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

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 (R2 = 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.