Packaging systems for the control of relative humidity of fresh fruits, vegetables and flowers with simultaneous regulation of carbon dioxide and oxygen

Abstract

A water permeable sealed container for preservation of produce such as fruit, vegetables and flowers made out of three layer laminate corrugated to form, further three to five layer construct. The layers also include a layer of Kraft paper fluting and layer of polymer which is enclosed between two layers of Kraft paper. The container has a lid, which absorbs water vapor and transmits water vapor from the interior of the container to the exterior through micro perforations. The container can also regulate relative humidity within a range of 75% to 85% for some foods by removing moisture from the food generated from respiration and suppressing product decay due to microorganisms. The laminate may be die cut to be formed into a range of box designs for vertical profiles that provide ventilation spaces between containers in a vertical stack and to provide airflow channels within a stack.

Description

FIELD OF THE INVENTION[0001]This invention relates to a novel process and storage container for the modified atmosphere preservation of fresh fruits, vegetables and / or flowers using preferential relative humidity levels. More particularly the invention pertains to the preserving of the food integrity and food safety in a sealed container which permits the exchange of oxygen carbon dioxide and water vapour to maintain high levels of carbon dioxide, low levels of oxygen and intermediate levels of relative humidity for optimum preservation of foods at refrigerated temperatures for extended storage periods.BACKGROUND OF THE INVENTION[0002]Consumers have come to expect the availability of a wide range for fresh, ripe fruits, vegetables and flowers year round. While most if not all of these commodities are available year round from either the southern or northern hemispheres, they are often not available due to the high cost of air-freight or the produce is picked immature to provide the ...

AI Technical Summary

Benefits of technology

[0046]The container top and bottom materials can to maintain internal humidity in the range of 75% RH to 90% RH by the use of polyamide materials and thickness of construction.

Problems solved by technology

While most if not all of these commodities are available year round from either the southern or northern hemispheres, they are often not available due to the high cost of air-freight or the produce is picked immature to provide the necessary storage life required for transport and distribution but does not achieve the full ripeness of a premium product.

In addition, fruit and vegetables picked immature are often more susceptible to mold, yeast and bacterial diseases that fully ripened fruit and vegetables.

While this application has a short term benefit, respiration of the product generates moisture which develops a saturated environment leading to the growth of bacteria, yeast and molds which affect product quality and food safety.

In addition, excessively high moisture levels lead to softening and necrosis of the product resulting in the rapid deterioration of quality.

While these laminates are constructed of two layers of kraft paper with an internal layer of low, medium, or high density polyethylene or other plastic material, the laminates do not have a function other than maintaining the strength of the formed box in water saturated environments.

The laminates created in these inventions did not have water vapor exchange capabilities, and the resultant high relative humidity created within the box resulted in condensation and accelerated microbial growth due to yeasts, molds and fungi and product quality loss due to condensation on the produce.

Although the nylon materials could absorb moisture from the interior of the bag, the films were barriers to the transmission of oxygen and carbon dioxide through the films.

The modified atmospheres created by this method were limited to combinations where the oxygen and carbon dioxide contents totalled 20%.

Additional limitations of the related art will become apparent to those of skill in the art upon the description of the specifications and study of the designs noted in the figures.

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