3, wherein the sugar is removed from the fruit juice in the form of an aqueous, sugary solution.

5. Low-calorie drink according to one of claims 1 to 4, wherein one or more so-called conductances, e.g., the titrifiable overall acid or the sugarfree extract content, are reduced in the desugarization of the fruit juice or at least a fruit juice mixture by not more than 50% of the original absolute content.

6. Low-calorie drink according to one of claims 1 to 5, wherein to sweeten the drink, preferably artificial, highly intensive sweeteners are used so that the caloric content of the sweetener can be practically negligible.

7. Low-calorie drink according to one of claims 1 to 6, wherein, depending on the desugarization process, concentrates of desugarized fruit juice are used as initial product.

8. Low-calorie drink according to one of claims 1 to 7, wherein at least partial fruit juices are used, which were dearomatized before the desugarization.

9. Low-calorie drink according to one of claims 1 to 8, wherein the dissolved mineral substances, lost in the desugarization, are replaced at least partially by the use of suitable mineral water.

10. Low-calorie drink according to one of claims 1 to 9, wherein a sweetener is added at least partially, which tastes similar to sugar.

11. Low-calorie drink according to one of claims 1 to 10, wherein components are added which were removed or lost in the desugarization or in process steps before that.

12. Low-calorie drink according to claim 11, wherein both foreign and fruit-specific additives are used, e.g., flavors, pectin, acids, e.g., citric acid.

13. Low-calorie drink according to one of claims 1 to 12, wherein for mixed drinks, fruit juices with a low natural sugar content, high content of acid, astringent substances, color, etc.
are added.

14. Low-calorie drink according to one of claims 1 to 13, wherein fruit juice or fruit juices with low sugar content and high content of acid, astringent substances, color, etc. are added as concentrate.

15. Low-calorie drink according to one of claims 1 to 14, wherein the natural sugar of the drink is replaced by low-calorie sugar until the caloric content of the drink is reduced by at least 25%.

16. Low-calorie drink according to one of claims 1 to 15, wherein fruit juice, which exhibits conductances after the desugarization, which deviate by about ?50% from the natural juice, for example, minus 50% and more for highly qualitative nectars, and plus 25% and more are used for mixing with other drinks, desserts, etc.

17. Process for the production of the drink according to one of claims 1 to 16, characterized by the following process steps:
a) the raw juice, optionally after the passage of one or more preliminary separating processes, is desugarized by sugar removal in a selective manner, if in direct contact with the fruit juice, b) before, during or after the process, diluting water is added to the juice passing through, if necessary, so that at least the water removed in the course of the desugarization is at least partially replaced, c) at the latest after the completed desugarization, low-calorie, especially artificial sweetener is added to the juice as at least partial replacement for the removed sugar.

18. Process according to claim 17, wherein in the case of possible loss of important substances during the desugarization, the latter are again concentrated by subsequent removal of water from the fruit juice.

19. Process according to claim 17 or 18, wherein if in direct contact with the fruit juice, only physical processes are used.

20. Process according to one of claims 17 to 19, wherein the raw juice is preferably fed in concentrated form to the desugarization.

21. Process according to one of claims 17 to 20, wherein before the desugarization, certain components of raw juice are separated and again added after the desugarization.

22. Process according to claim 21, wherein membrane processes are used for partial separation of the components.

23. Process according to claim 21 or 22, wherein an at least partial separation of polar, or electrically charged compounds, especially a deacidification of the raw juice, is performed especially by electrodialysis and/or ionically plugged diffusion membranes, and the separation of these compounds and a recycling to the desugarized juice is possible.

24. Process according to one of claims 21 to 23, wherein an at least partial separation of higher-molecular compounds takes place as sugar by sugar-selective reverse osmosis or nanofiltration, and a recycling of the higher-molecular components with low sugar content in the juice is possible.

25. Process according to one of claims 21 to 24, wherein in non-dearomatized juices, the flavor is separated before the desugarization and is again added after the desugarization.

26. Process according to one of claims 17 to 25, wherein the juice is analyzed after the desugarization for at least one so-called conductance and/or is measured directly.

27. Process according to one of claims 17 to 26, wherein the addition of the components in the juice separated before the desugarization takes place preferably at least before the conductance determination.

28. Process according to one of claims 17 to 27, wherein the amounts of the other additives are derived partially from the conductance determination and are adjusted correspondingly.

29. Process according to one of claims 17 to 28, wherein the desugarization of the raw juice is performed by a nanofiltration.

30. Process according to claim 29, wherein the removed retentate from the nanofiltration is concentrated and is fed separately for a use.

31. Process according to claim 29 or 30, wherein molecules, which are smaller than sugar molecules, are at least partially removed from the juice before the nanofiltration, e.g., also by nanofiltration or other membrane processes.

32. Process according to one of claims 17 to 31, wherein as initial product, clear juice, clarified, for example, by ultrafiltration or microfiltration, is used and cloudy substances, especially retentate from the ultrafiltration or microfiltration, are added to the juice according to known processes after the desugarization.

33. Process according to one of claims 1 to 32, wherein the retentate of a nanofiltration is fed to another sugar-separating process, which removes relatively little color, e.g., ion exclusion process, and the desugarized juice from the second sugar-separating process is added to the permeate of the nanofiltration.

34. Process according to one of claims 1 to 33, wherein in at least one of the membrane processes used in the process according to the invention, ionic or cationic, especially plugged membranes are used, and the membranes can be superimposed in addition also on an electric field.