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Critical Reviews in Food Science and... 2023Starch with a high amylose (AM) content (high AM starch, HAS) has attracted increasing research attention due to its industrial application potential, such as functional... (Review)
Review
Starch with a high amylose (AM) content (high AM starch, HAS) has attracted increasing research attention due to its industrial application potential, such as functional foods and biodegradable packaging. In the past two decades, HAS structure, functionality, and applications have been the research hotspots. However, a review that comprehensively summarizes these areas is lacking, making it difficult for interested readers to keep track of past and recent advances. In this review, we highlight studies that benefited from rapidly developing techniques, and systematically review the structure, functionality, and applications of HAS. We particularly emphasize the relationships between HAS molecular structure and physicochemical properties.
Topics: Starch; Amylose; Molecular Structure
PubMed: 35373669
DOI: 10.1080/10408398.2022.2056871 -
Wiley Interdisciplinary Reviews.... Mar 2017Interest in amylose and its hybrids has grown over many decades, and a great deal of work has been devoted to developing methods for designing functional amylose... (Review)
Review
Interest in amylose and its hybrids has grown over many decades, and a great deal of work has been devoted to developing methods for designing functional amylose hybrids. In this context, phosphorylase-catalyzed polymerization shows considerable promise as a tool for preparing diverse amylose hybrids. Recently, advances have been made in the chemoenzymatic synthesis and characterization of amylose-block-polymers, amylose-graft-polymers, amylose-modified surfaces, hetero-oligosaccharides, and cellodextrin hybrids. Many of these saccharides provide clear opportunities for advances in biomaterials because of their biocompatibility and biodegradability. Important developments in bioapplications of amylose hybrids have also been made, and such newly developed amylose hybrids will help promote the development of new generations of glyco materials. WIREs Nanomed Nanobiotechnol 2017, 9:e1423. doi: 10.1002/wnan.1423 For further resources related to this article, please visit the WIREs website.
Topics: Amylose; Biocompatible Materials; Glycogen; Metabolic Engineering; Phosphorylases; Polymerization
PubMed: 27506150
DOI: 10.1002/wnan.1423 -
Critical Reviews in Food Science and... Jan 2017Three main in vitro approaches can be distinguished for obtaining amylose (AM): enzymatic synthesis, AM leaching, and AM complexation following starch dispersion. The... (Review)
Review
Three main in vitro approaches can be distinguished for obtaining amylose (AM): enzymatic synthesis, AM leaching, and AM complexation following starch dispersion. The first uses α-d-glucose-1-phosphate (G1P), a glucosyl primer with a degree of polymerization (DP) of at least 4 and phosphorylase (EC 2.4.1.1), commonly from potatoes. Such approach provides AM chains with low polydispersity, the average DP of which can be manipulated by varying the reaction time and the ratio between G1P, primer, and enzyme dose. AM leaching is the result of heating a starch suspension above the gelatinization temperature. This approach allows isolating AM on large scale. The AM DP, yield, and purity depend on the heating rate, leaching temperature, shear forces and botanical origin. High leaching temperatures (80-85°C) result in mostly pure AM of DP >1000. At higher temperatures, lower purity AM is obtained due to amylopectin leaching. Annealing as pretreatment and ultracentrifugation or repetitive organic solvent-based precipitations after leaching are strategies, which improve the purity of AM extracts. When AM is separated by complex formation, complete dispersion of starch is followed by bringing AM into contact with, e.g., n-butanol or thymol. The resultant complex is separated from amylopectin as a precipitate. Complete starch dispersion without degradation is critical for obtaining AM of high purity. Finally, higher DP AM can be converted enzymatically into AM fractions of lower DP.
Topics: Amylose; Food Additives; Hydrolysis; Molecular Weight; Starch
PubMed: 25975749
DOI: 10.1080/10408398.2014.954030 -
Drug Development Research Sep 2021The helical structure of V-amylose offering a superior encapsulation affinity compared with the other polysaccharides, especially toward the amphiphilic or hydrophobic...
The helical structure of V-amylose offering a superior encapsulation affinity compared with the other polysaccharides, especially toward the amphiphilic or hydrophobic molecules; in addition to providing a higher resistance toward enzymatic hydrolysis support its applications as a potential drug delivery vehicle. Mainly, the glycosidic linkages and -CH - groups forming the hydrophobic cavity of V-amylose helix, and the glycosyl hydroxyl groups constituting its hydrophilic periphery promote the loading of a diverse range of molecules via van der Waals forces and hydrogen bonding interactions. These properties enable a high-loading efficiency, targeted delivery, and controlled release of the cargo drug molecules by V-amylose. Besides, V-amylose presents characteristics of an ideal drug delivery system, such as biocompatibility, physiological benevolence, nonimmunogenicity, and biodegradability. The V-amylose polysaccharide chains fold into left-handed single helix comprising of six glucose units in each turn having a pitch height of 7.91-8.17 Å. These structural features of V-amylose differentiate it from the parent amylose polysaccharide and enable the accommodation and nanoencapsulation of a wide range of therapeutics in the former. The tightly packed helical structure of V-amylose provides extraordinary resistance toward digestion by amylase compared with the linear polysaccharides, which supports the application of V-amylose as controlled drug release systems. The activity of the amylase enzyme produced by salivary glands, pancreas, gastrointestinal tract, and gut microbiota on amylose-based drug delivery vehicles promote enzyme-sensitive controlled oral and colon-specific release of the encapsulated drug. The single helical V-amylose with hydrophobic core and hydrophilic periphery forms inclusion complexes that improve the absorption and permeation of drugs having a high clogP index. The present commentary highlights the distinguished features of V-amylose as an imminent drug delivery system.
Topics: Amylose; Hydrogen Bonding; Hydrophobic and Hydrophilic Interactions; Pharmaceutical Preparations
PubMed: 33586190
DOI: 10.1002/ddr.21804 -
Journal of Food Science Apr 2019Amylose, as a polymeric carbohydrate, is a very attractive raw material owing to its performances. However, the acetylation of amylose separated from high amylose corn...
Amylose, as a polymeric carbohydrate, is a very attractive raw material owing to its performances. However, the acetylation of amylose separated from high amylose corn starch (HACS) will be beneficial to further improve its functional characteristics so that acetylated amylose (AA) is able to be well applied for some special situations. In this work, we chiefly discuss the optimization of acetylation conditions by a response surface methodology, property, and characterization of AA. The experimental results indicated that the acetylation of amylose was affected by some factors, such as reaction temperature, reaction time, amount of acetic anhydride, and pH. The blue value of amylose was changed by acetylation. Maltese crosses on the separated amylose particles disappeared owing to the separation. The crystalline structure of HACS was C-type, whereas the structure of AA was the immediate between B- and V-type. The acetylation lowered the onset temperature, peak temperature, and end temperature of amylose, but raised its melting enthalpy. PRACTICAL APPLICATION: Although inherent functional diversity of starch extracted from different biological sources adds to the range of applications, acetylated amylose, as an additive, will be better control the consistency and texture of some foods, enhance the strength of edible films, and improve the slow-release of drugs. It will also provide options for extending the scope of desired functional characteristics.
Topics: Acetylation; Amylose; Hydrogen-Ion Concentration; Molecular Structure; Starch; Temperature; Thermodynamics
PubMed: 30829409
DOI: 10.1111/1750-3841.14487 -
Macromolecular Rapid Communications Aug 2019Herein, the synthesis of amylose-coated, temperature-responsive poly(N-vinylcaprolactam) (VCL)-based copolymer microgels by enzyme-catalyzed grafting-from polymerization...
Herein, the synthesis of amylose-coated, temperature-responsive poly(N-vinylcaprolactam) (VCL)-based copolymer microgels by enzyme-catalyzed grafting-from polymerization with phosphorylase b from rabbit muscle is reported. The phosphorylase is able to recognize the oligosaccharide maltoheptaose as primer and attach glucose units from the monomer glucose-1-phosphate to it, thereby forming amylose chains while releasing inorganic phosphate. Therefore, to enable the phosphorylase-catalyzed grafting-from polymerization of glucose-1-phosphate from the PVCL-based microgels, the maltoheptaose primer is covalently attached to the microgel in the first synthesis step. This is realized by adding N-(2-aminoethyl)methacrylamide (AEMAA) as a comonomer to the PVCL microgel to integrate primary amino groups and subsequent coupling of maltoheptaonolactone. Both the PVCL/AEMAA microgel as well as the obtained microgel-maltoheptaose construct are characterized in detail by dynamic light scattering, electrophoretic mobility measurements, IR spectroscopy, and atomic force microscopy. From the microgel-maltoheptaose construct, the grafting-from polymerization of glucose-1-phosphate is performed by the addition of phosphorylase b. Atomic force microscopy images clearly demonstrate the formation of an amylose shell around the microgels. The developed amylose-coated microgels open up promising application possibilities, for example, as colloidal scavengers, since amylose helices can serve as host molecules for inclusion of hydrophobic guest molecules.
Topics: Amylose; Biocatalysis; Caprolactam; Microgels; Molecular Structure; Phosphorylases; Polymerization; Polymers
PubMed: 31162765
DOI: 10.1002/marc.201900144 -
Critical Reviews in Food Science and... 2015Acid hydrolysis is an important chemical modification that can significantly change the structural and functional properties of starch without disrupting its granular... (Review)
Review
Acid hydrolysis is an important chemical modification that can significantly change the structural and functional properties of starch without disrupting its granular morphology. A deep understanding of the effect of acid hydrolysis on starch structure and functionality is of great importance for starch scientific research and its industrial applications. During acid hydrolysis, amorphous regions are hydrolyzed preferentially, which enhances the crystallinity and double helical content of acid hydrolyzed starch. This review discusses current understanding of the effect of acid hydrolysis on starch structure and functionality. The effects of acid hydrolysis on amylose content, chain length distribution of amylopectin molecules, molecular and crystalline organization (including lamellar structure) and granular morphology are considered. Functional properties discussed include swelling power, gelatinization, retrogradation, pasting, gel texture, and in vitro enzyme digestibility. The paper also highlights some promising applications of acid hydrolyzed starch (starch nanocrystals) in the preparation of biodegradable nanocomposites, bio-hydrogen, and slowly digestible starch-based healthy foods.
Topics: Acids; Amylopectin; Amylose; Carbohydrate Conformation; Chemical Phenomena; Crystallization; Digestion; Hydrolysis; Molecular Structure; Nanocomposites; Starch; Structure-Activity Relationship
PubMed: 24915341
DOI: 10.1080/10408398.2012.684551 -
International Journal of Biological... Dec 2020Annealing behavior of amylose and amylopectin was unclear. In this work, high purity amylose and amylopectin were extracted from rice starch, and structural properties...
Annealing behavior of amylose and amylopectin was unclear. In this work, high purity amylose and amylopectin were extracted from rice starch, and structural properties of the retrograded rice starch, amylose, and amylopectin before and after annealing treatment were explored. It was found that the purity of the amylose and amylopectin was 95.64% ± 2.69% and 94.98% ± 0.97%, respectively. Their molecular weight was (2.93 ± 0.21) × 10 Da and (5.90 ± 0.13) × 10 Da, respectively. Besides, the relative crystallinities and ratios of 1047 cm/1022 cm of the retrograded rice starch and amylose were significantly increased by annealing treatment, while that of retrograded amylopectin did not change. These results clarified that amylose was more sensitive to annealing treatment than amylopectin, and amylose was more responsible for annealing of starch than amylopectin. The findings contributed to a better understanding of the annealing behavior of starch.
Topics: Amylopectin; Amylose; Chemical Fractionation; Chemical Phenomena; Molecular Weight; Oryza; Spectrum Analysis; Starch
PubMed: 32890568
DOI: 10.1016/j.ijbiomac.2020.08.245 -
Analytical and Bioanalytical Chemistry Nov 2017Amylose, one of the components of starch, is a glucose polymer consisting largely of long, linear chains with a few long-chain branch points. The chain-length (molecular...
Amylose, one of the components of starch, is a glucose polymer consisting largely of long, linear chains with a few long-chain branch points. The chain-length (molecular weight) distribution (CLD) of the component chains of amylose can provide information on amylose biosynthesis-structure-property relations, as has been done previously by fitting amylopectin CLDs to a model with physically meaningful parameters. Due to the presence of long chains, the CLD of amylose can currently best be obtained by size-exclusion chromatography, a technique that suffers from band-broadening effects which alter the observed distribution. The features of the multiple regions present in amylose chain-length distributions are also difficult to resolve, an issue that combines with band broadening to compound the difficulty of analysis and subsequent parameterization of the structural characteristics of amylose. A new method is presented to fit these distributions with biologically meaningful parameters in a way that accounts for band broadening. This is achieved by assuming that band broadening takes the form of a simple Gaussian over a relatively small region and that chain stoppage is a random process independent of the length of the substrate chain over the same region; these assumptions are relatively weak and expected to be frequently applicable. The method provides inbuilt consistency tests for its applicability to a given data set and, in cases where it is applicable, allows for the first nonempirical parameterization of amylose biosynthesis-structure-property relations from CLDs by using parameters directly linked to the activities of the enzymes responsible for chain growth and chain stoppage. Graphical abstract Model calculation illustrating the method described and showing the division between the three characteristic regions of a typical amylose chain-length distribution.
Topics: Amylose; Chemistry Techniques, Analytical; Molecular Weight; Structure-Activity Relationship
PubMed: 28948315
DOI: 10.1007/s00216-017-0639-5 -
AAPS PharmSciTech Apr 2022The two main components of starch - amylose and amylopectin, are responsible for its interaction with moisture. This study investigated how moisture sorption properties...
The two main components of starch - amylose and amylopectin, are responsible for its interaction with moisture. This study investigated how moisture sorption properties of the starches with different amylose-amylopectin ratio impacted tablet properties including drug stability. The starch samples were equilibrated to 33, 53, and 75% relative humidity (RH) and then assessed for tabletability, compactibility, and yield pressure. Effect of humidity on viscoelastic recovery was also evaluated. Tabletability and compactibility of high-amylose starch were better than that of high-amylopectin starch at 33 and 53% RH. However, at 75% RH, the reverse was observed. In terms of yield pressure, high-amylose starch had lower yield pressure than high-amylopectin starch. High-amylose starch tablets also exhibited lower extent of viscoelastic recovery than high-amylopectin starch tablets. The variations in the tableting properties were found to be related to relative locality of the sorbed moisture. Degradation of acetylsalicylic acid in high-amylose starch tablets at 75% RH, 40°C was less than the tablets with high-amylopectin starch. This observation could be attributed to the greater amount of water molecules binding sites in high-amylose starch. Furthermore, most of the sorbed moisture of high-amylose starch was internally absorbed moisture, therefore limiting the availability of diffusible sorbed moisture for degradation reaction. Findings from this study could provide better insights on the influence of amylose-amylopectin ratio on tableting properties and stability of moisture-sensitive drugs. This is of particular importance as starch is a common excipient in solid dosage forms.
Topics: Amylopectin; Amylose; Aspirin; Starch; Tablets
PubMed: 35445277
DOI: 10.1208/s12249-022-02266-0