Physical aging of glassy normal and waxy rice starches: Effect of aging temperature on glass transition and enthalpy relaxation

Hyun Jung Chung; Seung Taik Lim

doi:10.1016/S0144-8617(03)00077-8

Physical aging of glassy normal and waxy rice starches: Effect of aging temperature on glass transition and enthalpy relaxation

Hyun Jung Chung, Seung Taik Lim

Research output: Contribution to journal › Article › peer-review

44 Citations (Scopus)

Abstract

Effect of physical aging at different temperatures (T_a) on the amorphous transitions of normal and waxy rice starches has been investigated using differential scanning calorimetry (DSC). Glass transition temperature (T_g) increased, but ΔC_p at the T_g decreased, as the difference (T_g - T_a) between T_g and T_a increased, because the molecular mobility was reduced as the aging temperature was farther from T_g. The extent of relaxation was analyzed by determining the limiting relaxation enthalpy (ΔH_∞) at various aging temperatures. The ΔH_∞ versus T_g - T_a revealed the two different roles by kinetic and thermodynamic controls for the relaxation. When T_g - T_a was low (0 ∼ 30°C), ΔH_∞ increased with T_g - T_a, whereas when T_g - T_a was high (above 30°C), it decreased with T_g - T_a. At a constant T_g - T_a, the residual moisture raised ΔH_∞ due to plasticization effect. The effect of aging temperature on the relaxation temperature range was opposite to that on ΔH_∞, and the peak range became narrower as the moisture content increased. The ΔH_∞ and peak temperature range were different between normal and waxy rice starches. The normal rice starch had a higher ΔH_∞ and a narrower peak temperature range than did waxy rice starch.

Original language	English
Pages (from-to)	205-211
Number of pages	7
Journal	Carbohydrate Polymers
Volume	53
Issue number	2
DOIs	https://doi.org/10.1016/S0144-8617(03)00077-8
Publication status	Published - 2003 Aug 1

Bibliographical note

Funding Information:
This research was financially supported by Korea Research Foundation (KRF-2001-041-G00062).

Copyright:
Copyright 2008 Elsevier B.V., All rights reserved.

Keywords

Enthalpy relaxation
Glass transition
Physical aging
Rice starch

ASJC Scopus subject areas

Organic Chemistry
Polymers and Plastics
Materials Chemistry

Access to Document

10.1016/S0144-8617(03)00077-8

Cite this

@article{8683d54766df45acbf76499c36ae74f7,

title = "Physical aging of glassy normal and waxy rice starches: Effect of aging temperature on glass transition and enthalpy relaxation",

abstract = "Effect of physical aging at different temperatures (Ta) on the amorphous transitions of normal and waxy rice starches has been investigated using differential scanning calorimetry (DSC). Glass transition temperature (Tg) increased, but ΔCp at the Tg decreased, as the difference (Tg - Ta) between Tg and Ta increased, because the molecular mobility was reduced as the aging temperature was farther from Tg. The extent of relaxation was analyzed by determining the limiting relaxation enthalpy (ΔH∞) at various aging temperatures. The ΔH∞ versus Tg - Ta revealed the two different roles by kinetic and thermodynamic controls for the relaxation. When Tg - Ta was low (0 ∼ 30°C), ΔH∞ increased with Tg - Ta, whereas when Tg - Ta was high (above 30°C), it decreased with Tg - Ta. At a constant Tg - Ta, the residual moisture raised ΔH∞ due to plasticization effect. The effect of aging temperature on the relaxation temperature range was opposite to that on ΔH∞, and the peak range became narrower as the moisture content increased. The ΔH∞ and peak temperature range were different between normal and waxy rice starches. The normal rice starch had a higher ΔH∞ and a narrower peak temperature range than did waxy rice starch.",

keywords = "Enthalpy relaxation, Glass transition, Physical aging, Rice starch",

author = "Chung, {Hyun Jung} and Lim, {Seung Taik}",

year = "2003",

month = aug,

day = "1",

doi = "10.1016/S0144-8617(03)00077-8",

language = "English",

volume = "53",

pages = "205--211",

journal = "Carbohydrate Polymers",

issn = "0144-8617",

publisher = "Elsevier Ltd",

number = "2",

}

TY - JOUR

T1 - Physical aging of glassy normal and waxy rice starches

T2 - Effect of aging temperature on glass transition and enthalpy relaxation

AU - Chung, Hyun Jung

AU - Lim, Seung Taik

PY - 2003/8/1

Y1 - 2003/8/1

N2 - Effect of physical aging at different temperatures (Ta) on the amorphous transitions of normal and waxy rice starches has been investigated using differential scanning calorimetry (DSC). Glass transition temperature (Tg) increased, but ΔCp at the Tg decreased, as the difference (Tg - Ta) between Tg and Ta increased, because the molecular mobility was reduced as the aging temperature was farther from Tg. The extent of relaxation was analyzed by determining the limiting relaxation enthalpy (ΔH∞) at various aging temperatures. The ΔH∞ versus Tg - Ta revealed the two different roles by kinetic and thermodynamic controls for the relaxation. When Tg - Ta was low (0 ∼ 30°C), ΔH∞ increased with Tg - Ta, whereas when Tg - Ta was high (above 30°C), it decreased with Tg - Ta. At a constant Tg - Ta, the residual moisture raised ΔH∞ due to plasticization effect. The effect of aging temperature on the relaxation temperature range was opposite to that on ΔH∞, and the peak range became narrower as the moisture content increased. The ΔH∞ and peak temperature range were different between normal and waxy rice starches. The normal rice starch had a higher ΔH∞ and a narrower peak temperature range than did waxy rice starch.

AB - Effect of physical aging at different temperatures (Ta) on the amorphous transitions of normal and waxy rice starches has been investigated using differential scanning calorimetry (DSC). Glass transition temperature (Tg) increased, but ΔCp at the Tg decreased, as the difference (Tg - Ta) between Tg and Ta increased, because the molecular mobility was reduced as the aging temperature was farther from Tg. The extent of relaxation was analyzed by determining the limiting relaxation enthalpy (ΔH∞) at various aging temperatures. The ΔH∞ versus Tg - Ta revealed the two different roles by kinetic and thermodynamic controls for the relaxation. When Tg - Ta was low (0 ∼ 30°C), ΔH∞ increased with Tg - Ta, whereas when Tg - Ta was high (above 30°C), it decreased with Tg - Ta. At a constant Tg - Ta, the residual moisture raised ΔH∞ due to plasticization effect. The effect of aging temperature on the relaxation temperature range was opposite to that on ΔH∞, and the peak range became narrower as the moisture content increased. The ΔH∞ and peak temperature range were different between normal and waxy rice starches. The normal rice starch had a higher ΔH∞ and a narrower peak temperature range than did waxy rice starch.

KW - Enthalpy relaxation

KW - Glass transition

KW - Physical aging

KW - Rice starch

UR - http://www.scopus.com/inward/record.url?scp=0037411903&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0037411903&partnerID=8YFLogxK

U2 - 10.1016/S0144-8617(03)00077-8

DO - 10.1016/S0144-8617(03)00077-8

M3 - Article

AN - SCOPUS:0037411903

SN - 0144-8617

VL - 53

SP - 205

EP - 211

JO - Carbohydrate Polymers

JF - Carbohydrate Polymers

IS - 2

ER -

Physical aging of glassy normal and waxy rice starches: Effect of aging temperature on glass transition and enthalpy relaxation

Abstract

Bibliographical note

Keywords

ASJC Scopus subject areas

Access to Document

Other files and links

Fingerprint

Cite this