Nanocomposite flexible packaging to increase tomatoes shelf life without refrigeration

Abstract

Nanocomposite films based on polypropylene and talc were used to develop food flexible packaging. Two talc samples withdifferent morphologies (micro and macro-crystalline) were employed to formulate nanocomposites with several particleconcentrations (0, 1, 3 and 5% w/w). Films were obtained by blown film extrusion and flexible packages were prepared bythermo-sealing. Nanocomposites demonstrated to have good mechanical, optical and gas barrier properties. Tomatoes werepackaged and stored at 25 °C and 50% relative humidity without refrigeration. Control fruits (unpackaged tomatoes) werestored under the same conditions. Tomatoes were not previously treated for surface cleaning or for minimization of microbiologicalload. Packaged and control tomatoes were evaluated weekly to analyze packaging performance, in terms of fruitpreservation. Tomatoes? integrity was assessed through weight loss and by photographic recording over time. Maximumstorage time was determined by the detection of first signs of tomato rottenness. The weight loss rate associated to dehydrationof packaged tomatoes was significantly lower than control ones. An increment on talc concentration in packages induced aslower decrease in tomato weight. Films containing macro or microcrystalline particles allow to preserve tomato integrityfor 5 months, increasing their commercial shelf life, without refrigeration.