Characterization of starch based edible coatings

While market globalization and increasing use of minimally processed foods require increased product shelf life, environmental care constraints induce us to search for natural materials to be used in effective packaging systems. Both these issues can be addressed by using edible coatings based on naturally occurring polymers. The characteristics of basic materials need to be modified in formulated coatings to obtain satisfactory results. As edible coatings must act as a barrier, the correct measurement of transport properties is extremely important in product development and in assessing effectiveness. In the present work, different starch samples were tested to obtain edible films or coatings. After optimizing concentration, composition, dispersion and gelatinization time and temperature, a high amylose starch was selected for preparation of the films. Films obtained by casting were characterized for water and oxygen permeability developing suitable and simple testing methods, finding a water vapour transfer rate of about 32 g m(2) h(-1) and an oxygen transfer rate of 5.6 cm O-3(2) m(2) h(-1). They were also tested for protection from UV radiation by adding food-approved iron oxides.