IMPROVEMENTS IN OR RELATING TO COMESTIBLES

The present invention relates to comestibles, in particular fruit and vegetables of the kind having a relatively short shelf life. Inter alia, the invention relates to a non-GM based simple process of increasing the shelf life of such fruit and/or vegetables.

A common problem with many particularly nutritious fruits and vegetables post harvest concerns shrinkage, rotting and wilting. For example, shrunken and/or wilted broccoli or cauliflower is an unwelcome sight familiar to many, particularly on a Sunday lunch-time.

Huge quantities of fruit and vegetables are discarded domestically each week because they have become soft, rotten or have shrunk and/or have wilted - most probably because of a loss of cell wall turgor pressure, resulting from the loss of a substantial quantity of fluid via the cut end(s) of the fruit or vegetable, a phenomenon which is either unrecognised or underestimated by the fruit and vegetable consuming public.

This deterioration in quality is a preliminary step in the "rotting process", which gives rise to many secondary or additional effects some of which are caused by plant pathogens. Rot can also occur when pathogens enter open wounds on fruits and vegetables. One common source of open wounds is when the fruit becomes detached from the stem, leaving exposed soft tissue as a point of entry and quickly available substrate for pathogenic life. Infection spreads rapidly throughout the fruit and quickly moves into adjacent fruits as well accelerating the degradation process.

The present invention provides, at least to some extent, solutions to the problem of short shelf life in vegetables and fruits. In addition the invention provides nutritionally enhanced fruits and/or vegetables the shelf life of which has been extended by the present inventive method, and in particular a snack or desert frozen for direct consumption, absent an intervening thawing step, which is both low calorie and nutritious. Such snacks or deserts are envisaged as a healthy alternative to those presently consumed, particularly in the Western world, which contribute to obesity and morbid obesity in its various increasingly severe designations.

The use of small portion (snack sized) grapes could be a substitute for less healthy processed snacks in the prevention and treatment of obesity. Such portions must be appropriately packaged and may consist of grapes detached from the stem. A challenge however - is to prolong the integrity and freshness of the grape, which currently experiences rapid degradation once detached from the stem. Another challenge is the cost effective removal of the grape from the stem without damaging the integrity of the fruit.

According to the present invention there is provided a method of preventing or reducing desiccation and associated shrinkage of fruits and vegetables, susceptible to desiccation, attached to a stem which is detached from the plant structures supporting the said fruits or vegetables, comprising cauterising or otherwise sealing the cut end of the stem substantially immediately after detachment takes place. This prevents tissue from being exposed post detachment and acting as a point of entry for plant pathogens.

The cauterisation itself may be selected from the group consisting of physical and chemical cauterisation, and the sealing may comprise treating the cut end of the stem with hot liquefied wax which hardens on cooling, or treating the cut end of the stem with a viscous (preferably edible) oil. In a particularly preferred embodiment of the present inventive method, sealing the cut end of the fruit or fruit structure at the time of harvest to prevent the exit of water or entry of pathogens involves using a sealant (preferably a lipophilic material, possibly in the form of an oil or wax as indicated above) or heat to cauterize the tissues at the cutting point wherein the delivery of the sealant or heat to the cut surface is via the cutting tool itself- for example by coating the shearing instrument with the lipophilic material or through use of heat or caustic material (i.e. phosphoric acid) which will cauterize the tissue at the point of cutting.

Having said that, any conventional method to seal the cut end of the fruit or vegetable may also be used, such as dipping the said end into a reservoir of sealant or spraying the sealant on to the end.

As hinted at above, the sealing means may be via other than heat or coating with a lipophilic material and may thus comprise treating the cut end of the stem with an acid or alkali. Phosphoric acid at a suitable concentration may be used for this purpose, although

other, preferably edible, acids, such as ascorbic, acetic and tartaric may also be used likewise at a suitable concentration.

A particularly preferred acid, however, is phosphoric acid.

The skilled man reading this present disclosure will recognise that the inventive method is likely to add costs to the provision of fruit or vegetables produced by it in comparison with inferior prior art harvesting processes. In this respect it is intended that the fruit or vegetable subjected to this method preferably be of premium grade, or otherwise enhanced. In this regard, it is preferred that during the growth phase of the fruit or vegetable it has been treated with a pesticide which, unrelated to the principal mode of action of the pesticide, has coincidentally increased the concentration in the fruit or vegetable of compounds selected from the group consisting of polyphenols, vitamins, etc. This can be achieved by applying to the plant during its growing phase various pesticides, such as a fungicide such as Azoxystrobin, or other strobilurin or other effective fungicide or an insecticide such as thiamethoxam etc.

In the case that the cut end of the fruit or vegetable is sealed with a wax or oil, it is preferred that that contains an antimicrobial agent, which is heat stable in the case of the wax sealant.

Whilst the present inventive method can be applied to virtually any fruit or vegetable, a particularly preferred fruit is a seedless "table" grape and the plant structure supporting it prior to detachment is a vine.

The present invention also includes an oxygen impermeable, nitrogen filled container which contains an isolated fruit or vegetable, the container preferably being in the form of a flexible bag. The bag may be adapted, particularly in terms of size and strength, for use in vending machines. The bag may be coated with a light impenetrable coating, but nevertheless contain a window of transparent material - to enable the consumer to assess the contents whilst substantially protecting it from light induced degeneration. The fruit and/or vegetable contents of the container preferably have been subjected to the present inventive method as disclosed above so that the container comprises a premium grade, shelf-life-extended, food.

The present invention also includes a fruit or vegetable frozen for direct consumption without an intervening thawing step, coated with a vitamin or other nutrient enhancing coating, and or other edible coating which inhibits or prevents the growth of micro- organisms. The fruit or vegetable may be further coated with a coating which enhances the organoleptic experiences of the consumer. Whilst it is intended primarily that the second coating is one which is "healthy" in that, for example, it is low calorie and substantially salt free - other coatings falling outside this definition are not excluded. So preferred coatings are organic acids such as citric, tartaric and ascorbic. However the coating may also be comprised by chocolate or even cheese, in which case stilton, Wensleydale and camembert are particularly preferred examples.

Returning to "healthy" coatings - although not necessarily ones which fulfil the strict criteria as regards organoleptic quality enhancing ones, the coating may comprise omega three and/or omega 6 unsaturated fatty acids, such as eicosapentaenoic and docohexaenoic acids which might be useful in delivering to the consumer a useful quantity of an agent known to assist in the prevention and treatment of human cardiovascular disorders.

Once again, a particularly preferred embodiment of the fruit or vegetable frozen for direct consumption and coated as indicated above is a seedless "table" grape which in addition may have been subjected to the present inventive method.

In addition the present invention includes a process that removes the grape from the stem cost effectively and with minimal damage to the fruit comprising treating the fruit and or vegetable: (i) pre-harvest with agents which increase "shattering"; and/or (ii) post harvest through physical, environmental means. This process facilitates the removal of the fruit for further packaging as indicated above or for use in fresh cut preparations in combinations with other fruits. "Shattering" inducing agents include gibberellins.

For the avoidance of doubt — "shattering" refers to the detachment of fruit or vegetables from the stem. A non-mechanical method of intentionally causing a fruit to be separated from the supporting stem structure in order to facilitate packaging into a desired serving size without the introduction of fruit trauma as a course of the method.