Patent Application
20210068411
The present invention relates to an industrial system of cold dehydration of fruit and vegetables and, more generally, of all those foods suitable for drying through a new and innovative process that keeps the organoleptic and nutritive properties intact, and limits the process of oxidation as much as possible.
In industry jargon, the word “drying” is used when proceeding with natural means, exploiting the action of the rays of the sun to dehydrate a food (or any natural product: see medicinal herbs, tobacco . . . ) and extract the water present. On the other hand, when the process is artificial, as in the industrial sector, it is called “dehydration”.
Dehydration is a reaction resulting from a process that leads to the elimination of a molecule of water from the reactant molecule.
Dehydration eliminates the water present in food, so as to prevent deterioration due to fermentation by microbes (bacteria, molds, yeasts) or by enzymes activity. In this way, one can keep food for a long time without having to add preservatives and keeping the organoleptic and nutritional qualities intact.
In dehydration, hot air is used to eliminate water, after having scalded food in boiling water. This technology reproduces the ancient sun-drying process of foods.
Industrial dehydration developed at the beginning of the 20th century, by heating the food using hot air, gas, contact with hot surfaces or infrared radiation. Depending on the percentage of water present, the food is subjected to different temperatures: between 30° C. and 40° C. it is called a low temperature; between 50° C. and 60° C. medium temperature, while between 70° C. and 90° C. it is high temperature drying.
Among the various dehydration techniques in use, in the prior art, we may mention that of vacuum dehydration, which provides a pre-drying, at medium-high temperatures, to bring the product to a residual humidity of about 20%-30%. Subsequently, by means of the vacuum, the boiling/evaporation point of the water is lowered and it can thus be extracted at medium-low temperatures.
Another widely used technique is that of freeze-drying. Freeze-drying is a technological process that allows the total elimination of water from food, which is reduced to dehydrated powders. It is treated at temperatures ranging from −30° C. to −50° C., sold on the market as cold dehydrated products and used in raw food.
Freeze-drying, in addition to the high industrial cost, also exhibits other drawbacks, including, primarily, the alteration of the organoleptic and nutritive properties that, due to the aggressive treatment to which foods are subjected, are lost producing a change not only in consistency but also taste.
A first object of the present invention is therefore that of leaving the nutritional properties and the molecular structure of the macro- and micro-nutrients of foods unaltered, generating a healthy and genuine final product. To do this it is necessary to eliminate from the industrial process all sources of oxidation of food, in the first place oxygen.
The method described below, therefore, aims to make this innovation within the agricultural-food sector, providing a completely natural, healthy, organic/biodynamic product that maintains all the qualities, even nutritious ones, typical of fresh products.
According to the present invention, a dehydration method for fruit and vegetable products is described, including final packaging and oven, which effectively solves the above-mentioned problems.
The method, as we will see later, includes numerous advantages. Firstly, the substantial preservation of the nutritive and organoleptic properties of the products thus treated.
Secondly, foods are preserved for a long time because, from the moment they enter the dehydration and packaging laboratory, they come into the lowest possible contact with oxygen, heat, light and metals, all the main oxidation and deterioration factors.
This method, which is also useful for the biological and biodynamic certification of the whole product processing, advantageously consists of the following steps:
Advantageously, all the steps take place in a cool environment, substantially free of UV and dry rays, preferably at a temperature between 15° C. and 22° C., and humidity between 40% and 65%.
In a further, even more advantageous embodiment of the present invention, the energy and/or hot and dehumidified air necessary for the operation of the oven, with all its components just listed, comes from renewable sources such as, for example, photovoltaic systems, solar, thermal systems, etc.
The advantages offered by the present invention are clear in the light of the above description and will be even clearer from the accompanying figures and the related detailed description.
The invention will hereinafter be described in at least one preferred embodiment thereof by way of non-limiting example with the aid of the accompanying figures, in which:
The present invention will now be described purely by way of non-limiting or binding example with the aid of the figures, which illustrate some embodiments relative to the present inventive concept.
With reference to
After receiving the products to be processed in laboratory 100, a verification step 101 of their biological/biodynamic certification follows. Based on the outcome of the verification 101, the method can continue with the rejection 102 of the products whose verification 101 gave negative result N and with the reception 100 of other products, or, in the case of positive result Y, with washing 110, peeling 112 and cutting 114 of fruit and vegetables. This washing step 110 occurs with filtered drinking water.
Washing 110, peeling 112 and cutting 114 can be done either by hand or by special machinery, depending on the convenience and size and type of fruit and vegetables to be dehydrated.
In a preferred embodiment, the method object of the invention is dedicated to the dehydration and packaging of kiwifruit, both green, yellow and red, cut into slices. More in detail, the green kiwi is cut into slices 3 mm thick, whereas the yellow and red kiwi is 5 mm, due to the lower resistance to breakage.
After these steps, a recycling step 115 of the portions of kiwi, or other food, which results from peeling 112 and from cutting 114 follows. These waste parts are reused in other industrial processes such as, for example, those aimed at producing dehydrated fruit bases for snack bars.
In the cutting step 114, the knives used have ceramic blades or are coated with a ceramic material or any other non-metallic material, which could promote the oxidation of food.
At this point, the kiwi slices (or other cuts of other products) are placed on grids or on a conveyor belt according to the type of oven 60 which will be used in the subsequent cooking step 116. In the case of vertical oven 60, also called “static”, the slices are placed on special perforated trays 50 to facilitate the passage of dehumidified air, of dimensions 60 cm×60 cm, on which there are grids 51 of mesh 0.5 cm×0.5 cm, in non-stick food silicone material. In the case of a horizontal oven 60, also called “continuous”, the slices are laid on the various modules of a conveyor belt which passes through the internal space of said oven 60. These modules are made of thermoplastic material, suitable for food use, easily washable and provided with holes that allow the passage of dehumidified air for a homogeneous cooking of food.
The cooking step 116 in oven 60 is carried out at a temperature between 25° C. and 40° C., for a period of time ranging from 24 hours to 48 hours, with attention given to the fact that the temperature of the foodstuffs during the whole cooking step, does not exceed 40° C. The oven 60 is the most important technological equipment involved in the method object of the invention. Due to its features and also to the other precautions taken at the industrial plant where this method takes place, the nutritive and organoleptic features and flavor of the fruit and vegetables thus processed remain substantially unchanged, like the fresh product.
Said oven 60 has a dehumidification system and a gas burner (LPG), which heats the air to promote the dehydration of the food without oxidizing it. The oven 60 used in the subject method also comprises discharge and suctioning means located both at a first end 61 and at a second end 62. At 15 minute intervals, the air discharged (dehumidified) from the first end 61 of the furnace 60 and suctioned (containing the moisture of the product) by the second end 62 changes towards and is discharged from the second end 62 and suctioned by the first end 61.
In its preferred embodiment, the oven 60 which allows the carrying out of the present invention is a closed air cycle so as to dehydrate the food in an environment free of oxygen and light and, at the same time, maintain a sufficient quantity of oxygen outside to keep the laboratory a livable environment for the operators. Said oven 60 is provided with at least one oxygen extractor and/or at least one nitrogen/carbon dioxide generator which creates a protective atmosphere, free of oxygen, inside the oven 60 itself.
Optionally, the oven 60 is also provided with means which recover the heat and reuse it to favor the least energy consumption of the burner.
Once the pre-set time has elapsed for the complete drying of the kiwi slices, these are extracted from the oven 60 and placed immediately, by a special packaging machine, in a sealed package, filled with food nitrogen.
Said packaging will preferably be white, or in any case opaque, to prevent the contact with the sunlight from deteriorating the food.
The method, in the preferred embodiment and considered the best, up to now, comprises a further possible second packing step 120 in which a predetermined quantity of said fruit and vegetable products is taken from said opaque bags and packed into “Flow Pack” or any other desired package.
The last step of the method, i.e. storage 122, takes place in relatively dry, cool and dark rooms, which contribute to the preservation of dehydrated foods. Preferably, the storage warehouses will be at a temperature between 15° C. and 22° C., and humidity between 40% and 65%.
Finally, it is clear that modifications, additions or variants may be made to the invention described thus far which are obvious to a man skilled in the art, without departing from the scope of protection that is provided by the appended claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 102018000004819 | Apr 2018 | IT | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/IB2019/052873 | 4/8/2019 | WO | 00 |
