Abstract
The effect of drying conditions of the film-forming solution on thickness, moisture content, water vapor permeability, and tensile properties of alginate films were investigated. A long period of constant rate was observed in all conditions and the model proposed by Wang and Singh was able to adjust the drying data. As expected, there was a clear effect of temperature on drying kinetics; that is, increasing the drying temperature decreased the drying time. Considerable glycerol losses were observed when alginate gel was oven dried at temperatures above 40°C. Compared to other drying conditions, films oven dried at 60°C were thinner, had lower moisture content, and were less flexible.
ACKNOWLEDGMENT
The authors acknowledge the State of São Paulo Research Foundation (FAPESP) for financial support (Proc. 2008/52830-9).
Notes
Average (standard deviation) of three experimental determinations. Averages with the same lowercase superscript letter in the same column and with the same capital superscript letter in the same line indicate no significant difference by Tukey's test (p < 0.05).
Average (standard deviation) of three experimental determinations. Averages with the same lowercase superscript letter in the same column and with the same capital superscript letter in the same line indicate no significant difference by Tukey's test (p < 0.05). ND: not detectable.
Average (standard deviation) of three replicates. Averages with the same superscript letter in the same column indicate no significant difference by Tukey's test (p < 0.05).
a Average (standard deviation) of 10 experimental determinations.
b Average (standard deviation) of three experimental determinations.
Averages with the same superscript letter in the same column indicate no significant difference by Tukey's test (p < 0.05).