Optimization of microwave frying of potato slices

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Tezin Türü: Yüksek Lisans

Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Mühendislik Fakültesi, Gıda Mühendisliği Bölümü, Türkiye

Tezin Onay Tarihi: 2005

Öğrenci: MECİT HALİL ÖZTOP

Eş Danışman: SERPİL ŞAHİN, SERVET GÜLÜM ŞÜMNÜ

Özet:

The main objective of this study is to evaluate the effects of microwave frying process on the quality of potato slices and to optimize the process by using different statistical optimization techniques. Use of microwave frying for food products may be considered as a new way of improving the quality of the fried foods. In the first part of the study, the effects of microwaves on quality of fried potatoes (moisture content, oil content, color and hardness) were studied and the process was optimized by using Taguchi Technique. Microwave power level (400W, 550W and 700W), frying time (2.0, 2.5, 3.0 minutes) and oil type (sunflower, corn and hazelnut oil) were the parameters used in the study. Moisture content of potatoes decreased whereas oil content, hardness and ?E values of the potatoes increased with increasing frying time and microwave power level. The potatoes with the highest oil content were found to be the ones that were fried in the hazelnut oil. The optimum condition was found as frying at 550W microwave power level, for 2.5 minutes in sunflower oil. The potatoes that were fried at the optimum condition were determined to have lower oil contents compared to the ones fried conventionally.In the second part of the study, osmotic dehydration was applied prior to microwave frying process in order to reduce oil uptake and to evaluate the effect of osmotic dehydration with microwaves on quality of fried potatoes. The process was optimized by using both Taguchi Technique and Response Surface Methodology. Microwave power level (400W, 550W and 700W), frying time (1.5, 2.0, 2.5 minutes) and osmotic dehydration time (15, 30, 45 minutes) were the parameters used in the study. Osmotic dehydration treatment was conducted in a salt solution of 20 % (w/w) at 30oC. Moisture content decreased whereas oil content, hardness and ?E value of potatoes increased with increasing