<![CDATA[Postharvest deterioration of red bell pepper is closely associated with water loss, respiration, and microbial activity. Chitosan is a biodegradable, biocompatible polysaccharide with film-forming and antimicrobial properties that can be developed as an edible coating. This study aimed to isolate chitosan from roasted pulut cockle shells (Atrina pectinata) and evaluate its application as an edible coating for red bell pepper (Capsicum annuum L.). Chitosan was obtained through sequential deproteinization, demineralization, depigmentation, and deacetylation. The isolate was characterized by organoleptic properties, yield, moisture and ash contents, solubility, degree of deacetylation, and FTIR spectroscopy. Antibacterial activity against Staphylococcus aureus was evaluated by disk diffusion at chitosan concentrations of 3%, 6%, and 9%. Coating solutions containing 0%, 3%, 6%, and 9% chitosan were applied by dipping, and red bell peppers were evaluated after 8 days of storage. Triplicate data available in the thesis were reanalyzed descriptively and, where appropriate, by one-way ANOVA. The isolated chitosan was a white, odorless fine powder, soluble in 2% acetic acid, with a yield of 63.46%, moisture content of 4.26%, ash content of 3.84%, and a degree of deacetylation of 76.68%. Mean inhibition zones were 20.73 ± 1.45, 22.73 ± 2.75, and 23.83 ± 1.85 mm for 3%, 6%, and 9% chitosan, respectively; the difference among chitosan concentrations was not statistically significant (one-way ANOVA, p=0.260). After 8 days, weight loss was 19.20 ± 4.98% in the uncoated control and 5.59 ± 2.33% in the 9% chitosan group (overall ANOVA, p=0.008). The 9% coating group had a pH of 6.28 ± 0.15 and vitamin C content of 463.47 ± 56.58 mg/100 g. These findings support the potential of shell-derived chitosan as a postharvest coating, while several source-data units require verification before final publication.]]>
