MXPA99007009A - Chlorine generator for preservation of fruits and vegetables - Google Patents

Abstract

A chlorine generator for preserving fruits and vegetables includes a first layer of paper or polyethylene and a second layer of polyethylene. The first layer has a weight of from about 20 to about 70 g/m2 and is preferably made from a laja-type paper. It is preferred that at least one surface of the first layer is coated with a plastic permeable film, such as polyethylene, having a weight of from about 5 to about 25 g/m2. The two layers are joined together, preferably by thermal seal, to define one or more pockets. A hypochlorite material, such as calcium hypochlorite, is placed in the pockets. This material releases active chlorine gas upon reaction with moisture from said fruits and vegetables. Alternatively, the first layer can be impregnated with a mixture containing the hypochlorite (such as a mixture of hypochlorite and sodium chloride) and is preferably coated with a resin material.

Description

CHLORINE GENERATOR FOR FRUIT AND VEGETABLE CONSERVATION TECHNICAL FIELD The present invention relates to the preservation of fruits and vegetables (ie, product). Specifically, it refers to a chlorine generator, which is used for that purpose.

BACKGROUND OF THE INVENTION As fruits and vegetables consumed by city residents embark from ever larger distances, the need for effective preservation devices used during the transportation and storage of the product has become more important. It is known to use sulfur dioxide generators as preservatives when packing packed grapes in containers. The problem with this method is that the sulfur dioxide generated has a strong discoloration effect on the grapes. The discoloration of the grapes makes it difficto sell them to the consuming public. It is also known to spray aqueous solutions of hypochlorites into the containers used for the transport and handling of asparagus in order to provide a conservative effect. This technique is quite complex and difficto implement effectively, due to the need for hermetic controls in the aqueous concentrations of the hypochlorite used. When the concentration of hypochlorite is too high, the asparagus are attacked by the chemical and spoil. In addition, high concentrations of aqueous hypochlorite have a corrosion problem in the metal containers used for cold storage and shipping of the product. U.S. Patent 2,071,625 to Hass et al., Issued February 23, 1937, is directed to a method for preserving packaged baking products, particularly baking products susceptible to the development of microorganisms. The Hass et al. Patent discloses that the baking product that is to be conserved is wrapped in a wrapping material, which has been treated or impregnated with an innocuous compound that releases a germicidal, chlorine-free gas. The material that generates the chlorine is preferably clorazen or chloramine-T and dicloramine or dicloramine-T. This patent also discloses that sodium, potassium and calcium hypochlorites can be used as a source of chlorine. U.S. Patent 4,094,119 to Sullivan, issued June 13, 1978, describes a method for making a product used to supply volatile substances. The product includes a polypropylene backing layer, a non-woven material forming a reservoir layer, and a microporous polypropylene layer covering the reservoir layer. The three layers are joined together around their peripheral edge portions. The deposit layer stores and releases the volatile substance. The patent of E. U. A. 4,411,918, Cimino et al., Issued October 25, 1983, describes an apparatus for preserving food by generating a preservative gas. The gas generating device comprises a bowl type main container and an auxiliary container located inside the main container. The main container carries a solid chemical reagent. The auxiliary container carries a liquid chemical substance. The gas generation device is placed inside a storage or transport container of the product. Conservative gas is generated when the main auxiliary container is drilled, allowing the liquid chemical to react with the solid chemical reagent. The conservation gases described in this patent include carbon dioxide and sulfur dioxide. U.S. Patent No. 4,528,228 to Clevenger, issued June 9, 1985, discloses an atmospheric control damping pad for fruit. The pad comprises a top and a bottom sheet, which are joined together at their peripheral edges, and a cushioning material, which is enclosed between the top and bottom sheets. The cushioning material may include a chemical composition, such as calcium hydroxide, which absorbs carbon dioxide, or potassium permanganate, which oxidizes ethylene. Calcium chloride is also suggested, since it absorbs water and assists in cushion function of the pad through expansion. U.S. Patent No. 4,748,904, to Raseto et al., Issued June 7, 1988, discloses a multi-layered paper structure used to preserve fruits and vegetables during storage and transportation. The structure contains at least two, and preferably three, layers of paper, which are joined together to form a cavity. At least one of the paper layers is coated with a permeable film, such as polyethylene. The cavity contains a hypochlorite material. The patent teaches that the humidity of the fruit diffuses through the outer layers, where it reacts with the hypochlorite to form a chlorine gas, which diffuses back and acts as a preservative for the fruit. Chile's patent 35760, issued by Raseto on November 3, 1987, describes a similar paper-based chlorine generator for the preservation of fruit.

COMPENDIUM OF THE INVENTION The present invention is directed to a chlorine generator used for the conservation of fruits and vegetables. The generator includes a first layer consisting of paper or polyethylene, which is moist and permeable to gas, which has a weight of about 20 to about 70 g / m2 (preferably coated with polyethylene having a weight of about 5 to about 25). g / m2), and a second layer consisting of polyethylene having a weight of about 25 to about 70 g / m2 and a thickness of about 10 to about 17 microns. These layers are joined together through one or more joints, so that they form at least one cavity between them. Contained within this cavity is a hypochlorite material that releases active chlorine gas after the reaction with the moisture of the fruits and vegetables that are being conserved. The first layer is preferably made of paper and, most preferably, it is made of a "slab" type paper. The second layer is preferably a micropunched polyethylene film. The bonds between these two layers are preferably thermal salts.

The preferred embodiment of this invention has been found to be particularly effective in the control of Botrytis Cinérea in grapes. Grapes that are stored in conventional boxes and maintained at about 0 ° C for 35 or more days with the chlorine generators of the present invention show an effective concentration without any side effects, such as discoloration, browning, or dehydration. As used herein, all percentages and ratios are in "weight", unless otherwise specified.

DESCRIPTION OF THE DRAWINGS For the purpose of illustrating the present invention, a preferred embodiment is shown in the drawings. However, it is understood that the present invention is not limited to this specific embodiment and that variations that might have been obvious to those skilled in the art, based on the description herein, fall within the scope of the present invention. Figure 1 is an isometric view of a preferred embodiment of the present invention. Figure 2 is a sectional view of the preferred embodiment shown in Figure 1 taken along the sectional lines 2-2. Figure 3 is a sectional view of another embodiment of the present invention. Figure 4 is an enlarged cross-sectional view of a portion of the present invention, the site being observed in Figure 2.

DETAILED DESCRIPTION OF THE INVENTION Referring to the drawings, in which similar numbers indicate similar elements, a first embodiment of the chlorine generator of the present invention (10) is shown in Figures 1 and 2. The generator (10) of the present invention generally comprises a first layer (18) and a second layer (16). The first layer is made from a paper or polyethylene (as described below), which is permeable to moisture and gas and which has a weight of from about 20 to about 70 g / m2, preferably around 20 to 40 g / m2, and most preferably around 30 g / m2. This layer is preferably made of paper and most preferably is made of a "slab" type paper, which is made from the henequen fibers (sisalana agave plant), although other paper-based materials may be used. It is preferred that, when the first layer is made of paper, a surface of this first layer (18) is coated with a plastic film (30) having a weight of about 5 to about 25 g / m2, preferably about 10. at 20 g / m2, and most preferably around 12 g / m2. See Figure 4. Useful plastic materials include, for example, polyethylene. Even after coating, the first layer must remain permeable to moisture and gas. The coating can be on either or both sides of the first layer, although the coating on one side is preferred. The second layer (16) of the chlorine generator (which must be both permeable to moisture and gas) is made from a polyethylene material having a weight of about 25 to about 70 g / m2, preferably around 30 to 55 g / m2 and having a thickness of about 10 to about 17 microns, preferably about 12 to 15 microns. A preferred material is a high density nonwoven polyethylene film, which preferably is micropunched and is therefore permeable to both moisture and gas. The polyethylene can also be used in the form of an interlaced fabric, such as Tyvek, commercially available from duPont. The layers are joined together, preferably around their peripheral edges through a seal, preferably a thermal seal (14). Such seals are well known in the art. Alternatively, the thermal seal can be replaced either by gluing, sewing or through any other suitable means for joining or joining the layers together and preventing any leakage of spillage between the layers. The sealing of the layers, therefore, provides at least one cavity in the chlorine generator, which is used to maintain the hypochlorite material described below. Inside the chlorine generator (10), a plurality of thermal seals (or other types of) can be provided (12). These seals (12) are identical to those described in relation to the peripheral seals (14). The inner seals (12) join the layers in the internal regions in the generator, thus forming a plurality of cavities. The combination of seals (12 and 14) and layers (16 and 18) define cavities (24). See Figures 2 and 3. The cavity (24) is located between the two layers (16 and 18), which design the present invention. Through the proper use and placement of the seals, a plurality of such cavities can be formed having the same different sizes or sizes. A chlorine generating composition (26) is placed in one or more of the cavities. This composition comprises a hypochlorite material and can also include auxiliary components. Preferably, the chlorine generator contains a total of about 1 to about 20 grams of the chlorine generating composition. This total amount is then divided among the various cavities contained in the chlorine generator. The hypochlorite material used in the composition is generally either in granular or powder form. In general, it is of a commercial grade that is not absolutely pure. It is preferred that the hypochlorite material is an alkali metal or alkali metal hypochlorite, with calcium hypochlorite being preferred. Of course, it is obvious to those skilled in the art that any hypochlorite material that is capable of releasing chlorine after the reaction with moisture may be suitable for use in the present invention. The chlorine generating composition may also contain sodium chloride. Said composition generally comprises about 30%) to about 100% of the mixture of calcium hypochlorite and sodium chloride. It is preferred that the weight ratio of the hypochlorite to sodium chloride material be from about 1: 1 to about 1.5: 1. The diffusion characteristics of either the first layer (18) or the second layer (16) can be varied both in terms of moisture diffusion in the chlorine generator and the diffusion of chlorine gas outside the generator, in order to meet the particular needs of the type of fruit or the type or size of container where the chlorine generator is used. In an alternative structure, either the second layer (16) or, preferably, the first layer (18) is impregnated with a composition containing the hypochlorite material, or the hypochlorite material together with additional auxiliary components such as sodium, citric acid and / or calcium chloride. This impregnated layer can be coated with a resin material such as a vinyl resinous substance (e.g., vinyl acetate, polyvinyl alcohol), an elastomer (e.g. butadiene-acrylonitrile copolymer of natural rubber), a wax (for example, example, paraffin), or other materials, such as gelatin or starch, as well as mixtures of said materials. In addition to the optional hypochlorite material and sodium chloride, additional materials may be included in the chlorine generating composition. Inclusion or exclusion of such additional materials may have the effect of reducing or accelerating the rate at which chlorine is generated. For example, the inclusion of citric acid in the composition (so that the final composition contains from about 10% to about 60% citric acid, together with about 10% to about 70% hypochlorite and about 10% to 60% of sodium chloride) and calcium chloride (so that the final composition contains about 0.5% to 105 of calcium chloride) tends to increase the rate at which chlorine is generated. In addition, the size and configuration of the chlorine generator of the present invention can be varied based on the type of fruit to be treated and the type and size of the container used. For example, the total size of the generator can be increased or reduced depending on the amount of chlorine that is necessary to achieve the conservation task in a particular case. Also, the formula and amount of the hypochlorite composition, as well as the number of cavities included in the chlorine generator, the permeability of the cavities and the amount of chlorine generating composition in each cavity, can be varied. A second embodiment of this invention (10 ') is shown in Figure 3. The generator (10') consists of a first layer (18) and a second layer (16), which are identical to those described in the previous embodiment . In addition to these layers, this alternative embodiment includes a first additional layer (18 ') and / or a second additional layer (16') which are sandwiched between the first and second original layers. In this way, this alternative structure includes a sandwich aspect of multiple cavity layers, wherein the chlorine generating composition can be contained. Again, this type of structure allows for greater control of the amount and speed of the chlorine gas, which is generated from the present invention. The cavities are formed in this sandwich structure through conventional seals, such as thermal seals, or others, as described above. The chlorine generating composition is placed within one or more of the cavities; the preferred structures contain the chlorine generating composition in each cavity.

During use, the present invention is packaged in a container with fruits and / or vegetables. The invention can be placed in the container of fruits or vegetables before or after the product is placed in the container. The moisture of the product reacts with the hypochlorite material forming chlorine gas which acts as a preservative. The following examples illustrate the present invention.

Example 1 The generator consists of two layers, one of micropunched polyethylene, with a thickness of approximately 12 to 15 microns and a weight of approximately 40 g / m2, and the other of "slab" type paper, with a weight of approximately 30 g / m2, coated with polyethylene, weighing approximately 12 g / m2. These layers are joined together around their peripheral edges and at other points through thermal seal. The combination of thermal seals and layers defines six cavities of equal size. The external dimensions of the generator are a length of 46 cm and a width of 20.5 cm. The formulation of the chlorine generating composition used is as follows: Calcium Hypochlorite (commercial grade material) 3.5 g Sodium Chloride 1.9 g Citrus Acid 4.0 g Calcium Chloride 0.2 g The amount of formulation (compound mixture) per generator unit is 9.6 g. The amount per cavity is 1.6 g. This generator produces chlorine gas at a relatively fast rate and effectively conserves fruit (eg, grapes) when placed with them in a shipping container.

Example 2 The generator consists of two layers, one of micropunched polyethylene, with a thickness of approximately 12 to 15 microns and a weight of approximately 40 g / m2, and the other of "slab" type paper, with a weight of approximately 30 g / m2, covered with polyethylene, with a weight of around 12 g / m2. These layers are joined together around their peripheral edges and at other points through thermal seal. The combination of thermal seals and layers defines six cavities of equal size. The external dimensions of the generator are a length of 46 cm and a width of 20.5 cm. The formulation of the used chlorine generating composition placed in each cavity is as follows: Calcium Hypochlorite (commercial grade material) 1.2 g Sodium Chloride 0.6 g The amount of formulation (compound mixture) per generator unit is 1.8 g. The amount per cavity is 0.3 g. This generator produces chlorine gas at a slower speed relative to the generator of Example 1. It effectively preserves fruits (eg, grapes) when placed with them in a shipping container. The present invention may be modalized in other specific forms without departing from the spirit or essential attributes of the present invention.

Claims (20)

1. - A chlorine generator for preserving products, comprising: (a) a first layer comprising a sheet of paper or polyethylene, which is permeable to moisture and gas, and which has a weight of about 20 to about 70 g / m2; (b) a second layer consisting of a polyethylene sheet having a weight of about 25 to about 70 g / m2 and a thickness of about 10 to about 17 microns, one or more joints together joining said layers, so that less a cavity is formed between them; and (c) a chlorine generating composition comprising a hypochlorite material which is disposed in said cavity, the hypochlorite material releasing the active chlorine gas after the reaction the moisture of said product.

2. The chlorine generator according to claim 1, wherein the first layer is made of paper.

3. The chlorine generator according to claim 2, wherein the second layer is made of a micropunched polyethylene film.

4. - The chlorine generator according to claim 2, wherein the hypochlorite material is an alkali metal or alkaline earth metal hypochlorite.

5. The chlorine generator according to claim 4, wherein the hypochlorite material is calcium hypochlorite.

6. The chlorine generator according to claim 2, wherein the first layer is made of a "slab" type paper.

7. The chlorine generator according to claim 2, wherein at least one surface of the first layer is coated with a permeable film, said film having a weight of about 5 to about 25 g / m2.

8. The chlorine generator according to claim 7, wherein the permeable film is polyethylene.

9. The chlorine generator according to claim 2, wherein the weight of the first film is from about 20 to about 40 g / m2.

10. The chlorine generator according to claim 2, wherein the second layer has a weight of about 30 to about 55 g / m2 and a thickness of about 12 to about 15 microns.

11. The chlorine generator according to claim 2, wherein the chlorine generating composition comprises from about 30% to about 100% calcium hypochlorite and sodium chloride, wherein the ratio of calcium hypochlorite to sodium chloride sodium is from about 1: 1 to about 1.5: 1.

12. - The chlorine generator according to claim 11, wherein the hypochlorite mixture further comprises about 10% to about 60% citric acid and about 0.5% to about 10% calcium chloride.

13. The chlorine generator according to claim 2, characterized in that it contains from about 1 to about 20 g of said chlorine generating composition.

14. The chlorine generator according to claim 11, wherein the first layer is impregnated with a mixture comprising calcium hypochlorite and sodium chloride. 15.- The chlorine generator according to the claim 14, wherein the first layer is further coated with a resin selected from the group consisting of resinous vinyl substances, elastomers, waxes, gelatin and starch, said coating allowing the release of chlorine after the reaction of the hypochlorite material with moisture of said product. 16.- The chlorine generator according to the claim 15, wherein the resin is selected from the group consisting of polyvinyl acetate, polyvinyl alcohol, natural rubber, butadiene-acrylonitrile copolymer, paraffin, gelatin, starch and mixtures thereof. 17. A chlorine generator for preserving products according to claim 1, wherein: (a) said first layer consists of a "slab" type paper, which is permeable to moisture and gas; (b) said second layer consists of micropunched polyethylene; and (c) said chlorine generating composition comprises an alkaline earth metal or alkali metal hypochlorite and sodium chloride, wherein the ratio of hypochlorite to sodium chloride is from about 1: 1 to about 1.5: 1. 18.- The chlorine generator according to the claim 17, wherein said hypochlorite is calcium hypochlorite. 19.- The chlorine generator according to the claim 18, wherein at least one surface of the first layer is coated with a permeable polyethylene film, the layer having a weight of about 5 to about 25 g / m2. 20.- The chlorine generator according to the claim 19, wherein the first layer has a weight of about 20 to 40 g / m2, and said second layer has a weight of about 30 to 55 g / m2 and a thickness of about 12 to 15 microns.