Effects of pregelatinized flour and zein addition on the rice dough rheology and noodle properties

Abstract

The research was conducted to study the use of pregelatinized flour and zein as alternatives to gluten in rice noodles. The pregelatinized rice flour was produced by a drum drying with drum temperatures at 130 °C and 140 °C. High water absorption and water solubility index were observed in pregelatinized flour. Rice flour was substituted with pregelatinized flour at 60, 65, and 70 % (w/w) for the production of noodles. Rice doughs made from composited rice flour and pregelatinized flour could be sheeted, and cut into noodle strands. Doughs made from pregelatinized flour at all substitution levels exhibited elastic behavior. Pregelatinized flour provided water-binding properties and elasticity to the doughs. The highest tensile strength was observed in rice noodles partially substituted with pregelatinized flour, dried at 140 °C, at a 70 % addition level. Zein was added to rice flour and pregelatinized flour at 0.42, 1.47, and 2.52 % (w/w). Zein improved the viscoelastic properties of rice doughs, which exhibited a high storage modulus (G’). The extensibility of rice noodles increased when the addition of zein was increased to 2.5 %, with a 65 % pregelatinized flour substitution. This study provides useful information on the production of rice noodles made from sheeted doughs.