GB2179025A

GB2179025A - Packing horticultural produce

Info

Publication number: GB2179025A
Application number: GB08520358A
Authority: GB
Inventors: Edward Bohill
Original assignee: FLOWER FRANCHISERS
Current assignee: FLOWER FRANCHISERS
Priority date: 1985-08-14
Filing date: 1985-08-14
Publication date: 1987-02-25
Also published as: GB8520358D0

Abstract

A method of preserving a horticultural product, for example fresh fruit and vegetables, against deterioration comprises placing the product in a container of which at least a part is formed from a microporous film, and sealing the container.

Description

SPECIFICATION Horticultural product packaging The present invention is concerned with the packaging of horticultural products.

Products of this type, that is fruit and vegetables of all kinds, are an important part of the diet of most families and the discriminating consumer is increasingly demanding that the product should be fresh and in good condition at the time of purchase. However this requirement in turn requires that the product should have a reasonable shelf life between harvesting and the point of sale. After purchase, the consumer will be dissatisfied if the product deteriorates unduly quickly on his own shelf, so it is again important that the shelf life be good.

Conventional methods of displaying and packing horticultural products often do not meet the desired shelf life requirements and therefore the rate of wastage of soft fruit in particular maybe high. There is a need for an improved method of preserving fresh fruit and vegetables against deterioration. It is an object of the present invention to meet that need.

According to the present invention, an improved method of packaging a horticultural product comprises placing the product in a container of which at least a part is formed from a microporous film, and sealing the container.

The invention is applicable to the packaging of all types of fruit and vegetables and gives, in each case, an extension of the life of the product concerned.

However, it is of particular value for soft fruit and for those vegetables such as cauliflower, broccoli and lettuce which have a relatively short normal shelf life.

Thus, for example, while the invention may be applied to potatoes, carrots, cabbage and sprouts, the normal shelf life of these products is already adequate for many purposes. On the other hand, the benefits are considerable of applying the invention to soft fruit (including strawberries, rasperries and blackcurrants, for example), citrus fruit (in particular oranges, lemons and grapefruit), bananas, tomatoes and deciduous fruit (including apples, pears, peaches, apricots and plums, for example).

The container in which the horticultural product is placed may take many different forms, depending upon the particular product concerned, the manner in which it is desired to display that product, and other functional and aesthetic considerations. The essential requirement is that at least a part of that container should be of microporous film. Fruit and vegetables evolve ethylene during ripening and subsequent decay and it is believed that the invention works by allowing limited outward diffusion of the gaseous contents of the package until the diffusion is inhibited by moisture formation, while at the same time permitting inward diffusion of air to the contents. However, the invention should not be regarded as in any way limited by this theory, which is included in the present description merely to assist understanding.

Thus the container may be a flat sachet or bag or may be of any other convenient shape, for example shaped specifically to accommodate the fruit or vegetables to be contained therein, for example tomatoes. The container may be wholly of microporous film or may have only a part of its area formed therefrom. Thus it may, for example, have a panel of such film let into its structure or a whole face or side of the container may be of microporous film. In one preferred from of the invention, one part of the container is of microporous film and another part, if desired the rest thereof, is of transparent non-porous film through which the contents may be seen.

The foregoing description refers to the container but is is not necessary for the container to be pre-formed.

For example, the container may be formed at the same time as the product is packaged therein. Thus the container may be a flat sheet of microporous film wrapped around the contained products to form a container in situ. Such wrapping may be carried out manually or by machine.

When the products have been placed within the container, the latter is sealed with an air-tight seal. The sealing may be achieved using a suitable heat-sealing device or by means of adhesive tape.

It will be seen that the main steps of the present invention, that is the forming of the container, the placing of the horticultural product therein and the sealing of the container, are each adapted to continuous operation and therefore any one or more of these stages may be carried out on a continuous basis.

As a convenience to the purchaser, a handle may be incorporated in the structure of the container at any stage before, during or after the packing of the product therein. Thus a handle may be formed integral with the container or may be secured thereto, for example by stapling or heat-sealing or other method of adhesion, while the container is being sealed or after sealing.

The container may be printed or over-printed with advertising material or with information regarding the contents, their origin, their date of sealing, the "sell-by" date or any other topic.

The microporous film appears to function by a physical effect and therefore its structure, that is its microporosity, is believed to be more important than its chemical nature, provided always that it is of a material compatible with the contents of the container, that is neither harmful to nor harmed by said contents.

While from this point of view any microporous film, especially of plastics material, may be used, it is particularly preferred to use a microporous extruded polypropylene film. Such a film may be manufactured by incorporating chalk or similar material into its composition before extruding. We have found a particularly suitable microporous film to be a product sold by Van Leer (UK) Limited, in particular a product of that company having a porosity of 25 per cent at one atmosphere pressure.

By using the present invention, it has been found possible to extend substantially the shelf life of a range of horticultural products. It is of interest to note that in some cases the container becomes somewhat inflated in use, thereby giving increased stability to the structure overall and helping to prevent crushing of the contents from without, while still improving the shelf life of the contents against normal deterioration.

The invention will now be further described by means of the following examples, which are included herein by way of illustration of the invention.

Example 1 Several punnets of strawberries were placed, each within a separate sachet comprising a clear rectangular sheet of polypropylene film bonded down three of its sides to a sheet of microporous polypropylene film of 25% porosity (measured at 1 atm.). The open ends of the sachets were then heat-sealed.

An equal number of punnets of strawberries, each of which was covered with a sheet of clear cellulose film retained in place with a rubber band, was used as a control for comparison purposes.

After a test period of 8 days, in which all of the punnets were retained under normal ambient conditions, it was found that none of the fruit in the control punnets was suitable for consumption. Sixty per cent of the strawberries exhibited advanced growth of botrytis mould. By contrast of the strawberries contained in the sachets according to the method of the present invention, sixty per cent were completely sound, thirty per cent showed some signs of brown deterioration of the tissue, and a mere ten per cent showed the beginnings of the formation of botrytis mould. All of the sachets had inflated somewhat and were capable of bearing small loads without damage to the contents.

Example 2 Eight tomatoes, all having firm orange flesh and being in an edible condition, were selected. Four of these tomatoes were placed on a fibre tray and then placed together in a sachet as described in the previous example. The sachet was heat-sealed. The remaining four tomatoes were also placed on a fibre tray and were then shrink-wrapped in clear polypropylene film. All of the tomatoes were then left under ambient conditions for a period of eight days.

At the end of the test period, the shrink-wrapped tomatoes were all found to be in an advanced state of red colouration and softening of the tissue. They were all usable but very soft and more suitable for frying than for eating fresh. By contrast, the four tomatoes in the sachet showed no advanced deterioration. Two of these tomatoes had remained orange-coloured, while two had reddened but were still firm and tasty.

As will be seen, by means of the present invention, horticultural products are preserved in a good condition for longer periods and wastage may be significantly reduced.

Claims

1. A method of packaging a horticultural product, comprising placing the product in a container of which at least a part is formed from a microporous film, and sealing the container.

2. A method as claimed in claim 1, wherein the horticultural product is a soft fruit, a citrus fruit, bananas, tomatoes or a deciduous fruit.

3. A method as claimed in claim 1, wherein the horticultural product is cauliflower, broccoli or lettuce.

4. A method as claimed in any of the preceding claims, wherein the container is a flat sachet or bag.

5. A method as claimed in claim 4, wherein one face or side of said sachet or bag is of microporous film.

6. A method as claimed in any of the preceding claims, wherein the container is partly of microporous film and the rest of the container is of transparent non-porous film.

7. A method as claimed in any of the preceding claims, wherein the container is formed in situ around said horticultural product.

8. A method as claimed in any of the preceding claims, wherein the container is heat-sealed.

9. A method as claimed in any of the preceding claims, carried out on a continuous basis.

10. A method as claimed in any of the preceding claims, wherein a carrying handle is incorporated in the structure of the container.

11. A method as claimed in any of the preceding claims, wherein the microporous film is a microporous extruded polypropylene film.

12. A method as claimed in any of the preceding claims, wherein the microporous film has a porosity of 25 per cent at one atmosphere pressure.

13. A method of packaging a horticultural product, substantially as hereinbefore described with reference to the foregoing Examples.