Structures of large, medium and small starch granules of barley grain

Takeda, Yasuhito; Takeda, C.; Mizukami, Hiroyuki; Hanashiro, Isao

doi:10.1016/s0144-8617(98)00105-2

Cited by 129 publications

(87 citation statements)

References 23 publications

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“…Those changes might directly influence A-and B-granule formation. It was found the A-and B-granules differ in physicochemical properties and the altered distribution and ratio of starch granule forms can also be associated with worsen malting quality under high temperatures 20,24,28 .…”

Section: Discussionmentioning

confidence: 99%

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The Variation of β-amylase Activity and Protein Fractions in Barley Grains as Affected by Genotypes and Post-anthesis Temperatures

Wei

Dai

et al. 2009

Journal of the Institute of Brewing

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The variation of β-amylase activity and protein fractions in barley grains was evaluated using 148 barley genotypes grown in the field and two cultivars under in vitro culture with two temperature treatments during grain development. The results showed that there was significant genotypic variation in β-amylase activity and protein fraction content. Regression analysis indicated that β-amylase activity was positively correlated with total protein and the level of each of the protein fractions, with the correlation coefficient between β-amylase activity and hordein content being the highest. Furthermore, higher post-anthesis temperatures (32/26°C, day/night) significantly enhanced β-amylase activity and protein fraction content, presumably as a result of reduced starch content. Albumin and glutelin were the least and most affected, respectively, in comparison with the plants under lower temperature (22/16°C). Temperature post-anthesis also influenced the morphology of the starch A granule and the number of B granules, suggesting the altered starch structure may also be a reason for deteriorated malting quality under high temperatures.

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Section: Discussionmentioning

confidence: 99%

“…The A-and B-granules have different ratios in amylase to lipid content 20 . The B-granules have a higher lipid content and the A-granules have a higher amylose content 24,28 . The size of the starch granule is closely related to its physicochemical properties.…”

Section: Introductionmentioning

confidence: 99%

The Variation of β-amylase Activity and Protein Fractions in Barley Grains as Affected by Genotypes and Post-anthesis Temperatures

Wei

Dai

et al. 2009

Journal of the Institute of Brewing

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“…The amylopectin molecules of the A granules consist of substantially more B2 chains that extend through two clusters and lesser A and B1 chains that remain in a single cluster than the amylopectin of the B granules. 53,54) The amylopectin molecules that consist of more B2 chains extending through two clusters and carrying other B1 and A chains are likely to have cylindrical shaped structures. 54) The cylindrical shaped molecules, in turn, can be aligned into a platelet structure, which agrees with the parallel molecular arrangement in the disk shaped starch granules revealed by optical map studies.…”

Section: )mentioning

confidence: 99%

Current Understanding on Starch Granule Structures

2006

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Starch is the second largest biomass, next to cellulose, produced on earth and is the most available and economical commodity product. One major reason for starch being economically competitive is its semi crystalline granular structure. Starch is produced in the granular form; therefore, it is easily isolated through wet milling. The starch can then be derivatized and modified with various chemical reagents, washed to remove by products and residual chemicals, and centrifuged to recover the modified starch that provides improved properties for various end uses and market needs.Starch granules from different botanical sources have different characteristic shapes, sizes and morphology.1)The sizes of starch granules vary from submicron to more than 100 microns in diameter. The shapes of starch granules include spherical, disk, oval, polygonal, dome shape, elongated rod shape and compound starch. Most starch granules consist of two types of glucan, amylose and amylopectin. Amylopectin in the granule is present in the semi crystalline structure, whereas amylose is amorphous. Starch granules possess different types of crystallinity, displaying A , B and C type X ray patterns, depending on their amylopectin branch chain length.2) The A type polymorphic starch has a monoclinic unit cell, and the B type starch has a hexagonal unit cell.3,4) The C type polymorphic starch consists of a combination of the A type and the B type unit cells. Starches of different polymorphisms are known to display different enzyme digestibility.5 9) The A type polymorphic starch is easily digestible, but the B type and some C type starches are very resistant to enzyme hydrolysis. The aim of this paper is to review some of the recent advances on the understanding of the structure of starch granules and its impact on starch properties.Structure and location of amylose in the starch granule. The structure of amylose has been extensively analyzed and is shown to have multiple branches; the number of branches of amylose molecules depends on the molecular size and botanical source of the starch.10,11) Cereal starches have amylose of smaller molecular sizes than tuber and root starches. 12,13)Locations of amylose versus amylopectin. Relative locations of amylose and amylopectin were a matter of debate among scientists for decades. On the basis of different properties of starch granules isolated from different botanical sources, including amylose leaching, iodine vapor complexing with amylose, amylose formation of the V complex, and DMSO solubilization of starch granules, amylose is proposed of being separated from amylopectin in normal maize starch and being interspersed among amylopectin in potato starch. 14) Because amylose was known as linear molecules not being branched by starch branching enzymes during biosynthesis, it was hypothesized that amylose was synthesized in bundles, which was isolated from amylopectin and, thus, was not accessible to the starch branching enzymes. During the process of high temperature ethanol treatments to convert na...

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“…Hydrolysis of starch depends on the physical state and the particle size distribution of the starch granules 22,26 . It has previously been shown that starch granules in barley can be divided into two 19,27,54 or even three fractions 49 , with average particle sizes of 20 µm (large), 7.5 µm (medium) and 2.3 µm (small). These types of barley starch granules are characterized by different amylose: amylopectin ratios, as well as different structures and physicochemical properties.…”

Section: Introductionmentioning

confidence: 99%

Dry and Wet Milling of Malt. A Preliminary Study Comparing Fermentable Sugar, Total Protein, Total Phenolics and the Ferulic Acid Content in Non-Hopped Worts

Szwajgier

2011

Journal of the Institute of Brewing

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In this work, fermentable sugar, total protein, phenolics and ferulic acid content were estimated in sweet worts at different points of lautering. Transfer of these selected malt compounds into worts was analyzed in relation to the method of malt milling (wet milling of malt -the "test worts" or dry milling of maltthe "reference worts"). Glucose, maltose and maltotriose were more rapidly transferred into sweet worts at the early stages of lautering (40 hL and/or 80 hL of wort) after wet milling in comparison to dry milling. Total protein content in the test worts was significantly higher than in the corresponding reference worts at each stage of lautering. Transfer of phenolic compounds and ferulic acid (in the free as well as in the ester form) from the mash into sweet worts was significantly improved by dry milling, but not by wet milling. No difference in the total antioxidant activity was observed between the two types of worts. In conclusion, it can be stated that wet conditioning of malt before milling enhances the fast transfer of fermentable sugars and proteins from the mash into the sweet wort during lautering. Lautering is a time-consuming process, and time reduction without the loss of wort quality should be a priority. Therefore, wet milling can be of interest to professionals in the field as an interesting alternative method to improve the mashing process.

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Structures of large, medium and small starch granules of barley grain

Cited by 129 publications

References 23 publications

The Variation of β-amylase Activity and Protein Fractions in Barley Grains as Affected by Genotypes and Post-anthesis Temperatures

The Variation of β-amylase Activity and Protein Fractions in Barley Grains as Affected by Genotypes and Post-anthesis Temperatures

Current Understanding on Starch Granule Structures

Dry and Wet Milling of Malt. A Preliminary Study Comparing Fermentable Sugar, Total Protein, Total Phenolics and the Ferulic Acid Content in Non-Hopped Worts

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