Factors Affecting Gelatinization Properties of Wheat Starch

Studies on the Noodle Making Quality of Japanese Domestic Wheat Flours Part I

Abstract

Ge1atinization properties of Australian standard white (Western Australia) (ASW) and wheats representing the three major varieties grown in Japan were compared with respect to their suitability for Japanese-type noodle. Quality factors which affect on the starchge1atinization properties were studied using the Brabender Amylograph. The addit ion of NaCl caused a pronounced difference in the area under the sticking out portion of the amylogram during cooling stage (maximum viscosity during coo1ing stage) for flou rs milled from ASW and Japanese wheats. ASW, which possessed favorable characteristics for noodle making, showed a large area, whereas none or little area was observed for Japane se wheats This may relate to noodle quality, especially to noodle staling. Starches recove red from flours by wet-fractionation procedure contained soluble proteins. ASW starch sho wed a distinct high protein solubilities on the extraction with 1% sodium dodecyl sulf ate (SDS). Treatment of starches with 1% SDS resulted in a minimized variance of gelatiniza tion properties between ASW and Japanese wheats. On the basis of reconstitution studi es of SDS treated starches and their-solubles, somewhat unfavorable gelatinization propert ies of Japanese wheat were considered to be caused by SDS-solubles. Proteins of SDS-sol ubles were further analyzed by RP-HPLC, which showed somewhat different protein charac teristics