PHYSICOCHEMICAL PROPERTIES OF AUSTRALIAN FLOURS INFLUENCING THE TEXTURE OF YELLOW ALKALINE NOODLES

Flour properties of 25 Australian wheat cultivars were examined for th eir relationship to alkaline noodle quality. Rapid Visco Analyzer (RVA ) analyses of flours showed that RVA breakdown and final viscosity det ermined in both water and dilute sodium carbonate were significantly r elated to the alkaline noodle firmness, elasticity, and surface smooth ness. Flour swelling volume (FSV) of flours was negatively correlated with alkaline noodle firmness and elasticity, and positively correlate d with surface smoothness of cooked noodles. Use of a dilute sodium ca rbonate solution led to overall increases in both paste viscosity and FSV. High FSV and low RVA final viscosity values were associated with both the softest noodles and with cultivars containing a null allele f or granule-bound starch synthase on chromosome 4A. Flour protein conte nt and SDS sedimentation volumes were significantly related to noodle texture. The relationship between protein content and noodle firmness was dependent on the Null4A status of the flours and suggested an inte raction between starch and protein in determining noodle texture. Mult iple regression analysis using flour protein and FSV accounted for 76% of the variation in alkaline noodle firmness. A speculative model of noodle structure was developed based on a concept of the cooked noodle as a composite material.