Rheology of Glucomannan-Xylan Film-forming Solutions In the Process of Manufacturing Biofilms for 
Food Packaging

Kholoud Al-Ajlouni, Paul D. Fleming, and Alexandra Pekarovicova, Western Michigan University

Glucomannan-xylan blend films were prepared and their film-forming solutions ‘rheological properties were tested using Anton Paar Rheometer at 25°C at shear rates 0.1- 100 1/s. The viscoelastic properties were tested under constant shear strain 5% and frequency sweep 0.1-100 rad/s. Nano fibrillated cellulose (NFC) was added to the mixture to improve the strength property of the blend films. The viscosity of the film-forming solution of all samples showed that it is increased when the concentration of the glucomannan is higher and the NFC is added to the formulas. The solutions proved to be shear-thinning, their fluidity was visible at lower frequencies; gel formation was hindered by higher values of glucomannan concentrations in the blends which means longer drying time, but NFC addition contributed to gel formation in all samples.