Breathable and polyol based hydrogel food packaging

Abstract

Packaging of fresh fruits and vegetables is an important issue to preserve their shelf-life and quality and to protect them from early spoilage. Polymeric materials are predominantly used for fruit and vegetable packaging where bioplastics are more concerned for practical as well as an environmental friendly protection point of If the packaging materials polyol or biobased polymers, that are able to breath, can help to solve these problems. In this study, the breathability of PVP-CMC based hydrogel food packaging was examined in respect of suitability of the package in the preservation of quality and self-life of "table grapes" by monitoring the changes in the resistances of modified MWCNT sensors. The MWCNT sensors were prepared by polyvinyl alcohol (humidity measurement) and hexamethylenediamine (ethanol vapor measurement) and placed them inside and/or outside of the package for three weeks. The results obtained from the measurements of the PVP-CMC based hydrogel food package were compared with those of a traditional food package. In addition, before and after the packages were investigated by Fourier Transform Infrared Spectroscopy, hermogravimetric Analysis and Atomic Force Microscopy Analysis to confirm the changes in morphology and physico-chemical properties of the packaging materials. It has been noticed that the PVP-CMC package is more breathable compared to traditional one. It has also been observed that during the period of experiment the absorption and diffusion of water vapor occurred only in the case of the hydrogel based PVP-CMC food package, thus the "table grapes" remained as good as fresh after three weeks. No ethanol formation/fermentation process has been started during 3 weeks at room temperature.