Evaluation on Quality Indices and Retained Tocopherol Contents in the Production of the Rice-Based Cereal by Extrusion

YUAN-HUI LIN 1, CHIA-SHENG YEH 1 AND SHIN LU 2*

2. Department of Food Science, National Chung Hsing University, 250 Kuo-Kuang Rd, 402 Taichung, Taiwan

(Received: March 18, 2002; Accepted: July 5, 2002)

ABSTRACT

   Rice bran is rich in vitamin E, dietary fiber, mineral and fat. In this study, puffed rice ball was made from brown or milled rice flour by using twin-screw extruder. Two feed moisture (15 and 20%) and two screw speed (200 and 250 rpm) were set, and the physicochemical properties and content of a-, b-, ¡-, and d-tocopherols were determined. The data showed that extrudates made from brown rice had a high a and b value in color, expansion ratio, water solubility index, but low in L value, bulk density and water absorption index than that made from milled rice flour. Extrudates made from brown rice flour had the higher content of a- and ¡- tocopherols (4.8 and 5.7 mg/g). Regarding the effects of feed moisture and screw speed of extruder, the data showed that 15% feed moisture in flour and 250 rpm screw speed yielded to a high expansion ratio, high water solubility index, and low bulk density in the final products.