Physicochemical Properties And Starch Structure Of A Rice Mutant Reduced In Starch Paste Viscosity

The rice mutant reduced in starch paste viscosity is a novelty mutation. The major parameters of starch paste viscosity in mutant RSV-1 starch, i.e. peak paste viscosity, hot paste viscosity, and cool paste viscosity were significantly lower than those of the original parent. It will be dilute the thick after pasting, and it is hardly to be a state of gelatinization. Based on it's characteristics, the mutant may applied in many ways, i.e. starch film, nutrition rice noodles for infant, and so on.In this study, using a mutant reduced in starch paste viscosity (RSV-1) and its original parent(named as II-32B), variations in starch physicochemical properties and starch structure were investigated between RSV-1 and II-32B. Besides, the activity of enzyme in Metabolism of starch when grouting were researched.Followings are the main results:1) The apparent amylose content(AAC), gel consistency(GC), alkali spreading value(ASV) of mutant RSV-1 were higher than wild type. However, major parameters of starch paste viscosity in mutant RSV-1 starch, i.e. peak paste viscosity, hot paste viscosity, and cool paste viscosity were significantly lower than those of the original parent. Compared to the original parent, it had a similar peak time, but less energy cost during gelling. The feature of the pasted rice flour and morphology of starch granules in the endosperm of mutant RSV-1 were different from the original parent.2) The activity of sucrose Debranching enzyme (DBE), of RSV-1 are higher than those in II-32B when grouting. Contrarily, the activity of starch branching enzyme(SBE) lower in RSV-1.