STUDIES ON PREPARATION, POPPING AND FUNCTIONAL-PROPERTIES OF BULGUR WHEAT

Wheat was steeped to 36% moisture and agitated for 2 min in sand heate d to 170 degrees C. This dry heat bulgur was comparable to bulgur prep ared by steam treatment. The dry heat bulgur of 14% moisture content w as popped in hot (230 degrees C) sand medium. The expansion ratio of p opped bulgur was 2.1. Some of the functional properties of popped bulg ur flour were compared with native, 48 h malted and roller dried wheat flours. Water absorption index was highest for roller dried followed by popped and malted wheat, whereas water solubility index was highest for malted followed by roller dried and popped wheat. Roller dried wh eat exhibited higher cold paste viscosity (360 BU) than popped (30 BU) wheat. Popped wheat had a peak viscosity of 300 BU. The viscogram of malted wheat was typical of cereal flours when the enzyme activity of malt was inhibited. The gel permeation chromatograms of popped and rol ler dried wheat indicated thermal degradation of starch during popping and roller drying. The in vitro carbohydrate digestibility of popped wheat was higher than roller dried and malted samples. The scanning el ectron microscopic examination of native and popped bulgur revealed th at the endosperm of bulgur wheat was a homogenous mass containing gela tinized starch whereas that of popped bulgur was made up of thin layer s of popped starch with irregular air spaces.