Method for preserving foodstuffs

Abstract

A method for preserving foodstuffs, in which the foodstuffs are heated in the moist state in a container suitable for transport and storage with ventilation openings. The foodstuffs are heated for a defined period by a microwave, for at least such a time as hot steam forms in the container and exits through the ventilation openings. Gas is injected into the container after the heating process for at least partial compensation of the pressure drop in the container.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application is a continuation application of U.S. application Ser. No. 11 / 883,675 filed Apr. 7, 2008, which is a National Stage application of International Application No. PC / CH2006 / 000063, filed on Feb. 1, 2006, which claims priority of Swiss application number 00219 / 05, filed on Feb. 10, 2005. The complete disclosures of the aforementioned applications are incorporated herein by reference in their entirety.FIELD OF THE INVENTION[0002]The present invention relates to a method for stabilizing foods and in particular pasteurizing foods in which the foods are in a moist state inside a container suitable as a shipping and retail package and having a vent opening are heated by microwaves for a limited period of time but at least long enough so that hot steam forms in the container and escapes through the vent opening.[0003]For further use for shipping and retail, the vent opening of the container must be sealed, even if it is very small...

AI Technical Summary

Benefits of technology

[0005]Injection of the gas may be performed easily and rapidly in only a few seconds and under a pressure of a few bar, e.g., using a cannula. To this end, the cannula may be inserted through the vent opening However, the cannula is preferably used to puncture a wall of the container, and the container is flushed with the gas while expelling vapor through the vent opening It is thermally advantageous if the injection gas is precooled.

[0007]The seal on the puncture hole optionally created in the container wall during injection of the gas can be accomplished easily, e.g., by applying an adhesive patch to the container wall.

[0009]In comparison with an adhesive patch that is released under the influence of heat, however, a valve still has the advantage that it allows outgassing of the foods, for example, during storage, shipping and / or the retail phase. After a conventional pasteurization, the enzymatic activity of the food is usually only weakly pronounced as a cause of the evolution of gas.

[0018]By injection of a gas having a low oxygen content, as explained above, it is possible for the oxygen which is harmful for the stability of the foodstuffs to be removed, at least partially from the container. In addition, this reduction in the oxygen content can be supported by packaging the foodstuffs already under a reduced pressure in the container and / or in a protective gas atmosphere having a low oxygen content.

[0022]For conveyance of the container through the microwave tunnel and through the injection station, a conveyance mechanism is advantageously used. In particular, this may be the same conveyor system. To improve the economic aspect of the method, the containers may be conveyed in several rows side-by-side through the microwave tunnel and / or the injection station.

Problems solved by technology

A gas having little or no oxygen content is also preferred as the injection gas with which, in addition to the steam, the oxygen which is still present in the container but is especially harmful for the stability of the foodstuffs is flushed out of the container.

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