Amylase action pattern on starch polymers

Bijttebier, Annabel; Goesaert, Hans; Delcour, Jan A.

doi:10.2478/s11756-008-0169-x

Cited by 85 publications

(62 citation statements)

References 66 publications

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“…Our results suggest that the preferred site for hydrolysis on the 1,4-α-D-glucose polymer by α-amylase is at either the 5th or 6th 1,4-α-D-glucosidic bond at elevated temperatures (mashing, ~65°C), and at the 6th or 7th 1,4-α-D-glucosidic bond at more ambient temperatures (fermentation, ~25°C). This variation in preference for sites of hydrolysis at varying temperatures by α-amylases agrees with previous reports 2,21 . Apart from a site preference at approximately the 5th or 6th 1,4-α-D-glucosidic bond at elevated temperatures, and at the 6th or 7th 1,4-α-D-glucosidic bond at ambient temperatures, a possible preferential site of hydrolysis at approximately twice the distance along the polymer length (at the 10th glucosidic bond during mashing and at the 14th glucosidic bond during fermentation) was observed.…”

Section: Amylolytic Activity During Fermentationsupporting

confidence: 81%

The Evolution of Dextrins During the Mashing and Fermentation of All-malt Whisky Production

Vriesekoop

Rathband

MacKinlay

et al. 2010

Journal of the Institute of Brewing

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The production of malt whisky involves the mashing of barley malt, followed by the fermentation of the resulting wort without further treatment. While this process has many parallels to the production of an all-malt beer, one of the main differentiating steps during substrate preparation is the inclusion of a boiling step for the wort in the production of beer. Other than the destructive action of the boiling process on microorganisms, the boiling also destroys all malt enzyme activity. Since a typical whisky wash is not boiled it carries through a certain proportion of microbial activity associated with the malt, but more importantly it retains some enzyme activity that has been activated during the malting and mashing processes. The changes in sugars and dextrins during both mashing and fermentation of the resulting wash were investigated. Evidence of the continuous amylolytic activity during an unboiled, all-malt wash fermentation is shown; while no ongoing amylolytic activity could be deduced during the fermentation of a boiled all-malt wort. Furthermore, the data suggests that the amylolytic activity during mashing and fermentation are different with regards to α-amylase action linked to its multiple-attack action pattern as a function of substrate conformation, temperature, and effectiveness of potential hydrolytic events.

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Section: Amylolytic Activity During Fermentationsupporting

confidence: 81%

The Evolution of Dextrins During the Mashing and Fermentation of All-malt Whisky Production

Vriesekoop

Rathband

MacKinlay

et al. 2010

Journal of the Institute of Brewing

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“…This trend demonstrates that less branched structures were obtained as AO increased which is associated with the branch linkage analysis (Table 1). The action pattern of α-amylase involves a virtually random hydrolytic multiple attack to cleave starch into linear and branched dextrins (Bijttebier, Goesaert and Delcour, 2008) and requires at least a four glucose-unit linear segment between two branch points for catalysis (Damager et al, 2005). The low -limit dextrin content of the samples having low branch point density is in accordance with the specific action of -amylase on linear -1,4 chains.…”

Section: α-Limit Dextrin Structure and β-Amylolysis Limitmentioning

confidence: 75%

Structure of branching enzyme- and amylomaltase modified starch produced from well-defined amylose to amylopectin substrates

Sorndech¹,

Sagnelli

Meier

et al. 2016

Carbohydrate Polymers

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Highlights •Enzyme modification of starch systems with well-defined amylose:amylopectin ratios provides detailed insight into the effects of substrate branching on enzymatic chain transfer • High amylose substrates produce high branching rates, high M w, short chains and low amylolytic digestion when treated with branching enzyme alone or in combination with amylomaltase.• Not only branching density but also molar mass of the glucan product restricts dietary degradation by steric hindrance towards human pancreatic α-amylase and α-glucosidases. AbstractThermostable branching enzyme (BE, EC 2.4.1.18) from Rhodothermus obamensis in combination with amylomaltase (AM, EC 2.4.1.25) from Thermus thermophilus was used to modify starch structure exploring potentials to extensively increase the number of branch points in starch. Amylose is an important constituent in starch and the effect of amylose on enzyme catalysis was investigated using amylose-only barley starch (AO) and waxy maize starch (WX) in well-defined ratios. All products were analysed for amylopectin chain length distribution, α-1,6 glucosidic linkages content, molar mass distribution and digestibility by using rat intestinal α-glucosidases. For each enzyme treatment series, increased AO content resulted in a higher rate of α-1,6 glucosidic linkage formation but as an effect of the very low initial branching of the AO, the final content of α-1,6 glucosidic linkages was slightly lower as compared to the high amylopectin substrates. However, an increase specifically in short chains was produced at high AO levels. The molar mass distribution for the enzyme treated samples was lower as compared with substrate WX and AO, indicating the presence of hydrolytic activity as well as cyclisation of the substrate. For all samples, increased amylose substrate showed decreased α-and β-amylolysis. Surprisingly, hydrolysis with rat intestinal α-glucosidases was higher with increasing α-1,6 glucosidic linkage content and decreasing M w indicating that steric hindrance towards the α-glucosidases was directed by the molar mass rather that the branching density of the glucan per se. Our data demonstrate that a higher amylose content in the substrate starch efficiently produces α-1,6 glucosidic linkages and that the present of amylose generates a higher M w and more resistant product than amylopectin. The combination of BEAMBE provided somewhat more resistant α-glucan products as compared to BE alone.

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“…GH family 13 amylolytic enzymes include a-amylase (EC 3.2.1.1), maltogenic (EC 3.2.1.133) and other maltooligosaccharide-producing amylases (e.g. EC 3.2.1.60, EC 3.2.1.98) and debranching enzymes (pullulanase/isoamylase) (Bijttebier et al, 2008). Beta-amylase is inverting exoamylase and hydrolyze thea-(l,4)-linkages at the non-reducingendsofstarchmolecules.…”

Section: Enzyme Hydrolysis Of Starch By A-amylasementioning

confidence: 99%

The impact of heat-moisture treatment on the molecular structure and physicochemical properties of normal and waxy potato starches

Varatharajan

Hoover

Liu

et al. 2010

Carbohydrate Polymers

148

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Heat-moisture treatment (HMT) is a physical modification technique that modifies starch structure and properties without destroying its granular structure. HMT has been shown to cause starch chain interactions and crystallite disruption/reorientation within the amorphous and crystalline domains. However, the part played by amylose (AM) during HMT of starches is not properly understood. Furthermore, a systematic study has not been carried out to examine how variations in HMT temperatures influence molecular structure, physicochemical properties and digestibility of normal potato (NP) and waxy potato (WP) starches. Thus, the objective of this study was to determine changes to molecular structure, physicochemical properties and digestibility ofNP and WP starches on HMT at different temperatures (80,100,120 and l30°C) for 16 h at 27% moisture. Structural changes on HMT were monitored by scanning electron microscopy (SEM), confocal laser scanning microscopy (CLSM), polarized light microscopy (pLM), wide angle X-ray scattering (WAXS), attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectroscopy, fluorophore assisted capillary electrophoresis (FACE) and KlS spectra. Changes to physicochemical properties on HMT were determined by granular swelling, amylose leaching, gelatinization parameters and pasting properties. Digestibility of normal and waxy potato starches before and after HMT by porcine pancreatic a-amylase (PPA) was monitored by measuring initial velocity and by exarninationofthe granular structure at different stages of hydrolysis by SEM, CLSM and PLM. The results showed that structural changes on HMT were influenced by differences in starch chain mobility at different temperatures of HMT. Starch chain mobility, in turn, was influenced by the interplay between the extent to which B-type crystallites were transformed into A+B-type crystallites, kinetic energy imparted to starch chains and amylose content. The main type of structural changes influencing physicochemical properties at different temperatures of HMT were starch chain interactions (at 80 and IOO°C), disruption of hydrogen bonds between amylose-amylopectin and amylopectin-amylopectin (at 120 and l30°C), disorganization of amylopectin chains near the vicinity of the hilum (at 100, 120 and l30°C)andformationofinterruptedhelices(atl30°C).The susceptibility ofNP and WP starches towards a-amylase decreased at 80°C, but increased in the range 100 to l30°C. NPand WPstarches exhibited heterogeneity in degradation (NP>WP) Most studies have been on the impact ofHMT on the thermal properties, crystallinity and pasting propertiesofnorrnalstarches. Some researchers (Hoover and Manuel, 1996; Kweon el al., 2000;Zavareze et al., 2010) have attempted to explain the impact of HMT on the structure and physicochemical properties of starches varying in amylose content. However, the part played by amylose during HMT of starches is still not properly understood. Unlike in cereal starches, amylose has been shown to be co-crystallized with amylopectin...

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Amylase action pattern on starch polymers

Cited by 85 publications

References 66 publications

The Evolution of Dextrins During the Mashing and Fermentation of All-malt Whisky Production

The Evolution of Dextrins During the Mashing and Fermentation of All-malt Whisky Production

Structure of branching enzyme- and amylomaltase modified starch produced from well-defined amylose to amylopectin substrates

The impact of heat-moisture treatment on the molecular structure and physicochemical properties of normal and waxy potato starches

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