Preparation of chitinous films from shrimp shells and their use as semipermeable coatings for the shell-life extension of mangoes

Date

6-1996

Degree

Bachelor of Science in Chemistry

College

College of Arts and Sciences (CAS)

Adviser/Committee Chair

Milagros M. Peralta

Co-adviser

Veronica C. Sabularse

Abstract

Chitin was isolated by the sequential demineralization and deproteinization of shrimp shells, and was converted to chitosan and chitin acetate. The deacetylation of chitin to chitosan was carried out using the conventional method employing an aqueous solvent system. The preparation of chitin acetate involved acetylation of chitin with acetic anhydride in the presence of perchloric acid. The resulting chitin, chitosan and chitin acetate were characterized by solubility, viscosity, relative % acetyl content and IR analysis. Various chitosan-based formulations (chitosan, chitosan with emulsifier, commercial chitosan, chitosan-chitin acetate blend) were prepared and evaluated as coatings to extend the shelf-life of mangoes stored at 25°C. Color index, % weight loss, firmness, pH, total titratable acidity (% malic acid) and total soluble solids of coated mature green mangoes were determined and compared with untreated mangoes. Using these parameters, treatments using 1 % pure chitosan and 1 % chitosan-chitin acetate blend were shown to significantly (a=0.05) retard the ripening of mangoes relative to the control up to 14 days of storage without causing fermentation. Increasing the concentration of the polymers used for coating the fruits did not significantly result in further extension of shelf life and eventually caused fermentation of the fruits on the 14th day of storage.

Language

English

Location

UPLB Main Library Special Collections Section (USCS)

Call Number

LG 993.5 1996 C4 L67

Document Type

Thesis

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