Memorial University DAI: Effect of annealing on the molecular structure and physicochemical properties of bread wheat starches varying in amylose content

advanced search

Digital Archives Initiative
Memorial University - Electronic Theses and Dissertations 5

menu off

add document to favorites : add page to favorites : reference url

back to results : previous : next

Search this object:

0 hit(s) :: previous hit : next hit

View:

previous page : next page

Document Description

Title	Effect of annealing on the molecular structure and physicochemical properties of bread wheat starches varying in amylose content
Author	Lan, Haiyan
Description	Thesis (M.Sc.)--Memorial University of Newfoundland, 2008. Biochemistry
Date	2008
Pagination	xii, 266 leaves : ill. (some col.)
Subject	Starch--Analysis; Thermal analysis; Wheat--Analysis
Degree	M.Sc.
Degree Grantor	Memorial University of Newfoundland. Dept. of Biochemistry
Discipline	Biochemistry
Language	Eng
Notes	Bibliography: leaves 204-260.
Abstract	Starch from normal (CDC teal), high amylose (line 11132) and waxy (99WAX27) bread wheat cultivars was isolated and its morphology, composition, structure and properties were studied before and after annealing. Granule diameters, total phosphorus, total amylose, lipid complexed amylose chains, crystallinity, gelatinization temperature range, gelatinization enthalpy, swelling factor (at 90°C), and amylose leaching (at 90°C) ranged from 2-38µm, 0.007-0.058%, 26.9-32.3%, 13.4-18.7%, 28.6-42.8%, 12.7-14.3°C, 11.3-13.3 J/g, 27.6-72.1 and 22.2-26.2%, respectively. Peak viscosity, thermal stability, set-back and susceptibility towards acid hydrolysis followed the order: 99WAX27 >CDC teal >11132, 11132 >CDC teal >99WAX27, CDC teal > 99WAX27 >11132, and 99WAX27 >11132 >CDC teal, respectively. Susceptibility towards α-amylase hydrolysis followed the order: 99WAX 27 > 11132 > CDC teal (<24h) and 11132 >CDC teal >99WAX27 (>24h). The extent of retrogradation measured by spectroscopy and differential scanning calorimetry followed the order: 11132 > CDC teal >99WAX27 and 99WAX27 >CDC teal >11132, respectively. In all starches, concentration of amylase (apparent & total), lipid complexed amylose chains, gelatinization temperature range, swelling factor, amylose leaching, peak viscosity, final viscosity, set-back, light transmission, susceptibility towards α-amylase and acid hydrolysis and the proportion of small (2 to 8 µm) B-type granules decreased on annealing. However, thermal stability and crystallinity increased on annealing, whereas enthalpies of gelatinization and retrogradation and the amylopectin chain length distribution remained unchanged in all starches. Pores and indentations were formed on the granule surfaces of CDC teal and 99WAX27 starches on annealing.
Type	Text
Resource Type	Electronic thesis or dissertation
Format	Image/jpeg; Application/pdf
Source	Paper copy kept in the Centre for Newfoundland Studies, Memorial University Libraries
Local Identifier	a2544027
Rights	The author retains copyright ownership and moral rights in this thesis. Neither the thesis nor substantial extracts from it may be printed or otherwise reproduced without the author's permission.
Collection	Electronic Theses and Dissertations
Scanning Status	Completed
PDF File	(25.04 MB) -- http://collections.mun.ca/PDFs/theses/Lan_Haiyan.pdf
CONTENTdm file name	4811.cpd