BERRY PACKAGING WITH CONTROLLED RESPIRATORY GAS RELEASE AND ITS PACKAGING PROCESS

Abstract

The present invention relates to berry packaging and its packaging process, specifically a Modified Atmosphere Packaging (MAP) based packaging system designed to extend the shelf life of berries without the use of chemical preservatives. The packaging according to the present invention comprises a thermoformed polypropylene plastic container with a thickness of 680–720 µm and a transparent anti-fog casting polypropylene plastic cover sheet with a thickness of 50–65 µm equipped with micro-perforations measuring up to 100 micrometers for controlled release of respiratory gases. The perforated cover sheet has a longitudinal and transverse tensile strength of 30–70 MPa respectively and an elongation of 50–200%, while the plastic container has an elongation at break greater than 500%, so that the packaging is mechanically stable during sealing, storage, and distribution.The invention also includes a process for packaging berries which includes the steps of placing picked and selected berries into a plastic container, removing air from the container, filling a modified gas composition consisting of 3–5% O₂ gas, 3–7% CO₂ gas, and 90–94% N₂ gas, then closing and sealing the container using a porous cover sheet at a temperature of 165–175°C. The process is capable of producing dew-free conditions in less than 12 hours at a storage temperature of 0–4°C.