Infrared-assisted microwave drying in the production of bread crumbs


Tezin Türü: Yüksek Lisans

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

Tezin Onay Tarihi: 2005

Öğrenci: SUZAN TİREKİ

Danışman: SERVET GÜLÜM ŞÜMNÜ

Özet:

This study is aimed to investigate the possibility of using halogen lamp-microwave combination oven for production of bread crumbs and to determine the drying conditions in this oven to produce bread crumbs with the highest quality. Bread crumb dough was dried from about 40.9% to 8% moisture content by conventional oven, microwave, infrared and infrared-assisted microwave drying. In the experiments 30%, 50% and 70% halogen lamp and/or microwave powers were used. As a control, conventional oven drying at 75°C was used. Conventional drying time was reduced significantly with the usage of infrared, microwave and infrared-assisted microwave drying. Percent reduction in the drying time was found as 96.5-98.6% for microwave, 80.2-94.0% for infrared and 96.8-98.6% for infrared-assisted microwave drying. Contribution of microwave drying was about nine fold of that of infrared drying in infrared-assisted microwave drying. In conventional drying moisture content decayed exponentionally with time whereas in microwave drying it showed a linear decrease. Infrared and infrared-assisted microwave drying fitted the same non-linear model. Total color change values were lower in microwave and higher in infrared drying with respect to the conventional drying. When drying was done by infrared-assisted microwave drying similar color values with the conventionally dried bread crumbs were encountered. Microwave, infrared and infrared-assisted microwave drying methods were effective in increasing water binding capacity. As long as time and energy reduction and high quality were considered, the optimum condition in infrared-assisted microwave drying for production of bread crumbs can be selected as 50% microwave and 30% halogen lamp power.