Preparation and characterization N, O- carboxymethyl chitosan and its use as an edible coating for the shelf-life preservation of bell peppers (Capsicum annuum L.)

Date

4-2007

Degree

Bachelor of Science in Chemistry

College

College of Arts and Sciences (CAS)

Adviser/Committee Chair

Veronica C. Sabularse

Abstract

N.O-Carboxymethyl chitosan (NOCC) was synthesized by mercerization and etherification of chitosan. The synthesized NOCC was characterized in terms of physico-chemical analyses and proximate analyses. Results of the analyses showed that chitosan was converted to its carboxymethyl derivative. NOCC was most soluble in NaOH solutions and water. The synthesized NOCC had a degree of substitution (DS), intrinsic viscosity, molecular weight (MW) of 0.47, 15.57, and 0.942 x 106, respectively. The degree of polymerization (DP) of NOCC was 4,321. Coating formulations containing NOCC together with some additives were prepared and used to coat bell peppers to determine the ability of the synthesized product to extend the shelf life of bell pepper. Physical and chemical analyses of the bell pepper fruits stored at ambient temperature were done on a two-day interval. The NOCC coatings were able to retard color change in bell peppers but were not able to act as a barrier to moisture loss. This was indicated by its inability to minimize shriveling, softening and weight loss of bell peppers. Disease severity and incidence in the treated fruits were relatively low considering that disease only appeared on the 12th day of storage. On the other hand, the ability of NOCC coatings to delay fruit ripening was evident from the lower titratable acidity (TA), total soluble solids (TSS), and higher pH of the coated fruits during storage. NOCC was able to retard ripening of bell pepper fruits. The antioxidant activity (AOA) and total phenolic content (TPC) of treated bell pepper fruits were also determined. It was found that the AOA and TPC increased from day 0 to day 15. The NOCC coated fruits were found to have lower AOA and TPC. It was able to delay the rate of the ripening process of bell peppers compared to other treatments. The ability of NOCC to retard ripening as indicated by the delay in changes of some physical and chemical characteristics strengthens its potential as a coating for shelf-life preservation of bell pepper fruits.

Language

English

Location

UPLB Main Library Special Collections Section (USCS)

Call Number

"LG 993.5 2007 C4 /M36"

Document Type

Thesis

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