Effects of microwave irradiation on film made of pectin / Nuurul Aeliah Abdullah

The effects of microwave irradiation on pectin film through subjecting the pectin solution to microwave treatment prior to its conversion into a solid film were investigated. The pectin solution was treated by microwave at 80 W for 2, 4, 8, 16, 30 and 50 min. The formed film was then subjected to Fourier transform infra-red spectroscopy, molecular weight and thermogravimetric analysis. Practically, pectin­ pectin interaction via O-H functional groups decreased, while pectin-pectin interaction via C-0 functional groups increased in film with the introduction of microwave during the course of film preparation. In the case of polymer chain length, the molecular weight of pectin in film was found to reduce upon subjecting the pectin solution to microwave irradiation particularly for a prolonged period of time. The thermal stability of pectin film was increased particularly for sample made of pectin solution treated by microwave at 80 W for 16 min. A marked increase in the thermal stability of pectin film was attributed to the interplay between pectin-pectin interaction and pectin molecular weight.