Dual modification of Sago starch: effects of sequence and levels of STMP: STPP and propylene oxide

Kong, Si Mun (2009) Dual modification of Sago starch: effects of sequence and levels of STMP: STPP and propylene oxide. Universiti Malaysia Sabah. (Unpublished)

[img]
Preview
Text
ae0000000637.pdf

Download (3MB) | Preview

Abstract

An attempt was carried out by employing a 2x2x3 Factorial Design consisting of thirteen runs (inclusive of native), to study the effects of levels and modification sequence on physicochemical properties of hydroxypropylated (HP) and cross-linked (Cl) sago starches. The physicochemical properties include swelling, solubility, clarity, apparent viscosity, pasting and thermal properties. Somehow, cross-linking exhibited more pronounced effect on most of the responses studied as compared to hydroxypropylation. Swelling, solubility and clarity shared similar trends; reporting that modification sequence and concentration of cross-linking significantly influenced (p>0.05) these attributes; while increased concentrations of PO showed no significant (p>0.05) effect on swelling, solubility and clarity of paste. The coefficient correlation of cross-linking with these attributes were strongly negative (swelling power: r = - 0.905; solubility: r = - 0.878; and clarity: r = - 0.904). Apparently, these attributes affect the other physico-chemical properties. At fixed levels of 5:5, apparent and peak viscosity increased significantly (p<0.05) with increasing PO; due to the increased associative forces within starch granules which enhanced hydration. The correlation between hydration (solubility) and peak viscosity (r = 0.878) were proven to be positively related, hence supporting the above statement. However, at fixed concentration of PO, increasing S:S decreased both peak and apparent viscosity ; due to reinforced bonding between starch granules which subsequently decreased swelling and starch viscosity. Strong negative coefficient correlation were found between peak viscosity and degree of cross-linking (r = - 1.000). As modification sequence was reversed, viscosities of CL -HP starches decreased as compared to HP-CL starches; but only for samples with 0.01% S:S. The impact of reagent levels and modification sequence influenced the setback in a way similar to that of final viscosity but differed distinctly from breakdown. Although effect of levels significantly (p<0.05) influenced these attributes, no distinct trend was found as the PO concentration gradually increased or even when sequence was switched. Nevertheless, increment in S:S volumes significantly (p<0.05) decreased breakdown, while it increased setback and final viscosity of dual-modified starches. In terms of thermal behaViOUrs, sequence and levels of S:S did not have any significant (p<0.05) effect; but increasing amount of PO noticeably decreased (p<0.05) gelatinization transition temperature.

Item Type: Academic Exercise
Uncontrolled Keywords: Sago, Sago starches, Physio-chemical properties, Physio-chemical
Subjects: ?? TP248.13-248.65 ??
Divisions: SCHOOL > School of Food Science and Nutrition
Depositing User: Unnamed user with email storage.bpmlib@ums.edu.my
Date Deposited: 18 Jun 2012 08:55
Last Modified: 23 Oct 2017 04:29
URI: http://eprints.ums.edu.my/id/eprint/4381

Actions (login required)

View Item View Item

Browse Repository
Collection
   Articles
   Book
   Speeches
   Thesis
   UMS News
Search
Quick Search

   Latest Repository

Link to other Malaysia University Institutional Repository

Malaysia University Institutional Repository