Influence of homogenization conditions on physical properties and antioxidant activity of fully biodegradable pea protein-alpha-tocopherol films

In this study, antioxidant biodegradable films based on pea protein and alpha-tocopherol were successfully developed by solution casting. The effect of both the homogenization conditions (rotor stator and microfluidizer) and the relative humidity (RH) on the microstructure and physical properties (transparency, tensile, oxygen and water vapour barrier properties) of pea protein/alpha-tocopherol-based films was evaluated. The addition of alpha-tocopherol produced minimal changes in the films transparency, while providing them with antioxidant properties and improved water vapour and oxygen barrier properties (up to 30 % in both water vapour and oxygen permeability) when films were at low and intermediate RH. The addition of alpha-tocopherol in microfluidized films gave rise to an increase in their resistance to break and extensibility (up to 27 % in E values) at intermediate and high RH. These results add a new insight into the potential of employing pea protein and alpha-tocopherol in the development of fully biodegradable antioxidant films which are of interest in food packaging The authors acknowledge the financial support from the Spanish Ministerio de Educacion y Ciencia throughout the project AGL2010-20694, co-funded by FEDER. Author M.J.Fabra is a recipient of a Juan de la Cierva contract from the Spanish Ministerio de Economia y Competitividad. Fabra, MJ.; Jiménez, A.; Talens Oliag, P.; Chiralt, A. (2014). Influence of homogenization conditions on physical properties and antioxidant activity of fully biodegradable pea protein-alpha-tocopherol films. Food and Bioprocess Technology. 7(12):3569-3578. https://doi.org/10.1007/s11947-014-1372-0 ASTM (1995). Standard test methods for water vapor transmission of materials. Standards Desingnations: E96-95. In: Annual Book of ASTM Standards (pp. 406-413); American Society for Testing and Materials: Philadelphia, PA. ASTM (2001). Standard test method for tensile properties of thin plastic sheeting. Standard D882. In: Annual book of American Standard Testing Methods (pp 162-170). D882. Philadelphia:ASTM. Bertan, L. C., Tanada-Palmu, P. S., Siani, A. C., & Grosso, C. R. F. (2005). Effect of fatty acids and “Brazilian elemi” on composite films based on gelatin. Food Hydrocolloids, 19(1), 73–82. Byun, Y., Kim, Y. T., & Whiteside, S. (2010). Characterization of an antioxidant polylactic acid (PLA) film prepared with alpha-tocopherol, BHT and polyethylene glycol using film cast extruder. Journal of Food Engineering,