Assesment of pore development, oil and moisture distribution in frying

Thesis Type: Postgraduate

Institution Of The Thesis: Orta Doğu Teknik Üniversitesi, Faculty of Engineering, Department of Food Engineering, Turkey

Approval Date: 2015




The main objective of this study was to evaluate the relationship between moisture content, oil uptake, pore development and shrinkage of the potatoes during frying and to investigate the effects of pretreatment on these quality parameters. Moreover, determination of the differences between crust and core region of potatoes during frying was aimed. It was also aimed to correlate Magnetic Resonance imaging (MRI) results with moisture and oil contents of the potatoes. In the first part of this study, pretreatment effects on the quality of the potatoes were evaluated. Pre-drying and pre-coating with hydroxyprophylmethylcellulose was applied to potatoes as a pretreatment and potatoes were fried for 4, 8, 12, 16 and 20 min. Moisture content, oil content, porosity, shrinkage and MR images of the potatoes were evaluated. In the second part of the study, difference between crust and core region of the potatoes were evaluated in terms of moisture and oil content, porosity and pore size distribution. As a result of the study, pretreatments decreased moisture and oil contents but increased shrinkage. Oil content of the crust was found to be higher while moisture content and porosity were lower as compared to core region. Oil content results were found to be correlated with moisture content and shrinkage. According to results of MRI, oil and moisture distribution was observed qualitatively and signal intensity results of the water suppression images were found to be correlated with oil contents of the potatoes quantitatively.