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Sequential cooling methods and apparatus

The present invention relates to sequential cooling of products, including methods and processes of cooling as well as equipment and installations used to conduct the cooling.

In one embodiment, the present invention relates to cooling manufactured products, including processed food products or other products. The present invention is not necessarily limited to food or edible products, but can include a wide variety of food and non food products.

In other embodiments, the present invention relates generally to harvesting of products that can be used as a food, particularly harvesting produce such as fresh fruit, vegetables or the like. More particularly, the present invention relates to the post harvest treatment and processing of produce and to the storing and handling of fresh produce. Even more particularly, the present invention relates to immediate post harvest cooling and handling of fresh produce, such as fruit, vegetables and the like.

In still further embodiments, the present invention relates to the use of a cooling installation, such as for example a cooling tunnel for cooling fruit and vegetables after harvesting so as to minimise or reduce the chances of spoilage or deterioration of the fruit or vegetables during storage.

In other embodiments, the cooling tunnel is compartmentalized, segregated or sectioned into cells, preferably with adjustable movable barriers between adjacent cells, to provide different areas for cooling the produce to different predetermined temperatures, preferably in sequence or in a prearranged order, in order to prolong the storage of the produce before the onset of spoilage or deterioration of the produce.

The present invention finds particular application as a method of cooling fresh produce in such a manner that the cooling is quicker and more effective, obviating the need to store the fruit after packing for relatively long periods in order to cool the packed produce to a suitable temperature for transporting the produce.

Although the present invention will be described with particular reference to one form of a handling centre or installation having one form of cooling tunnel allowing fresh fruit, such as grapes, to be processed and packed in a cooled environment in a manner which significantly reduces cooling time prior to transit of the fruit, it is to be noted that the scope of the present invention is not limited to the described arrangement, but rather the scope of the present invention is more extensive, so as to include other methods and other apparatus for cooling food materials, to the use of the various methods and apparatus for treating materials other than fruit and vegetables including non edible manufactured goods, and to other aspects of handling materials in an induced environment, such as a cooled environment, in order to reduce or minimise adverse conditions developing in the produce, particularly in or during storage.

Fresh fruit and vegetables, commonly referred to as fresh produce, need to be harvested as a first step in providing the fresh produce to the ultimate consumers. However, as soon as fresh produce is harvested, ie., picked, it commences to deteriorate or degrade, primarily through loss of moisture, which often results in the produce being unacceptable for sale to the ultimate customers at some later date, particularly after short or long term storage. The rate of spoilage of the fresh produce is temperature dependent; the warmer the temperature, the faster the spoilage rate.

Fresh fruit and vegetables are usually harvested during the height of the growing season, which is generally the warmest part of the year. Accordingly, the fresh fruit and vegetables are usually harvested in a hot or at least warm environment. In these conditions, as soon as the fruit is picked, it commences to deteriorate through loss of moisture owing to being exposed to high ambient temperatures. The longer the fresh produce is exposed to high temperature, the greater the extent of deterioration. However, the extent of the deterioration is often not manifest until the produce is in storage or is bought by consumers, much to their disappointment and annoyance.

Although there have been previous attempts to cool the fresh produce as soon as possible or to handle the fresh produce in cool conditions as soon as practical after harvesting, such previously available methods have not been entirely successful for one or more reasons.

One of the disadvantages of currently employed cooling methods is the time it takes to cool the fresh produce and the space needed to store the cooling fruit. Even using forced air for cooling the environment or atmosphere, it can take up to in excess of about 24 hours to cool fruit and vegetables from high ambient temperature to temperatures that allow transportation of the produce to markets. Therefore, the area required within which to locate the produce whilst it is being cooled to a low temperature over the up to 24 hour period is extremely high, particularly during intensive harvest seasons in which there is a high yield of produce, most of which requires cooling simultaneously. Any harvested material which cannot be cooled quickly because of the unavailability of cooled storage space usually cannot be sold, and certainly cannot be sold at a premium price to consumers which results in loss of income to growers, distributors and sells of the produce.

Traditionally, boxes of packed fruit typically at temperatures of between about 25° C. to about 35° C. required about 24 hours of being stored in racks or similar storage assemblies in order for the produce to be chilled to between about 0° C. and 1° C. before the produce could be transported to market since produce is typically transported at this temperature by refrigerated trucks. The cost of providing racking or shelving of the type required is expensive, not only for the capital cost of the shelving, but also the cost of cooling the air required for circulation among the racks and other fittings.

Not only is the physical size of the installation of the equipment necessary to cool a full harvest for up to 24 hours great, but also the capital cost and cost of operating the equipment is extremely high, which detracts further from the profits available to the growers. Thus, there is a need for a relatively cost effective and efficient cooling system which requires less space and/or takes less time than available methods to cool produce to a temperature where it can be further processed, such as for example, transported to market.

Another problem of currently used cooling methods is that forced air is blown over and around the containers of produce so that the cooling air contacts the top and sides of the container only, resulting in uneven cooling of the produce contained within the container. In many instances, the top layer or layers of produce located in the open top containers is cooled excessively, whilst fruit contained within the interior or in the bulk of the container is cooled inadequately. Furthermore, in storage the heat from the relatively warmer produce located internally within the container is radiated to the relatively cooler produce around the edges which results in the produce being on average at a warmer temperature for a longer time than is desirable thereby further promoting spoilage and a short storage life. The unevenness of cooling and the unmeasured subsequent radiation of heat leads to high variability of the produce in terms of quality and shelf life, not only between batches of produce but also leading to high variability within the one container. The variability of produce within the one container detracts significantly from the reputation of the grower, so that it is difficult for the grower to command premium prices unless further processing of the produce occurs, such as for example, by reclassifying the contents of a container into different groups, such as one group having longer shelf life and others having short shelf life. All of this further processing adds to the cost to the grower.

Therefore, there is a need to provide an improved method, system, arrangement and/or apparatus for cooling products, including the post harvest cooling and handling of fresh produce which results in more consistent and reproducible cooling of the products and produce, so that the produce has more uniform storage qualities.

Further, there is a need for a more efficient cooling system which obviates the need to have expensive and extensive racking or shelving to store produce whilst it cools sufficiently for transportation to market.

Accordingly, it is an aim of the present invention to provide a method and apparatus of cooling individual product or produce items so as to provide more consistent storage quality, and also to cool the produce in a shorter time than hithereto was possible.

According to one aspect of the present invention, there is provided a method of cooling a product, particularly a food product or material comprising the steps of:

providing the product in a container;

subjecting the product to a cooling environment in order to cool the product located in the container,

wherein each individual item of product within the container is subjected to a cooling environment so as to more or less substantially uniformly cool the product to reduce or minimise the variability of storage properties or characteristics of the product.

According to another aspect of the present invention, there is provided a method of minimising and/or reducing the extent or deterioration or degradation of a product, particularly a food material comprising:

forming or harvesting the product;