The eff ect of adding a hydrocolloid on the structural, mechanical and barrier properties of zein-based blend fi lms is evaluated.Zein-oleic acid blend fi lm with added xanthan gum (Z-OA-XG) showed higher water solubility (13.09 %) and opacity (8.49AU/mm) than zein-oleic acid (Z-OA) fi lm (10.80 % and 5.19 AU/mm, respectively).Furthermore, Z-OA fi lm had greater fl exibility with lower Young's Modulus (YM=5.02MPa) and higher elongation at break (η=10.62%); nonetheless, it was less resistant to tension (tensile strength σ=8.5 MPa) than Z-OA-XG fi lm, which showed YM, η and σ of 6.38 MPa, 6.66 % and 10.485 MPa, respectively.Both fi lms had glossy and homogeneous structure with comparable water vapour and oxygen barrier properties around 4.39•10 -11 and 1.82•10 -13 g/(Pa•s•m), respectively.Based on that, xanthan gum structure infl uenced mainly mechanical and light barrier properties of zein-oleic acid blend fi lms.