Akademik Veri Yönetim Sistemi
Tezin Türü: Yüksek Lisans
Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Mühendislik Fakültesi, Gıda Mühendisliği Bölümü, Türkiye
Tezin Onay Tarihi: 2009
Öğrenci: NALAN UYSAL
Eş Danışman: SERPİL ŞAHİN, SERVET GÜLÜM ŞÜMNÜ
Özet:The main objective of this study was to optimize the roasting conditions of hazelnuts in microwave-infrared and microwave-convective heating combination ovens by using response surface methodology. It was also aimed to construct regression models for the prediction of quality parameters of hazelnuts as a function of processing conditions. The independent variables were microwave power (10, 30, 50, 70 and 90%), upper-lower infrared power (10, 30, 50, 70 and 90%) and roasting time (2, 3, 4, 5 and 6 min) for microwave-infrared combination roasting. Microwave power (70, 140 and 210W), air temperature (90, 150 and 210°C) and roasting time (5, 15 and 25 min) were the independent variables of microwave-convective heating combination oven. As control, hazelnuts roasted in conventional oven at 150°C for 20 min were used. The quality parameters were L* value, a* value, fracture force and moisture content of the hazelnuts for both microwave assisted ovens. The optimum roasting conditions of microwave-infrared combination oven were determined as 2.5 min of roasting time at 613.8W microwave power, 1800W upper infrared power, and 300W lower infrared power. Hazelnuts roasted at the optimum condition had comparable quality with the conventionally roasted ones. When micro- wave infrared combination oven was used, conventional roasting time of hazelnuts was reduced by 87.5%. Optimum roasting conditions of microwave-convective heating combination oven were 140 W microwave power, 150°C air temperature and 20 min roasting time. High regression coefficients were calculated between the experimental data and predicted values showing that RSM is capable in predicting quality parameters of hazelnuts during microwave assisted roasting.