Procedure for packaging cut fruit and use of packaging

Abstract

The current invention concerns a method for packaging fruit comprising the following steps. First, the fruit is washed with a peracetic acid solution, after which the fruit is cut. The cut fruit is divided into portions between 50 grams and 3000 grams. Each portion is packed in a plastic container, which is covered with a perforated plastic film. A label is placed over the film. The plastic film is preferably made of polyethylene terephthalate and 70 to 80 perforations per m² are made in it. The label covers between 30% and 60% of the film. In a second aspect, the invention concerns the use of packaging such as in the method.

Description

1 METHOD FOR PACKAGING SLICED FRUIT USE OF PACKAGING TECHNICAL DOMAIN 5 The invention relates to a method for packaging sliced ​​fruit, where the packaging is adapted to the shelf life of the fruit. STANDDER TECHNIEK 10 In the current fruit packaging industry, there are various challenges that affect the quality and shelf life of packaged fruit. A major problem is preserving the freshness of cut fruit, especially in modified atmosphere packaging (MAP), where the goal is to slow down the respiration of the fruit by regulating the air composition. However, commonly used packaging materials cannot optimally ensure the necessary gas exchange and can contribute to the accumulation of moisture, which can lead to condensation. This increases the risk of mold growth, spoilage, and loss of texture, especially in fruits sensitive to moisture, such as berries, melons, and citrus fruits.20 In addition, many conventional films, although breathable, are often unable to exercise sufficient control over airflow and moisture management. This leads to a loss of fruit quality after a relatively short storage period. Some packaging features perforations, but these are often not sufficiently optimized for specific fruit types, leading to suboptimal performance, such as premature ripening or insufficient moisture regulation. Another problem is the complexity of packaging different fruit types in a single type of film. Different fruits have varying needs regarding moisture regulation and gas exchange. Some fruit types, such as apples and pears, produce ethylene gas, which accelerates the ripening process, while other fruit types, such as berries or grapes, are sensitive to pre-drying. Finding a universal solution for these diverse needs without compromising fruit quality remains a challenge. 35 Finally, there is the issue of the effectiveness of labels and their influence on the breathable properties of the film.In traditional packaging, the label can block or restrict air circulation, meaning the benefits of breathable films are not fully utilized. This can lead to an imbalance between the necessary visibility of brand and product information and the necessary functions of the film, such as preserving the freshness of the fruit. US20200281233 describes a method for handling a perishable product, including determining a desired result of the product handling, chosen from cleaning, protection, preservation, or improvement of the perishable product. EP1647489 describes a device for packaging fresh vegetables and fruit in containers covered with a sealed layer of film containing a perforator to make holes in the film with a variable density, adapted to the metabolism of the contents.In summary, the main problems in the fruit packaging industry are the insufficient control of moisture and gas exchange, the lack of flexibility for different fruit types, the limited effectiveness of existing perforations, and15 the influence of labels on the breathability and properties of the film. The present invention aims to find a solution to at least some of the above-mentioned problems. 20 SUMMARY OF THE INVENTION The invention concerns a method for packaging fruit in accordance with claim 1. The method involves, among other things, covering a container with a perforated film. The film contains perforations that ensure controlled gas exchange and moisture regulation, which preserves the freshness of the fruit for longer. The label covered part of the film, so that both branding and the breathable properties of the film are preserved. Further preferred forms are described in conclusions 2 to 10. 30 In a second aspect, the invention concerns the use of a combination of a perforated film with a label according to conclusions 11 to 13.DETAILED DESCRIPTION 35 In a first aspect, the present invention concerns a method for packaging fruit, which comprises the following steps. First, the fruit is washed with a peracetic acid, after which the fruit is cut. The cut fruit is divided into BE2024 / 5895 3 portions between 50 grams and 3000 grams. Each portion is packed in an airtight plastic container, which is covered with an air-permeable plastic film. A label is placed over the film. The plastic film is preferably made of polyethylene terephthalates and 70 to 80 perforations per m² are made in it. The label covers between 30% and 60% of the film. 5 In the fruit industry, packaging material plays a crucial role in maintaining the quality, freshness and shelf life of fruit. Because fruit is a living product, it remains it takes in the eye. During this breathing process, the fruit absorbs oxygen and releases carbon dioxide, which is essential for the metabolic processes.10 Incorrect packaging can disrupt this process, which can lead to accelerated ripening, loss of quality, or the development of mold and spoilage. Breathable packaging, such as perforated films, has been developed to address this challenge. Strategically placed perforations in the film enable controlled gas exchange. This ensures that oxygen and carbon dioxide concentrations within the packaging are tailored to the needs of the fruit. This balance helps to regulate respiration, preserve freshness, and extend shelf life. 20 In addition, breathable packaging offers benefits in terms of food safety. It prevents the accumulation of moisture within the packaging, which reduces the risk of microbial growth. Moreover, such packaging makes it possible to package fresh-cut fruit, which is particularly sensitive to quality loss, attractively and safely for consumers.In a time when sustainability25 and waste reduction are becoming increasingly important, breathable packaging is also compatible with recyclable materials, such as PET, making it not only functional but also environmentally friendly. Consumer perception plays a role in assessing the quality and30 freshness of the packaged product. When a non-breathable film is used, gas formation can occur within the packaging as a result of fermentation. This causes the packaging to bulge, which can give the consumer the impression that the product is no longer fresh or may be spoiled. This visual effect can significantly reduce the attractiveness of the product in the eyes of the consumer35 and thereby negatively influence sales. The use of a breathable film can prevent this problem by enabling a controlled exchange of gases, which makes the packaging aesthetically and functionally more attractive. BE2024 / 5895 4 In a form, the label is applied to the perforated film and covers between 30% and 60% of the surface of the film.The amount of film covered has been carefully chosen to balance both the aesthetic and functional aspects of the packaging. By allowing the label to cover only a portion of the film, sufficient space remains for the perforations to fulfill their function of air circulation and breathing, which is essential for maintaining the freshness of the fruit. At the same time, the label offers sufficient space for brand identification, product information, and other relevant data such as the best-before date, ingredients, or origin of the fruit. The choice to allow the label to cover between 30% and 60% of the film ensures that the brand or product information is visible without impeding the breathable properties of the film. This also helps to maintain the visual appeal of the product, as the fruit itself remains clearly visible to the consumer, which increases the attractiveness of the product. The label can be strategically placed above. be placed, for example on the side or in the corners, so that the perforations and the structure of the film remain clearly visible.In one design form, the plastic film comprises perforations with a diameter. The diameter is the largest dimension of the perforation. The perforations have a diameter between 1µm and 1000µm, preferably between 10µm and 500µm, and even more preferably between 40µm and 300µm. The diameter determines the degree of gas exchange and moisture regulation. Smaller perforations are suitable for fruit varieties with a slow respiration rate, while larger perforations are better for products with an intensive respiration process. The perforations can be uniform in size and density, evenly distributed over the film, which guarantees consistent gas exchange over the entire packaging. This is particularly useful when the packaged product is homogeneous and has a uniform respiration intensity, such as with cut fruit of a single type. In other design forms, the perforations can vary in size or density over the film, depending on the functional requirements of the packaging.This can be applied, for example, to adapt specific parts of the packaging to different breathing needs within a mixed fruit package. Larger perforations or a higher perforation density can be applied in areas where breathing intensity is higher, or to provide targeted ventilation and prevent moisture accumulation in specific zones. This flexibility makes it possible to develop packaging suitable for a wide range of applications, including combinations of different fruit types with varying breathing needs. In a design form, perforations have a mutual distance, in other words, the shortest distance between two individual perforations. This lies between 0.5 cm and 10 cm, but preferably between 1 cm and 5 cm. This distance is a parameter that influences the functionality of the breathable packaging. A distance between perforations that is too small can lead to excessive gas exchange, causing the fruit to dry out faster or the oxygen balance to be disturbed.On the other hand, too large a distance can provide insufficient ventilation, which can result in the accumulation of moisture and carbon dioxide, thereby increasing the risk of mold formation or loss of quality. The choice of spacing depends on various factors, such as the type of fruit, the rate of respiration, the relative humidity in the packaging, and the desired shelf life. For fruit varieties with a high respiration rate, such as sliced ​​melon or pineapple, a smaller distance between the perforations can be chosen. This ensures sufficient gas exchange to support respiration needs and prevent moisture accumulation. For fruit with a lower respiration rate, such as apples or grapes, a larger distance may suffice to maintain a balanced atmosphere in the packaging. Furthermore, the distribution of the perforations can vary across the surface of the film. In some designs, the spacing is uniform, which provides constant ventilation across the entire packaging.In other cases, the distances can vary, for example by placing perforations closer together in zones where higher ventilation is required, such as in the center of the container where the concentration of fruit is often higher. This design with variable perforation density offers the possibility to further optimize packaging for specific needs, such as reducing moisture accumulation in the core of the packaging or supporting uniform ripening. In one design form, the film is perforated via mechanical perforation, laser perforation, thermal perforation, pneumatic perforation, or chemical perforation. The different techniques each offer specific advantages and applications. The choice of perforation method depends on factors such as the type of film, the required precision of the perforations, the production speed, and the desired functionality of the packaging. A widely used method is mechanical perforation, where needles or pins are mechanically pressed into the foil to create perforations.This method is relatively simple and cost-effective, especially for applications where uniform perforation sizes and distribution are sufficient. Mechanical perforation is often used in mass production processes and offers consistent results at high volumes. However, the disadvantage of this technique is that precision can be limited, especially with very small perforations. A more advanced option is laser perforation, in which a laser beam is used to burn precise openings into the film. This technique offers an exceptional degree of control over the size, shape, and placement of the perforations. Laser perforation is particularly suitable for applications where small and uniform perforations are required, such as diameters between 40µm and 100µm. Furthermore, laser perforation makes it possible to create complex patterns, including variable perforation densities or advanced structures specifically tailored to the breathing needs of the packaged fruit.An additional advantage of laser perforation is that it is contactless, thereby minimizing the risk of contamination or damage to the film. Another method that can be applied is thermal perforation, in which heated pins or needles are used to melt openings in the film. This process creates smoother edges around the perforations, which can help prevent tearing in the film and maintain the strength of the packaging. Thermal perforation is often used for films that are prone to tearing or for applications where the perforations must not only be breathable but also maintain mechanical stability. Additionally, pneumatic perforation can be employed, using air pressure to create perforations in the film. This technique is less common but can be useful in specific situations where no physical contact with the film is desired or where certain material properties must be preserved.35 An innovative and less conventional method, chemical perforation, in which a chemical process is used to create microscopic openings in the film. This technique is mainly applied to very thin films or in situations where extremely small perforations are required that are difficult to achieve with mechanical or laser techniques. BE2024 / 5895 7 Each of these methods can be tailored to the specific requirements of the packaging. For example, for a film that requires uniform breathability over the entire surface, mechanical or thermal perforation can be applied. For packaging with variable perforation densities or very precise openings, laser perforation is the ideal choice. By selecting the right perforation technique, the breathable packaging can not only improve the shelf life and quality of the fruit, but also be adapted to the practical requirements of production, logistics, and consumer preferences. In a preferred form, the film is perforated via mechanical perforation or via laser perforation.In a specific form, the plastic film has a weight expressed per square meter. The weight lies between 10 g / m² and 100 g / m², more preferably between 10 g / m² and 60 g / m², and most preferably between 30 g / m² and 40 g / m². The weight of the film plays a role in the balance between mechanical properties, functionality, and costs. A lighter weight, for example between 10 g / m² and 20 g / m², is suitable for applications where minimalism in material use and durability are a priority. However, such lightweight films are less suitable for heavy loads or transport conditions where the packaging is exposed to shocks or pressure, because the mechanical strength of lighter films is generally lower. They are ideal for fruit varieties that are less susceptible to bruising or for packaging that is stored and transported primarily in controlled environments. Heavier films, with a weight closer to 100 g / m², on the other hand offer higher strength and durability.They are suitable for applications where packaging must withstand rough handling, such as on long transport routes or for export.30 These films are also more resistant to tearing and leaking, which can be important when packaging fruit with a high moisture content. However, the disadvantage of such heavier films is that they are less flexible and can increase costs and the environmental impact due to higher material consumption.35 The most balanced choice lies in the mid-segment, between 30g / m² and 40g / m², where the advantages of strength and flexibility are combined with efficient material use. These films offer sufficient mechanical strength to safely package and protect various types of fruit, including cut fruit, during transport. At the same time, they are light enough to minimize the total weight of the packaging, which offers advantages in terms of cost and logistical efficiency. BE2024 / 5895 8 5 The weight of the film also affects the functionality of the perforations.Lighter films can be perforated more easily, especially with techniques such as mechanical or thermal perforation, because less force is required to penetrate the material. For heavier films, laser perforation can be more effective, because this technique offers precision without compromising the structural integrity of the film. Furthermore, the weight can influence air permeability and gas exchange, factors that are important for maintaining the quality and freshness of the packaged fruit. Plastic film has an external dynamic friction coefficient, a value that indicates the degree of resistance when two surfaces of the film slide past each other. This property is essential in applications where the behavior of the film during handling, stacking, transport, and use plays a crucial role. The external dynamic friction coefficient, usually expressed as a dimensionless number, is measured according to standardized test methods, such as ASTMD1894, to guarantee consistency and comparability.The value of the dynamic friction coefficient can vary depending on the type of plastic, surface treatments, and any coatings applied to the film. For films used in fruit packaging, this coefficient25 typically lies between 0.3 and 0.4. This range offers an optimal balance between grip and smoothness. A lower coefficient, for example closer to 0.3, ensures that the film slides easily over surfaces. This is beneficial in automated packaging processes, where low friction ensures smooth handling and minimizes disturbances or damage. Conversely, low friction can be undesirable during stacking,30 because the risk of shifting and instability of stacked packages increases. On the other hand, a higher friction coefficient, closer to 0.4, offers more grip between the film and adjacent surfaces. This can be advantageous for stackable packaging, where the stability of boxes or trays during transport and storage is important.However, excessive friction can lead to processing problems, such as jamming of film rolls in packaging machines or extra energy consumption during unrolling of the film. BE2024 / 5895 9 The external dynamic friction coefficient can be adjusted by surface treatments such as corona or plasma treatments, or by applying coatings such as silicone or wax. These treatments can alter the interaction of the film with other surfaces to increase or decrease friction, depending on the desired application. In addition, the dynamic friction coefficient is important for the interaction between the film and the packaged fruit itself. In case of direct contact, excessive friction can lead to damage to the fruit surface, especially with delicate varieties such as grapes or soft sliced ​​fruit. Therefore, the film is often designed with a carefully selected friction coefficient that is compatible with the intended use. In one version, the plastic film has an external dynamic friction coefficient between 0.3 and 0.4, measured according to ASTMD1894-01.15 Temperature is a crucial parameter in the food industry because it has a direct influence on the quality, safety, and shelf life of food products. At every stage of the food chain, from harvest to consumption, temperature control plays a central role in preventing spoilage, limiting microbial growth, and preserving the nutritional value and sensory properties of products. 20 In the processing of fresh products such as fruit, temperature control is of vital importance. During harvesting and storage, cooling is often used to slow down the respiration process of the fruit, which helps preserve freshness and taste. Typical temperatures for fruit storage are between 2°C and 4°C, which is known as the temperature range in which microbial growth is limited and enzymatic processes are slowed down. For sensitive fruit varieties such as berries and cut fruit, strict temperature control is even more important because these products are particularly susceptible to rapid quality loss.In one form, the method of the present invention is carried out at a temperature between 0°C and 7°C, but preferably between 2°C and 4°C. During processing, such as washing and cutting fruit, temperature is used not only to prevent spoilage, but also to improve the efficiency of cleaning agents such as peracetic acid. The action of such a solution can vary depending on the temperature, whereby excessively high temperatures may reduce effectiveness or cause undesirable chemical reactions BE2024 / 5895 10, while low temperatures may prolong cleaning time. The concentration of the peracetic acid is preferably between 50 and 100 ppm. Temperature also plays an important role during the packaging phase. Fruit packaged in breathable films requires a refrigerated environment to prevent condensation inside the packaging. Condensation can lead to increased humidity, which significantly increases the risk of mold growth and spoilage.Moreover, temperature fluctuations during transport and storage can lead to changes in the respiration rate of the fruit, which can negatively affect shelf life. Therefore, packaging materials such as perforated films are often selected and designed with temperature control in mind, where the perforations help regulate gas exchange and moisture balance. The plastic container in which the fruit is packed plays an important role in maintaining the freshness and quality of the product. The container protects the fruit against physical damage during transport and storage, and ensures that the fruit is presented in a hygienic and safe manner. In addition, the design of the container is often aimed at optimizing air circulation, which helps regulate the fruit's respiration and prevent condensation. 20 In a design form, the plastic container is manufactured from material selected from the group of, but not limited to, polyethylene terephthalate (PET), polyethylene (PE), polypropylene (PP).In one preferred form, the plastic container is manufactured from PET. These materials not only offer the necessary strength and protection, but can also be easily recycled, which contributes to sustainability in the packaging industry. Once the fruit has been placed in the plastic containers, they are covered with perforated film to allow for optimal aeration of the fruit while simultaneously preserving freshness and quality. In one version, the film is attached to the container via thermal welding, whereby the edges of the film and the container are joined together using heat. This method ensures a firm and reliable seal, which not only provides a hermetic seal but also prevents the film from coming loose during transport or storage. Thermal welding is a cost-effective and efficient way to secure the film35 and also provides a watertight and airtight seal that protects the freshness of the fruit.BE2024 / 5895 11 In a further form of implementation, this fastening is achieved via mechanical locking, whereby the film is clamped into a specially designed groove or edge of the container. This technique is less energy-intensive than thermal welding, but can be just as effective in securing the film, especially for lighter applications or smaller containers. 5 In another form of implementation, this fastening is achieved by using glue or tape to attach the film to the container. An acrylate-based adhesive or another food-safe adhesive can be used here that adheres well to both plastic and film. Gluing offers flexibility in production and can be applied to small or complex packaging where thermal welding might be difficult10 or expensive. The use of tape can also be useful for temporary closures or for applications where films can be quickly and easily adjusted or removed.In addition, a combination of techniques can be used, such as thermal welding of the main edges of the film and the use of glue or tape on the corners or extra edges for extra strength. This can help to better position the film and prevent it from shifting, especially in situations where packaging is handled or transported intensively. In one implementation form, the film is affixed with a label after application to the container to display important product information, brand identification, and other relevant data. The label plays an essential role in communicating information to the consumer, such as the contents of the packaging, the expiration date, the origin of the fruit, and nutritional information. Moreover, the label can serve as a marketing instrument by making the brand logo visible, which contributes to brand recognition and consumer loyalty. The method of applying the label to the film has been carefully selected to maintain the integrity of the packaging and to ensure the readability of the information.Some designs use an acrylate-based adhesive that adheres well to both the film and the plastic of the container, without compromising the freshness or breathability of the film. This adhesive is resistant to moisture and temperature variations, ensuring the label remains securely in place, even when stored under varying conditions.35 The label can be applied either partially or completely over the film, depending on the packaging requirements and the amount of information to be displayed. Covering a portion of the film with a label ensures that the perforations and breathability of the film remain intact, while at the same time presenting the necessary information clearly and visually attractively. In some cases, the label may also offer additional functionality, such as containing a barcode for product tracking or a QR code for access5 to additional product information.In addition, in some cases use is made of thermochromic ink or other technologies that react to temperature changes, causing the label to change color to indicate the freshness or safety of the fruit. This10 can help consumers assess the quality of the fruit, especially during longer storage periods. The application of labels in combination with perforated films not only helps to beautify and inform the packaging, but also offers additional opportunities for interaction with the consumer, which can contribute to the overall product experience.15 In a second aspect, the present invention concerns the use of a combination of a perforated plastic film with at least one label. The plastic film comprises 70 to 80 perforations per m² and the label covers between 30% and 60% of the film. In one design form, one, two, three or more labels are placed over the plastic film20.In one design, perforated plastic film is used to shield cut fruit from the environment outside the packaging, while simultaneously ensuring a controlled exchange of gases and moisture to preserve the freshness of the fruit. The perforations in the film are carefully designed to allow air circulation, which slows down the ripening process and prevents condensation inside the packaging. This contributes to the preservation of the texture, aroma, and taste of the fruit for a longer period. 30 In a presentation form, the fruit is selected from the group of sliced ​​melons, oranges, apples, mangoes, pineapples, pears, bananas, strawberries, grapes, kiwis, peaches, plums, mandarins, lemons, limes, berries, papayas, or combinations thereof. Each type of fruit has specific needs regarding respiration and moisture regulation, and the perforated foil plays a crucial role in this.For strawberries, for example, which are susceptible to mold growth due to excessive humidity, the film can be perforated in such a way that moisture can move without the fruit drying out. For fruit varieties such as apples or pears, which produce ethylene gases that accelerate the ripening process, the film ensures that these gases can escape efficiently, thereby preserving freshness for longer. The perforated film can be further adapted to the specific requirements of different fruit types, so that packaging fruit in various shapes is possible without compromising the quality or appearance of the product. Due to the versatility of the film, it is suitable for a wide range of fruit types, from soft and delicate fruit such as berries, to firmer fruit such as apples and citrus fruits. The use of perforated film is a practical and efficient solution for packaging sliced ​​fruit on a large scale, with benefits for both the producer and the consumer in terms of product quality, shelf life, and convenience.In what follows, the invention is described by means of non-limiting examples that illustrate the invention, and which are not intended or should not be interpreted to limit the scope of the invention. 15 EXAMPLES A package of sliced ​​fruit is covered with a perforated plastic film that is breathable and keeps the fruit fresh for longer. The film is made of polyethylene terephthalate (PET) and has perforations with a diameter between 50µm and 250µm, with a distance between the perforations of 2cm. These perforations ensure controlled gas exchange, which is essential for maintaining the freshness of the fruit by regulating oxygen and carbon dioxide levels and reducing moisture accumulation. 25 In a comparative experiment, a package of 75 grams of sliced ​​mango is covered. with the same film. Packaging 1 is covered with a label, whereby 90% of the film is covered. Packaging 2 is covered with a label, whereby 45% of the film is covered. The label is applied with an acrylate adhesive.30 In packaging1 the film cannot function properly in its breathable role because the perforations are largely blocked by the label. Air circulation is restricted, resulting in an accelerated accumulation of moisture and reduced gas exchange. As a result, the fruit spoils faster because the humidity level35 in the packaging is not properly regulated and the ethylene gases produced by the fruit cannot escape. The packaging bulges as a result of the gases produced by the fermentation of the sugar that is naturally present in fruit. After 2 days in storage, the sliced ​​mangoes begin to wilt in the packaging and mold spots develop, which significantly shortens the shelf life of the fruit. Packaging leaves a significantly larger area of ​​the perforations free, which benefits the breathable function of the film. The perforations ensure that air can circulate well and that the ethylene gases can escape effectively.This keeps the fruit fresh longer, because the moisture balance in the packaging is better maintained and the ripening process is slowed down. After 2 days in storage, mangoes retain their texture and taste, resulting in greater customer satisfaction and less waste.10 BE2024 / 5895.