scholarly journals Amylose content and micromorphology of popcorn progenies with different popping expansion volumes

2020 ◽  
Vol 50 (2) ◽  
Author(s):  
Ana Izabella Freire ◽  
Elisa de Melo Castro ◽  
Ariana Mota Pereira ◽  
Renata Ranielly Pedroza Cruz ◽  
Filipe Bittencourt Machado de Souza ◽  
...  

ABSTRACT: Popcorn (Zea mays var. everta) has a higher commercial value than common maize, in addition to being a popular food among consumers. Today, there is a constant search for cultivars with superior performance for several traits of interest in the case of popcorn, yield and popping expansion. On this basis, this project proposes to characterize progenies of popcorn with different values of expansion capacity regarding chemical composition and micromorphology. Kernels from the fifth cycle (C5) of intrapopulation recurrent selection were evaluated. The progenies were selected based on the popping expansion volume of their kernels. The kernels were quantified for amylose and analyzed for starch granule arrangement and pericarp thickness by scanning electron microscopy. Progenies with low popping expansion volume (0 and 7 mL g-1) showed amylose contents of 21.24 and 20.18%, respectively; a less compact endosperm, with individual starch granules interspaced with empty spaces; and pericarp thickness between 40.94 and 38.99 µm, respectively. By contrast, progenies with high popping expansion volume (30 and 35 mL g-1) showed amylose contents of 23.92 and 26.10%; a vitreous endosperm; more-compact starch granules without empty spaces in between; and pericarp thickness between 107.66 and 107.84 µm. Progenies with higher popping expansion volume exhibited a thicker pericarp, a high amylose percentage and a more-compact endosperm, whereas those with the lower expansion volumes showed a thinner pericarp, a lower amylose percentage and individual starch granules.

2012 ◽  
Vol 550-553 ◽  
pp. 1513-1521
Author(s):  
Sirirat Thothong ◽  
Klanarong Sriroth ◽  
Rattana Tantatherdtam ◽  
Amnat Jarerat

To improve the miscibility of native rice starch granules and poly(butylene adipate-co-terephthalate)(PBAT), rice starch was hydrolyzed by a mixture of α-amylase and amyloglucosidase. The obtained porous rice granular starch was then mechanically blended with PBAT by single screw extruder. Many pits and holes on the surface of starch granules were observed by scanning electron microscopy (SEM). The rough surface of the rice starch granules improved the compatibility of the polymers in the blends, which consequently increased the tensile strength and the elongation at break. In addition, SEM also revealed that the porous granules were homogeneously distributed in the polymer matrix with no appearance of gaps.


2018 ◽  
Author(s):  
Wenzhi Zhou ◽  
Shanshan Zhao ◽  
Shutao He ◽  
Qiuxiang Ma ◽  
Xinlu Lu ◽  
...  

AbstractHigh amylose starch, a desired raw material in the starch industry, can be produced by plants deficient in the function of branching enzymes (BEs). Here we report the production of transgenic cassava plants with starches containing up to 50% amylose due to the constitutive expression of hair-pin dsRNAs targeting the BE1 or BE2 genes. A significant decrease in BE transcripts was confirmed in these transgenic plants by quantitative real-time RT-PCR. The absence of BE1 protein in the BE1-RNAi plant lines (BE1i) and a dramatically lower level of BE2 protein in the BE2-RNAi plant lines (BE2i) were further confirmed by Western blot assays. All transgenic plant lines were grown up in the field, but with reduced biomass production of the above-ground parts and storage roots compared to wild type (WT). Considerably high amylose content in the storage roots of BE2i plant lines was achieved, though not in BE1i plant lines. Storage starch granules of BE1i and BE2i plants had similar morphology as WT, however, the size of BE1i starch granules were bigger than that of WT. Comparisons of amylograms and thermograms of all three sources of storage starches revealed dramatic changes to the pasting properties and a higher melting temperature for BE2i starches. Glucan chain length distribution analysis showed a slight increase in chains of DP>36 in BE1i lines and a dramatic increase in glucan chains between DP 10-20 and DP>40 in BE2i lines, compared to that of WT starch. Furthermore, BE2i starches displayed a B-type X-ray diffraction pattern instead of the A-type pattern found in BE1i and WT starches. Therefore, cassava BE1 and BE2 function differently in storage root starch biosynthesis; silencing of cassava BE1 or BE2 caused various changes to starch physico-chemical properties and amylopectin structure. We also report that remarkably high amylose content in cassava starch has been first obtained in transgenic cassava by silencing of BE2 expression, thus showing a high potential for future industrial utilization.


2011 ◽  
Vol 150 (1) ◽  
pp. 45-52 ◽  
Author(s):  
Y. NI ◽  
Z. WANG ◽  
Y. YIN ◽  
W. LI ◽  
S. YAN ◽  
...  

SUMMARYStarch granule size distribution of wheat is an important characteristic that can affect its chemical composition and functionality. Phosphorus (P) fertilization has been studied extensively; however, little is known about its impact on starch granule size distribution in wheat. In the present study, two high-yield winter wheat cultivars were grown under different P fertilization conditions to evaluate its effect on starch granule size distribution and starch components in wheat grains at maturity. P fertilization resulted in a significant increase in the proportions (both by volume and by surface area) of B-type (<9·9 μm equivalent diameter (e.d.)) starch granules, with a reduction in those of A-type (>9·9 μm e.d.) starch granules. The P fertilization also increased starch content, amylose content and amylopectin content at maturity. However, P fertilization conditions significantly reduced the ratio of amylose to amylopectin, which showed a significant positive relationship with the volume proportion of granules 22·8–42·8 μm e.d. but was negatively related to the volume proportion of granules 2·8–9·9 μm e.d.


2012 ◽  
Vol 12 (2) ◽  
pp. 156
Author(s):  
Zita Letviany Sarungallo ◽  
Budi Santoso ◽  
Eduard Frasisco Tethool

The aim of this research was to evaluate the physicochemical and functional properties of aibon (Brugueiragymnorhiza L.) starch. Research’s results show that the form of aibon starch granule was ellips like kidney, withsize of 5-4.5 μm, has high amylose content of 32.35%, and gelatinization temperature of 85.5-95oC. It also has highsolubility (7oBrix) and swelling powered of 14.83% at 90oC. Pasting behavior of starch suspension (6.5%, w/v)shows the initial pasting temperature at 85.5oC and peak viscosity 200 BU reached at 93oC. The wide range ofgelatinization temperature makes aibon starch resistant to high heat temperature. Functional characters thatmake aibon starch important for industrial application are its non-adhesive and un-sticky paste, increasing viscositywhile it was heated, unstable gel forming, and low stability to freezing-thawing cycle. Aibon starch also haspotential usage for carbohydrate base products that need starch which has heat resistant granule but does notneed starch that has high viscosity paste.


2011 ◽  
Vol 396-398 ◽  
pp. 1493-1497 ◽  
Author(s):  
Yong Le Liu ◽  
Xiang Hong Li ◽  
Jian Yu ◽  
Fa Xiang Wang ◽  
Jian Hui Wang

The effects of germination on physicochemical, morphological and rheological properties of rice starch from germ-remaining polished rice (GRPR) have been investigated. The properties of starches from raw GRPR, brown rice and germinated brown rice were also characterized as the comparison. The results showed that a decrease in amylose content was observed after germination and the amylose content of germinated GRPR was lower than that of germinated brown rice. Scanning electron microscopy did not reveal any distinct difference in the appearance of the starches except some slight alteration of the starch granule edges. Rheological investigation illustrated that the starches of GPRG with lower amylose content showed lower peak G’ in the four rice samples.


2016 ◽  
Vol 96 (2) ◽  
pp. 176-182 ◽  
Author(s):  
Wenyang Li ◽  
Suhui Yan ◽  
Xiaqing Shi ◽  
Congyu Zhang ◽  
Qingqin Shao ◽  
...  

The granule size distribution of starch strongly influences its physicochemical properties and the functionality of wheat. Twelve wheat cultivars grown in east China’s Huanghuai region were used for investigating the granule size distribution, amylose content, and their interrelationship. The results showed that the volume distribution of starch granules show the typical bimodal with peak values in the ranges of 4.44–5.36 µm and 21.7–23.82 µm, respectively. Surface area distribution of granules was also bimodal with peak values in the ranges of 2.53–3.06 µm and 19.8–21.7 µm, respectively. The limits between the two populations both occurred at 10 µm. A typical population of number distribution of granules with peak values in the range of 0.52–0.67 µm. Proportions of granules <2.6 µm, 2.6–10 µm, and 10–40 µm were in the range of 10.06–13.63%, 28.54–41.6%, and 45.4–61.3% of total volume, respectively. Proportions of granules <10 µm were in the range of 99.9% of the total number. The amylose content was significant and negatively correlated to volume percentage of granule <10 µm, and significant and positively correlated to the volume percentage of granule 22–40 µm.


1982 ◽  
Vol 62 (1) ◽  
pp. 19-27
Author(s):  
L. KAMARA ◽  
A. BOUDREAU ◽  
F. CASTAIGNE

The examination of ultra-thin sections by the scanning electron microscope was performed comparing spring wheat Laval-19 with several types of wheat of increasing hardness (Yorkstar, Concorde and Neepawa) using both whole kernels and the corresponding flours. The hardness properties of each type of wheat was determined using an Instron Tensile Testor. In hard wheats, we observed a tightly packed structure showing little or no air space in the endosperm. The adhesion between proteins and starch granules was strong enough to break the starch granule rather than to separate at the interface. The soft wheats appeared to have a much looser structure with many intergranular air spaces and no broken starch granules. The microscopy of the flours illustrated the integrity of the starch-protein matrix in the hard flours and a mixture of free starch granules, free protein, and small aggregates of protein and starch in soft flours. The Instron measurements were in agreement with the microscopic examination and both techniques indicated clearly the differences in hardness between soft and hard, leaving the spring wheat Laval-19 a type of wheat intermediary between soft and hard.


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