TY - JOUR
T1 - Moisture sorption isotherms, isosteric heat of sorption and glass transition temperature of murtilla (Ugni molinae T.) berry
AU - Ah-Hen, Kong S.
AU - Lemus-Mondaca, Roberto
AU - Mathias-Rettig, Karen A.
AU - Vega-Gálvez, Antonio
AU - López, Jessica
N1 - Publisher Copyright:
© 2014 by De Gruyter 2014.
PY - 2014/12/1
Y1 - 2014/12/1
N2 - Adsorption and desorption isotherms of fresh and dried murtilla (Ugni molinae Turcz) berries were determined at 20, 40 and 60°C using a gravimetric technique. The experimental data obtained were fitted to eight models, namely GAB, BET, Henderson, Caurie, Smith, Oswin, Halsey and Iglesias-Chirife. A non-linear least square regression analysis was used to evaluate the models. The GAB model best fitted the experimental data. Isosteric heat of sorption was determined from the equilibrium sorption data using the Clausius-Clapeyron equation and was found to decrease exponentially with increasing moisture content. The enthalpy-entropy compensation theory applied to the sorption isotherms indicated an enthalpy controlled sorption process. Glass transition temperature of murtilla was determined by differential scanning calorimetry and modelled as a function of moisture content by the Gordon-Taylor equation and as function of water activity by Roos and Khalloufi models, which proved to be excellent tools for predicting glass transition of murtilla.
AB - Adsorption and desorption isotherms of fresh and dried murtilla (Ugni molinae Turcz) berries were determined at 20, 40 and 60°C using a gravimetric technique. The experimental data obtained were fitted to eight models, namely GAB, BET, Henderson, Caurie, Smith, Oswin, Halsey and Iglesias-Chirife. A non-linear least square regression analysis was used to evaluate the models. The GAB model best fitted the experimental data. Isosteric heat of sorption was determined from the equilibrium sorption data using the Clausius-Clapeyron equation and was found to decrease exponentially with increasing moisture content. The enthalpy-entropy compensation theory applied to the sorption isotherms indicated an enthalpy controlled sorption process. Glass transition temperature of murtilla was determined by differential scanning calorimetry and modelled as a function of moisture content by the Gordon-Taylor equation and as function of water activity by Roos and Khalloufi models, which proved to be excellent tools for predicting glass transition of murtilla.
KW - entropy/enthalpy
KW - glass transition
KW - murtilla berries
KW - water sorption models
UR - http://www.scopus.com/inward/record.url?scp=84917672668&partnerID=8YFLogxK
U2 - 10.1515/ijfe-2014-0153
DO - 10.1515/ijfe-2014-0153
M3 - Article
AN - SCOPUS:84917672668
SN - 2194-5764
VL - 10
SP - 583
EP - 594
JO - International Journal of Food Engineering
JF - International Journal of Food Engineering
IS - 4
ER -