Influence of hydroxypropylmethylcellulose addition and homogenization conditions on properties and ageing of corn starch based films

[EN] Edible films based on corn starch, hydroxypropyl methylcellulose (HPMC) and their mixtures were prepared by using two different procedures to homogenize the film forming dispersions (rotor-stator and rotor-stator plus microfluidizer). The influence of both HPMC-starch ratio and the homogenization method on the structural, optical, tensile and barrier properties of the films was analysed. The ageing of the films was also studied by characterizing them after 5 weeks' storage. Starch re-crystallization in newly prepared and stored films was analysed by means of X-ray diffraction. HPMC-corn starch films showed phase separation of polymers, which was enhanced when microfluidization was applied to the film forming dispersion. Nevertheless, HPMC addition inhibited starch re-crystallization during storage, giving rise to more flexible films at the end of the period. Water barrier properties of starch films were hardly affected by the addition of HPMC, although oxygen permeability increased due to its poorer oxygen barrier properties.The authors acknowledge the financial support from the Spanish Ministerio de Economia y Competitividad throughout the project AGL2010-20694, co-financed with FEDER funds. A. Jimenez also thanks Conselleria de Educacio de la Comunitat Valenciana for the FPI grant. Author M.J. Fabra thanks the support of Campus de Excelencia Internacional from Universitat Politecnica de Valencia.Jiménez Marco, A.; Fabra Rovira, MJ.; Talens Oliag, P.; Chiralt, A. (2012). Influence of hydroxypropylmethylcellulose addition and homogenization conditions on properties and ageing of corn starch based films. Carbohydrate Polymers. 89(2):676-686. doi:10.1016/j.carbpol.2012.03.07567668689