Enzymatic Hydrolysis Of Native Granular And Modified Starch Below Gelatinization Temperature

The effects of mild heat treatment, cross-linking and annealing towards the susceptibility of granular starch to enzymatic hydrolysis at sub-gelatinization temperature (35ºC) were investigated. Mild heat-treatment was carried out at 60ºC for 30 minutes. Cross-linking was performed by re-acting th...

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Main Author: Yussof, Nor Shariffa
Format: Thesis
Language:English
Published: 2010
Subjects:
Online Access:http://eprints.usm.my/41937/
http://eprints.usm.my/41937/1/Nor_Shariffa_Yussof_HJ.pdf
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author Yussof, Nor Shariffa
author_facet Yussof, Nor Shariffa
author_sort Yussof, Nor Shariffa
building USM Institutional Repository
collection Online Access
description The effects of mild heat treatment, cross-linking and annealing towards the susceptibility of granular starch to enzymatic hydrolysis at sub-gelatinization temperature (35ºC) were investigated. Mild heat-treatment was carried out at 60ºC for 30 minutes. Cross-linking was performed by re-acting the starches with 1% epichlorohydrin (ECH), while for annealing the starches were annealed at 50ºC for 72 hours. Tapioca and sweet potato starches were subjected to enzymatic hydrolysis with a mixture of fungal α-amylase and glucoamylase at 35°C for 24 hours. The dextrose equivalent (DE) value of heat-treated starch increased significantly compared to native starch i.e. 36% to 50% and 27% to 34% for tapioca and sweet potato starch, respectively. The DE of cross-linked tapioca starch decreased significantly from 36% to 28%. Both annealed tapioca and sweet potato starches were hydrolyzed to a greater degree compared to native starch. Scanning Electron Microscopy (SEM) examination on hydrolyzed starches showed that enzymatic erosion occurred mainly at the surface of starch granules. Hydrolyzed heat-treated starch exhibited rougher surface and porous granules compared to native starch. SEM micrograph revealed that hydrolyzed cross-linked starches had less porous granules as compared to their native counterparts. Both hydrolyzed annealed starches had more porous granules and rougher surface as compared to native starch due to enzymatic erosion.
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format Thesis
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institution Universiti Sains Malaysia
institution_category Local University
language English
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publishDate 2010
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spelling usm-419372019-04-12T05:26:55Z http://eprints.usm.my/41937/ Enzymatic Hydrolysis Of Native Granular And Modified Starch Below Gelatinization Temperature Yussof, Nor Shariffa T1-995 Technology(General) The effects of mild heat treatment, cross-linking and annealing towards the susceptibility of granular starch to enzymatic hydrolysis at sub-gelatinization temperature (35ºC) were investigated. Mild heat-treatment was carried out at 60ºC for 30 minutes. Cross-linking was performed by re-acting the starches with 1% epichlorohydrin (ECH), while for annealing the starches were annealed at 50ºC for 72 hours. Tapioca and sweet potato starches were subjected to enzymatic hydrolysis with a mixture of fungal α-amylase and glucoamylase at 35°C for 24 hours. The dextrose equivalent (DE) value of heat-treated starch increased significantly compared to native starch i.e. 36% to 50% and 27% to 34% for tapioca and sweet potato starch, respectively. The DE of cross-linked tapioca starch decreased significantly from 36% to 28%. Both annealed tapioca and sweet potato starches were hydrolyzed to a greater degree compared to native starch. Scanning Electron Microscopy (SEM) examination on hydrolyzed starches showed that enzymatic erosion occurred mainly at the surface of starch granules. Hydrolyzed heat-treated starch exhibited rougher surface and porous granules compared to native starch. SEM micrograph revealed that hydrolyzed cross-linked starches had less porous granules as compared to their native counterparts. Both hydrolyzed annealed starches had more porous granules and rougher surface as compared to native starch due to enzymatic erosion. 2010-04 Thesis NonPeerReviewed application/pdf en http://eprints.usm.my/41937/1/Nor_Shariffa_Yussof_HJ.pdf Yussof, Nor Shariffa (2010) Enzymatic Hydrolysis Of Native Granular And Modified Starch Below Gelatinization Temperature. Masters thesis, Universiti Sains Malaysia.
spellingShingle T1-995 Technology(General)
Yussof, Nor Shariffa
Enzymatic Hydrolysis Of Native Granular And Modified Starch Below Gelatinization Temperature
title Enzymatic Hydrolysis Of Native Granular And Modified Starch Below Gelatinization Temperature
title_full Enzymatic Hydrolysis Of Native Granular And Modified Starch Below Gelatinization Temperature
title_fullStr Enzymatic Hydrolysis Of Native Granular And Modified Starch Below Gelatinization Temperature
title_full_unstemmed Enzymatic Hydrolysis Of Native Granular And Modified Starch Below Gelatinization Temperature
title_short Enzymatic Hydrolysis Of Native Granular And Modified Starch Below Gelatinization Temperature
title_sort enzymatic hydrolysis of native granular and modified starch below gelatinization temperature
topic T1-995 Technology(General)
url http://eprints.usm.my/41937/
http://eprints.usm.my/41937/1/Nor_Shariffa_Yussof_HJ.pdf