FIELD OF THE INVENTION

This invention relates to anti-fungal packaging for produce, and a method of controlling fungal growth on produce, which reduces decay of produce whilst packaged.

BACKGROUND TO THE INVENTION

Produce such a fruit and vegetables is packaged for distribution, display and sale. The packaging can take many forms. An important aspect of the packaging is that the produce, especially fresh produce, be displayed in the packaging for visual inspection by customers prior to purchase. It is critical for fresh produce to remain fresh and visually appealing for as long as possible.

Many types of fresh produce, such as fruit, is highly susceptible to perishing. This includes perishing from fungal decay. In the case of fruit, including without limitation for example fruit such as grapes, the fruit is susceptible to fungal decay from the growth of fungal pathogens such as Botrytis Cineria. The physical characteristics of fruit, such as high sugar concentration and soft texture, in combination with the conditions to which they are subjected whilst packaged, transported and displayed, such as high humidity and temperatures suitable for fungal growth, render such fruit very vulnerable to fungal growth such as Botrytis Cineria.

Botrytis Cineria is a genus of anamorphic fungi in the family Sclerotiniaceae. Botrytis Cineria (also known as grey mould) belongs to the group hyphomycetes and has about 30 different species. Bunch rot is the most evasive disease of grape clusters in the world. This is caused by Botrytis Cineria, and it can occur anytime during the growing season. Grapes are most likely to be damaged near harvest and in packaging, and the pathogen can overcome a cluster very quickly.

Botrytis Cineria is favoured by cool temperatures (18° to 21 °C) and high relative humidity and may sporulate on dead or dying plant tissue. It can also be severe at higher temperatures. Spots on grape berries appear water-soaked at first, and then are covered by countless mycelia and spores. The optimum temperature for fungal growth is around 24°C, but it can withstand temperatures as low as -1 °C. Temperature therefore plays a less important role than relative air humidity. As long as the relative air humidity is high, Botrytis Cineria can attack in all temperatures.

Conventionally, this problem is combatted with limited success by including perforations in packaging and placing absorbent sheets underneath the fruit. This is aided by the use of sheets impregnated with sodium metabisulphite that emits SO2 gas when it comes in contact with moisture. These are called the SO2 pads, and the SO2 gas inhibits to fungal growth, such as Botrytis Cineria.

The use of these conventional measures requires additional materials, such as the absorbent sheets and the SO2 pads, and additional measures such as perforating (puncturing) the packaging. None of this is ideal.

It is also not desirable to treat the fruit itself with fungicides, since this has the potential of adverse effects on people consuming the fruit, and on the environment.

There are more advanced methods used in preventing fungal growth, such as Botrytis Cineria. This includes the mixing of anti-fungal agents into the material from which packaging films are manufactured. This is a technically complicated and costly process, which would also require at least reconfiguration of the machines used to produce the plastic packaging films.

Once produced, there are also limits on how such films can be used in that the films have to be activated through a separate thermal process before they can be used.

There is a need for a simple and cost effective and efficient anti-fungal packaging for fruit, and a cost effective and efficient method of controlling fungal growth on produce.

OBJECTIVE OF THE INVENTION

It is an objective of the invention to provide anti-fungal packaging for produce and a method of controlling fungal growth on produce which at least partly overcomes the abovementioned problems. SUMMARY OF THE INVENTION

In accordance with the invention there is provided anti-fungal packaging for produce that is susceptible to decay from fungal growth, the anti-fungal packaging comprising a plastics material film with anti-fungal ink printed on at least a side of the film that will operatively be in contact with a space within which the produce that is to be protected against fungal growth is operatively contained, and which space is at least partly closed off from its external environment by the film; and with the anti-fungal ink comprising a water-dissolvable ink into which an anti-fungal agent is mixed at a predeterminable ratio.

There is further provided for the dissolvable ink to comprise a water-based glycol ether-free acrylic emulsion.

There is still further provided for the plastics material film to comprise a polyethylene-based blown film comprising one or more of the polymers from the group of polymers including LDPE, LLDPE, HDPE, MHDPE and mLLDPE (PolE-Map and/or PenFlo).

There is also provided for the produce to comprise fruit, and preferably grapes, for the fungal growth to comprise Botrytis Cineria, and for the anti-fungal ink to be printed in a coating weight determined to provide about 2,4 grams active anti-fungal additive per square meter film per kg of grape mass.

According to a further aspect of the invention there is provided a method controlling fungal growth on produce that is susceptible to decay from fungal growth which comprises printing anti-fungal ink comprising a water-dissolvable ink into which an anti-fungal agent is mixed at a predeterminable ratio onto a side of a plastics material film that will operatively be in contact with a space within which the produce is operatively contained, with the space operatively being at least partly closed off from its external environment by the film.

There is further provided for the anti-fungal ink to be printed on the film by means of a flexographic plate and an anilox roller, in a thickness determined to give a predeterminable coating weight relative to the mass of the produce to be protected.

These and other features of the invention are described in more detail below. DETAILED DESCRIPTION OF THE INVENTION

Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings.

The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.

The use of "including," "comprising," or "having" and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items.

Unless specified or limited otherwise, the terms "mounted", "connected", "engaged" and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings and are thus intended to include direct connections between two members without any other members interposed therebetween and indirect connections between members in which one or more other members are interposed therebetween. Further, "connected" and "engaged" are not restricted to physical or mechanical connections or couplings. Additionally, the words "lower", "upper", "upward", "down" and "downward" designate directions in the drawings to which reference is made.

The terminology includes the words specifically mentioned above, derivatives thereof, and words or similar import. It is noted that, as used in this specification and the appended claims, the singular forms "a," "an," and "the," and any singular use of any word, include plural referents unless expressly and unequivocally limited to one referent.

As used herein, the term “include” and its grammatical variants are intended to be nonlimiting, such that recitation of items in a list is not to the exclusion of other like items that can be substituted or added to the listed items.

The invention is described with reference to controlling fungal growth, such as Botrytis Cineria, in packaged grapes. To control the fungal growth the aim is to either kill or inhibit the formation of the spores on the grape berries and or stems. Packaging for the grapes include a polyethylene-based blown film comprising one or more of the polymers from the group of polymers including LDPE, LLDPE, HDPE, MHDPE and mLLDPE. (PolE-Map and/or PenFlo). A water-based glycol ether-free acrylic emulsion for use in water-based inks for film substrates is used as the dissolvable ink for the film.

The surface of the polyethylene film, that is intended to be in contact with the space within which the grapes are contained, is coated with a dissolvable ink that is mixed with an antifungal additive . The anti-fungal additive is mixed with the acrylic water-based ink at a desired percentage, which is based on the mass of the grapes to be protected in the packaging.

The acrylic water-based ink is applied with a flexographic plate and an anilox roller to the film to give a coating weight relative to the mass of the grapes to be protected.

The grapes are then packaged in the coated anti-fungal film, with the anti-fungal ink coating facing the grapes. This is done in a manner that provides the grapes with a fully enclosed environment that prevents moisture from escaping from the packaging.

This is contrary to conventional wisdom, in that conventional anti-fungal treatments dictates that moisture must be allowed to escape form the packaging to combat anti-fungal growth. Therefore, conventionally absorbent pads are included in the packaging and plastic films are perforated.

The anti-fungal packaging of the invention does not require moisture to be removed.

Instead, water from the humidity in the container condenses on the surface of the film. The water dissolves some of the ink that contains the anti-fungal agent, or dissolves anti-fungal agent from the ink deposit on the film. This dissolution increases the concentration of the anti-fungal agent in the moisture in the container environment, which then condenses and deposits on the spores and on the grapes. This inhibits fungal growth on the grapes.

The grapes can be packed directly into the packaging without cooling. Once packed it will then go into the cold chain transportation.

The anti-fungal agent is mixed with the acrylic water-based ink at the desired percentage based on the mass of the grapes to be protected. It has been established that about 2,4 grams active anti-fungal additive per square meter film per kg of grape mass delivers suitable results.

The ratio will depend on the pack quantity of grapes or other berries. The dosing can be controlled, which makes it possible to use the anti-fungal packaging of the invention, and the method of the invention, for a broad range of packed fruit. It has been established that it is effective from as little as 200 grams of fruit up to about 9 kg of fruit.

It will be appreciated that the embodiment described above is given by way of example only and is not intended to limit the scope of the invention. It is possible to alter aspects of the embodiment without departing from the essence of the invention.

It is envisaged that the packaging and method of the invention could be used to protect all types of fruit that are vulnerable to fungal growth. Also, the application is not limited only to fruit but extends to any produce that is susceptible to fungal growth. The specific dosing will be empirically determined for each type of produce. For example, the dosages for grapes and for strawberries may very well be different.

Despite these differences, the principle of protecting these types of produce remains the same.

Use of the anti-fungal packaging and the method of the invention obviates the need for absorbent pads, perforations, SO2 pads, and complicated film production methods with costly adaptations to equipment.

Instead, conventional printing technology can be used to print anti-fungal agent that is dissolved in a water based acrylic ink that is consumer and environmentally friendly.

Apart from fresh produce such as fruit, it is also envisaged that the invention may also be applied to other consumables such a bread and pastries and liquids or soft prepared foods that are also susceptible to decay from fungal growth, and which are also packaged in films.