Amylose Component Research Articles

Ultrasound assisted techniques for starch modification to develop novel drug delivery systems: A comprehensive study

Starch derived from plants plays an essential role in pharmaceuticals due to its components Amylose and Amylopectin, which form essential granules for drug delivery. Its biocompatibility and cost-effectiveness make it indispensable in pharmaceutical formulations, facilitating controlled drug release and tablet breakdown. The effectiveness and safety of drug formulations are often hindered by challenges such as low solubility and stability. In order to overcome these obstacles, current research is focused on modifying the properties of starch. The goal is to improve its solubility, swelling, erosion, stability, and ability to release drugs. A promising solution that has emerged is ultrasound-based modification. This technique has shown great potential in transforming starch granules, leading to improved solubility, degradability, and control over drug release. Not only is this method efficient and quick, but it also has the added benefit of being eco-friendly. This discussion will explore the mechanisms behind the modification of starch based on ultrasound, delving into both the physical and chemical changes that occur in starch granules. The analysis explores the utilization of modified starch induced by ultrasound in the field of drug delivery, investigating its stability and compatibility with biological systems. By exploring the capabilities and difficulties associated with the use of ultrasound to change starch for the delivery of drugs, we highlighted its potential as a leading and effective methodology.

Research on rice starch gel preparation and crosslink network structure-rheological property based on direct-writing 3D printing

Amylopectin and amylose components are natural polymers within rice starch granules, intertwined in specific conditions to form gel polymerized with pore crosslink network, has potential printing properties. In this study, a rice starch gel preparation scheme is proposed for stable properties, and starch granule phase transition mechanism is analyzed based on RVA test during preparation, it can be divided into four-stage, swelling, reacting, homogenizing and self-assembling stages. Gel surface tension and contact angle tested with starch concentration effect, a correlation is developed, reflecting a competition result to gel droplet macro-morphology between the intermolecular cohesion and crosslink network. SEM is used to reveal typical crosslink structures of different starch molecular component proportions, providing objective support for starch gel rheologic property change. Results indicate gel interior crosslink network formed under concentration 12 %, the gel with amylose 4.475 % presents better printing accuracy. Gel shear modulus positively correlated with amylose proportion. Japonica gel under 20 % is of higher viscosity and rapid reassembly ability after interior crosslink network is broken. Max dynamic viscosity is positively correlated with starch concentration. The study aims to provide theoretical and practical support for in-depth analysis of rice starch material application in direct-write 3D printing.

A co-carrier for plasmid DNA and curcumin delivery to treat pancreatic cancer via dendritic poly(l-lysine) modified amylose

Pancreatic cancer is one of the most lethal malignancies in the world and remains one of the leading causes of cancer related death. For its treatment, a lot of investigations have dealt not only with individual chemotherapy by using polymeric carriers to deliver anticancer drugs, but also with individual gene therapy by using polymeric carriers to deliver nucleic acids such as small interfering RNA (siRNA) and plasmid DNA. However, relatively few studies have been focused on the co-delivery of gene and anticancer drug by multifunctional polymeric carriers for its synergistic therapy. In this work, a DPLL-functionalized amylose (ADP) was prepared by the click reaction between azidized amylose and propargyl focal point poly(l-lysine) dendrons, and then used to co-deliver plasmid pIRES2-EGFP-TNFα and curcumin for pancreatic cancer treatment. Due to the internal hydrophobic cavity of amylose component, ADP could load efficiently curcumin with anticancer activity and showed a sustained release behavior. Moreover, the curcumin-loaded ADP could form colloidally stable nanocomplexes with plasmid DNA in aqueous system due to the existence of cationic poly(l-lysine) dendrons and exhibited high gene transfection efficiency. The in vitro and in vivo tests confirmed the effectiveness of using ADP to co-deliver plasmid pIRES2-EGFP-TNFα and curcumin for synergistic therapy of pancreatic cancer.

Odor-scavenging capabilities of pre-formed “empty” V-type starches for beany off-flavor compounds

Off-flavors have garnered significant attention in research due to their impact on overall flavor, which leads consumers to avoid purchasing or consuming food products with off-flavors, even if they offer health benefits. However, there has been limited research on encapsulating off-flavor compounds as a means to mask them and to improve the flavor profiles of food products. Starch, particularly its amylose component, is well-known for its ability to form inclusion complexes (ICs) with various small molecules, providing protection and controlled release of these encapsulated guest molecules. The complexation interaction between starch and guest compounds is influenced by factors such as the structure and chemistry of the guest, as well as the process method and parameters. In the present study, nine different beany off-flavor compounds, including hexanal (HAL), 3-hexanol (HOL), benzaldehyde (BAL), 1-octen-3-ol (OOL), 1-octen-3-one (ONE), 2-pentylfuran (PTF), trans-2-nonenal (NAL), trans, trans-2,4-nonadienal (NAD), and trans, trans-2,4-decadienal (DEC) were used as model off-flavors to examine their complexation ability with three types of preformed “empty” V-type high amylose maize starches (HAMS), namely V6h, V7, and V8. The successful formation of inclusion complexes was characterized using complementary techniques, including X-ray diffraction (XRD), differential scanning calorimetry (DSC), and gas chromatography-mass spectrometry (GC-MS). The results revealed that the complexation of off-flavor compounds with the starches did not significantly alter the original structures of the starches. Additionally, the IC samples prepared using the gas phase (GP) approach exhibited significantly higher encapsulation efficiency compared to the direct contact (DC) approach, as indicated by GC-MS analysis. Among the V-type starches, V6h HAMS demonstrated the highest complexation efficiency for all selected beany off-flavor compounds when the ICs were prepared using the GP approach. This study suggests that both V6h and V8 starches exhibit effective scavenging abilities for beany off-flavor compounds. Further, complexation properties depend on the properties of the off-flavor compounds, the type of V starch used, and the IC preparation approach.

Encapsulation and retention profile of thymol in the preformed “empty” V‐type starch inclusion complex

AbstractStarch, especially its amylose component can form inclusion complex (IC) with various small molecules, such as flavor and aroma compounds. Complexation of flavor compounds using starch matrices is driven by the hydrophobic interaction and the successful complexation may increase the retention of flavor compounds. In the present study, thymol (2‐isopropyl‐5‐methylphenol) at two different concentrations was introduced into three types of V‐type crystalline starches that have different inner helical cavity size, namely V6h, V7, and V8, and the formed ICs were characterized by X‐ray diffraction (XRD) and differential scanning calorimetry (DSC). The encapsulation efficiency (EE), loading efficiency (LE), and retention profile were determined by gas chromatography‐mass spectrometry (GC‐MS). The results indicated that when preparing ICs using V6h high amylose maize starch (HAMS) at a starch/thymol mass ratio of 2:1, the helical cavity of V6h helices was expanded and resulted in the formation of V7 crystals. Such circumstance could be owing to the cyclic structure of thymol and caused the minor phase transition at T2 of around 110°C observed in DSC. While in other conditions, the complexation with thymol did not alter the structure of starch. The EE and LE results suggested that V6h‐type HAMS exhibits higher capability to encapsulate thymol compared to V7 and V8 HAMS. All ICs demonstrated potent flavor retention ability and retained more than 70% of thymol after 8 h treatment. This study suggested that preformed “empty” V‐type starch could act as a potential matrix to encapsulate thymol, and this encapsulation technology should enable targeted applications of thymol for food processing and formulation applications.

CRISPR/Cas9-Mediated Mutagenesis of the Granule-Bound Starch Synthase Gene in the Potato Variety Yukon Gold to Obtain Amylose-Free Starch in Tubers.

Potato (Solanum tuberosum L.) is the third most important food crop after rice and wheat. Its tubers are a rich source of dietary carbohydrates in the form of starch, which has many industrial applications. Starch is composed of two polysaccharides, amylose and amylopectin, and their ratios determine different properties and functionalities. Potato varieties with higher amylopectin have many food processing and industrial applications. Using Agrobacterium-mediated transformation, we delivered Clustered regularly interspaced short palindromic repeats and CRISPR-associated protein 9 (CRISPR/Cas9) reagents to potato (variety Yukon Gold) cells to disrupt the granule-bound starch synthase (gbssI) gene with the aim of eliminating the amylose component of starch. Lugol-Iodine staining of the tubers showed a reduction or complete elimination of amylose in some of the edited events. These results were further confirmed by the perchloric acid and enzymatic methods. One event (T2-7) showed mutations in all four gbss alleles and total elimination of amylose from the tubers. Viscosity profiles of the tuber starch from six different knockout events were determined using a Rapid Visco Analyzer (RVA), and the values reflected the amylopectin/amylose ratio. Follow-up studies will focus on eliminating the CRISPR components from the events and on evaluating the potential of clones with various amylose/amylopectin ratios for food processing and other industrial applications.

Coalescence and directed anisotropic growth of starch granule initials in subdomains of Arabidopsis thaliana chloroplasts

Living cells orchestrate enzyme activities to produce myriads of biopolymers but cell-biological understanding of such processes is scarce. Starch, a plant biopolymer forming discrete, semi-crystalline granules within plastids, plays a central role in glucose storage, which is fundamental to life. Combining complementary imaging techniques and Arabidopsis genetics we reveal that, in chloroplasts, multiple starch granules initiate in stromal pockets between thylakoid membranes. These initials coalesce, then grow anisotropically to form lenticular granules. The major starch polymer, amylopectin, is synthesized at the granule surface, while the minor amylose component is deposited internally. The non-enzymatic domain of STARCH SYNTHASE 4, which controls the protein’s localization, is required for anisotropic growth. These results present us with a conceptual framework for understanding the biosynthesis of this key nutrient.

Complexation ability and physicochemical properties of starch inclusion complexes with C18 fatty acids

Starch, especially its amylose component, is well-known to form inclusion complexes with a variety of small molecules such as fatty acids. The structure of the lipid guest could affect its complexation ability and other properties such as thermal stability. The present study aimed to investigate the complexation ability and the physicochemical properties of high amylose maize starch (HAMS) inclusion complexes with C18 fatty acids of various numbers and positions of double bonds, including octadecanoic (stearic, SA), (Z)-octadec-9-enoic (oleic, OA), (E)-octadec-9-enoic (elaidic, EA), (9Z,12Z)-octadeca-9,12-dienoic (linoleic, LA), (9Z,12Z,15Z)-octadeca-9,12,15-trienoic (α-linolenic, ALA), and conjugated linoleic acids (CLA). Two complexation methods were used, which are the DMSO method and the “empty” V-type method. The formation, structural characteristics, and thermal properties of inclusion complexes formed were examined by complementary techniques including differential scanning calorimetry (DSC), X-ray diffraction (XRD), and Fourier transform infrared (FTIR) spectroscopy. As the guest fatty acid became more unsaturated and as the number of double bonds increased, the dissociation temperatures of HAMS-fatty acid inclusion complexes formed decreased with either complexation method. The DMSO method resulted in the formation of Form I inclusion complexes only, whereas the “empty” V-type method promoted the formation of Form II inclusion complexes with higher thermal stability. In addition, ethanol concentration was found to influence the formation of inclusion complexes when using the “empty” V-type method, and intermediate concentrations were more favorable to maintain a stable and flexible amylose helical structure to form inclusion complexes with higher crystallinity and thermal stability.

Proteomics and Post-Translational Modifications of Starch Biosynthesis-Related Proteins in Developing Seeds of Rice.

Rice (Oryza sativa L.) is a foremost staple food for approximately half the world’s population. The components of rice starch, amylose, and amylopectin are synthesized by a series of enzymes, which are responsible for rice starch properties and functionality, and then affect rice cooking and eating quality. Recently, proteomics technology has been applied to the establishment of the differentially expressed starch biosynthesis-related proteins and the identification of posttranslational modifications (PTMs) target starch biosynthesis proteins as well. It is necessary to summarize the recent studies in proteomics and PTMs in rice endosperm to deepen our understanding of starch biosynthesis protein expression and regulation, which will provide useful information to rice breeding programs and industrial starch applications. The review provides a comprehensive summary of proteins and PTMs involved in starch biosynthesis based on proteomic studies of rice developing seeds. Starch biosynthesis proteins in rice seeds were differentially expressed in the developing seeds at different developmental stages. All the proteins involving in starch biosynthesis were identified using proteomics methods. Most starch biosynthesis-related proteins are basically increased at 6–20 days after flowering (DAF) and decreased upon the high-temperature conditions. A total of 10, 14, 2, 17, and 7 starch biosynthesis related proteins were identified to be targeted by phosphorylation, lysine acetylation, succinylation, lysine 2-hydroxyisobutyrylation, and malonylation, respectively. The phosphoglucomutase is commonly targeted by five PTMs types. Research on the function of phosphorylation in multiple enzyme complex formation in endosperm starch biosynthesis is underway, while the functions of other PTMs in starch biosynthesis are necessary to be conducted in the near future.

Effects of amylose and amylopectin chain-length distribution on the kinetics of long-term rice starch retrogradation

Understanding the characteristics of long-term starch retrogradation is critical for developing functional foods with desirable textural attributes. The long-term retrogradation kinetics of 10 different rice starches with a wide range of amylose content were thus investigated in this study, focusing on their relations with the starch chain-length distributions (CLDs). Correlation analysis between the retrogradation parameters from differential scanning calorimetry (DSC) with starch CLDs showed for the first time that the amylose content had a parabolic relationship with the melting conclusion temperature and enthalpy of long-term retrograded starches, indicating that the amylose component has a bi-directional effect on the long-term amylopectin retrogradation property. Furthermore, the amount of amylose short-medium chains and amylopectin medium chains were negatively and positively correlated with the melting onset temperature of long-term retrograded starches, respectively. The information learnt from this study could be applied in the rice industry to improve the textural attributes of cooked rice.

Study on components and structure of difference Vietnamese starch sources

In this study, we focused was on the determination of amylose and amylopectin components of starch from different plant sources in Vietnam by UV-VIS spectroscopy. Besides, the distribution of natural starch structure and crystallization level of different starches was also evaluated by FT-IR, XRD analysis methods. By UV-VIS absorption spectroscopy, we could quantify amylose and amylopectin contents which are the two main components in different starch sources in Vietnam. Our results have showed that corn starch sample had the highest amylose content at 28.22%wt. The degree of morphology in the structure is evaluated through FT-IR spectroscopy method and the crystallization ability of starch was determined by XRD diffraction method. These results showed that although the amylose content of arrowroot starch sample (27.24%) is higher than that of cassava starch (10.31%) or rice starch samples (17.10%), but the tightness rearrange level in the structure of dong starch is the smallest (0.2089) compared to cassava starch (0.2793) or rice starch (0.6645). After all these effective results, starch sample having the good properties and degree of crystallization as well as suitable amylose pectine content will be selected to for further plasticization and modification for the application in elaboration of biodegradable starch based composite materials.

Structure and properties of starch and flour of four Brazilian sweet potatoes (Ipomoea batatas) cultivars

Starch is the most natural polymer used in the food and non-food industry. Sweet potato is among the world’s most important, versatile and underexploited food crops; its composition depends on the planting strategy, climatic conditions, cultivar, geographic region, soil quality, and other. The physical-chemical characteristic and functional properties depends also of the amylose, amylopectin ratio and the molecular components of amylose and amylopectin. In this study, the structural and physicochemical properties of starches from four sweet potato genotypes cultivated in Brazil were compared. Starch granules of roots of sweet potato all exhibited oval and irregular shapes with granule sizes ranging from 8 to 30 µm. Amylose contents of roots of sweet potato starches differed from 9.7 to 15.1%. Ratios of 1045/1022 and 1022/995 cm−1 of Fourier transform infrared spectra varied in the range of 0.8114–0.8558 and 0.9046–0.9347, respectively, which means that the genotypes present different structure ordering. Also, the digestibility, swelling power, and solubility showed some differences between the starches, probably due to the differences in amylose and amylopectin contents and granules sizes. The different genotypes showed similar thermal stability. Our study indicated the sweet potato genotypes are greatly influenced the amylose content, structure order, the degree of short-range order, granule size, digestibility, swelling power and solubility of sweet potato genotypes. Keywords: Biopolymer; Carbohydrate; Ipomoea batatas; new starch quality

Natural Polymorphisms in Arabidopsis Result in Wide Variation or Loss of the Amylose Component of Starch.

Starch granules contain two Glc polymers, amylopectin and amylose. Amylose makes up approximately 10% to 30% (w/w) of all natural starches thus far examined, but mutants of crop and model plants that produce amylose-free starch are generally indistinguishable from their wild-type counterparts with respect to growth, starch content, and granule morphology. Since the function and adaptive significance of amylose are unknown, we asked whether there is natural genetic variation in amylose synthesis within a wild, uncultivated species. We examined polymorphisms among the 1,135 sequenced accessions of Arabidopsis (Arabidopsis thaliana) in GRANULE-BOUND STARCH SYNTHASE (GBSS), encoding the enzyme responsible for amylose synthesis. We identified 18 accessions that are predicted to have polymorphisms in GBSS that affect protein function, and five of these accessions produced starch with no or extremely low amylose (< 0.5% [w/w]). Eight further accessions had amylose contents that were significantly lower or higher than that of Col-0 (9% [w/w]), ranging from 5% to 12% (w/w). We examined the effect of the polymorphisms on GBSS function and uncovered three mechanisms by which GBSS sequence variation led to different amylose contents: (1) altered GBSS abundance, (2) altered GBSS activity, and (3) altered affinity of GBSS for binding PROTEIN TARGETING TO STARCH1-a protein that targets GBSS to starch granules. These findings demonstrate that amylose in leaves is not essential for the viability of some naturally occurring Arabidopsis genotypes, at least over short timescales and under some environmental conditions and open an opportunity to explore the adaptive significance of amylose.

Influence of Chain Structures of Starch on Water Absorption and Copper Binding of Starch‐Graft‐Itaconic Acid Hydrogels

Bio‐based hydrogels destined for use as low cost renewable biosorbents are synthesized. The impact of the two components of starch, amylose, and amylopectin, on the properties of the hydrogels is assessed. Hydrogels are synthesized by solution based graft copolymerization of itaconic acid monomers on a corn starch backbone in the presence of an acrylamide crosslinker and the potassium persulfate/sodium bisulfite redox initiator pair. Three types of corn starch are used: normal corn starch, waxy starch, and high amylose starch. The amylose:amylopectin ratios are: 27:73 for normal starch (NS), 70:30 for high amylose starch (HAS), and 0:100 for waxy starch (WS). Swelling tests performed in a variety of solutions show no significant differences in swelling capacity among the hydrogels. The hydrogels also perform similarly in copper adsorption tests. Overall, these results indicate that native corn starch is as effective as amylopectin and amylose‐rich starch.

Rheological and microstructural characteristics of rice starch–tara gum mixtures

ABSTRACTEffects of tara gum (TG) at different TG concentrations (0.2–0.6% w/w) on the rheological and pasting properties of rice starch (RS) pastes (5% w/w) were studied. Confocal laser scanning microscopy (CLSM) observation was also conducted to investigate the possible interaction between RS and TG. All RS–TG mixture pastes exhibited a pseudoplastic shear-thinning characteristic (n = 0.17–0.26). RS alone displayed a highly thixotropic behaviour as compared to RS–TG mixtures, showing that the thixotropic loop area markedly decreased in the presence of TG. Consistency index (K), apparent viscosity (ηa,100), storage moduli (G′), and loss moduli (G″) values increased with increasing TG concentration. Viscous characteristics in the RS–TG mixture system were more pronounced compared to the control (0% TG) as evidenced by their higher tan δ values. Rapid visco-analysis showed that the addition of TG resulted in a significant increase in the peak, breakdown, final, and setback viscosities, and their viscosities also increased with an increase in TG concentration. These results suggested that the synergistic effect of TG addition on rheological and pasting properties of RS pastes appeared to be due to phase separation process that occurred as a result of incompatibility between TG and amylose component in starch, as confirmed by CLSM micrographs.

Morphologies and gelatinization behaviours of high-amylose maize starches during heat treatment

The granule morphologies and gelatinization behaviours of high-amylose maize starches during heating treatment were investigated by confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM). Maltese crosses demonstrated that the high-amylose maize starches maintained a granular structure even at 120°C. The granules of high-amylose maize starches swelled slightly at 100°C and swelled remarkably at approximately 120°C. The destruction of the starch structure began at the centre and expanded rapidly to the periphery. The intense fluorescence of high-amylose maize starch granules gradually became feeble, and the darker region spread outward during heating at 130°C for 30min, indicating that the amylose component may have been damaged and shifted. The starch granules treated at 140°C were substantially destroyed, and the CLSM, normal light microscopy (NL) and SEM images displayed no discernible granules, which indicated that the original starch granules formed a continuous integrated matrix.

An Insight into the Glycemic Index of Rice

Glycemic index of rice is a highly complex trait. Rice varieties possessing slowly digestible starch (high amylose) are potentially characterized to have low glycemic index and can be useful for management of type II diabetes. Understanding genetic mechanisms underlying starch biosynthesis and metabolism of cooked rice can pave the way for developing efficient breeding and selection strategy for combining high grain yield with low glycemic index. In this context, reverse genetics can prove useful. Available rice genome sequence information encoding key enzymes involved in biosynthesis of amylose component of starch can unravel novel alleles involving single nucleotide polymorphisms (SNPs). A multi-allelic waxygene (Wx) encoding Granule-Bound Starch Synthase I (GBSS I) enzyme is known to determine amylose content in rice endosperm. Potential molecular markers are now available to detect GBSS I alleles (SNPs) associated with five classes of amylose (waxy: 0–5%, very low: 5–12%, low: 12–20%, intermediate: 20–25%, and high:25–33%). These can be routinely used to assist breeding programme. Besides, the presence of intra-class variations in amylose content could be attributed to additional regulatory elements or environmental conditions.

Effects of ionic liquid 1-allyl-3-methylimidazolium chloride treatment on the microstructure and phase transition of cornstarch

The effect of ionic liquid treatments containing various concentrations of 1-allyl-3-methylimidazolium chloride (AMIMCl) on the morphology and phase transition of cornstarch was observed using a differential scanning calorimeter (DSC), a scanning electron microscope (SEM), an optical microscope, X-ray diffraction (XRD), and a confocal laser scanning microscope (CLSM). After treatment with 50% AMIMCl, amylopectin endotherms were formed at higher temperatures, accompanied by an increase in absorbed enthalpy. However, slight changes were observed in the granular appearance and relative crystallinity (RC) of cornstarch. Upon increasing the experimental AMIMCl concentration, a remarkable loss of crystalline structure was observed in starch and the relative endotherm shifted to a lower temperature. Finally, after processing with 100% AMIMCl, disintegrated particles without an ordered structure were produced and induced no pronounced thermal change in the DSC diagram. In addition, the amylose components of normal starch, including amylose–lipid complexes, were significantly affected by the presence of AMIMCl in the solvent mixture. These components were, however, noticeably absent from granules at AMIMCl concentrations higher than 50%.

Utilization of the field experiment results of University of Debrecen in the development of maize-based bio-ethanol production

Maize is currently the single raw material of bio-ethanol production in Hungary. The aim of our examinations is the observation of yield andnutritional characteristics of commercial maize hybrids in Hungary from the aspect of efficient bio-ethanol production. We set up a randomized block field trial. We determined the starch content and starch yield (t ha-1) of the 51 maize hybrids involved in the field trial.In laboratory conditions, we examined the amylose and amylopectin ratio and the amount of resistant starch of the selected 20 maize hybrids.According to our results, there is a significant difference between the starch yield the amylose component of the starch content and resistant starch of the examined maize hybrids. Our studies reveal that maize as a raw material must be selected based on the cultivation objectives. If the objective is bio-ethanol production, detailed knowledge of starch content is necessary. There is a significant difference among commercial maize hybrids in Hungary in terms of characteristics determining the producible amount of bio-ethanol.

Thermal dissolution of maize starches in aqueous medium

Starches are insoluble in neutral water at room temperature. However, if they are heated beyond the boiling point of water in a closed container, they eventually dissolve. The dissolution profile depends on the type of starch. The dissolution processes of maize starches were monitored in real time by measuring the transmittance of starch dispersion/solution while it was heated. It was found that the dissolution of starches in water results from the degradation of the two components of starches, amylopectin and amylose. Starches from both normal maize and waxy maize were fully dissolved in water when their aqueous solution was heated to approximately 174 °C. Upon cooling to room temperature, amylopectin remained in a solubilized state while amylose molecules were retrograded. For starch solutions that have been heated to higher than 191 °C, the color turned brown and the retrogradation of amylose was not observed.