Isoamylase-type debranching enzymes (ISAs) play an important role in determining starch structure. Amylopectin - a branched polymer of glucose - is the major component of starch granules and its architecture underlies the semi-crystalline nature of starch. Mutants of several species lacking the ISA1-subclass of isoamylase are impaired in amylopectin synthesis. Consequently, starch levels are de...

The sulfhydryl oxidase (SHOxase; EC. 1.8.3.2) which catalyzes the oxidation of sulfhydryl groups to disulfides was purified from Aspergillus niger using a combination of chromatographies. The influence of SHOxase on starch properties was tested by rheometer, farinographand scanning electron microscopy (SEM). Moreover, the gelatinization and retrogradation were studied by differential scanning c...

Rice (Oryza sativa) endosperm is mainly occupied by homogeneous polygonal starch from inside to outside. However, morphologically different (heterogeneous) starches have been identified in some rice mutants. How these heterogeneous starches form remains unknown. A high-amylose rice line (TRS) generated through the antisense inhibition of starch branching synthase I (SBEI) and SBEIIb contains fo...

Mutations at the rug5 (rugosus5) locus have been used to elucidate the role of the major soluble isoform of starch synthase II (SSII) in amylopectin synthesis in the developing pea embryo. The SSII gene maps to the rug5 locus, and the gene in one of three rug5 mutant lines has been shown to carry a base pair substitution that introduces a stop codon into the open reading frame. All three mutant...

The problem of branching in glycogen and starch has been the subject of interest ever since Cori and Cori (I, 2) isolated the phosphorolytic enzyme from animal tissues and Hanes (3) found a similar enzyme in plants. Examination of polysaccharides produced by these enzymes when glucose-l-phosphate was used as a substrate showed that, similar to amylose, they had a linear configuration in which t...

The purpose of this study was to assess the properties of resistant starch (RS) III prepared from elephant foot yam starch using pullulanase enzyme. Native and gelatinized starches were subjected to enzymatic hydrolysis (pullulanase, 40 U/g per 10h), autoclaved (121°C/30 min), stored under refrigeration (4°C/24h) and then lyophilized. After preparation of resistant starch III, the morphological...

The pasting and gel textural properties of corn starch in syrup at different concentrations were investigated by Rapid Visco Analyzer (RVA) and Texture profile analysis (TPA) tests. The results showed that the pasting temperatures of corn starch greatly increased, especially at higher sugar concentration. Increasing concentration of syrup caused an increase in peak, trough and final viscosity o...

Enzymatic modification is an effective method to inhibit starch retrogradation. However, lack of quantification relationships between enzymatic and retrogradation makes the improvement unpredictable. In this study, maltogenic α-amylase (MA) was used treat wheat granules restrain retrogradation, aiming elucidate mechanism MA hydrolysis on establish a quantitative relationship degree (DH) Scannin...

Amylopectin concentration in barley endosperm has important effects on grain quality and end-use. In this study, quantitative trait locus (QTL) analysis together with genome-wide association studies (GWAS) were performed to identify markers linked to grain amylopectin content respectively using a doubled haploid (DH) population of 178 lines and a collection of 185 diverse barley germplasms both...