Water adsorption isotherms of freeze-dried tuna meat

M. Shafiur Rahman, Shyam S. Sablani, Mohammed H. Al-Ruzeiqi, Nejib Guizani

Research output: Contribution to journalArticle

11 Citations (Scopus)

Abstract

Water adsorption isotherms of freeze-dried tuna were measured at 5°C, 22°C, and 50°C using an isopiestic method. Water sorption modeling was carried out using Brunauer-Emmett-Teller (BET), Guggenheim-Anderson-deBoer (GAB), and Norrish equations. The BET equation predicted equilibrium moisture content (EMC) with a mean relative error of 9.6% (0.113 <aw <0.45). The GAB equation predicted EMC with a mean relative error of 9.6% and 12.3% without and with temperature dependence of C and K terms (constants related to heat of sorption of mono- and multilayers), respectively. The Norrish equation predicted the water activity with a mean relative error of 10.6%. Modeling with the BET equation predicted monolayer moisture content (Mo,b) of 4.8% to 6.0% depending upon the temperature ranging from 5°C to 50°C, while the GAB equation predicted monolayer moisture Content (Mo,g) from 3.8% to 8.8% for the same temperature range. Net isosteric heat of sorption, determined using the Clausius-Clapeyron equation, varied from 13.5 to 0.9 kJ/mol when moisture content changed from 4.8% to 33.5% dry basis (d.b).

Original languageEnglish
Pages (from-to)767-772
Number of pages6
JournalTransactions of the American Society of Agricultural Engineers
Volume45
Issue number3
Publication statusPublished - May 2002

    Fingerprint

Keywords

  • BET
  • Fish
  • GAB
  • Norrish models
  • Quality
  • Storage
  • Water activity

ASJC Scopus subject areas

  • Agricultural and Biological Sciences (miscellaneous)

Cite this