Chemical Modification Of Starch Research Articles

Viability of Ecofriendly Ionic Liquids in Starch Plasticization and Modification

AbstractIonic liquids (IL) have emerged as the potential class of solvents for various chemical processes and reactions, including gelatinization and chemical modification of starch. Through various studies it has been established that expensive nature of ILs can be counter balanced by employing the mixture of IL/water instead of pure ILs. The IL/water system has the advantage to plasticize starch more effectively due to their synchronal effect and rational viscosity. The properties of ILs can be tempered by preferring particular cations/anions according to the specific type of starch which may be helpful in convenient dissolution and modification of starch. Starch can be modified by esterification or etherification reaction in IL medium to alter their properties and to use it in various application areas. Starch dissolution is subjected to various parameters like type of starch, nature of IL, ratio of IL/water, and temperature which has been discussed elaborately in the present review paper.

Starch benzoylation in supercritical CO2. A novel sustainable route towards biodegradable hydrophobic polymeric materials

Starch is one of the best candidates to replace non-renewable plastics thanks to its plentiful availability in nature, and low cost. Food industry produces large amount of starch-containing waste, which are not utilizable as nutrients, therefore have potential for non-food applications. However, some of the physicochemical characteristics of starch, such as low thermal stability and high hydrophilicity are undesirable for many applications. Supercritical CO2 is an attractive alternative media for the chemical modification of starch due to its unique tuneable properties, non-toxicity and reduced cost. In this study we performed the benzoylation of starch using vinyl benzoate via a base-catalysed transesterification reaction in supercritical CO2 employing different reaction conditions (temperature, pressure, reaction time, reagents feed) obtaining a wide range of degrees of substitution (0.01-3.00), as determined via elemental analysis and NMR. The modified starches were fully characterized (FT-IR, TGA, DSC, SEM, contact angle, rheology), revealing an overall increased hydrophobicity and improved thermal stability while retaining most of their biodegradability potential. To the best of our knowledge, this is the first report of benzoylation of starch in supercritical CO2 (scCO2), paving the way for the industrial application of this novel solvent in the hydrophobization of starches.

Chemically Modified Starches as Food Additives.

Starch is a renewable and multifunctional polysaccharide biopolymer that is widely used both in the food industry and other areas of the economy. However, due to a number of undesirable properties in technological processes, it is subjected to various modifications. They improve its functional properties and enable the starch to be widely used in various industries. A modified starch is a natural starch that has been treated in a way that changes one or more of its initial physical and/or chemical properties. Chemical modification consists of the introduction of functional groups into starch molecules, which result in specific changes in the physicochemical and functional properties of starch preparations. The bases of chemical modifications of starch are oxidation, esterification or etherification reactions. In terms of functionality, modified preparations include cross-linked and stabilized starches. These starches have the status of allowed food additives, and their use is strictly regulated by relevant laws. Large-scale scientific research is aimed at developing new methods of starch modification, and the use of innovative technological solutions allows for an increasingly wider use of such preparations. This paper characterizes chemically modified starches used as food additives, including the requirements for such preparations and the directions of their practical application. Health-promoting aspects of the use of chemically modified starches concerning resistant starch type RS4, encapsulation of bioactive ingredients, starch fat substitutes, and carriers of microelements are also described. The topic of new trends in the use of chemically modified starches, including the production of biodegradable films, edible coatings, and nanomaterials, is also addressed.

Effects of electron beam irradiation on ozone-modified potato starch film

Functional starch-based films are promising materials being developed at different laboratories. Native and modified starches are two materials being employed for this purpose. Chemical modification of starch generally involves esterification, etherification, or oxidation of the units that make up the starch polymers. Ozone constitutes an advanced oxidation technology for starch modification. In this work, properties of two kinds of materials - ozone-modified potato starch and irradiated ozone-modified potato starch-based films - were evaluated. Potato starch films were submitted to electron beam irradiation with doses up to 40 kGy. Films were produced by the casting technique using native and ozonated potato starch, glycerol as the plasticizer, and water as the solvent, and characterized in term of solubility and absorption of water, determination of oxygen gas transmission rate and Fourier Transform infrared Spectroscopy (FTIR) analysis. Ozone-modified potato starch presented strong alterations on pasting properties, with drastic reduction of viscosity values, water solubility and oxygen permeability. The data reported in this work contribute to the understanding of the ozone-modification process on starch and suggests further possibilities of industrial applications of ozonation on biomaterials.

PLA/modified-starch blends and their application for the fabrication of non-woven fabrics by melt-blowing

Blends of polylactic acid (PLA) and thermoplastic starch (TS) with and without chemical modification were obtained by melt extrusion and used to obtain non-woven fabrics by melt-blowing for the first time. Different TS were obtained by reactive extrusion from native cassava, oxidized, maleated, and dual modified (oxidized and maleated) starch. The chemical modification of starch decreases the difference in viscosity and favors blending, resulting in more homogeneous morphologies, unlike the blends with unmodified TS, which displayed a visible phase separation with large TS droplets. The dual modified starch showed a synergistic effect to process TS by melt-blowing. Regarding non-woven fabrics, values in diameter (2.5–82.1 μm), thickness (0.4–0.6 mm), and grammage (49.9–103.8 g/m2) were explained due to differences in viscosity of the components, and to the fact that during melt the hot air preferentially stretches and thins the areas without large droplets of TS. Moreover, plasticized starch acts as a flow modifier. The porosity of the fibers increased with the addition of TS. Further studies and optimization of blends with low contents of TS and type starch modification will be necessary to completely understand these systems with very complex behavior to obtain non-woven fabrics with improved properties and application.

Phosphorylation of Alkali Extracted Mandua Starch by STPP/STMP for Improving Digestion Resistibility.

The chemical modifications of starch granules have been adopted to improve the characteristics, viz., paste clarity, resistant starch content, thermal stability, and so forth. The modified starch has been applied as a biopolymer in developing various preparations of food, nutraceutical, and pharmaceutical importance. The present work is focused on phosphorylation of alkali extracted mandua starch for improving digestion resistibility. The phosphorylation of mandua starch extracted from grains of Eleusine coracana (family Poaceae) was carried out by sodium tripolyphosphate/sodium trimetaphosphate at alkaline pH. After chemical treatment of mandua starch, the resistant starch (RS) content was increased significantly. The digestibility of chemically modified starch (CMS) was decreased down after treating by the phosphorylation process. The digestibility of CMS and alkali extracted mandua starch (AMS) in simulated intestinal fluid was found to be 32.64 ± 1.98% w/w and 61.12 ± 2.54% w/w, respectively. After chemical modification of mandua starch, a decrement was observed in amylose content, water-binding capacity, and swelling power. In the three-stage decomposition pattern of CMS studied by thermal gravimetric analysis, the significant changes in decomposition behavior also affirmed the impact of cross-linking in the improvement of stability of internal structure and resistibility of starch. In Fourier transform infrared (FTIR), the formation of the P=O bond was observed in CMS at 1250 cm-1. The acute and sub-acute toxicity studies in terms of behavioral, haematological, and enzymological parameters for CMS were not different significantly from AMS and control (p > 0.05). The cellular architecture of the liver and the kidney were found normal after consumption of CMS. The results revealed that significant increment in RS fraction occurred after cross-linking of mandua starch. The prepared starch may be applied in developing various formulations of food and pharmaceutical importance.

Anionic and Ampholytic High-Amylose Starch Derivatives as Excipients for Pharmaceutical and Biopharmaceutical Applications: Structure-Properties Correlations.

Many chemical modifications of starch are realized in organic (mostly methanol) phase, allowing high degrees of substitution (DS). Some of these materials are used as disintegrants. To expand the usage of starch derivative biopolymers as drug delivery system, various starch derivatives obtained in aqueous phase were evaluated with the aim to identify materials and procedures which would generate multifunctional excipients providing gastro-protection for controlled drug delivery. Chemical, structural and thermal characteristics of anionic and ampholytic High Amylose Starch (HAS) derivatives under powder (P), tablet (T) and film (F) forms were evaluated by X-ray Diffraction (XRD), Fourier Transformed Infrared (FTIR) and thermogravimetric analysis (TGA) methods and correlated with the behavior of tablets and films in simulated gastric and intestinal media. At low DS, the HAS carboxymethylation (CMHAS) in aqueous phase, generated tablets and films that were insoluble at ambient conditions. The CMHAS filmogenic solutions, with a lower viscosity, were easier to cast and gave smooth films without the use of plasticizer. Correlations were found between structural parameters and the properties of starch excipients. Compared to other starch modification procedures, the aqueous modification of HAS generated tunable multifunctional excipients that may be recommended for tablets and functional coatings for colon-targeted formulations.

Effect of Chemical Modification By Oxidation and Esterification Process On Properties of Starch: A Review

Starch is a carbohydrate or polysaccharide consisting of a large number of glucose units linked through glycosidic bonds and containing different amounts of amylose and amylopectin as macromolecules. Starch modification can be done physically, chemically, and enzymatically. The process of chemical modification of starch aims to separate the long glucose chains from the polymer molecules in order to reduce the high viscosity of the unmodified starch solution and thus maximize the possible amount of starch in technical applications This modification involves exploiting the many hydroxyl groups present in starch granules to introduce functional groups, resulting in changes in physicochemical and functional properties such as gelatinization, paste, and retrogradation properties of starch. Esterification and oxidation are types of chemical modification processes that can be applied to improve starch characteristics. However, the chemical modification process did not affect the morphology and had little effect on changing the structure of the starch

Chemical Modifications of Starch; A Prospective for Sweet Potato Starch

The current review presents the potential chemical modifications and applications of sweet potato starch in food and non-food industries. Native starch in general and particularly sweet potato starch characteristics have several functional features and applications in biomedicine as well as in the food industry. Modified starch is expected to enhance such characteristics as discussed in this review. For instance, due to the polymeric and branching nature of starch; the starch is usually less soluble, absorbs less water and oil, and shows a strong ability to bind to iodine. Also, native starches have significantly lower digestibility values under enzymatic treatment. Starch modifications, therefore are designed to enhance one or more of the above-mentioned limitations; thereby, modification of starch can alter the physicochemical characteristics of the native starch to improve its functional characteristic.
 Starches can be modified using physical methods (annealing, heat moisture treatment, pre-gelatinization, and other non-thermal processes), chemical methods (etherification, acetylation, acid modification, cationic linking, esterification, cross-linking, and oxidation), enzymatic modification methods, genetic alteration process or combination of them.

Method of Starch Acetylation and Use of Acetylated Starch as Polymer in Pharmaceutical Formulations

Starch is used as a key polymer in pharmaceutical industries since long back for various purposes such as binder, disintegrating agent, bulking agent, film former and many more. But as per the purpose of dosage forms it’s used get changed. Currently scientists are more focused on controlled and sustained release dosage forms. Since, native starch does not meet up the demand of controlled or sustained release, so there is need of modifying the polymer as per dosage form requirement. Modification of starch can be done by physical, chemical, enzymatic, and genetic method. Among all, the current article is focusing on chemical modification of starch, especially the acetylation. Acetylation of starch can be done using different acetylating agent such as acetic anhydride (AA), and glacial acetic acid etc. and sodium hydroxide (NaOH), pyridine and sulphuric acid etc as a catalyst. The native structure of starch can be less efficient, since its functional properties are less stable to process condition such as high temperature, shear stress and exposure to acidic media, which decreases its use in industrial application. Acetylated starches facilitate higher stability and resistance to retrogradation or crystallization, enhanced granular size, swelling power, and water absorption capacity, which provides good flow and compression properties. It reduces the pasting temperature and solubility. It makes the acetylated starch as a good candidate for customizing the overall performance of native starch, which may be used as the controlled release or sustained release polymer in pharmaceutical dosage form.

Chemical Modifications of Normal and Waxy Potato Starches Affect Functional Properties of Aerogels.

Aerogels are of increasing interest because of their exceptionally large surface area, porous structure, and low weight. Despite the significant increase in interest in the subject of starch-based aerogels, the number of detailed studies is rather scarce, which is especially evident in the case of chemically modified derivatives. Therefore, the study aims to evaluate the physicochemical properties of aerogels from chemically modified potato starch preparations (E 1422 and E 1450) obtained both from normal and waxy starches. Aerogels were prepared through the retrogradation of starch pastes followed by the gradual replacement of water with ethyl alcohol. The obtained preparations were characterized in terms of their bulk density, oil-binding capacity, as well as the texture and rheological properties of the formed pastes. Moreover, their usefulness was evaluated in an emulsion system employing rheological and low-field NMR methods. The obtained aerogels were characterized by a lower bulk density of 0.18-0.59 g/cm3 and 5.4-6.6 times higher oil-binding capacity compared to native potato starch. The chemical modification of starch helped to further alter the functional properties of the obtained aerogels, making them more effective oil binders, emulsifiers, and stabilizers (increasing the stability from 55 to 90%), which was especially evident for E 1450 preparation. Amylose content improved the aerogel properties, as waxy preparations were characterized by worse functional properties with the only exception of improved thickening ability. The most beneficial properties for the preparation of emulsions were observed for the aerogel obtained based on E 1450 normal potato starch.

Factorial Design to Stimulate Biomass Development with Chemically Modified Starch

The present study is focused on mathematical modeling by testing the benefits of modified potato starch in the biomass production of microorganisms, such as the fungus type. Microorganisms need a carbon source for the biomass development. In different industries, microorganisms, such as the Penicillium type, are used for the extraction of different important compounds utilized in biotechnologies. The aim of this study is to establish some important parameters in order to stimulate the biomass production in the presence of chemically modified starch. The carbon sources used in this research are glucose, native potato starch, and chemically modified potato starch. The chemical modification of potato starch was realized with green chemical compounds in order to not influence biomass development. The chemical characterization of starch and modified starch was important in order to confirm the chemical modification of starch. The response function in mathematical modeling is the amount of biomass developed when there are varied parameters. The varied parameters for the factorial design are as follows: time of biomass development, mass report of glucose:starch (G:S), and mass report of glucose:modified starch (G:MS). The results obtained for the optimal values are as follows: 6 days for the biomass development, 1:1.35 for the mass report of G:S, and 1:1.27 for the report of G:MS.

Effect of pH on the Redox and Sorption Properties of Native and Phosphorylated Starches.

Starch is a common biopolymer that can be used for removing heavy metal ions from aqueous solutions. A valuable property of starch is its functional diversity, which can be enhanced by chemical modification. Hydroxyl groups enclosed in the starch and formed during hydrolysis act as reducing agents of Cr(VI). The sorption properties of native starch depend mainly on the presence of carboxyl groups formed during redox processes and basic centers created during acid hydrolysis, while the superiority of phosphorylated starch is related to the presence of phosphate groups binding Cr(III) ions. The effectiveness of starch depends on a series of equilibria established in its aqueous suspension and chromate ions solution, where the pH is the driving force for these processes. In this article, a systematic discussion of pH changes being the consequence of chemical reactions unraveling the extraordinary functionalities of starch was given. It also explained the influence of establishing equilibria and chemical modifications of starch on the efficiency of chromium ion removal. This allowed for the development of a comprehensive mechanism for the interaction of Cr(VI) and Cr(III) ions with native and phosphorylated starch.

Retrogradation in radiation-synthesized cassava starch/acrylic acid super water absorbent and its effect on gel stability

The effects of long-term storage and retrogradation on the stability of the gel properties of radiation-synthesized super water absorbents (SWA) made from cassava starch and acrylic acid were explored in this study. Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), differential scanning calorimetry (DSC), and transmission electron microscopy (TEM) analyses were used to explore the retrogradation phenomenon. TEM and scanning area electron diffraction (SAED) images revealed the presence of starch nanocrystallites and increase of crystalline state in SWA matrix after 24 months storage. FT-IR peak ratios and enthalpy changes in DSC analysis also confirmed retrogradation of aged SWA samples. However, no sharp peak was observed in XRD diffractograms which is mainly due to the nanostarches present in the SWA. The most critical property affected by starch retrogradation in SWA is the degree of swelling. The degree of swelling of SWA was greatly reduced from 148 to 30 g/g while the gel fraction remained stable after 24 mos. The aged SWA samples with low degree of swelling due to retrogradation returned to their high and stable soil water content after 15 d in unsterile pure garden soil. Despite being exposed to high energy gamma radiation of starch with acrylic acid to form SWA, wherein possible oxidation and chemical modification of starch may take place, retrogradation can still occur. Lowering the storage temperature evidently suppressed the effect of starch retrogradation in SWA. Suppression of starch retrogradation in the optimized SWA is crucial to prolong its marketable life.

Physicochemical properties and solubility of sweet potato starch-based edible films

This study aimed to develop a sweet potato starch (SPS)-based edible film with improved water solubility. Initially, types of sweet potatoes were used, and their characteristics were analyzed to select the most appropriate variety for edible films. Shingeonmi was finally selected, and a chemical modification of starch, acetylation with different concentrations of acetic anhydride (1, 5, and 9 mL), was conducted to improve the water solubility. During the film-forming process, amidated pectin (AP) and calcium chloride (CaCl2) were also compounded to enhance the solubility. The developed native and acetylated SPS films, with or without the two substances, were further used to investigate various physicochemical properties and water solubility. Acetylated SPS-based films with AP and CaCl2 showed excellent water solubility (99.16%) than the native SPS one, indicating the beneficial effect of variables (acetylation, AP, and CaCl2) for enhanced water solubility. These results imply the potential use of the developed water-soluble film to package food ingredients and products such as vegetables, bakery, meat, or seafood due to the enhanced solubility and edibility.

A review on octenyl succinic anhydride modified starch-based Pickering-emulsion: Instabilities and ingredients interactions.

Pickering emulsions endow attractive features and a wide versatility in both food and nonfood fields. In the last decades, a noticeable interest has emerged toward the use of octenyl succinic anhydride (OSA)-starch to improve the long-term stability in such systems. In this review, instabilities were pointed out, where a new kinetic equilibrium was observed in Pickering emulsions assigned to migration and size variations of particles. These features were monitored using rheological measurements to understand microstructure and droplets mobility. The elastic modulus (G'), the viscous modulus (G″), and tan(δ) values were attributed to the transition from solid to fluid and assigned to the instability of the formulation regardless of the type of the system configuration. The novelties in using OSA-modified starch, were also exposed. The chemical modification of starch decreased creaming for months. Interaction between OSA-modified starches and some ionic components (potassium, magnesium, and calcium) as well as hydrocolloids and proteins reduced creaming and coalescence due to dense interfacial film. Furthermore, the key parameters (oil fraction, fatty acids composition, oxidative stress oil polarity, and oil viscosity) that govern oil phase in Pickering emulsion, were analyzed. These parameters were found to be positively correlated to the stability of Pickering emulsions.

Progress in Starch-Based Materials for Food Packaging Applications

The food packaging sector generates large volumes of plastic waste due to the high demand for packaged products with a short shelf-life. Biopolymers such as starch-based materials are a promising alternative to non-renewable resins, offering a sustainable and environmentally friendly food packaging alternative for single-use products. This article provides a chronology of the development of starch-based materials for food packaging. Particular emphasis is placed on the challenges faced in processing these materials using conventional processing techniques for thermoplastics and other emerging techniques such as electrospinning and 3D printing. The improvement of the performance of starch-based materials by blending with other biopolymers, use of micro- and nano-sized reinforcements, and chemical modification of starch is discussed. Finally, an overview of recent developments of these materials in smart food packaging is given.

Starch-Mucilage Composite Films: An Inclusive on Physicochemical and Biological Perspective.

In recent years, scientists have focused on research to replace petroleum-based components plastics, in an eco-friendly and cost-effective manner, with plant-derived biopolymers offering suitable mechanical properties. Moreover, due to high environmental pollution, global warming, and the foreseen shortage of oil supplies, the quest for the formulation of biobased, non-toxic, biocompatible, and biodegradable polymer films is still emerging. Several biopolymers from varied natural resources such as starch, cellulose, gums, agar, milk, cereal, and legume proteins have been used as eco-friendly packaging materials for the substitute of non-biodegradable petroleum-based plastic-based packaging materials. Among all biopolymers, starch is an edible carbohydrate complex, composed of a linear polymer, amylose, and amylopectin. They have usually been considered as a favorite choice of material for food packaging applications due to their excellent forming ability, low cost, and environmental compatibility. Although the film prepared from bio-polymer materials improves the shelf life of commodities by protecting them against interior and exterior factors, suitable barrier properties are impossible to attain with single polymeric packaging material. Therefore, the properties of edible films can be modified based on the hydrophobic–hydrophilic qualities of biomolecules. Certain chemical modifications of starch have been performed; however, the chemical residues may impart toxicity in the food commodity. Therefore, in such cases, several plant-derived polymeric combinations could be used as an effective binary blend of the polymer to improve the mechanical and barrier properties of packaging film. Recently, scientists have shown their great interest in underutilized plant-derived mucilage to synthesize biodegradable packaging material with desirable properties. Mucilage has a great potential to produce a stable polymeric network that confines starch granules that delay the release of amylose, improving the mechanical property of films. Therefore, the proposed review article is emphasized on the utilization of a blend of source and plant-derived mucilage for the synthesis of biodegradable packaging film. Herein, the synthesis process, characterization, mechanical properties, functional properties, and application of starch and mucilage-based film are discussed in detail.

Effect of Rice Starch Hydrolysis and Esterification Processes on the Physicochemical Properties of Biodegradable Films

AbstractPolymers such as starch are promising in the substitution of synthetic polymers in food packaging, but they present some inferior physicochemical properties. The chemical modification of starch can reduce the limitations of these polymers and make them suitable for packaging production. Therefore, the aim of this study is to elaborate, evaluate, and characterize biodegradable films produced from rice starch modified by hydrolysis and esterification processes. Rice starch hydrolyzed with 0.1 and 0.5 M hydrochloric acid (HCl) and rice starch esterified with 2% and 10% citric acid (CA) are used to produce the packages. The films are characterized in terms of their mechanical properties, optical characteristics, structural and thermal properties, water vapor permeability (WVP), water solubility (WS), and hydrophobicity. Films formulated from hydrolyzed starch show an increase in tensile strength (TS) (11.17 MPa) when compared to the control (1.83 MPa). In addition, the films obtained from hydrolyzed starch present lower solubility (15.6%) and higher relative crystallinity (RC) (71.6%) when compared to the control. The films produced by esterified starch show greater surface hydrophobility with a contact angle of 72.6° while the control shows an angle of 45.8°. Based on the above, the esterified and hydrolyzed starches are promising for the development of sustainable packaging.

Effect of Starch Laurate Addition on the Properties of Mango Kernel Starch Films

Abstract In this work, starch obtained from mango kernel seeds was applied in the preparation of films in combination with its hydrophobic derivatives. Chemical modification of starch was carried out at two different concentrations of vinyl laurate, in dimethyl sulfoxide, under basic catalysis. The degrees of substitution of the starch laurates were 2.4 and 0.3, respectively. None of the products formed films when dispersed in water. However, blends of starch/starch laurate (degree of substitution = 0.3) formed films after microfluidization of their aqueous suspensions. The blends with up to 15% wt of starch laurate (degree of substitution = 0.3) resulted in films of higher elongation at break, higher opacity and lower tensile strength and elastic modulus. The microfluidization of biopolymer suspensions was crucial to obtain films with lower water vapor permeability. X-ray diffraction results corroborated to the mechanical properties of the films, showing that the incorporation of starch laurate reduced the starch films crystallinity.