WO2017220801A1

WO2017220801A1 - Packaging of respiring produce

Info

Publication number: WO2017220801A1
Application number: PCT/EP2017/065590
Authority: WO
Inventors: Bastiaan Rinke Anthony Groeneweg; Paulus Josephus Benedictus VAN DE LOO
Original assignee: 't Groene Loo B.V.
Priority date: 2016-06-23
Filing date: 2017-06-23
Publication date: 2017-12-28
Also published as: NL2017035B1; NL2017035A; EP3475187A1

Abstract

Method for packing respiring produce (2) and packaged whole-sale container (1). The method comprises the following consecutive steps: • - a batch of the produce is put in a whole-sale container; • - the container is individually wrapped in a water vapor permeable film; • - air content between the film and the container is reduced; • - the film is closed.

Description

PACKAGING OF RESPIRING PRODUCE

The present invention relates to a method of packaging re^¬ spiring produce, such as fresh agricultural produce, such as vegetables, mushroom, fruits, herbs, and/or flowers, in par^¬ ticular whole-sale batches of such produce.

To enhance shelf life of fresh respiring produce, such as fruit, vegetables, herbs, mushrooms or flowers, the produce can be packed using so-called modified atmosphere packaging (MAP) technology. The produce are packed in a microperforated film allowing restricted exchange of oxygen, carbon dioxide and other gases between the interior of the package and the ambient atmosphere. This reduces respiration of the fruits, vegetables or flowers. Reducing respiration slows down ripening, and spread of pathogens, inhibit toughening and

undesirable change in color, smell and taste of the produce.

Packaging films used with MAP packaging include micro-perforated transparent films. Such films may have a limited transmission rate for water vapor. Films with a high vapor transmission rate have been developed enabling to control the humidity level as well as the gas composition in the sealed package. Such films are particularly useful for the prolonged storage of respiring produce are sensitive to moisture. These films are commonly referred to as modified atmosphere/modified humidity packaging (MA/MH) films . A bio-degradable example of such a film is disclosed in WO 2016/071922.

After harvesting, fresh produce is transported in containers, such as crates and transported to a distributor or packer. Part of the harvest is re-packed for whole-sale trade, usually in qualities and batch-sizes conform orders of a whole-sale buyer. This whole-sale trade may involve long term storage and international transport. The whole-saler, or packer, will re-pack the produce in retail volumes and supply the retail volumes to consumer shops. MAP films and MA/MH films are typically used for packing retail volumes. Wholesale batches, comprising a plurality of retail volumes, are typically packed in stackable and pallet- izable containers, rather than film bags. In practice, MAP or MA/MH films are used as liners within such wholesale packaging boxes. The liners are bags put in the boxes before filling the boxes with the produce. The liners are then folded to close them. The boxes are stacked on pallets or similar carriers for transport. The liners are put in the boxes by hand which is labor-intensive. Another drawback is that customs officials may need to remove all the liners in case of a pest control treatment .

Occasionally, a pile of palletized wholesale packages is wrapped as a whole by means of a micro-perforated film. This is for instance disclosed in US 4,886,372. This may be useful, e.g., with long-term international transportation of such produce. If international borders are crossed, customs officers may need to check the produce and they may need to unpack the complete pallet.

It is an object of the invention to provide a way of effi^¬ ciently and cost effective packaging of wholesale batches of respiring produce.

The object of the invention is achieved with a method for packing produce, comprising the following consecutive steps:

- a batch of the produce is put in a container;

- the container is wrapped in a vapor permeable film;

- air content between the film and the container is reduced;

- the film is closed, in particular closed to prevent gas exchange bypassing the film.

Such a method can efficiently be carried out, e.g., using conventional flow wrapping machines. Since air is removed from the package, no air is trapped between the film and the con^¬ tainers causing possible air bubbles that might hinder a dense stacking .

Furthermore, a method is disclosed of packaging respiring produce, the method comprising the steps of:

collecting one or more batches of fresh respiring produce ;

- selecting products from one or more of the batches to assemble a whole-sale consignment or shipment;

- packing the whole-sale consignment into a whole-sale container ;

- wrapping the individual whole-sale container in a va^¬ por permeable film and closing the film, e.g., by sealing it, such that gas exchange bypassing the film is avoided.

The wrapped containers can then be palletized on a car^¬ rier, e.g., a pallet for long-distance transport, e.g., to a retailer. In this respect, long-distance transport is

transport in a transport container suitable for transport by a motorized vehicle, in particular a ship, truck or airplane, e.g., a container with a conditioned atmosphere, e.g., a reefer container.

The consignment is, e.g., assembled in accordance with specifications provided by an order from a buyer.

The retailer will typically unpack wrapped the whole-sale consignment and re-pack it in smaller retail portions.

A whole-sale container is a container with sufficient vol^¬ ume to contain a plurality of regular consumer portions, for instance a container with sufficient volume to contain more than 1 kilo of the produce or a container with a volume V > 1,5 liter. The containers can be bags, crates, boxes, bottles or any other suitable types of palletizable containers. Par^¬ ticularly useful are rectangular stackable boxes without protruding parts, such as cardboard boxes. A good vapour exchange is obtained if the water vapor transmission rate (WVTR) is at least about 5 gms/ 24hr/m² at 38° C and 90% relative humidity (RH) , e.g., at least about 50 gms/ 24hr/m² at 38° C and 90% RH, e.g., at least about 200 gms/ 24hr/m² at 38° C and 90%, e.g., about 50 - about 300 gms/

24hr/m² at 38° C and 90% relative humidity (RH) , measured in accordance with ASTM standard F1249-06.

The WVTR is mainly determined by the type of film material used. Good results are for example obtained with films com- prising biodegradable polymers, polyhydroxyalkanoates (PHAs), poly-3-hydroxybutyrate (PHB) , polyhydroxyvalerate (PHV) , poly- hydroxyhexanoate (PHH) , cellulose acetate, nitrocellulose, polylactic acid, polybutylene succinate (PBS), polycaprolac- tone (PCL) , polyanhydrides etc. The film may for example comprise a partly or fully laminated structures, or a single layer substrate, for instance multi-layer paper laminate, pol^¬ ymeric laminate, single layer polymeric films etc. A layer of metallization may also be provided. The film can for example be made by extrusion processes such as blowing, casting or calendaring processes. Examples of particularly suitable films are disclosed in WO 2016/071922.

The film may for example have an oxygen transmission rate (OTR) between 1000 - 4000 CC/24hr/m² at 23° C, measured in ac^¬ cordance with ASTM standard F2622.

The film's transmission rate for oxygen and carbon dioxide is mainly determined by the presence of microperforations in the film. Such microperforations serve to control the oxygen concentration in the package atmosphere and facilitate ex^¬ change of gases through the packaging material, but hinder contamination of the packed material from outside sources. The oxygen concentration should be low enough to slow down aging processes, but at the same time high enough to prevent anaero^¬ bic processes such as bacterial growth. The microperforations in the film may provide a total open area configured to estab^¬ lish the desired oxygen and/or carbon dioxide transmission rate. Openings allow for increasing the transmission rate of a poorly transmitting material, wherein the total open area may be determined by the number and sizes of the microperfora^¬ tions. The film may have a first transmission rate for the first substance and a second transmission rate for the second substance, the open area for the first or second transmission rate should be determined with the first or second transmis- sion rate, respectively, taken into account. The

microperforations may for example have an open area of below 1 mm², e.g., below 0.5 mm², e.g. about 0.25 mm². The microperfo- rations may for example have a diameter of 200 μιη or less.

Laser perforation is an effective manner to provide such microperforations fast, reliable and in desired locations. A suitable laser perforation apparatus is for example disclosed in WO 2006/063609.

Although the containers can be wrapped manually, this step can also be automated, e.g., using suitably sized flow packing or flow wrapping machines. Flow pack machines configured for use with film widths of at least 1000 mm, e.g., at least 1200 mm, e.g., at least 1300 mm can be used, particularly for wrap^¬ ping whole-sale containers. The film can be supplied as a continuous roll or as pre-sized separate sheets. Pre-perfo- rated films can be used, or the film can be perforated with the perforations of the desired size and number. In case of continuous films the film is cut into sheets of a desired length. Containers filled with the respiring produce are sup^¬ plied by a conveyer and pass a folding station where a sheet is folded over the container.

During packing air can be removed for example by suction or by applying a pressure to the folded film by means of a pressure tool, e.g., a cushion, a sponge or a bristle or the like. By applying a suction, e.g., applying a subnormal pres^¬ sure below ambient pressure, air is removed from the film packaging before it is sealed, e.g., by means of a heat seal to such extent that the film can be pressed against the outer walls of the container without formation of air bubbles. The head space in the container remains filled with air. The seal is air tight, so the only gas exchange between the two oppo^¬ site sides of the package film is via the microperforations .

After the film is applied and sealed, the packed contain- ers can be piled on a pallet or a similar carrier. To enable dense stacking whole-sale containers are typically rectangular boxes, e.g., cardboard boxes, having straight walls without projecting edges or other protruding parts. A more stable stack is obtained if the containers are stacked in a staggered manner, e.g., with containers of a layer overlapping at least two containers of a next layer, like brickwork.

The containers on the pallet can be of the same size and shape, or containers of different size and/or shape can be used. Since whole-sale containers for fresh produce typically contain typically have a volume of at least 3 liter.

The containers will typically be cardboard boxes or con^¬ tainers of wood or plastic.

Optionally, the containers can have side wall provided with one or more openings at head space level to allow suffi- cient gas exchange via the packaging film after the containers are stacked on top of one another. The head space is the space in the container between the packed product and the top edges of the container.

The invention will be further explained with reference to the accompanying drawings showing an exemplary embodiment.

Figure 1: shows a whole-sale box;

Figure 2: shows a pallet with whole-sale boxes. Figure 1 shows a whole-sale container 1 containing fresh produce 2, such as fresh fruit products or vegetables. In the shown embodiment, the wholesale container 1 is a stackable rectangular cardboard box with sidewalls having openings 3 above the level of the head space 4 in the box 1. The head space 4 is the empty space within the whole-sale box 1 above the packed produce 2.

The box 1 is wrapped with a vapour permable film 5 having a water vapor transmission rate (WVTR) of more than 5 gms/ 24hr/m² at 38° C and 90% relative humidity (RH) , such as the FlexFresh™ film, available from Perfo Tec, the Netherlands. The film 5 is microperforated, e.g., with perforations having a diameter below 200 μιη in order to provide an oxygen transmission rate (OTR) of at least 1000 CC/24hr/m² at 23° C. The film 5 is wrapped using a flow wrapping or flow packing machine folding the film over all sides of the whole-sale box 1. During wrapping air is removed from the film's enclosure to such extent that the remaining air volume fits within the box's head space 4. As a result, a close and dense stacking of the boxes is not hindered by remaining air bubbles between the film and the outside of the box 1. The air is removed, for ex^¬ ample by suction or by mechanical pressure, e.g., exerted by one or more cushions or bristles.

The edges of the film 5 are sealed, e.g., by hot sealing. The seal 6 is gastight so essentially all gas transmission and vapour transmission takes place via the film 5. In the shown embodiment of Figure 1 the seal 6 extends centrally over the full width of the top surface of the box 1.

Figure 2 shows a pallet 7 carrying a pile or stack 8 of whole-sale boxes 1. Each box 1 is individually wrapped with a film 5 as explained above with reference to Figure 1. Boxes 1A of a layer overlap two boxes IB of a next layer and form a brickwork pattern, stabilizing the stack 8. All boxes 1 are accessible from the outside. With a few cuts a customs officer will be able to cut open all films of the stack 7, for in^¬ stance in case of a pest control treatment.

Claims

1. Method for packing respiring produce, comprising the following consecutive steps:

- a batch of the produce is put in a whole-sale container;

- the container is individually wrapped in a vapor permea- ble film;

- air content between the film and the container is reduced;

- the film is closed.

2. Method according to claim 1 wherein a film is used having a vapor transmission rate (WVTR) of at least 5 gms/ 24hr/m² at 38° C and 90% relative humidity (RH) , e.g., 5 - 300 gms/

24hr/m² at 38° C and 90% relative humidity (RH) .

3. Method according to claim 1 wherein a film is used having microperforations .

4. Method according to claim 3, wherein the film has an oxygen transmission rate (OTR) of at least 1000 CC/24hr/m² at 23° C.

5. Method according to any preceding claim, wherein air is removed by suction.

6. Method according to any preceding claim, wherein the containers are boxes which are stacked on a carrier, such as a pallet .

7. Method according to claim 6, wherein boxes of a layer overlap at least two boxes of a next layer.

8. Method according to claim 6 or 7, wherein boxes are used with at least one sidewall provided with at least one opening at head space level.

9. Method according to any preceding claims, wherein the containers are stackable rectangular boxes with a volume of least 3 liter.

10. Whole-sale container comprising fresh produce, wherein the whole-sale container is wrapped with a microperforated film having a vapor transmission rate (WVTR) of at least 5 gms/ 24hr/m² at 38° C and 90% relative humidity (RH) .

11. Carrier comprising a stack of containers with respiring produce, wherein the containers are packed in accordance with any preceding claim.