2.5. Statistical analysis
At least three specimens were tested for each composition and data were subjected to one-way analysis of variance (ANOVA). This analysis was conducted to investigate the effect of plasticizer content (20, 30, 40 or 50 wt% sorbitol) and processing conditions (pH 7 or 10) on the film properties such as barrier properties (contact angle), optical properties (gloss, colour and transparency), and mechanical properties (tensile strength and elongation at break). Tukey’s test was used for multiple comparisons with the level of significance set at P < 0.05. The analysis was carried out using a SPSS computer program (SPSS Statistic 20.0). Data is presented as mean values the standard error of the mean.