Natural compounds as light stabilizer for a starch-based biodegradable polymer

The photooxidation behavior of a commercial starch-based biodegradable polymer, i.e., new generation Mater-Bi, loaded with natural stabilizers was investigated in consideration for outdoor agricultural applications. The photooxidation behavior of the biodegradable films was monitored mainly by mechanical tests and spectroscopic analysis. In order to formulate biodegradable films without any synthetic compounds, suitable for outdoor applications and with good photooxidation stability, antioxidants such as alpha-tocopherol and quercetin (Q) were considered. The results obtained using natural compounds were compared with those obtained by using a synthetic antioxidant and a light stabilizer. Among the investigated natural compounds, the flavonoid compound seemed to work better than the antioxidant and the improvement in the photooxidation behavior of the biodegradable film was very similar to that obtained using the synthetic light stabilizer. A flavonoid compound can be considered as an outstanding natural stabilizer to replace synthetic light stabilizers in the formulation of 100% natural compounds based films, suitable for outdoor applications.