High water vapor permeability ethylene-vinyl acetate copolymer composite for fresh holy basil (Ocimum sanctum L.) Packaging

Abstract

Fresh fruits and vegetables still respire, which causes large amount of water vapor inside the package. This results in the growth of fungal and bacterial pathogens and defection in the external appearance. To solve this problem, the packaging film with an appropriate value of gas permeability that matches the respiration rate of fresh fruits and vegetable products will be used. In this study, we produced EVA copolymer composite packaging films by melt blending EVA copolymer with diatomite and sorbitan monostearate additives and adjusted gas permeability which includes water vapor transmission rate (WVTR) and oxygen transmission rate (OTR) to be in the range of 73.88 - 87.60 g/m2 ·day, and 3,662.47 - 11,342.80 cc/m2·day, respectively. The packaging films had tensile strength in the range of 15.94 – 24.77 MPa and water contact angle in the range of 9.0° - 87.7°. To test the performance of the packaging films, fresh holy basil was packed in a pouch made from selected EVA copolymer composite packaging films (EVADSM) that had a suitable rate of permeation of water vapor and oxygen gas to extend the shelf life of fresh holy basil or commercial perforated polypropylene film. The pouches were kept at 10±0.5 °C for 3 weeks. The packaging test results show that, at similar storage time, fresh holy basil packed in a EVA copolymer composite pouch had lower weight loss and weight of deteriorated basil compared with those kept in a commercial perforated polypropylene pouch. At storage temperature of 10 °C, the commercial perforated polypropylene can prolong the shelf life of holy basil at a satisfactory quality for 6 days and the selected EVA copolymer composite pouch (EVADSM) can prolong shelf life of holy basil at a satisfactory quality for 14 days