The shx shrunken endosperm mutation of barley is the only one described with its primary effect on Type I, primer-independent soluble starch synthase (SSS). The mutant produces grains with only 31% of the normal dry weight of starch, associated with a decrease in A-granule dimensions. We investigated the structure of shx and normal cv. Bomi barley amylose and amylopectin. Surprisingly, both amy...

The effect of mulberry leaf tea (MT) on texture, microstructure, starch retrogradation, and antioxidant capacity rice noodles was investigated. Addition MT powder at 5 to 25% increased protein, fiber, noodles. presence phenolic compounds in enhanced firmness elongation noodles, while fiber disrupted the noodle resulting lower high concentration. kept for 7 days 4°C had total content times highe...

A method is described whereby amyloplasts from immature barley (Hordeum distichum L.) endosperm could be separated into two populations of large and small amyloplasts at all stages of development. The small amyloplasts had more amylopectin than the large at early stages, but by 60 days after anthesis, the large had the greater proportion of amylopectin. Starch synthetase activity was associated...

To elucidate the relationship between the substrate size and geometric shape of the catalytic site of Thermus maltogenic amylase, Gly50, Asp109, and Val431, located at the interface of the dimer, were replaced with bulky amino acids. The k(cat)/K(m) value of the mutant for amylose increased significantly, whereas that for amylopectin decreased as compared to that of the wild-type enzyme. Thus, ...

The relative molecular size distributions of a selection of starches (waxy maize, pea and maize) that had received differing amounts of damage from ball milling (as quantified by susceptibility to alpha-amylase) were compared using analytical ultracentrifugation. Starch samples were solubilised in 90% dimethyl sulfoxide, and relative size distributions were determined in terms of the apparent d...

“Pan de Muerto” is a traditional bread type, emblematic of Mexican bakery. This work’s objectives were defining its characteristics, determining the effect fat content, and storage conditions on staling, examining relative impact these crystallization starch retrogradation. Staling was evaluated via changes in Young’s modulus. Fat retrogradation studied considering thermal crystalline propertie...

Cotton plants (cv. Coker 100) were exposed to a 14-hour dark period. Starch degradation occurred with no accumulation of sugars due mainly to translocation. Considerable amounts of starch degradation products however were detected from leaves after phloem transport was blocked. A minor component (10 to 25% of total starch) with a linear structure, amylose, was preferentially degraded, whereas t...

Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, Iowa 50011 (A.M.M., M.G.J.); Commonwealth Scientific and Industrial Research Organization Plant Industry, G.P.O. Box 1600, Canberra, Australian Capital Territory 2601, Australia (M.K.M.); and Unité Mixte de Recherche 8576 Glycobiologie Structurale et Fonctionnelle, Laboratoire de Chimie Biologique, Bâtim...