Molecular Structure and Organization of Starch Granules from Developing Wheat Endosperm

Abstract

Cereal Chem. 91(6):578-586Wheat starches isolated from seeds harvested between 7 and 49 days after anthesis (DAA) were fractionated into large (>8 μm) and small (<8 μm) granules and studied for starch structure and architecture. Starch granules at 7 DAA possessed unimodal size distribution, whereas it was bimodal at later maturity stages. The apparent amylose fraction of starch granules at early maturity (7 and 14 DAA) consisted of intermediate-type materials, whereas starch at later maturity stages (28 and 49 DAA) contained branched amylose. Wide-angle X-ray scattering (WAXS) revealed a well-developed polymorphic structure already at 7 DAA. Although the presence of a small proportion of B-type crystallites mixed with A-type crystallites was observed in the X-ray diffractogram of starches at early maturation (7 and 14 DAA), it was masked by the A-type crystallites at later maturity stages. However, the large granules had a higher proportion of B-type crystallites and lower relative crystallinity (RC) than their small-granule counterpart. The iodine absorption properties of the starch granules demonstrated different levels of mobility of the starch polymers at different stages of maturity and the mobility of more glucan polymers in the large granule population compared with the small granules at the same maturity stage. Iodine did not change the characteristic A-type crystalline pattern of starch, but it increased RC. Changes in peak width at half height based on WAXS data further suggested the possible interaction of iodine with amylopectin intercluster chain segments and branch chains in formation of inclusion complexes. MATERIALS AND METHODS Materials.Eastern hard red spring wheat (cv. Hobson) at five different stages of kernel development (7, 14, 28, 35, and 49 DAA) were harvested in Ontario, Canada, in 2009. Heads were tagged when 50% of the spikes within the head were anthesized.

Differences in multi-segmental spine kinematics between patients with different stages of axial spondyloarthritis and healthy controls

“…Each specific task was instructed and practiced before start of the actual motion capture. For forward and side bending, participants were instructed to perform the task following the instructions of the modified-Schober task and the bilateral side flexion task from the BASMI (Braun et al, 2014). For axial rotation, participants were instructed to rotate the trunk following protocols of previous literature (Schinkel-Ivy et al, 2014).…”

“…The effects of local onset of spinal inflammation on spinal mobility and maladaptive functional behaviour might have influenced contradicting results of previous research (Del Din et al, 2011;Mangone et al, 2011). This study therefore firstly aimed to investigate differences in multi-segmental spinal kinematics (six regions) and the hips during maximal ROM tasks in all three planes between two homogeneous patient subgroups: (1) an early stage group of patients with active inflammatory sacroiliitis, and (2) a late stage group of patients with passive grade 3 or 4 sacroiliac bone formation , without actual disease-related inflammation (Braun et al, 2014;Hermann et al, 2012;Zochling, 2011). Secondly, we aimed to investigate if clinically relevant movement profile subgroups exist in axSpA and if they are related to pain, and to fear of movement and (re)injury beliefs.…”

Poly(methyl methacrylate) modified Starch: their preparations, properties and applications

“…The hydroxyl groups present in the Starch molecule may be used for this purpose [35] . Being biodegradable, biocompatible and non-toxic in nature, Starch has gained a lot of attention from the researchers [24,37,38] . Starch can be treated with plasticizers to avoid the brittleness in the films and make it shatter resistant [39,40] .…”

“…Diameter (µm) Shapes Amylose (%) large canna Starch [22,23] 62 -94 B-type, oval-shaped granules 38.7 medium canna Starch [22,23] --------oval and elliptical -------small canna Starch [22,23] 14-35 round and polygonal 29.2 small wheat Starch [24] 2-8 bimodal spherical shaped B-granules 23.0 large wheat Starch [24] 12-20 bimodal disc shaped A-granule 30.0 small potato granules [25] 5-20 spherical or ellipsoidal 212.5 medium potato granules [25] 25-40 ellipsoidal to irregular 250.8 large potato granules [25] 40-85 cuboidal 274.6 rice granules [26] 4.46-7.2 polygonal 29.7 Blackgram [27] 12.8-14.4 Round, elliptical, oval shaped 32.9-34.3 kidney bean [27] 15.5-60.5 Kidney shaped 35.9 large chick pea [27,28] 17 -29 Spherical, oval shaped 30.2 small chick pea [28] 6 -7 oval shaped 25.6 large maize granules [29] 5-20 spherical shaped 26.4 small maize granules [29] >5 Angular-shaped 21.7 large barley Starch [30] 15-32 bimodal with large disk-shaped 24~29 small barley Starch [30] 2-3 bimodal 23 ~ 25 ability, very good weather resistance and good mechanical properties [50] . Apart from these, MMA and PMMA are also used to modify the surface of fillers like Cellulose and Starch via grafting reaction.…”

“…The biodegradability study showed about 13% weight loss when SCN content was 30% in the blend. There are some reports which reported that the poly(methyl methacrylate) grafted Starch blended with natural rubber latex enhances the tensile strength of the blend [24,69] . Baishya and Maji [70] reported the synthesis of a bio-based composite of Starch and wood flour.…”