Comparison in glass transition and enthalpy relaxation between native and gelatinized rice starches

Hyun Jung Chung, Eun Jung Lee, Seung Taik Lim

Research output: Contribution to journalArticle

94 Citations (Scopus)

Abstract

Native and gelatinized rice starches were compared in their glass transition and enthalpy relaxation at various water contents using a differential scanning calorimetry (DSC). In a low moisture content range (8-18%), the glass transition temperature (T g) of native starch was higher (up to 20°C) than that of gelatinized starch, and the difference became greater as the moisture content decreased. Heat capacity change (ΔC(p)) at T g became substantially higher by gelatinization. Plasticizing effect of water on the glass transition in the low moisture content range followed the Couchman-Karasz equation. The glass transition temperature (T g′) of native starch with sufficient moisture (40 or 60%) also appeared higher (-6.8 or -6.0°C) than that of gelatinized starch (-10.0 or -7.7°C), but ice-melting occurred in broader temperature range with smaller ΔH when the starch was gelatinized. Upon extended storage up to 14 days at 4°C, the gelatinized starch showed increased T g′ but decreased ice-melting enthalpy due to the water incorporation in recrystallization of starch. Enthalpy relaxation appeared only when the moisture was <20% regardless of gelatinization. The relaxation peak increased in magnitude as the moisture content increased, and appeared as 'T g overshoot' at a moisture content above 12% due to superimposed glass transition, whereas at a moisture content below 12%, it located in a temperature range far below glass transition, showing a 'sub-T g endotherm'.

Original languageEnglish
Pages (from-to)287-298
Number of pages12
JournalCarbohydrate Polymers
Volume48
Issue number3
DOIs
Publication statusPublished - 2002 May 15

Fingerprint

glass transition
rice starch
enthalpy
Starch
Glass
Glass transition
Enthalpy
Moisture
starch
water content
glass transition temperature
gelatinization
Transition Temperature
melting
Ice
Freezing
ice
Water
Melting
Temperature

Keywords

  • Enthalpy relaxation
  • Glass transition
  • Rice starch

ASJC Scopus subject areas

  • Food Science
  • Biochemistry

Cite this

Comparison in glass transition and enthalpy relaxation between native and gelatinized rice starches. / Chung, Hyun Jung; Lee, Eun Jung; Lim, Seung Taik.

In: Carbohydrate Polymers, Vol. 48, No. 3, 15.05.2002, p. 287-298.

Research output: Contribution to journalArticle

@article{c50908d0898b41d681abceab3bda2957,
title = "Comparison in glass transition and enthalpy relaxation between native and gelatinized rice starches",
abstract = "Native and gelatinized rice starches were compared in their glass transition and enthalpy relaxation at various water contents using a differential scanning calorimetry (DSC). In a low moisture content range (8-18{\%}), the glass transition temperature (T g) of native starch was higher (up to 20°C) than that of gelatinized starch, and the difference became greater as the moisture content decreased. Heat capacity change (ΔC(p)) at T g became substantially higher by gelatinization. Plasticizing effect of water on the glass transition in the low moisture content range followed the Couchman-Karasz equation. The glass transition temperature (T g′) of native starch with sufficient moisture (40 or 60{\%}) also appeared higher (-6.8 or -6.0°C) than that of gelatinized starch (-10.0 or -7.7°C), but ice-melting occurred in broader temperature range with smaller ΔH when the starch was gelatinized. Upon extended storage up to 14 days at 4°C, the gelatinized starch showed increased T g′ but decreased ice-melting enthalpy due to the water incorporation in recrystallization of starch. Enthalpy relaxation appeared only when the moisture was <20{\%} regardless of gelatinization. The relaxation peak increased in magnitude as the moisture content increased, and appeared as 'T g overshoot' at a moisture content above 12{\%} due to superimposed glass transition, whereas at a moisture content below 12{\%}, it located in a temperature range far below glass transition, showing a 'sub-T g endotherm'.",
keywords = "Enthalpy relaxation, Glass transition, Rice starch",
author = "Chung, {Hyun Jung} and Lee, {Eun Jung} and Lim, {Seung Taik}",
year = "2002",
month = "5",
day = "15",
doi = "10.1016/S0144-8617(01)00259-4",
language = "English",
volume = "48",
pages = "287--298",
journal = "Carbohydrate Polymers",
issn = "0144-8617",
publisher = "Elsevier Limited",
number = "3",

}

TY - JOUR

T1 - Comparison in glass transition and enthalpy relaxation between native and gelatinized rice starches

AU - Chung, Hyun Jung

AU - Lee, Eun Jung

AU - Lim, Seung Taik

PY - 2002/5/15

Y1 - 2002/5/15

N2 - Native and gelatinized rice starches were compared in their glass transition and enthalpy relaxation at various water contents using a differential scanning calorimetry (DSC). In a low moisture content range (8-18%), the glass transition temperature (T g) of native starch was higher (up to 20°C) than that of gelatinized starch, and the difference became greater as the moisture content decreased. Heat capacity change (ΔC(p)) at T g became substantially higher by gelatinization. Plasticizing effect of water on the glass transition in the low moisture content range followed the Couchman-Karasz equation. The glass transition temperature (T g′) of native starch with sufficient moisture (40 or 60%) also appeared higher (-6.8 or -6.0°C) than that of gelatinized starch (-10.0 or -7.7°C), but ice-melting occurred in broader temperature range with smaller ΔH when the starch was gelatinized. Upon extended storage up to 14 days at 4°C, the gelatinized starch showed increased T g′ but decreased ice-melting enthalpy due to the water incorporation in recrystallization of starch. Enthalpy relaxation appeared only when the moisture was <20% regardless of gelatinization. The relaxation peak increased in magnitude as the moisture content increased, and appeared as 'T g overshoot' at a moisture content above 12% due to superimposed glass transition, whereas at a moisture content below 12%, it located in a temperature range far below glass transition, showing a 'sub-T g endotherm'.

AB - Native and gelatinized rice starches were compared in their glass transition and enthalpy relaxation at various water contents using a differential scanning calorimetry (DSC). In a low moisture content range (8-18%), the glass transition temperature (T g) of native starch was higher (up to 20°C) than that of gelatinized starch, and the difference became greater as the moisture content decreased. Heat capacity change (ΔC(p)) at T g became substantially higher by gelatinization. Plasticizing effect of water on the glass transition in the low moisture content range followed the Couchman-Karasz equation. The glass transition temperature (T g′) of native starch with sufficient moisture (40 or 60%) also appeared higher (-6.8 or -6.0°C) than that of gelatinized starch (-10.0 or -7.7°C), but ice-melting occurred in broader temperature range with smaller ΔH when the starch was gelatinized. Upon extended storage up to 14 days at 4°C, the gelatinized starch showed increased T g′ but decreased ice-melting enthalpy due to the water incorporation in recrystallization of starch. Enthalpy relaxation appeared only when the moisture was <20% regardless of gelatinization. The relaxation peak increased in magnitude as the moisture content increased, and appeared as 'T g overshoot' at a moisture content above 12% due to superimposed glass transition, whereas at a moisture content below 12%, it located in a temperature range far below glass transition, showing a 'sub-T g endotherm'.

KW - Enthalpy relaxation

KW - Glass transition

KW - Rice starch

UR - http://www.scopus.com/inward/record.url?scp=0037093570&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0037093570&partnerID=8YFLogxK

U2 - 10.1016/S0144-8617(01)00259-4

DO - 10.1016/S0144-8617(01)00259-4

M3 - Article

AN - SCOPUS:0037093570

VL - 48

SP - 287

EP - 298

JO - Carbohydrate Polymers

JF - Carbohydrate Polymers

SN - 0144-8617

IS - 3

ER -