Preparation and characterization of carboxylmethyl-starch from carabao mango (Mangifera indica L.) seed starch

Date

4-2010

Degree

Bachelor of Science in Chemistry

College

College of Arts and Sciences (CAS)

Adviser/Committee Chair

Veronica C. Sabularse

Abstract

Starch was isolated from mango (Mangifera indica) seed and modified by carboxymethylation in order to evaluate their physico-chemical and functional properties to suggest its possible use in food preparation. The results showed that mango seed starch (MSS) had an amylose content of 24.93 ± 1.68 and carboxymethyl-starch (CMS) prepared in isopropanol had a DS of 0.12 ± 0.02. CMS had a higher MW and DP (23.99x106 Da and 148,107. respectively) than MSS (6.34x106 Da and 39.141). Scanning electron microscopy (SEM) showed smooth surfaces with negligible deformations in starch granules but a substantial number of damaged starch contamination. CMS granules also showed smooth surfaces but with sonic wrinkling and scarring attributed to the carboxyrnethylation process. Generally. CMS appeared to have better functional properties than MSS. Apparent viscosity revealed that at room temperature (25°C). CMS was more viscous and shear stress resistant than MSS. Peak viscosity, breakdown. setback and consistency were lower for CMS than MSS. Pasting temperature could not be deduced from the data through RVA-4 since it exhibited notable dissolution in cold water, its pasting profile being similar to pregelatinized starch. From gel consistency flow patterns, both MSS and its carboxymethylate formed gels with a soft consistency. life ('MS product exhibited greater freeze-thaw stability. Lower syneresis of CMS paste than that of MSS in repeated freeze-thaw cycles and its higher light transmittance suggested the capacity of carboxymethyl group to impede retrogradation. CMS exhibited better solubility. swelling power and water retention capacity than MSS.

Language

English

Location

UPLB Main Library Special Collections Section (USCS)

Call Number

LG 993.5 2010 A13 G65

Document Type

Thesis

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