Search

Edible films are thin layer(s) of bio-based material formed as a part of food to extend their shelf-life. Whey Protein films are proposed to have good mechanical properties and ability to form transparent films. This study was carried out to understand the effects of combining whey protein, pectin and alginate on some physical and mechanical properties of films

Prooxidant additives represent a promising solution to the problem of environmental polymer waste. Its accelerate the photo- and thermo-oxidation of the materials and consequently, going throw a polymer chain cleavage, make the materials more susceptible to biodegradation. The aim of this work was to test the ECM prooxidant additive into a Polypropylene polymer film, usually used in the food packaging field, in order to understand the performance of the resulting material. Multilayer type films (Polymer/Al film/paper) used for biscuit packaging and other film samples by comparison were analysed. Thermal (DTA/TG, DSC), mechanical (stress/strain curves evaluation) and barrier properties to O2 and CO2 gas of film samples where evaluated. Spectroscopic FTIR/ATR analysis was also performed. In comparison a Polylactic acid (PLA) biodegradable polymer was used. Tests were performed before and after food contact. The materials used in the research were supplied from an Italian Industry and are normally used to package biscuits. Films were made in PP, with ECM additives as prooxidant for polymer materials, to make the polymer biodegradable.

Currently one of the main challenges of food industry is to develop novel products with high quality and safety, in order to respond with efficiency to the habit changes of exigent consumers. In this direction, the “ready to use” frozen products are in continues development, because they offer long-term storage of products which usually have a relatively short shelf- life, such as fish, meat and vegetables. The “ready to use” products could be submitted to some pre-treatments prior freezing (e.g. blanching, pre-frying, cooking) drastically reducing their time of preparation at domestic level. Another main objectives of industries is the reduction of environment pollution due to the plastic packaging materials; therefore many study have been done in order to develop innovative recyclable and/or biodegradable materials suitable for food products. The aim of this work was to study the influence of biodegradable/compostable packaging on the stability of frozen pre-fried cauliflower. For this purpose the samples were stored in three different films: polyethylene monolayer (PE), PE with a specific additive, biodegradable/compostable film, at three different temperature -8, -18, -28 °C for several months. The samples were analysed frozen, thawed and after standardized frying (5 min at 170°C). Beyond the qualitative analyses (colour, texture, water content, freezable water content, peroxides, sensory evaluations), the physico-chemical characterisation of the plastic film has been done.

The impacts of chemical treatment and modified atmosphere on enzymatic changes in minimally processed apples were evaluated. Slices of apple cultivars Golden Delicious and Red Delicious were packed in plastic bags with modified atmospheres: 85% N2, 5% O2, 10% CO2 (MA) and 78% N2, 21% O2, 1% other gases (NA). The changes in colour, firmness, polyphenoloxidase activity, total phenols content and concentration of single phenols during storage were measured. It has been found that the effects of storage atmosphere and antioxidant treatment were not as important as the choice of apple cultivar. Red Delicious is a cultivar with high concentration of phenolic compounds and high activity of polyphenoloxidase; therefore it is difficult to limit the very fast enzymatic changes and subsequent discoloration.

This work reports some results of an experimental study on the permeability and thermal behaviour of commercial Polypropylene (PP) film used for fresh-cut potatoes packaging. The permeability of PP material was tested and studied using O2, CO2 and N2 pure gases and different mix of them, normally used for modified atmosphere packaging (MAP) in comparison to Air, in order to understand if it will be possible to extend the shelf life of food product designed for catering field. The temperature influence (from 5 to 40°C) on permeability data, was analyzed before and after 4, 8, 12, 15 and 20 days of food contact, pointing out the dependence between temperature and gas transmission rate (GTR), solubility (S), diffusion coefficient (D) and time lag (tL) parameters. The activation energies of the permeation at the tested different gases were determined. Moreover, the thermal behaviour of packaging was studied by Differential Scanning Calorimetry (DSC) and Thermogravimetric analysis (TG) to well understand the structural stability of the polymer used in the experiments. Moreover, FTIR/ATR spectroscopy analysis was also performed, in order to study the eventual influence of the food contact on the chemical characteristics of the polymer films.

Prooxidant additives represent at the moment a promising solution to the problem of environmental polymer waste. It accelerate the photo- and thermo-oxidation of the materials and consequently, going throw a polymer chain cleavage, render the materials more susceptible to biodegradation. The aim of this work was to test an EVA prooxidant additive into a Oriented Polypropylene polymer film used in the food packaging field, to understand the performance of the resulting material (degradation/stabilization). Barrier properties to O2 and CO2 gas where evaluated. The activation energies (E) of the permeation process were determined with the different gases used in the experiments. Metallised film (polymer/Al) and multilayer type films (Polymer/Al film/paper) were analysed in the experiment. In comparison a Polylactic acid (PLA) biodegradable polymer was used. Tests were performed before and after food contact, for several days, at different temperature (25, 35 and 45°C) at 50% of relative humidity, during a thermo-oxidative degradation and after plasma aging simulation.