WO2007074196A1

WO2007074196A1 - Dehydrated grape must and spray method for obtaining same

Info

Publication number: WO2007074196A1
Application number: PCT/ES2006/000715
Authority: WO
Inventors: Maria Soledad PÉREZ COELLO; María Consuelo DÍAZ MAROTO; Carmen DE TORRES SÁNCHEZ-SIMÓN
Original assignee: Universidad De Castilla-La Mancha (Uclm)
Priority date: 2005-12-28
Filing date: 2006-12-27
Publication date: 2007-07-05

Abstract

The invention relates to dehydrated grape must and to a spray method for obtaining same in powder form. The dehydrated grape must takes the form of an easy-to-handle, very stable white powder having a density of between 0.4-06 g/cm3, which is not very hygroscopic and which has a moisture content of 2 %. The volume of the inventive dehydrated grape must has been reduced by up to 90 %, while the weight thereof has been reduced by up to 70 %. In addition, the grape must has a water activity of between 0.14-0.25. The grape must has a prolonged storage life and can be transported easily and economically since it occupies less space, weighs less and does not require refrigeration. The must does not experience a significant loss of volatile compounds, while conserving C6 alcohols, terpenes and benzenes. The must is a good flavour enhancer which can be used in the production of food products, in confectionery and as a sweetener in the food industry. The invention also relates to grape must which has been dehydrated using the spray method and which includes the anti-caking additive maltodextrin at a percentage of 10 %-25 % in homogeneous solution with the must. The liquid spray is introduced into a drying chamber with hot air at between 110-160 °C, such as to obtain very fast drying. The water activity of the dehydrated product is less than 0.25 and the outlet temperature is between 60-85 °C.

Description

MUST OF DEHYDRATED GRAPE

AND ATOMIZATION PROCEDURE

FOR YOUR OBTAINING

Technical sector

The present invention relates to the food industry and the wine industry sector.

State of the art The present invention has as background and priority the

Spanish Divisional Patent No. P200601890, entitled: "Dehydrated grape must and atomization procedure for obtaining it", filed on July 14, 2006 before the Spanish Patent and Trademark Office, from the original Spanish Invention Patent No. 200503218 , entitled: "Obtaining powdered must by atomization and lyophilization techniques", which on behalf of the same University of Castilla-La Mancha (UCLM) was deposited on December 28, 2005 before the same Spanish Patent Office and Marks

Explanation of the invention

The dehydration of products, such as fruits, constitutes a highly recommended way of preserving them by offering a longer prolongation over time than other options, such as the pasteurization of fruit juices whose storage does not exceed twelve months, while from an economic point of view dehydration is more profitable as regards the storage and transport of the dehydrated product compared to processes such as freezing and concentration that entail additional costs for maintenance and handling, while requiring refrigeration in the transport of the product, which does not happen with dehydration .

The present invention relates to grape must that is dehydrated in order to be able to preserve it for long periods of time in order to reduce the problem of loss of large surpluses of grape must during the harvest seasons, in which it takes place the maximum production of the same, and that is lost quickly due to its high capacity to ferment.

To avoid the problem of rapid fermentation and consequent loss of grape must in the state of the art, the use of sulfur is known, which also prevents microbial growth, but the percentages in which the legal use of that product is currently allowed are increasingly low and on the other hand does not always solve the problems that are intended to be avoided with its use.

Dehydration of grape must is also advisable from an economic point of view as it is more profitable in terms of storage and transport, due to the notable reduction in its volume, compared to other procedures, such as freezing and concentration, which they are more expensive and their handling is more complicated, since dehydration allows grape must to be stored at room temperature and its transport does not require refrigeration mechanisms.

Also, dehydration of grape must, when performed under mild conditions, ensures high retention of its properties organoleptic which are those that give it its value.

Technical solution provided by this invention

With the present invention, a dehydrated grape must in powdery and very low hygroscopic form containing 2% moisture is added to the indicated state of the art relating to the conservation of fruit juices.

With the elimination of practically the total water, the volume of the grape must decreases to 90% and the weight to 70%. Its water activity is between 0.140-0.250, which prevents the growth of microorganisms. In the same way it is not possible to generate chemical reactions of degradation of nutrients as well as compounds responsible for the organoleptic characteristics of grape must. From the above characteristics it follows that it is a product whose storage and transport is much simpler and cheaper than in the case of the original product since it requires less space, weighs less and does not need refrigeration.

The methods of analysis of volatile compounds show that the loss or deterioration thereof is not significant, preserving compounds such as Ce alcohols _, terpenes as well as benzene compounds. All these are responsible for herbaceous aromatic notes, flowers, fresh smell etc. All this gives the dehydrated grape must according to the present invention the ability to be a good flavor enhancer in the manufacture of numerous food products, which together with its presentation as a powdery solid determines that it is particularly usable for preparation of pastry products, or as a sweetener in the food industry.

In the processes normally used for the elimination of water, high temperatures are used, which causes, due to the existence of a large amount of sugars together with the presence of amino acids, the formation of compounds, such as those derived from furfural that provide unpleasant aromas, as well as derivatives of lactones that give rise to the same results. However, in the case of dehydrated grape must according to the procedure claimed in this divisional patent, when using mild conditions and when using rapid drying, the formation of said compounds is not significant.

From the foregoing it is concluded that the present invention provides the obtaining of a dehydrated grape must capable of being preserved for long periods of time and that, in addition, it has almost the full potential of the grape for winemaking.

The foregoing also allows the dehydrated grape must object of the present invention to be used in cold weather areas, particularly in northern European countries, in the process of

"Chaptalización", which is the addition of sugar from must to musts with low sugar content.

The present invention relates to obtaining the said dehydrated grape must by means of the atomization process, which implies a reduction of liquid size in small droplets, thereby increasing the surface-volume ratio, which increases the speed of dehydration

The atomization process consists in obtaining a powder product from a liquid material that is finely pulverized and enters .in contact with a stream of hot air, allowing rapid drying and obtaining a dry powder.

The main characteristics of this process are therefore the uniformity of the final product and very short drying times, of the order of 1 second. This is possible because of the small particle size, a diameter of 10-200 μm, which gives the drying air a very large surface area per unit volume.

Most of the drying occurs in conditions that favor drying at a constant speed and therefore the temperature of the solids barely rises above the temperature of the wet bulb.

If the operating conditions are correct and the equipment is well designed, the residence time of the dried particles in the drying chamber can be controlled to be minimal and thus overheating of the dry product does not occur.

In this way it is achieved that the substances responsible for the aroma and flavor of the atomized food are retained during the process. But, in addition, in the process of spray drying it is necessary to take into account the product to be dehydrated. That is, there are two types of products, the so-called "non-gummy" and the "gummy". The latter generate numerous problems when carrying out the process. This type of gummy product is formed by those that are rich in sugars, such as fruit juices or purees, causing this to be a technically difficult process, due to the high hygroscopicity and thermoplasticity of the same in conditions of high humidity and temperature.

This product transformation behavior into something Gummy is due to a low Vitreous Transition Temperature (Tg) presented by the low molecular weight sugars that constitute the juice of feints. The Vitrea Transition is an intermolecular phenomenon in which cooperative movements of segments of the chain take place depending on the capacity of movement within the system, this being considered a second-order phase transition, unlike the melting point that would be first . This transition is generally characterized by discontinuities in the physical, mechanical and thermal properties of food. The measurement of thermal and mechanical properties is the essence of the techniques used to study this phenomenon. In particular, Differential Scanning Calorimetry (DSC Differential Scanning Calorimetry) is used. The principle on which the method is based is the measurement of the difference in energy flow between two substances, one of them reference, when subjected to the same controlled temperature program.

The problems caused by this phenomenon in the drying process is that the liquid to be dried is transformed into something rubbery and highly adherent to the walls of the drying chamber (place where the initial product comes into contact with the hot air) diminishing the yield, giving rise to the complete fusion of the product without getting to form dust.

To avoid the aforementioned problem, the present invention introduces a modification of the product in the process with the intention of raising the glass transition temperature of the feed liquid. To this end, this invention incorporates an anti-caking agent, Maltodextrin, as an additive to the feed liquid. The consequence of using this type of additive is that the Tg rises, which allows a higher temperature to be used in the drying air, which results in products with lower humidity and more stable. However, the concentration of these should not be any since the technical limits of operation of the system will have to be taken into account, since they increase the viscosity interfering with the operation of the atomizer.

The indicated Maltodextrin is a glucose polymer that is used as an additive that lacks smell, color and taste, in addition to having an affordable price. There are different types of Maltodextrins that differ fundamentally by their DE: Equivalent Dextrose, which is defined as the percentage of reduced sugar calculated as dextrose based on its dry weight. In other words, the number of glucoses that make up the polymer chain. This union between glucose units is usually through α-type links (l-> 4) and ED less than 20.

Once the product is obtained as a powder, a series of physical properties must be considered to which the ease with which the product can be reconstituted and its stability must be attributed. Among them is water activity, density, solubility and wettability. Density is a very important fact to take into account from an economic point of view, since if it is low it can greatly increase packaging costs. This property depends on the chemical composition, the feed and the air occluded in the particles.

Advantages of the invention

The main advantages of obtaining grape must dehydrated through the atomization process object of the present invention in contrast to the procedure for obtaining dehydrated grape must by the lyophilization process object of the original Invention Patent No. 200503218 (2) are the following:

In the lyophilization process it is necessary to freeze the product so that the elimination of water occurs by sublimation, which entails more time and more energy expenditure in the preparation of the samples. The lyophilizer works at very low pressures, which means a high economic expense.

The time required to dehydrate the grape must by lyophilization is 18 hours, while dehydration by atomization takes about 1 hour, requiring no additional process.

The maintenance of the organoleptic characteristics is very similar in both techniques.

Preferred mode of implementation of the invention The dehydrated grape must object of the present invention, dehydrated through a claimed atomization process, is obtained from the preparation of a homogeneous solution consisting of original must and a percentage between 10 % and 25% of Maltodextrin anti-caking additive, which will depend on the percentage of dry extract present in the grape must juice that is intended to dehydrate.

The mixture is then introduced to the head of atomization through a peristaltic pump.

Subsequently, the spraying or disintegration of the liquid in the atomizer head is produced by the pressure exerted by a gas, in this case the air, which is introduced at a pressure between 400-800 L / h.

The sprayed liquid is introduced into a drying chamber in which it comes into contact with hot air causing very rapid drying. The inlet temperature to which the air is applied is between 110-160 ⁰ C, thus ensuring the practical elimination of water, which results in a dehydrated product with a water activity between 0.14 and 0.25, the temperature being output between 60-85 ⁰ C.

The separation of the humid air from the dry product is produced by the action of an air vacuum that drags the product into the collecting chamber. As drying is so rapid, no deterioration occurs due to high temperatures as in other dehydration methods.

The final product of dehydrated grape must obtained by means of the now claimed atomization process is powdery, very little hygroscopic, with the greatest possible stability, in the form of white powder of easy handling, with a density between 0.4 and 0.6 g / cm ³ , with a water activity between 0.14 and 0.25, which prevents microbial growth, which is easily reconstitutable and decreases the volume of grape must up to 90% and up to 70% in weight, keeping the product dehydrated properties Organoleptic grape must by offering a very high retention of volatile compounds. What has been described constitutes a faithful reflection of the present invention, having to consider the characteristics of the same that have been exposed in a broad and non-limiting sense, being circumstances that are merely formal, secondary or accessory that do not alter the essentiality are indifferent and changing. which is then claimed.

Claims

I ^a . Dehydrated grape must and atomization procedure to obtain it, characterized by being dehydrated in the form of a very low hygroscopic white powder, of great stability, easily manageable and reconstitutable, which can be stored at room temperature for a long time and at low cost.

2 ^a . Dehydrated grape must, according to the preceding claim, characterized by offering a density between 0.4 and 0.6 g / cm ³ . 3 ^a . Dehydrated grape must, according to previous claims, characterized by a water activity between 0.14 and 0.25.

4 ^a . Dehydrated grape must, according to previous claims, characterized in that with respect to the hydrated product it offers a decrease of up to 90% in terms of volume, which favors its storage and transport, as well as of 70% in terms of weight .

5 ^a . Dehydrated grape must, according to previous claims, characterized by containing a large amount of sugar, glucose and fructose that allows its use as a sweetener without causing volume increase.

6 ^a . Atomization process for obtaining dehydrated grape must, according to previous claims, through an atomization process under mild conditions, characterized in that it maintains the organoleptic properties of the dehydrated product by offering a very high retention of volatile compounds, achieving stability major and minor thermal hygroscopicity of the product when using as an additive the anti-caking agent Maltodextrin from a homogeneous solution consisting of original grape must and a percentage of additive Maltodestrin between 10% and 25%; the mixture is introduced to the atomization head through a peristaltic pump; then the spraying or disintegration of the liquid in the atomizer head is produced by the pressure exerted by a gas, in this case the air, which is introduced at a pressure between 400-800 L / h .; the sprayed liquid is introduced into a drying chamber in which it comes into contact with hot air causing very rapid drying; the inlet temperature to which the air is applied is between 110-160 ⁰ C, thus ensuring the practical elimination of water, which results in a dehydrated product with a water activity between 0.14 and 0.25, the temperature being 60-85 ⁰ C air outlet; The separation of the humid air from the dry product is produced by the action of an air vacuum that drags the product into the collecting chamber; The product obtained with this procedure does not suffer deterioration because the drying process is so rapid due to the high temperatures. 7 ^a . Dehydrated grape must obtained by the atomization process object of the preceding claim 6 ^a .