Aminoacids as non-traditional plasticizers of maltodextrins fast-dissolving films

Abstract

This study explored the effect of aminoacids as non-traditional plasticizers of maltodextrins fast dissolving films. 5% w/w glycine and proline decreased the glass transition temperature (Tg) of maltodextrins from 102.6±2.0°C to 73.1±1.4°C and 76.1±0.7°C, respectively; meanwhile the binary mixture made with lysine had a Tg value of 83.6±2.2°C. At the same time, all aminoacids increased the ΔCp values. The shift of the thermal data were due to profound effect on the hydrogen bonding as evidenced by ATR-FTIR spectra since the OH stretching and scissoring bands decreased of about 15-26 cm(-1). A linear relationship was found (R(2)=0.9334) between HOH scissoring wavenumbers and Tg values. The addition of glycine and proline resulted effective in reducing the elastic modulus (about 50%) and tensile strength (about three times) and, therefore, can be used to increase the film ductility.

Keywords: ATR-FTIR spectroscopy; DSC; Fast-dissolving films; Maltodextrins; Plasticization; Tensile properties.