Plant Material
Cavendish banana of which skin color were more yellow than green and free of visible physical and fungal
infection were purchased from the commercial market. Fresh banana were selected for uniform size, shape, and
color prior to coating.
2.2. Preparation of chitosan edible coating
Several chitosan with various DD was produced in the laboratory scale via deacetylation process of shrimp waste.
Two different DD of chitosans, i.e. 70% and 80% were selected for being used as edible coating of banana. The
chitosan (CH) with various concentrations (1, 1.5, 2% w/w) was prepared by dissolving the corresponding amount
of chitosan in the solution containing 0.6% w/w acetic acid. The mixture was heated to 90°C while stirring until
more or less homogeneous. If TEA emulsifier was included in the solution, TEA of 0.15% w/w was added after
fifteen minutes stirring at 90oC. The solution was then cooled down to a room temperature and stirring was
continued until ten hours in order to achieve emulsion with good stability.
2.3. Sample preparation
Bananas were washed with running water and dried naturally at room temperature. Afterwards, they were dipped
into chitosan coating solution of various concentrations and degree of deacetylation for 1 minute. The coated
samples were stored at room temperature of 30+2°C. All sample preparation was done in duplicates. All samples
were analyzed per day to study the effect of edible coating on the quality of bananas. The qualities of bananas were
observed for several days until they looked overripe.
2.4. Weight loss determination
Weight loss was measured every day and calculated based on the comparison of the weight of the coated sample at
its initial condition and its final condition. The percentage of weight loss was calculated by equation:
(1)
x100%
initial weight