TY - JOUR
T1 - Thermal characteristics of a water soluble extract obtained from pomegranate skin
T2 - Developing a state diagram for determining stability
AU - Al-Rawahi, Amani
AU - Rahman, Mohammad Shafiur
AU - Waly, Mostafa
AU - Guillemin, Gilles J.
N1 - Funding Information:
This study was funded by His Majesty's Research Trust Fund SR/AGR/FOOD/11/01 . Authors would like to acknowledge the support of the Sultan Qaboos University towards this research in the area of functional foods and health supplements. Special thanks to Dr. Ann Mothershaw for checking the English and clarity of the paper.
PY - 2013/7
Y1 - 2013/7
N2 - A water-soluble extract of pomegranate peel was prepared and freeze-dried to measure its thermal characteristics as a function of moisture and temperature. Moisture contents of the freeze-dried extracts varied from 0.018 to 0.950g/g sample. A state diagram of the extract was developed by measuring the freezing curve, glass transition line and ultimate maximal-freeze-concentration conditions. The freezing point decreased with increasing solids; whereas glass transition decreased as solid levels decreased. The freezing point and glass transition were modelled using Chen's model based on the Clausius-Clapeyron equation, and Gordon-Taylor equation, respectively. The ultimate maximal-freeze-concentration conditions were (Tm')u equal to -32.2°C and (Tg‴)u equal to -33.4°C, and the characteristic solids content, Xs' was 0.52g/g sample (i.e. un-freezable water, Xw'=0.48g/g sample), respectively. Similarly the value of Tg' (i.e. vertical line passing through (Tm')u and crossing the glass transition line) was determined as -76.0°C.
AB - A water-soluble extract of pomegranate peel was prepared and freeze-dried to measure its thermal characteristics as a function of moisture and temperature. Moisture contents of the freeze-dried extracts varied from 0.018 to 0.950g/g sample. A state diagram of the extract was developed by measuring the freezing curve, glass transition line and ultimate maximal-freeze-concentration conditions. The freezing point decreased with increasing solids; whereas glass transition decreased as solid levels decreased. The freezing point and glass transition were modelled using Chen's model based on the Clausius-Clapeyron equation, and Gordon-Taylor equation, respectively. The ultimate maximal-freeze-concentration conditions were (Tm')u equal to -32.2°C and (Tg‴)u equal to -33.4°C, and the characteristic solids content, Xs' was 0.52g/g sample (i.e. un-freezable water, Xw'=0.48g/g sample), respectively. Similarly the value of Tg' (i.e. vertical line passing through (Tm')u and crossing the glass transition line) was determined as -76.0°C.
KW - Freezing point
KW - Glass transition
KW - Maximal-freeze-concentration condition
KW - Phenolic compounds
KW - Stability
KW - Un-freezable water
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U2 - 10.1016/j.indcrop.2013.04.021
DO - 10.1016/j.indcrop.2013.04.021
M3 - Article
AN - SCOPUS:84878537452
SN - 0926-6690
VL - 48
SP - 198
EP - 204
JO - Industrial Crops and Products
JF - Industrial Crops and Products
ER -