ES2926917A1 - Edible film and coating and manufacturing method (Machine-translation by Google Translate, not legally binding) - Google Patents

Abstract

Edible film and coating, made from fruits and/or vegetables that contain functional compounds intended to provide the packaged product or packaging material with improved characteristics (sensory, nutritional and/or microbiological). The raw material is fruit and/or vegetables, or waste or residues from the processing of these foods, in the form of purees, extracts or juices, which are dispersed with a polymer and a plasticizer, to achieve a mass from which they are obtained. sheets in the form of films, or deposited on top of the food, or the food is immersed in the solution, to form an edible coating. (Machine-translation by Google Translate, not legally binding)

Description

DESCRIPTION

Edible film and coating and manufacturing method

Technical sector

The product object of this invention is mainly aimed at the traditional packaging sector, reducing the production of non-biodegradable waste and providing the food with beneficial properties for health derived from the raw material used to make the product.

For example, a film made according to the invention could be used to separate fillets, so that the use of these films would improve the nutritional profile of said fillets, since it enriches them with nutrients in which they are deficient, such as fiber, while Since it is susceptible to being cooked (since it is a food material), so it is not thrown away as would be the case with plastic used in containers in a conventional way, the environmental impact of waste management is reduced. plastic waste.

State of the art

In any nursery or agricultural production in which strawberries, red fruits and other horticultural products (carrots, leeks, etc.) are produced, large amounts of waste are generated that are not marketed, and therefore cause substantial losses that could be used for another purpose, such as the production of edible films or coatings.

Edible films and coatings made from fruit and vegetable waste have multiple advantages. In the first place, they can extend the useful life of the product, giving the food a remarkable antioxidant power due to the intrinsic properties of the raw material. In addition, the use of other traditional containers that can have harmful effects on human health due to substances such as Bisphenol A, which is used to manufacture polycarbonate (used in food containers), would be limited. This substance can be transmitted to food by different factors such as temperature or dissolution, causing possible adverse effects on the kidney, liver and mammary glands according to Regulation (EU) 10/2011 of the commission of 01/14/2011 on materials and plastic objects to come into contact with food, the maximum daily limit of this substance is 0.004mg/Kg of body weight/day.

On the other hand, it would help to considerably reduce the use of plastics in homes, since currently non-biodegradable plastic is a very important environmental problem, since most of the containers used are made of this material, which takes approximately 150 years to degrade. In 2015, more than 300 million tons of plastics were produced in the world, it is also calculated that every 90 minutes 2000 tons end up in the oceans and, if this trend does not change, many scientists predict that in 2050 there will be more plastics that fish in our seas.

The development of edible films and coatings can represent a promising and environmentally friendly advance, which would allow not only to reduce the amount of plastics but also the cost derived from their elimination. In addition, edible coatings can give foods interesting properties such as moisture control or reduction of the lipid oxidation process. For this reason, the partial replacement of plastics in food packaging by non-harmful protective organic substances is an idea worthy of evaluation by the competent bodies.

Document US8715763B2 describes films made from fruits, vegetables or a combination thereof that have the thinness, strength, flexibility and freshness to serve as alternatives or substitutes for algae-based films such as nori, while providing the nutrition and fruit and vegetable flavor. These films are useful for wrapping a multitude of foods and can be used to provide wrapped foods, including, for example, sushi and onigiri wrapped in fruit and vegetables. In this document, the fruit or vegetable purée that they use as raw material is adapted in humidity based on the percentage of solids that they need by means of pasteurization and drying.

On the contrary, in the present invention a pre-treatment consisting solely of blanching is proposed. This thermal process consists of applying a temperature of around 100°C for a very short period of time. This fact allows enzymes to be inactivated without altering the nutritional and organoleptic properties of fruits and vegetables. In addition, it is a process that is very profitable, so that the revaluation of by-products is scalable at an industrial level.

Explanation of the invention

Based on the prior art, an objective of the present invention is to provide an edible film and coating with which to preserve foods while maintaining their organoleptic properties, while increasing the shelf life of the food for as long as possible.

In addition, these types of films or coatings provide foods with antioxidant properties derived from the raw material used to make them, increasing their nutritional properties, so they are expected to have an optimal impact on human health.

The production of plastics and non-biodegradable packaging is also reduced, as well as substances that are harmful to the body produced by the components of traditional packaging and the waste and residues of vegetables and fruits not marketed.

The European Commission has an objective for 2030 that consists of a Europe that uses its resources, that is energy neutral and that the economy is circular. This project adds to this objective because the supply of raw materials is sustainable, the environmental impact of both plastic and horticultural waste is reduced and costs are minimized by the recirculation of still useful products.

In order to achieve the proposed objectives, mentioned in the previous sections, the invention proposes an edible film and coating, made from fruits and/or vegetables, which have the characteristics of claim 1.

Research carried out by the inventors has led to the conclusion that it is possible to obtain films produced with fruit and/or vegetable purées, since they mainly contain water, proteins, cellulosic and pectic substances in a natural way. However, it has also been observed that edible films and coatings composed exclusively of fruit and/or vegetable puree often have poor consistency, mechanical resistance and barrier properties, so it is necessary to add some edible hydrocolloid as plasticizing agents to improve its physical properties. In some cases, the purees themselves form layers that cannot even be separated from the mold surface as continuous films, making the addition of biomacromolecules of paramount importance to increase film cohesion. Pectin is a good binding agent for these purposes. These bio-macromolecules can be extracted from plants (eg starch, pectin and cellulose), animals (collagen, gelatin and chitosan), microorganisms (eg bacterial cellulose) and algae (including alginate and carrageenan).

On the other hand, these investigations have also led to the conclusion that it is possible to resort to the use of plasticizers (they can be part of the polymeric, internal macromolecules, or non-volatile substances of low molecular weight that do not chemically bind to the main, external chain), to obtain materials with reduced brittleness and stiffness, as well as greater flexibility, stretchability and toughness. Thus, glycerol, a small polyol with 3 hydroxyl groups, has been pointed out as the best plasticizer for water-soluble polymers, also providing flexibility to the film. Likewise, other food-grade plasticizers can be used for the production of edible films, such as low molecular weight sugars (for example, fructose-glucose syrups and honey), polyols (for example, derivatives of glyceryl and propylene glycols), lipids and derivatives (including phospholipids, fatty acids, lecithin, oils and waxes) and water.

Fruit and vegetable-based edible films may contain functional compounds intended to provide the packaged product or packaging material with improved characteristics (sensory, nutritional and/or microbiological), thus playing an active role when interacting with food. Polyphenols, including tannins, flavonoids, and derivatives of phenolic acids, are also secondary plant metabolites with antimicrobial and antioxidant effects. Furthermore, they are known to scavenge active oxygen in the human body and exert various biological functions such as antioxidant, anticancer, anti-inflammatory, and anti-atherosclerogenic, among others.

The raw material for the preparation of the film and/or coating object of the invention are essentially by-products of fruits and/or vegetables, in the form of purees, extracts or juices, which become part of the film or coating in a percentage in weight between 10% and 65% of the total.

In addition to the polymers (for example pectin) that fruits and/or vegetables contain, the composition of the film and/or coating of the invention incorporates other polymers, such as pectin, until the content of these compounds in the total weight of the product obtained is between 2.2% and 4.5%, these compounds being responsible for the formation of the film.

In the composition of the film and/or coating of the invention, the participation of at least one plasticizer is also required; preferably vegetable glycerin (glycerol) or sorbitol, both products also of vegetable origin, in a proportion between 3% and 8% of the total weight of the product obtained, since these compounds are necessary to provide elasticity to the edible film on the surface of food.

Finally, as a solvent, distilled water is added in a proportion between 5-20% of the total weight of the product.

In a preferred embodiment, antioxidants, such as citric acid and/or ascorbic acid, are also added in a proportion of between 0.5 and 1% of the total weight of the mixture.

In an alternative embodiment, instead of pectin, 1.5% chitosan is added in an aqueous solution with 1% acetic acid.

The development of the present invention has been carried out on the basis of using purees, extracts or juices of strawberries, carrots, apples or any combination thereof as raw material. However, the invention is not considered limited exclusively to these types of fruits and/or vegetables.

An example of a film developed according to the invention, using carrots as raw material, is used to separate meat and fish. Thanks to the flavors that derive from these films, it can have a double purpose: on the one hand, to preserve the food for as long as possible and, on the other, to serve it while the food is being cooked, enhancing its flavor and providing it with additional flavors when it enters into contact with heat and dissolve. In this way, its attractiveness for the market is increased, for example, for children and young people, groups that do not comply with the recommendations for daily fruit and vegetable intake, being a tool to encourage their consumption. As well as, this type of food is enriched in nutrients that are deficient, such as fiber and certain antioxidant vitamins in meat and fish products.

In another alternative example, a coating of fruits, such as strawberries, is made. Strawberry is a fruit that ripens quickly and deteriorates due to the action of fungi and their mycotoxins. The packaging of strawberries with coatings made from the same fruit would lengthen the shelf life of this food since this type of coating performs antioxidant and antimicrobial functions, preventing the proliferation of fungi in the product. The The coating would act as if it were a skin of the food, making it much more stable to spoilage due to its reduced moisture content and water activity. Furthermore, due to their high polarity, most coatings are good gas barriers but poor moisture barriers. As a result, these semi-permeable barriers can create modified atmosphere packaging systems, whose respiratory gases (oxygen and carbon dioxide) can be exchanged in a controlled manner and lead to slower metabolism and ethylene production, resulting in the preservation of strawberries. longer.

A similar coating could be obtained from and for apples, or from and for other types of fruit.

A substitute for the use of algae in the preparation of foods that contain them, such as sushi, has also been developed. Sushi is a highly demanded food currently in our population. However, it may have the drawback that for some consumers its taste is not pleasant and, for others, its consumption is discouraged due to its high iodine content. Substituting the algae that covers the food for these films or coatings with fruit and vegetable residues, the product is given greater versatility, different flavors are produced (even better known) and the product is brought closer to consumers who cannot take algae for its iodine content.

The manufacturing process developed here leads to an edible film and/or coating with good properties from a nutritional, sensory and bioactive point of view. This process includes the operations described below:

a) Previous operations with the raw materials, in which they are extracted and selected and then washed, disinfected and crushed with a blender until they form a puree, extract or juice, which will constitute a percentage between 10% and 65% of the total of the product obtained.

b) A dispersion is formed with these by-products and a plasticizer, preferably 1-3% pectin, which is kept stirred at about 80°C until completely dissolved. Glycerol is also added, in a proportion between 3% and 8% of the total weight of the product obtained.

c) Homogenization of the solution, keeping it stirred for about 2 hours at 80°C.

If it were to be applied as a coating, it could be used without further immersion of the food directly in the solution. It can also be applied by spraying on the surface of the food.

To manufacture the films, it is necessary to pour the solution on a surface, dry it and then unfold it on the surface in the form of sheets, which are stored rolled up or in plastic bags, in the absence of light and under controlled temperature and humidity conditions.

Particularly when the raw material basically consists of apples or carrots, before crushing the fruits and/or vegetables, they are cut into cubes, scalded in boiling water with lemon juice and drained and dried for several hours.

In a variant of the described process, in the dispersion phase of the pectin and glycerol, citric and/or ascorbic acids are also added, in a proportion between 0.5 and 1% of the total weight of the mixture, whose function is to prevent the oxidation of the fruits and/or vegetables used.

In the dispersion phase of glycerol and pectin that are naturally added to fruits and/or vegetables, pectin can be replaced by chitosan, at 1.5% previously dissolved for about 2 hours in an aqueous solution with a 1% acetic acid.

The process developed here allows the preparation of edible films and coatings that improve the shelf life and quality of the food products where they are applied, since they constitute a barrier against physical and mechanical damage. The films and/or coatings themselves act as a barrier to oxygen and water, reducing oxidation reactions and retaining moisture, improving quality and increasing shelf life. Another advantage of edible films or coatings is that the release of antioxidant compounds is gradual throughout the useful life of the product.

The process of the invention provides as its main novelty the use of by-products from the fruit and/or horticultural industry without undergoing prior pre-treatment such as dehydration, which increases not only the cost of production, but also the environmental impact.

To complement the description that is being made, some examples of the manufacture of films and coatings are developed below, using as a basis for the same various types of fruit (strawberries, apples...) and vegetables (carrots...). In all of them these vegetables were added after being blanched and crushed and pectin and glycerol were added to these solutions, the latter as a plasticizer. Citric acid and ascorbic acid have also been used as preservatives. In other examples, films have also been made with other polymers such as chitosan.

Example 1.

Strawberry remains are used, which are washed, disinfected and crushed with a blender.

- On the one hand, 1-3% pectin is dispersed while stirring at 80°C until completely dissolved, and then 7.5% glycerol and 0.625 g of citric and ascorbic acid are added.

- Then the strawberry puree is added in a percentage between 10% and 65%; so that the mixture obtained reaches a pectin content between 2.2% and 3.6%.

- Finally, the solution is kept for 2 hours at 80°C until the solution is homogeneous.

Example 2:

It is an alternative variant of the previous example in which the strawberries are first cut into cubes of about 2 cm, they are thrown into boiling water with lemon juice for 5 minutes; and subsequently crushed with a blender.

Example 3:

In another variant, instead of pectin, 1.5% chitosan is added in an aqueous solution with 1% acetic acid for 2 hours until completely dissolved.

Example 4:

In this case, carrot residues are used, which are washed, disinfected and cut into 2 cm cubes. They are thrown into boiling water with lemon juice for 5 minutes. They are removed and left in a strainer for several hours to release as much water as possible, before being crushed with the blender.

Next, 1-3% pectin was dispersed while stirring at 80°C until completely dissolved, then 7.5% glycerol and 0.625 g of citric and ascorbic acid were added. The carrot puree was added in a percentage between 10-65%, reaching a content of pectin ranging from 2.8% to 3.6% and the solution was kept for 2 hours at 80°C until completely dissolved.

Example 5:

In this alternative example, apple waste is used, which is washed, disinfected and cut into 2 cm cubes and then thrown into boiling water with lemon juice for 5 minutes. They are removed and left in a colander for several hours to release as much water as possible, and then they are crushed with a blender.

Next, 1-2% pectin was dispersed while stirring at 80°C until completely dissolved, then 7.5% glycerol and 0.625 g of citric and ascorbic acid were added. The apple puree was added, reaching a pectin content that accounted for 3-4.5% of the total, and the solution was kept for 2 hours at 80°C until completely dissolved.

Using apples as an alternative fruit, there is also the possibility of adding chitosan, at 1.5% and in an aqueous solution with 1% acetic acid for 2 hours until completely dissolved. Subsequently, 1.5% glycerol is added as a plasticizer; then applesauce is added at 10% to 65% along with 0.625g of ascorbic acid and citric acid. In this step, the solution can be homogenized.

Once the nature of the invention has been described, as well as a preferred embodiment, it is evident that the invention is capable of industrial application, in the indicated sector.

Likewise, it is stated for the appropriate purposes that the materials, shape, size and arrangement of the elements described may be modified, as long as this does not imply an alteration of the essential characteristics of the invention that are claimed below.

Claims (11)

1. - Edible film and coating comprising : - fruits and/or vegetables, or waste or residues from the processing of these foods, in the form of purees, extracts or juices, in a percentage by weight between 10% and 65% of the total product obtained; - at least one polymer, pectin, either added or naturally present in added fruits and/or vegetables, whose content in the total weight of the product obtained is between 2.2% and 4.5%; - at least one plasticizer, glycerol, in a proportion between 3% and 8% of the total weight of the product obtained; Y - distilled water. 2. - Edible film and coating according to claim 1, further comprising : citric and ascorbic acids in a proportion between 0.5 and 1% of the total weight of the mixture. 3. - Film and edible coating, according to any of the preceding claims, comprising , in addition to the pectin that they naturally have in the fruits and/or vegetables added, 1.5% chitosan in an aqueous solution of acetic acid. 4. - Film and edible coating, according to any of the preceding claims, characterized in that the fruits and / or vegetables added in the form of purees, extracts or juices, are: strawberries, carrots, apples or any combination thereof. 5. - Method of manufacturing an edible film and coating, which includes the following phases: - an initial phase in which fruits and/or vegetables are washed, disinfected and crushed with a blender until they form a puree, extract or juice; - disperse 1-3% pectin while stirring at about 80°C until completely dissolved and then add glycerol, in a proportion between 3% and 8% of the total weight of the product obtained; - then add the fruit and/or vegetable puree in a percentage between 10% and 65% of the total product obtained; - maintain the solution for about 2 hours at 80°C until the solution is homogeneous. 6. Method, according to claim 5, characterized in that to obtain coatings, the solution obtained in claim 5 is deposited on top of the food, or the food is submerged in the solution and subsequently drained. 7. Method, according to claim 5, characterized in that to obtain films, the solution in claim 5 is distributed in sheets that are stored stacked or rolled. 8. - Method according to claim 5, characterized in that for obtaining coatings the solution obtained in claim 5 is sprayed on the surface of the food. 9. - Method according to claim 5, characterized in that prior to crushing the fruits and/or vegetables are diced, scalded in boiling water with lemon juice and drained and dried for several hours 10. - Method according to any of claims 5-9, characterized in that in the dispersion phase of the pectin and glycerol, citric and ascorbic acids are added in a proportion between 0.5 and 1% of the total weight of the mixture. 11. - Method according to any of claims 5-9, characterized in that in the dispersion phase of glycerol and pectin that naturally have added fruits and / or vegetables, chitosan is added, in a 1.5 % previously dissolved for about 2 hours in an aqueous solution with 1% acetic acid.