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Email: packlab@unimi.it
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Bio-based materials


Edible films

Edible films have been widely used for preserving food quality, protecting against detrimental factors such as moisture loss, oxidation, rancidity, flavor loss etc. Many examples are retrievable in the scientific literature dealing with applications of edible films on different food systems. Protein, polysaccharides and lipid have been the most widely exploited macromolecules to produce such materials. Although edible films have shown great benefits when applied as external layer to foods, no many examples can be found on the application of edible films between different components of a same food system. In our lab, starting from a real case, we developed a new coating acting as a physic-chemical barrier against moisture migration between two parts of a same food. In particular, our research conducted on a bakery product called ‘Amaretto’, which basically is an almond-based cookie. Its composition yields a dome-shaped cookie characterized by an external dry-crunchy crust and a moist-soft inner core. As expected, the moisture migration between core and paste negatively affects ‘Amaretto’ shelf-life, which is normally 7-days long. After this time, “Amaretto’ gets totally hard and dry. In order to limit moisture migration, an edible film was developed with our research group. Our results demonstrated that such a layer, to be used on the almond paste during the cookie preparation, acts as a barrier in limiting the moisture transfer between the two domains of the cookie, whose shelf life was so extended up to three weeks.

Section of an ‘Amaretto’ cookie. The blue layer is the edible coating placed between the dry external crust and the soft core. The blue color of the coating is due to the methylene blue, which has been used just to highlight the coating otherwise non visible.


Nanocomposite PLA flexible packages

This research project is focused on the synthesis and characterisation of Polylactic acid (PLA) polymers with improved properties to be used in food packaging.
PLA is one of the most promising polymers deriving from renewable sources, but its use has been quite limited up to now because of its cost (it costs more than twice if compared to PET or PE) and because some of its properties are not good enough for the final use in packaging.
The research project aims at synthesising PLA materials that constitute a step forward if compared to the PLA commercially available, both because of improved properties and because of a lower production cost. To increase mechanical and barrier properties the team will develop PLAs with a complex macromolecular architecture using polyfunctional comonomers and containing mineral nanoparticles: the complex architecture will help in building up mechanical properties, increasing molecular weight, and mineral lamellar nanoparticles will help in giving superior barrier properties to gases.


Starch-based rigid packages

In recent years various attempts have tried to obtain compositions capable of combining excellent biodegradability characteristics with good properties in order to obtain food packaging products and disposable items, which can be dispersed and degraded naturally in the environment. In this project a composition comprising natural polysaccharides, such as starch, plasticizers, proteins, transglutaminase and water, has been found to have optimal workability characteristics for producing rigid, semi-rigid, and rubbery biodegradable items, preferably useful for packaging, and in particular suitable for contact with foods. It is important to have a good blending of all the components by a turbo mixer apparatus. The best technique to produce starch-based trays proved to be the injection moulding after granules production. It has been observed that the presence of proteins, in particular cross-linked proteins by Transglutaminase, is able to improve the mechanical properties and to reduce a little the water sorption of starch-based rigid trays. Further work should be done to increase the water resistance of the products.

Publication: Carcano C. Mascheroni E. Starch-based compositions and related use and obtainment process. Application number WO2008EP50805 20080124, Priority number(s): PT20070103646 20070126; IT2007MI00457 20070307.