2.5. Vitamin C determination
The concentration of vitamin C in banana was determined by a spectrophotometric method14, 15. Ten grams of
banana was homogenized in about 100 ml of 4% w/w H2C2O4 solution. The mixture was filtered in order to separate
the solid residue from the liquid. The liquid was then diluted to a certain volume with H2C2O4. For the calibration
process, the standard solutions were prepared from 100 μg.ml-1 ascorbic acid solution in a certain volume of 4%
w/w H2C2O4 was added with 1 ml of 50 μg.ml-1 CuSO4.5H2O solution (pH = 6). The absorbance values were
recorded at 249 nm.
2.6. Sensory Analysis
Sensory evaluation was performed by 20 panelists, after seven days of storage at 30+2°C, on samples that had
been dipped in 1; 1.5; 2% (w/w) of chitosan (DD: 70%; 80%) in 0.6% acetic acid or dipped in this solution by using
triethanolamine as emulsifier. Multiple comparison tests with a six point numerical scale performed to distinguish
level of several sensory parameters among chitosan coated samples within the specified DD. The parameters
evaluated were color, aroma, and texture. The following numerical scale was used for scoring these attributes: 1.
very good, 2. good, 3. slightly good, 4. slightly bad, 5. bad and, 6. very bad.
2.7. Statistical Analysis
The results of sensory tests were analysed using non-parametric statistics of Friedman test as a two way analysis.
Multiple comparisons were performed through