Starch Properties, Modifications, and Applications

Trends in biopolymer science applied to cosmetics

The term biopolymer refers to materials obtained by chemically modifying natural biological substances or producing them through biotechnological processes. They are biodegradable, biocompatible and non-toxic. Due to these advantages, biopolymers have wide applications in conventional cosmetics and new trends and have emerged as essential ingredients that function as rheological modifiers, emulsifiers, film-formers, moisturizers, hydrators, antimicrobials and, more recently, materials with metabolic activity on skin. Developing approaches that exploit these features is a challenge for formulating skin, hair and oral care products and dermatological formulations. This article presents an overview of the use of the principal biopolymers used in cosmetic formulations and describes their sources, recently derived structures, novel applications and safety aspects of the use of these molecules.

Preparation and characterization of the bonding performance of a starch-based water resistance adhesive by Schiff base reaction

Starch is one of the important raw materials for the preparation of biomass adhesives for its good viscosity and low-cost properties. However, the drawbacks of poor water resistance and bonding performance seriously restrict its application in the wood industry. To resolve those problems, an environment-friendly renewable, and high water resistance starch-based adhesive (OSTH) was prepared with oxidized starch and hexanediamine by Schiff base reaction. In order to optimize the adhesive preparation process, the effect of different oxidation times and oxidant addition on the mechanical performance of plywood were investigated. In addition, the curing behavior characteristics, thermomechanical properties, and thermal stability of the OSTH adhesives were analyzed by differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), and thermogravimetric analysis (TG). Fourier-transform infrared (FTIR) spectrometry and Liquid Chromatography-Mass Spectrometry (LC-MS) were used to explain the reaction mechanisms involved. The results show this adhesive has an excellent bonding performance at the oxidation time of 12 h with 11 % (w/w, dry starch basis) NaIO4 as an oxidant. The dry shear strength, 24-hour cold water, and 3-hour hot water (63 °C) soaking shear strength of the plywood bonded with this resin were respectively 1.87 MPa, 0.96 MPa, and 0.91 MPa, which satisfied the standard requirement of GB/T 9846-2015 (≥0.7 MPa). Thus, this study provided a potential strategy to prepare starch-based wood adhesives with good bonding performance and water resistance.

Structural diversity, functional versatility and applications in industrial, environmental and biomedical sciences of polysaccharides and its derivatives - A review

Recent efforts on the expansion of sustainable and commercial primal matters are essential to enhance the knowledge of their hazards and noxiousness to humans and their environments. For example, polysaccharide materials are widely utilized in food, wound dressing, tissue engineering, industry, targeted drug delivery, environmental, and bioremediation due to their attractive degradability, nontoxicity and biocompatibility. There are numerous easy, quick, and efficient ways to manufacture these materials that include cellulose, starch, chitosan, chitin, dextran, pectin, gums, and pullulan. Further, they exhibit distinctive properties when combined favourably with raw materials from other sources. This review discusses the synthesis and novel applications of these carbohydrate polymers in industrial, environmental and biomedical sciences.

Antidotes in Clinical Toxicology-Critical Review

Poisoning and overdose are very important aspects in medicine and toxicology. Chemical weapons pose a threat to civilians, and emergency medicine principles must be followed when dealing with patients who have been poisoned or overdosed. Antidotes have been used for centuries and modern research has led to the development of new antidotes that can accelerate the elimination of toxins from the body. Although some antidotes have become less relevant due to modern intensive care techniques, they can still save lives or reduce the severity of toxicity. The availability of antidotes is crucial, especially in developing countries where intensive care facilities may be limited. This article aims to provide information on specific antidotes, their recommended uses, and potential risks and new uses. In the case of poisoning, supportive therapies are most often used; however, in many cases, the administration of an appropriate antidote saves the patient's life. In this review, we reviewed the literature on selected antidotes used in the treatment of poisonings. We also characterised the antidotes (bio)chemically. We described the cases in which they are used together with the dosage recommendations. We also analysed the mechanisms of action. In addition, we described alternative methods of using a given substance as a drug, an example of which is N-acetylcysteine, which can be used in the treatment of COVID-19. This article was written as part of the implementation of the project of the Polish Ministry of Education and Science, "Toxicovigilance, poisoning prevention, and first aid in poisoning with xenobiotics of current clinical importance in Poland", grant number SKN/SP/570184/2023.

Effect of Starch Type and Pre-Treatment on the Properties of Gelatin–Starch Foams Produced by Mechanical Foaming

Incorporating biopolymers in packaging foams can contribute to a more circular packaging system, utilizing renewable and compostable materials. Gelatin, with its favorable physicochemical properties, allows for producing gelatin foams via mechanical foaming, a well-established and low-investment process. To improve foam properties, starch can be added to the gelatin formulation. However, the variability in the properties of starch powders can impact the polymer blend and, consequently, the properties of the dry foam. This study aimed to investigate the impact of different starch powders from different botanical origins (tapioca and corn) and treatments (native or pregelatinized) on the properties of gelatin–starch foams produced by mechanical foaming. The study successfully produced foams with densities of approximately 45–50 kg/m3 and compression properties comparable to EPS (expanded polystyrene) foams. The starch type and pre-treatment significantly influenced the properties of the foam. Pregelatinized starches exhibited slightly higher densities due to lower foamability caused by higher viscosity. Using starch exhibiting total loss of birefringence led to denser foams with greater compression properties than those with starch with a certain degree of crystallinity remaining. Therefore, selecting the appropriate starch type is crucial when developing starch-based materials to ensure optimal material and processing properties align with application requirements.

Biopolymer - A sustainable and efficacious material system for effluent removal

Undesired discharge of various effluents directly into the aquatic ecosystem can adversely affect water quality, endangering aquatic and terrestrial flora and fauna. Therefore, the conceptual design and fabrication of a sustainable system for alleviating the harmful toxins that are discharged into the atmosphere and water bodies using a green sustainable approach is a fundamental standpoint. Adsorptive removal of toxins (∼99% removal efficacy) is one of the most attractive and facile approaches for cleaner technologies that remediate the environmental impacts and provide a safe operating space. Recently, the introduction of biopolymers for the adsorptive abstraction of toxins from water has received considerable attention due to their eclectic accessibility, biodegradability, biocompatibility, non-toxicity, and enhanced removal efficacy (∼ 80-90% for electrospun fibers). This review summarizes the recent literature on the biosorption of various toxins by biopolymers and the possible interaction between the adsorbent and adsorbate, providing an in-depth perspective of the adsorption mechanism. Most of the observed results are explained in terms of (1) biopolymers classification and application, (2) toxicity of various effluents, (3) biopolymers in wastewater treatment and their removal mechanism, and (4) regeneration, reuse, and biodegradation of the adsorbent biopolymer.

Thermal properties of different types of starch: A review

Starch is present in high amount in various cereals, fruits and roots & tubers which finds major application in industry. Commercially, starch is rarely consumed or processed in its native form, thus modification of starch is widely used method for increasing its application and process stability. Due to the high demand for starch in industrial applications, researchers were driven to hunt for new sources of starch, including modification of starch through green processing. Thermal properties are significant reference parameters for evaluating the quality of starch when it comes to cooking and processing. Modification of starches affects the thermal properties, which are widely studied using Differential scanning calorimeter or Thermogravimetric analysis. It could lead to a better understanding of starch's thermal properties including factors influencing and expand its commercial applications as a thickener, extender, fat replacer, etc. in more depth. Therefore, the review presents the classification of starches, factors influencing the thermal properties, measurement methods and thermal properties of starch in its native and modified form. Further, this review concludes that extensive research on the thermal properties of new sources of starch, as well as modified starch, is required to boost thermal stability and extend industrial applications.

Lignin and Keratin-Based Materials in Transient Devices and Disposables: Recent Advances Toward Materials and Environmental Sustainability

Rising concerns and the associated negative implications of pollution from e-waste and delayed decomposition and mineralization of component materials (e.g., plastics) are significant environmental challenges. Hence, concerted pursuit of accurate and efficient control of the life cycle of materials and subsequent dematerialization in target environments has become essential in recent times. The emerging field of transient technology will play a significant role in this regard to help overcome current environmental challenges by enabling the use of novel approaches and new materials with unique functionalities to produce devices and materials such as disposable diagnostic devices, flexible solar panels, and foldable displays that are more ecologically benign, low-cost, and sustainable. The prerequisites for materials employed in transient devices and disposables include biodegradability, biocompatibility, and the inherent ability to mineralize or dissipate in target environments (e.g., body fluids) in a short lifetime with net-zero impact. Biomaterials such as lignin and keratin are well-known to be among the most promising environmentally benign, functional, sustainable, and industrially applicable resources for transient devices and disposables. Consequently, considering the current environmental concerns, this work focuses on the advances in applying lignin and keratin-based materials in short-life electronics and single-use consumables, current limitations, future research outlook toward materials, and environmental sustainability.

Upcycling Biodegradable PVA/Starch Film to a Bacterial Biopigment and Biopolymer

Meeting the challenge of circularity for plastics requires amenability to repurposing post-use, as equivalent or upcycled products. In a compelling advancement, complete circularity for a biodegradable polyvinyl alcohol/thermoplastic starch (PVA/TPS) food packaging film was demonstrated by bioconversion to high-market-value biopigments and polyhydroxybutyrate (PHB) polyesters. The PVA/TPS film mechanical properties (tensile strength (σ_u), 22.2 ± 4.3 MPa; strain at break (ε_u), 325 ± 73%; and Young’s modulus (E), 53–250 MPa) compared closely with low-density polyethylene (LDPE) grades used for food packaging. Strong solubility of the PVA/TPS film in water was a pertinent feature, facilitating suitability as a carbon source for bioprocessing and microbial degradation. Biodegradability of the film with greater than 50% weight loss occurred within 30 days of incubation at 37 °C in a model compost. Up to 22% of the PVA/TPS film substrate conversion to biomass was achieved using three bacterial strains, Ralstonia eutropha H16 (Cupriavidus necator ATCC 17699), Streptomyces sp. JS520, and Bacillus subtilis ATCC6633. For the first time, production of the valuable biopigment (undecylprodigiosin) by Streptomyces sp. JS520 of 5.3 mg/mL and the production of PHB biopolymer at 7.8% of cell dry weight by Ralstonia eutropha H16 from this substrate were reported. This low-energy, low-carbon post-use PVA/TPS film upcycling model approach to plastic circularity demonstrates marked progress in the quest for sustainable and circular plastic solutions.

Transparent, flexible, and multifunctional starch-based double-network hydrogels as high-performance wearable electronics

To meet the increasing demands of sustainability and eco-friendliness, biopolymer-based hydrogels combining flexibility and ionic conductivity have drawn great attention for green and wearable sensors. However, the preparation of transparent, flexible, durable, and highly sensitive biopolymer hydrogel-based sensors for strain/pressure and humidity sensing remains a challenge. Herein, a facile one-step strategy is proposed to fabricate transparent, highly flexible, and multifunctional starch/polyacrylamide double-network hydrogels based on natural renewable starch. The resultant hydrogels exhibit fast self-adhesive ability and present high flexibility attributing to the double network consisting of cross-linked starch and polyacrylamide. Then the hydrogels can be assembled as transparent, self-adhesive, flexible, highly sensitive, and multifunctional strain/pressure and humidity sensors for accurate healthcare monitoring. The hydrogel-based sensor shows ultrahigh sensitivity to humidity (35-97% relative humidity). The multifunctionality and biological advantages of starch-based hydrogels offer potential applications in next-generation green and wearable electronics.

Processing Matters in Nutrient-Matched Laboratory Diets for Mice-Energy and Nutrient Digestibility

Starch gelatinization is a major determinant of carbohydrate digestibility and varies with diet processing. Laboratory rodent diets are often marketed as identical, but are sold in different forms, regardless of the markedly higher starch gelatinization in extruded than in pelleted diets. Our hypothesis was that this would impact energy and nutrient digestibility in mice fed pellets or extrudate, respectively. Trial 1 showed that feeding C57BL/6 mice a standard maintenance diet in extruded form results in a significantly higher digestibility of organic matter, energy, and carbohydrates than the identical diet in pelleted form. The replication of the experiment, however, revealed a variation between batches of the same pelleted diet regarding starch and total dietary fiber contents. Given the significant differences in diet digestibility and the potential impacts of digestibility on nutrient utilization, the intestinal microbiome, and intermediary metabolism, trials performed with differently processed diets are not comparable. This might partly explain failures to reproduce results, especially in gastrointestinal or microbiome research. Considering this impact on experimental animals, the degree of starch gelatinization should be declared in the diet information for laboratory animal diets. The differences between batches of laboratory animal diets as observed in the pellets are not acceptable.

Hydrophobizing cellulose surfaces via catalyzed transesterification reaction using soybean oil and starch

Biodegradable modified natural polymers have great potential in curbing the threat of plastic pollution, but are still uncompetitive to petrochemical-based plastic. In this study, starch was hydrophobized by treating starch-dimethyl sulfoxide solutions with soybean oil at high temperature in the presence of sodium carbonate, then spray-coated on paper. The modified starch was evaluated by Fourier-transform infrared spectroscopy analysis and contact angle value measurement of coated paper. FTIR analysis confirmed the substitution of hydroxyl groups with fatty acid ester and provided an estimate of the degree of substitution. The contact angle value of starch-coated paper surfaces was 121°, and was 111° after 10 min, demonstrating the high hydrophobicity and potential of the modified starch coating as a water-resistant treatment. The high hydrophobicity of the coated paper was due to formation of a textured surface with two levels of roughness, caused by the deposition of rough hydrophobic starch particles on paper fibers.

Structural, rheological, pasting and textural properties of granular cold water swelling maize starch: Effect of NaCl and CaCl2

In this study granular cold water swelling (GCWS) starches were subjected to 0, 50, 100, 150 and 200 mM NaCl and CaCl₂ and their effects on microstructure, rheological, pasting, and textural properties were determined. SEM images revealed that NaCl decreased the thickness of GCWS starch paste cell walls while, CaCl₂ resulted in formation of denser and more homogenous pastes. The atomic force microscopy (AFM) results showed that NaCl increased the surface wrinkles of starch granules but CaCl₂ reduced the roughness of starch granule surface. Zeta potential measurements showed both salts reduced the negative values and CaCl₂ was more effective than NaCl. The steady shear measurements showed the shear thinning behavior of the samples. Starch pastes incorporated with NaCl had lower consistency coefficient (K) and apparent viscosity. However, the CaCl₂ containing samples were more viscous. The pasting and textural parameters were increased by the increase of CaCl₂ but decreased with NaCl.

Deciphering Structures of Inclusion Complexes of Amylose with Natural Phenolic Amphiphiles

Amylose inclusion complexes were prepared in aqueous solution with the amphiphilic moiety 3-pentadecylphenol via a direct mixing method. Attenuated total reflection Fourier transform infrared spectroscopy as well as differential scanning calorimetry confirmed the formation of amylose inclusion complexes. The morphology of the synthesized complexes is sensitive to temperature, and X-ray data revealed that the inclusion complexes exhibited distinct structures at different temperatures. Small-angle X-ray scattering data indicated ordered lamellar structures of the synthesized complexes at room temperature, and wide-angle X-ray scattering profiles showed the transformation of the crystalline structure as a function of the temperature. The results of this research will help to understand the relationship between the inclusion complex structures with temperature.

Formaldehyde Use and Alternative Biobased Binders for Particleboard Formulation: A Review

Formaldehyde-based resins are conventionally used as a binder in formulation of particleboard. Epidemiologic studies have shown that formaldehyde is carcinogenic. Efforts to reduce the health hazard effects of the fomaldehyde-based resin in the particleboard formulation have included use of scavengers for formaldehydes and use of an alternative binder. Use of scavengers for the formaldehyde increases the cost and maintenance of particleboard formulation. There is no proof that scavengers eliminate the emission of formaldehyde from particleboard. Use of biobased binders in particleboard formulation provides an alternative for eliminating use of the formaldehyde-based resin. However, the alternative is hindered by challenges, which include limitations of physical and mechanical properties. The challenge has continuously been acted upon through research. The paper presents an overview of the use of starch as an alternative binder. Improvement over time of the starch and limitations thereof requires to be addressed. Use of the modified starch has shown increased particleboard performance. Mechanical strength, such as modulus of rupture, modulus of elasticity, and internal bonding in particleboards, however, remains to be a challenge.

Effect of Biodegradable Binder Properties and Operating Conditions on Growth of Urea Particles in a Fluidized Bed Granulator

Granulation is an important step during the production of urea granules. Most of the commercial binders used for granulation are toxic and non-biodegradable. In this study, a fully biodegradable and cost-effective starch-based binder is used for urea granulation in a fluidized bed granulator. The effect of binder properties such as viscosity, surface tension, contact angle, penetration time, and liquid bridge bonding force on granulation performance is studied. In addition, the effect of fluidized bed process parameters such as fluidizing air inlet velocity, air temperature, weight of primary urea particles, binder spray rate, and binder concentration is also evaluated using response surface methodology. Based on the results, binder with higher concentration demonstrates higher viscosity and higher penetration time that potentially enhance the granulation performance. The viscous Stokes number for binder with higher concentration is lower than critical Stokes number that increases coalescence rate. Higher viscosity and lower restitution coefficient of urea particles result in elastic losses and subsequent successful coalescence. Statistical analysis indicate that air velocity, air temperature, and weight of primary urea particles have major effects on granulation performance. Higher air velocity increases probability of collision, whereby lower temperature prevents binder to be dried up prior to collision. Findings of this study can be useful for process scale-up and industrial application.

Physicochemical properties of partially α-glucan-coated normal corn starch formed by amylosucrase from Neisseria polysaccharea

Amylosucrase (AS) is a glycosyltransferase that produces linear α-1,4 glucans using sucrose as the sole substrate. In this study, for various applications, α-glucan-coated starch (α-GCS) was produced by AS (20 U/L_reactant) from Neisseria polysaccharea to improve the physicochemical properties of raw normal corn starch (NCS) by applying different reaction conditions (i.e., varying the substrate concentration, pH, and temperature). Field-emission scanning electron microscopy (FE-SEM) and X-ray diffraction (XRD) showed that raw NCS was successfully coated by α-glucan. Differential scanning calorimetry (DSC) and rapid viscosity analyses (RVA) of the α-GCS confirmed that the α-glucan coating decreased the degree of retrogradation. Notably, compared to raw NCS as a control, starch retrogradation was significantly (p < 0.05) decreased by 13.7% after five weeks. Therefore, the novel α-GCS can be applied as a functional material for controlled retrogradation in the starch-based food industry for shelf-life extension.

Recent Trends in the Fabrication of Starch Nanofibers: Electrospinning and Non-electrospinning Routes and Their Applications in Biotechnology

Electrospinning a versatile and the most preferred technique for the fabrication of nanofibers has revolutionized by opening unlimited avenues in biomedical fields. Presently, the simultaneous functionalization and/or post-modification of as-spun nanofibers with biomolecules has been explored, to serve the distinct goals in the aforementioned field. Starch is one of the most abundant biopolymers on the earth. Besides, being biocompatible and biodegradable in nature, it has unprecedented properties of gelatinization and retrogradation. Therefore, starch has been used in numerous ways for wide range of applications. Keeping these properties in consideration, the present article summarizes the recent expansion in the fabrication of the pristine/modified starch-based composite scaffolds by electrospinning along with their possible applications. Apart from electrospinning technique, this review will also provide the comprehensive information on various other techniques employed in the fabrication of the starch-based nanofibers. Furthermore, we conclude with the challenges to be overcome in the fabrication of nanofibers by the electrospinning technique and future prospects of starch-based fabricated scaffolds for exploration of its applications.

New Evidences on the Process Sensitivity of Some Renewable Blends Based on Starch considering Their Melt Rheological Properties

The degradability and processability of new renewable materials based on starch and PVOH were studied using the melt flow index (MFI) method by measuring the melt rheological properties which depend not only on the extrusion conditions and material formulation but also on the macromolecule characteristics which can be modified by chemical degradation. These results were correlated with other material properties like color and cross-linking degree. The obtained results show that flowing in the melted state of the studied materials is accompanied by a second process of chains chemical degradation. It was observed that, at the same level of additivation, under identical extrusion conditions, the melted blends with corn starch as main component are highly mechanically sensitive and degrade mostly by chains scission and those with PVOH as major component are highly temperature sensitive and degrade mainly by cross-linking. The obtained results show also that each PVOH-starch blend requires particular formulation and individual windows of melt processing conditions. These results are a good proof that the MFI method is a good path to study the degradability and moldability of process sensitive polymeric materials like those based on starch and PVOH.

Thorough chemical modification of wood-based lignocellulosic materials in ionic liquids

Homogenous acylation and carbanilation reactions of wood-based lignocellulosic materials have been investigated in ionic liquids. We have found that highly substituted lignocellulosic esters can be obtained under mild conditions (2 h, 70 degrees C) by reacting wood dissolved in ionic liquids with acetyl chloride, benzoyl chloride, and acetic anhydride in the presence of pyridine. In the absence of pyridine, extensive degradation of the wood components was found to occur. Highly substituted carbanilated lignocellulosic material was also obtained in the absence of base in ionic liquid. These chemical modifications were confirmed by infrared spectroscopy, (1)H NMR, and quantitative (31)P NMR of the resulting derivatives. The latter technique permitted the degrees of substitution to be determined, which were found to vary between 81% and 95% for acetylation, benzoylation, and carbanilation, accompanied by similarly high gains in weight percent values. Thermogravimetric measurements showed that the resulting materials exhibit different thermal stabilities from those of the starting wood, while differential scanning calorimetry showed discrete new thermal transitions for these derivatives. Scanning electron microscopy showed the complete absence of fibrous characteristics for these derivatives, but instead, a homogeneous porous, powdery appearance was apparent. A number of our reactions were also carried out in completely recycled ionic liquids, verifying their utility for potential applications beyond the laboratory bench.

Determination of the amylose-amylopectin ratio of starches by iodine-affinity capillary electrophoresis

This paper describes the application of capillary electrophoresis to separate and quantify the main polysaccharide components, amylose and amylopectin, present in starch samples. The separation is based on the well-known affinity of these compounds to iodine. The starch components could be effectively separated in less than 7 min using an uncoated fused-silica 'bubble cell' capillary. The proposed method has been applied for the quantitative determination of the soluble amylose content and the ratio amylose-amylopectin in commercial starches. It is shown that the present method is reliable, gives detection limits in the order of 0.1 mg mL(-1), is faster than other methodologies reported in the literature, and can be easily applied to the analysis of different starches. In spite of differences in solubility of amylopectin from different sources, a reasonable estimate of the amylose-amylopectin ratio could be made. Additionally, it was shown that the resulting profiles obtained after hydrolysis with isoamylase and alpha-amylase can provide information on the structure of the starches studied.

Preparation and Properties of Starch-Based Colloidal Microgels

Novel starch microgels were prepared by emulsion cross-linking and characterized with respect to shape, volume, and mass density. Starch microgels appear to be negatively charged ( approximately -50 mV), with a particle size varying as a function of the type of cross-linker (ca. 0.25-10 microm). Environmental scanning electron microscopy observations show a dependence of the particle swelling on the cross-linking density. Viscosimetry reveals that starch microgels behave as charged polymers, where the reduced viscosity increases with dilution (anomalous viscosity behavior) for sufficiently low kappaalpha (ca. kappaalpha <3), the ratio of the particle radius (a), and the Debye length (kappa(-1)). Analogous results are obtained for reference-charged rigid silica spheres, which approach the hard sphere limit for increasing ionic strengths. The shape of the microgels appears to play a minor role in the anomalous viscosity behavior, which is more likely dominated by electrostatic effects.

Amylopectin aggregation as a function of starch phosphate content studied by size exclusion chromatography and on-line refractive index and light scattering

Starches with a natural 65-fold span in covalently bound phosphate content were prepared from five different crops including sorghum, cassava, three potato varieties and an exotic ginger plant, Curcuma zedoaria, with extreme starch phosphate content. These starches were subjected to size exclusion chromatography with refractive index detection (SEC/RI). A simple and rapid method for starch solubilisation was used. The conditions during solubilisation (2 M NaOH) and separation (10 mM NaOH, 50 degrees C) were such as enabling > 94% recovery of the starch without detectable degradation. The aggregation properties of the starch was investigated using on line refractive index/multi angle laser light scattering (RI/MALLS) detection. Three major regions in the SEC profile were identified, consisting of large amylopectin aggregates, amylopectin particles with radius of gyration (Rg) of approx 200 nm (400 nm blocklets) and amylose. A procedure for correction of light scattering signals spread over the SEC profile as a result of aggregate tailing was developed. The significance of the relative amounts of these three molecular species on standard starch pasting parameters, as measured by a Rapid Visco Analyzer (RVA), was investigated. Starches with a high amount of amylopectin aggregates showed high peak viscosities. Moreover, very high amounts of starch bound phosphate or amylose appears to suppress the content of large aggregates resulting in low viscosity.