| 摘要 |
A flexible, plastic food package is provided having an elongate opening check valve with an air removal port that allows repeated opening and resealing of the package for removal of air and moisture by vacuuming. The vacuum is established by removing air through the air removal port which encloses a compressible foam material that can be repeatedly penetrated by a blunt-tip aspiration needle associated with a vacuum pump. Following closure of the check valve and inducing a vacuum, the foam material will be compressed to seal the package. The closing force of the valve is sufficient to maintain a vacuum in the package, e.g., -90 kPa at a low temperature of e.g., -60 C for a long period of time. The closing force of the valve can be overcome by hand to enable opening of the food package and access to food therein. Loss of vacuum by migration of air into the package can be reestablished by means of the aspiration needle. The compressed foam in the air removal port will seal along the entry area of the needle when it is withdrawn, and enables repeated use for long periods of time and at extremely low temperatures while still retaining the flavor and edibility of the food due a considerable reduction of ice formation on the frozen food.
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