Edible films of methyl cellulose, stearic acid and polyethylene glycol, made by the emulsion method, were constructed with varying volume fractions of stearic acid. These films were evaluated for water vapor permeability. There was a significant decrease in the water vapor permeability through these films with increasing stearic acid volume fractions up to 22%. Subsequent increase in the stearic acid volume fraction resulted in an increase in the water vapor permeability. This was attributed to inadequate filling of the void volume within the stearic acid crystallites by methyl cellulose‐polyethylene glycol matrix. Very high water vapor permeability values were obtained for pure stearic acid films. Scanning electron microscopy revealed intercrystallite air passages. an empirical mathematical model adequately expressed the change in permeability of these heterogeneous films up to 22% stearic acid fractions.
|Original language||English (US)|
|Number of pages||10|
|Journal||Journal of Food Processing and Preservation|
|State||Published - Oct 1994|