DEVELOPMENT OF EXTRUDED TAR0 PRODUCTS

Abstract

ABSTRACTA study was made of the effect of protein supplementation on the extrudability of tare flour. The tare flour was prepared from Bun‐long taro corms by washing, peeling, slicing, air drying, and grinding prior to extrusion into rice, noodle, and macaroni. To improve the extrudability and nutritional qualities of these tare products, mung bean flour or soy protein were added to the dough before extrusion. Prepared with dough moisture content of 30% and 40% w/w, and dough temperatures of 21° and 82°C, extruded taro products were measured for their organoleptic (color, surface smoothness, and eating qualities) and objective (color, texture, protein level, and energy value) qualities. Results showed that the addition of 15% mung bean flour to taro flour improved the firmness, of the rice and noodle. Soy protein also improved the texture of taro rice with 30% and 40% dough moisture and macaroni with 30% dough moisture. The addition of either mung bean flour or soy protein improved the smoothness of taro rice only very little. Product color intensity (measured with extracts as the absorbance ratio of 520 nm/422 nm) decreased considerably in taro rice after the addition of soy protein or mung bean flour, but only slightly in taro noodle and macaroni. Hunter color measurements indicated we similar color in all the cooked, extruded taro samples. Protein supplement can be incorporated into the extruded taro samples to make them comparable in protein and energy level to conventional wheat products and rice. It was concluded that taro flour can be extruded successfully into rice, noodle or macaroni by proper adjustment of initial dough temperature and moisture content. Protein enrichment improved to a limited extent the overall quality of extruded tare samples.