Study of contact angle, wettability and water vapor permeability in carboxymethylcellulose (CMC) based film with murta leaves (Ugni molinae Turcz) extract

Edible films have been extensively studied with the aim to find an adequate formulation that allows improving the food quality and safety. Both wettability and water-barrier properties are two important parameters that must be considered for adequate design of edible coatings. The aim of this work was to measure the contact-angle of film solution based on carboxymethylcellulose (CMC) with murta leave (Ugni molinae Turcz) extract to estimate the wettability on apple and quince skin and measure the water vapor permeability (WVP) of films. The results show that murta leave extract did not affect the contact angle and wettability measured on the fruits surface. However, differences were obtained between apple and quince skin which can be explained because dispersive component of surface tension of quince skin was lower than apple skin. The WVP was not affected by murta leave extract incorporation. This allows concluding that the film properties assayed were not modified by incorporation of murta leave extract ecotype 14-4. (C) 2011 Elsevier Ltd. All rights reserved.