State diagram of freeze-dried garlic powder by differential scanning calorimetry and cooling curve methods

M. Shafiur Rahman, Shyam S. Sablani, N. Al-Habsi, S. Al-Maskri, R. Al-Belushi

Research output: Contribution to journalArticle

Abstract

The state diagram of freeze-dried garlic powder was developed using freezing curve, glass transition line, and maximal-freeze-concentration condition. Freezing points of garlic powder were measured by differential scanning calorimetry (DSC) and the cooling curve method, whereas glass transitions were measured by DSC. The freezing curve and glass transition line were modeled using the Clausius-Clapeyron equation, adjusted with unfreezable water, and the Gordon-Taylor model, respectively. Maximal-freeze-concentrated condition was found as Xw′ (characteristic water content) = 0.82 [Xs′ (characteristic solids content) = 0.18] with the characteristic temperature of glass formation being Tg′ (characteristic glass transition) = -38.6°C and Tm′ (characteristic end point of freezing) = -26.0°C. Other characteristic glass transitions Tg″ and Tg‴ equal to -29.3°C and -48.6°C, respectively.

Original languageEnglish
JournalJournal of Food Science
Volume70
Issue number2
Publication statusPublished - Mar 2005

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Keywords

  • Cooling curve
  • Differential scanning calorimetry (DSC)
  • Freezing point
  • Garlic
  • Glass transition
  • Maximal-freeze-concentration condition

ASJC Scopus subject areas

  • Food Science

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