TY - JOUR
T1 - The Impact of Blanching and High-Pressure Pretreatments on Oil Uptake of Fried Potato Slices
AU - Al-Khusaibi, Mohammed K.
AU - Niranjan, Keshavan
N1 - Funding Information:
Acknowledgments The authors thank the Sultan Qaboos University (SQU) for the financial support of this work. They also thank Dr. Hong Wei, School of Systems Engineering, University of Reading for her help using Matlab software for image processing.
PY - 2012/8
Y1 - 2012/8
N2 - The effect of high-pressure (HP) pretreatment on oil uptake of potato slices is examined in this paper. Potato slices were treated either by HP or thermal blanching, or a combination of thermal blanching followed by HP prior to frying. The effect of HP on starch gelatinization and potato microstructure was assessed by differential scanning calorimeter and environmental scanning electron microscope (ESEM), respectively. After treatments, the slices were fried in sunflower oil at 185 °C for a predetermined time. Frying time was either kept constant (4 min) or varied according to the time needed to reach a desired moisture content of ≈2%. The high pressure applied in this study was found not to be sufficient to cause a significant degree of starch gelatinization. Analysis of the ESEM images showed that blanching had a limited effect on cell wall integrity. HP pretreatment was found to increase the oil uptake marginally. When frying for a fixed time, the highest total oil content was found in slices treated at 200 MPa for 5 min. The oil content was found to increase significantly (p<0. 05) to 41. 23 ± 1. 82 compared to 29. 03 ± 0. 21 in the control slices. The same effect of pressure on oil content was found when the time of frying varied. On the other hand, HP pretreatment was found to decrease the frying time required to achieve a given moisture content. Thus, high-pressure pretreatment may be used to reduce the frying time, but not oil uptake.
AB - The effect of high-pressure (HP) pretreatment on oil uptake of potato slices is examined in this paper. Potato slices were treated either by HP or thermal blanching, or a combination of thermal blanching followed by HP prior to frying. The effect of HP on starch gelatinization and potato microstructure was assessed by differential scanning calorimeter and environmental scanning electron microscope (ESEM), respectively. After treatments, the slices were fried in sunflower oil at 185 °C for a predetermined time. Frying time was either kept constant (4 min) or varied according to the time needed to reach a desired moisture content of ≈2%. The high pressure applied in this study was found not to be sufficient to cause a significant degree of starch gelatinization. Analysis of the ESEM images showed that blanching had a limited effect on cell wall integrity. HP pretreatment was found to increase the oil uptake marginally. When frying for a fixed time, the highest total oil content was found in slices treated at 200 MPa for 5 min. The oil content was found to increase significantly (p<0. 05) to 41. 23 ± 1. 82 compared to 29. 03 ± 0. 21 in the control slices. The same effect of pressure on oil content was found when the time of frying varied. On the other hand, HP pretreatment was found to decrease the frying time required to achieve a given moisture content. Thus, high-pressure pretreatment may be used to reduce the frying time, but not oil uptake.
KW - Deep-fat frying
KW - High-pressure processing
KW - Image analysis
KW - Oil uptake
KW - Starch gelatinization
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U2 - 10.1007/s11947-011-0562-2
DO - 10.1007/s11947-011-0562-2
M3 - Article
AN - SCOPUS:84864405551
SN - 1935-5130
VL - 5
SP - 2392
EP - 2400
JO - Food and Bioprocess Technology
JF - Food and Bioprocess Technology
IS - 6
ER -