Hydroxypropyl Starch Research Articles

Study on preparation and physicochemical properties of hydroxypropylated starch with different degree of substitution under microwave assistance

Compared with the traditional method, the microwave assisted method can greatly shorten the reaction time of hydroxypropyl starch and improve product quality. The microwave assisted conditions and physicochemical properties of natural corn starch were studied. Response surface methodology was used to optimize the reaction conditions of three-level-three-factorial center composite design. The optimum parameters were as follows: the additive amount of propylene oxide was 8%, the radiation time was 6.08 min, and the microwave power was 303.43 W. The optimal degree of substitution (DS) of hydroxypropyl starch was determined by the optimal conditions predicted by RSM, which was 0.0729 mg/g. The analysis of physicochemical properties showed that with the increase of the DS of starch derivatives, the transparency (4% to 8.81%), the volume ratio of the condensing volume (21.11% to 33.11%), the hydrophilic (0.73 g/g to 2.46 g/g), and the hydrophobicity (0.67 g/g to 1.01 g/g), and the water evolution rate (46.91% to 36.16%) decreased. Fourier transform infrared spectroscopy showed that the enhancement of peak intensity at 1149 cm−1 indicated the successful introduction of hydroxypropyl group. Scanning electron microscopy showed that the surface morphology of corn starch was affected to some extent. The modification did not change the crystalline type of starch, which was still A type.

Preparation and Characteristics of Starch Esters and Its Effects on Dough Physicochemical Properties

As a recyclable natural material, starch is an important raw material in food and other fields. The native starch by esterification could improve the performance of the original starch and expand its range of application. This article reviews the preparation process of acetylated distarch adipate, starch sodium octenylsuccinate, starch acetate, hydroxypropyl starch, and starch phosphate and research into the influence of starch esters on dough. At the same time, it forecasts the trend of starch esters and application prospect in the future research.

Hydroxypropyl starch‐based films reinforced by incorporation of alkalized microcrystalline cellulose

Environment friendly and biodegradable composite films comprised of alkalized microcrystalline cellulose (MCC) and hydroxypropyl starch (HPS) have been developed by a solution casting method. The particle sizes and crystal structure of alkalized MCC have been investigated by Laser Diffraction Particle Size Analyzer and X‐ray diffraction. The surface morphology of MCC/HPS films have been observed by scanning electron microscopy. Meanwhile, the enhanced thermal stability has been confirmed by thermogravimetric analysis and Differential scanning calorimetry. Incorporating alkalized MCC into HPS, composite films show raised glass transition temperature (increased by 13.31%), strengthened mechanical properties (increased by 13.72%), and reduced water vapor permeation (reduced by 75.27%). As‐prepared alkalized MCC/HPS composite films could not only be employed as an most promising candidate for developing green food packaging materials, but also endow themselves with substitute for petroleum plastic products while concomitantly promoting the development of sustainable materials. POLYM. COMPOS., 40:E856–E864, 2019. © 2018 Society of Plastics Engineers

Hydroxypropyl and nanocrystal derivatives of white (Colocasia antiquorium) and red (Colocasia esculenta) cocoyam starches: functional, pasting, thermal and structural properties

Hydroxypropyl starch derivatives were prepared from the reaction of propylene oxide with the native starches of white and red cocoyam under alkaline conditions while starch nanocrystal derivatives were produced via acid hydrolysis method. The native starches and their hydroxypropyl derivatives were analyzed for functional behaviours, pasting properties, thermal properties, X-ray diffractometry and morphology while the starch nanocrystals were analyzed for solubility, X-ray diffractometry and morphology. Molar substitution values of the hydroxypropyl starch derivatives ranged between 0.23 and 0.26 and their degree of substitution ranged between 0.02 and 0.03. After derivation, the swelling power and water solubility of the native starches increased from 12.74 ± 0.02 to 21.36 ± 0.04 g/g (white cocoyam starch, WCS), 12.17 ± 0.04 to 18.06 ± 0.04 g/g (red cocoyam starch, RCS) and 11.61 ± 0.03 to 21.20 ± 0.06% (WCS), 12.21 ± 0.02 to 25.36 ± 0.05% (RCS) respectively. Except breakdown, all the pasting parameters (peak viscosity, hot paste viscosity, cold paste viscosity, setback, peak time and pasting temperature) significantly decreased (p < 0.05) as the levels of substitution increased. The gelatinization temperatures and peak height index reduced with an increase in substitution levels. Both native and hydroxyproylated starches exhibited CB-type X-ray patterns while the nanocrystals had V-type patterns. The starch nanocrystals formed precipitates with chloroform, but were practically insoluble in other solvents. The morphology of their microstructures revealed that the native starches were spherical and polygonal in shape while the nanocrystal starches appeared as aggregates. The starches studied could serve as alternative sources in meeting the ever-increasing demands of starch for food and non-food applications.

Developments in Hydroxypropylation of Starch: A Review

Because hydroxypropyl starch (HPS) represents an important chemical modification of starch, extensive studies on hydroxypropylation are being carried out at various research centers worldwide. The present review summarizes development of methods for determination of the MS (molar substitution)/DS (degree of substitution) of hydroxypropyl starch, location of hydroxypropylation reaction sites in granules and on amylose and amylopectin molecules, and factors affecting reaction efficiency. Also presented is an overview of changes of physicochemical properties of starch that result from hydroxypropylation. Specifically reviewed are the effects of hydroxypropylation on granule morphology, crystallinity, thermal properties, swelling, and solubility; pasting, paste, and retrogradation properties; rheological and textural properties of HPS gels; and digestibility and uses of HPS.

On the investigation of thermal/cooling-gel biphasic systems based on hydroxypropyl methylcellulose and hydroxypropyl starch

This work investigates the rheology, structure, and properties of novel thermal/cooling-gel biphasic systems formed by hybridization of hydroxypropyl methylcellulose (HPMC) as a thermal gel and hydroxypropyl starch (HPS) as a cooling gel. Due to the different gelation properties, HPS became the dispersed phase in the other continuous phase at low temperatures, and so did HPMC at high temperatures. However, the dispersed phase could play a dominant role in the viscosity, thixotropy, and gel properties of the blends, and subsequently affect the crystalline structure, fractal structure, mechanical properties, oxygen permeability, and thermal stability of the blend films. Moreover, the rheological properties and the film structure and performance could also be varied by the chemical modification of starch. Hydroxypropylation could break the starch intermolecular hydrogen bonding, disrupt its ordered structure, inhibit the molecular rearrangement, and result in a softer gel texture that was more compatible with HPMC. With a higher degree of hydroxypropyl substitution, the resultant blend films were more amorphous and flexible but exhibited decreased mechanical properties and oxygen permeability. The knowledge obtained from this work could provide guidance to further developing various thermal/cooling-gel multi-phasic systems with desired properties and functionality.

Rheological Properties of Xanthan Gum, Hydroxypropyl Starch, Cashew Gum and Their Binary Mixtures in Aqueous Solutions

Large volumes of drilling fluids are used while drilling oil wells. Water‐based fluids are widely used because they are generally less expensive and more environmentally correct than synthetic fluids. Polymers are used in drilling fluids with different functions. This article reports a study of the rheological behavior of solutions containing xanthan gum (XG), hydroxypropyl starch (HPS) and cashew gum (CG), as well as their binary mixtures, to evaluate the applicability of CG (an abundant product in Brazil's northeastern region) in aqueous fluid formulations. The results show the potential to use CG in mixtures with XG. The thixotropic effect is confirmed by hysteresis loop analysis; the rheological behavior is satisfactorily described by the Ostwald‐de Waele and Casson models; the aqueous solutions containing XG/HPS mixtures present higher consistency indexes than the XG/CG mixtures; and the activation energy values of the XG/CG mixtures are governed by the CG fraction.

Effect of plasticizers on microstructure, compatibility and mechanical property of hydroxypropyl methylcellulose/hydroxypropyl starch blends

Polymer film blends of hydroxypropyl methylcellulose (HPMC) and hydroxypropyl starch (HPS) were produced with an incorporation of three different plasticizers, including polyethylene glycol (PEG), glycerol and 1, 2-propylene glycol (PG) respectively, and the influence of these plasticizers were compared and studied by X-ray Diffraction (XRD), small angel X-ray Scattering (SAXS), optical microscope and dynamic mechanical analysis (DMA). Results showed that multi-scale structure of the blends were greatly affected by the plasticizers and therefore caused significant changes in mechanical properties. In the course, blends with glycerol presented lamellar structure rather than self-similar structure. Moreover, crystalline degree was increased with an order of glycerol > PEG > PG, whereas the compactness of amorphous region of all samples was decreased by PEG and PG.

Interaction of blockers on drilling fluids rheology and its effects on sealing of fractures and prevention of filtrate invasion

Drilling fluids from oil wells play an important role in the drilling operations, including cleaning and maintaining well stability, as well as cooling and lubricating the drill bit. Invasion of fluid in the rock formation, through natural or induced fractures, can compromise the entire well. In this work we evaluated the effect of combination of viscosifiers xanthan gum (XG), carboxymethylcellulose (CMC), Hydroxypropylstarch (HPS) and bentonite in the interaction with lost circulation materials diatomaceous earth (DE) and hydrogel (HG). The main objective was to obtain a product with adequate rheological properties showing viscoelastic behavior and minimizing loss of fluid to the wellbore. Tests of X-ray diffraction (XRD) and zeta potential were performed to analyze the interactions between the particles present in the fluids. With rheological tests we studied the effects of the addition of different components on the fluid rheology. XRD technique showed that the bentonite deflocculated only in polymer suspensions with DE. The results of zeta potential suggest that only the fluid with Hydroxypropylstarch and HG was completely flocculated and unstable, showed through particle sizes distribution tests. The gel modulus (G′) and viscous modulus (G″) of the fluids were affected by the interaction of bentonite layers with lost circulation materials particles, with significant increase of G′ with the addition of HG to the suspension. There was a decrease of viscosity due to agglomeration of HG and DE particles, an increase of G’ can be observed as well. Among all the fluids, the suspension of CMC and bentonite showed better affinity with the HG lost circulation material, presenting thermal stability and a wide range of particle size, essential property to avoid the loss of fluid through the fractures and pores of the rock formation.

Tunable d-Limonene Permeability in Starch-Based Nanocomposite Films Reinforced by Cellulose Nanocrystals.

In order to control d-limonene permeability, cellulose nanocrystals (CNC) were used to regulate starch-based film multiscale structures. The effect of sphere-like cellulose nanocrystal (CS) and rod-like cellulose nanocrystal (CR) on starch molecular interaction, short-range molecular conformation, crystalline structure, and micro-ordered aggregated region structure were systematically discussed. CNC aspect ratio and content were proved to be independent variables to control d-limonene permeability via film-structure regulation. New hydrogen bonding formation and increased hydroxypropyl starch (HPS) relative crystallinity could be the reason for the lower d-limonene permeability compared with tortuous path model approximation. More hydrogen bonding formation, higher HPS relative crystallinity and larger size of micro-ordered aggregated region in CS0.5 and CR2 could explain the lower d-limonene permeability than CS2 and CR0.5, respectively. This study provided new insight for the control of the flavor release from starch-based films, which favored its application in biodegradable food packaging and flavor encapsulation.

Tuning inkjet printability of hydroxypropylated-starch-based coatings by mineral selection

Coatings based on hydroxypropylated starch (HPS) provide extraordinary print density with dye-based inkjet inks, but their suitability for pigment-based inks can be limited due to inadequate carrier medium (water) absorption and colorant fixation. In the present work, HPS-based coatings were tailored for both a pigmentbased and a dye-based ink by adding silicate minerals or acid clay (both Lewis and Br&#xF6;nstedt acid sites present in the acid clay). Substrate-ink interaction and colorant distribution were investigated via uncoated gloss and print quality indicators such as print density, ink bleeding tendency and delta gloss after printing with desktop printers. Three-dimensional z-stack CLSM images taken from printed samples revealed substantial differences in ink holdout and penetration characteristics between the studied materials. Pigment-filled HPS coatings showed up to 60% increase in print density compared to uncoated reference substrate and an increase of up to 35% compared to plain HPS coating with dyebased inks. In case of pigment-based ink, the increase was 17% between plain HPS coating and acid-clay-filled HPS coating. In addition, a combination of HPS and silicate mineral decreased ink bleeding substantially, but lower print gloss compared to substrate initial gloss was observed with the majority of experimental coatings. It was found that the pigment type affects substantially the unprinted gloss, which is naturally high in the case of pure HPS coating, but also the observed drastic difference in substrate permeability may explain the differences in print quality. The findings suggest that coating morphology, together with chemical interactions between starch and mineral and coated substrate and ink, has a key role in achieving high gloss and good print quality.

Re-evaluation of oxidised starch (E1404), monostarch phosphate (E1410), distarch phosphate (E1412), phosphated distarch phosphate (E1413), acetylated distarch phosphate (E1414), acetylated starch (E1420), acetylated distarch adipate (E1422), hydroxypropyl starch (E1440), hydroxypropyl distarch phosphate (E1442), starch sodium octenyl succinate (E1450), acetylated oxidised starch (E1451) and starch aluminium octenyl succinate (E1452) as food additives.

Following a request from the European Commission, the EFSA Panel on Food Additives and Nutrient sources added to Food (ANS) was asked to deliver a scientific opinion on the re‐evaluation of 12 modified starches (E 1404, E 1410, E 1412, E 1413, E 1414, E 1420, E 1422, E 1440, E 1442, E 1450, E 1451 and E 1452) authorised as food additives in the EU in accordance with Regulation (EC) No 1333/2008 and previously evaluated by JECFA and the SCF. Both committees allocated an acceptable daily intake (ADI) ‘not specified’. In humans, modified starches are not absorbed intact but significantly hydrolysed by intestinal enzymes and then fermented by the intestinal microbiota. Using the read‐across approach, the Panel considered that adequate data on short‐ and long‐term toxicity and carcinogenicity, and reproductive toxicity are available. Based on in silico analyses, modified starches are considered not to be of genotoxic concern. No treatment‐related effects relevant for human risk assessment were observed in rats fed very high levels of modified starches (up to 31,000 mg/kg body weight (bw) per day). Modified starches (e.g. E 1450) were well tolerated in humans up to a single dose of 25,000 mg/person. Following the conceptual framework for the risk assessment of certain food additives, the Panel concluded that there is no safety concern for the use of modified starches as food additives at the reported uses and use levels for the general population and that there is no need for a numerical ADI. The combined exposure to E 1404–E 1451 at the 95th percentile of the refined (brand‐loyal) exposure assessment scenario for the general population was up to 3,053 mg/kg bw per day. Exposure to E 1452 for food supplement consumers only at the 95th percentile was up to 22.1 mg/kg bw per day.

Preparation and properties of microcrystalline cellulose/hydroxypropyl starch composite films

In this paper, microcrystalline cellulose (MCC)/hydroxypropyl starch (HPS) composite films are prepared by the solution casting method, and the effect of different amounts of microcrystalline cellulose on the properties of the films is investigated. The structure of MCC/HPS composite materials is characterized by Fourier transform infra-red and scanning election microscopy, and thermal stability, mechanical properties, hygroscopicity, and water vapor permeability of the composite films are also tested. According to the test results, with increasing MCC amounts, glass transition temperature, thermal stability, and tensile strength of MCC/HPS composite films are improved, while the hygroscopicity and water vapor permeability of MCC/HPS composite materials are decreased. When the content of MCC reaches 6 wt%, the maximum increase of the glass transition temperature is about 9.63 °C, and the tensile strength of MCC/HPS composite films are increased by 300% compared with that of HPS films. Moreover, the addition of MCC helps to expand the application of hydroxypropyl starch in the packaging field.

A Study on the Effects of Starches on the Properties of Alkali-Activated Cement and the Potential of Starch as a Self-Degradable Additive

An urgent problem of geothermal energy source development is how to cut down the production costs. The use of temporary sealing materials can reduce the costs associated with the circulation lost by plugging, and increase the production by self-degradation. Based on the utilization of starches as self-degradable additives in the medical field, this paper investigated the effects of three kinds of starches, namely corn starch (CS), hydroxypropyl starch (HPS) and carboxymethyl starch (CMS) on the properties of alkali-activated cement (AAC). In addition, the thermal properties of starch, the compressive strength and microstructures of the cement with starch were tested, to evaluate the potentiality of starch as self-degradable additive for geothermal cement. The analysis showed that: (1) all the starches have the effect of increasing the apparent viscosity, prolonging the setting time and reducing the static fluid loss of alkali-activated cement; (2) the addition of starch increased the number of pores in 200 °C-heated cement, facilitated the leaching process, and thus promoted the self-degradation; and (3) among the three starches, CMS has the most potential as a self-degradable additive.

Characterization and utilization of hydroxypropylated rice starches for improving textural and storage properties of rice puddings

This work investigated the effect of hydroxypropylation on the physicochemical characteristics of Basmati and Irri rice starches with milk and water. The effect of hydroxypropylated starches on the storage, texture stability and sensory characteristics of rice pudding was studied. Pudding was prepared by replacing 3%, 5% and 10% of Irri rice flour with native and hydroxypropylated starches isolated from two predominant rice varieties of Pakistan; Irri and Basmati. Syneresis was not observed in pudding made with hydroxypropylated starches and native basmati starch. On the contrary, pudding prepared with Irri rice flour and Irri starches showed poor keeping quality. Sensory analysis showed that modification of rice starches did not significantly alter the color, flavor, taste and overall acceptability of pudding. The results suggested that rice pudding, a very popular dessert of South Asia could be prepared with improved storage characteristics using hydroxypropylated starches without altering the taste and acceptability of the product.

Zeta potential changing self-emulsifying drug delivery systems containing phosphorylated polysaccharides.

The aim of the study was to develop novel zeta potential changing self-emulsifying drug delivery systems (SEDDS) containing phosphorylated polysaccharides. Starch and hydroxypropyl starch (HPS) were phosphorylated by utilizing phosphorus pentoxide. The modified starches, starch phosphate (SP) and hydroxypropyl starch phosphate (HPSP), were loaded into SEDDS and investigated regarding particle size, zeta potential, stability and cell viability. The release of immobilized phosphate by intestinal alkaline phosphatase (IAP) was analyzed via malachite green assay. In parallel, the resulting shift in zeta potential of SEDDS was determined. Furthermore, Transwell chambers were applied in order to evaluate the mucus diffusion behavior of SEDDS utilizing fluorescein diacetate (FDA) as marker. The amount of attached phosphate for SP and HPSP revealed to be 119μmol/g and 259μmol/g, respectively. SEDDS consisting of 10% glycerol, 30% Capmul MCM, 30% Cremophor EL and 30% Captex 355 showed a droplet size of 39±12nm, stability over 240min and no significant decrease in cell viability within the applied concentrations. SEDDS containing 3mg/ml HPSP with a phosphate release of 204μmol/g, demonstrated a shift in zeta potential from -6.3mV to +1.0mV applying isolated IAP. Zeta potential changing SEDDS achieved a 2.5-fold and 5.4-fold higher amount of diffused FDA compared to the references within mucus permeation studies. SEDDS containing HPSP represent comparable high mucus diffusion properties emphasized by a highly significant change in zeta potential.

Understanding physicochemical properties changes from multi-scale structures of starch/CNT nanocomposite films

From the view of multi-scale structures of hydroxypropyl starch (HPS)/carbon nanotube (CNT) nanocomposite films, the film physicochemical properties were affected by comprehensive factors including molecular interaction, short range molecular conformation, crystalline structure and aggregated structure. The less original HPS hydrogen bonding that was broken, less decreased order of HPS short range molecular conformation, lower film crystallinity and larger size of micro-ordered regions contributed to higher tensile strength and Young’s modulus of the film with CNT content of 0.5% (g/g, CNT in HPS). The higher film overall crystallinity and larger size of micro-ordered regions of the film with CNT content of 0.05%–0.3% compared with those of control contributed to better film barrier property. The addition of CNT with the content of 0.05%–0.5% broke the original HPS hydrogen bonding and decreased the order of starch short range molecular conformation, which counteracted the positive effect of CNT on the thermal stability of the material, thus thermal degradation temperature of these nanocomposite films did not increase. But the sharp increase of film crystallinity increased film thermal degradation temperature. This study provided a better understanding of film physicochemical properties changes which guides to rational design of starch-based nanocomposite films for packaging and coating application.

Utilization of chemically modified pearl millet starches in preparation of custards with improved cold storage stability

Custards were prepared using five ingredients: milk powder, modified pearl millet starch, sugar, vanilla essence and water. The effect of adding hydroxypropylated starch (HPS), succinylated starch (SUS), oxidised starch (OXS) and acetylated starch (ACS) on cold storage stability, pasting, textural and sensory properties was studied and compared to custards containing native pearl millet starch (NS). Interestingly, all chemically modified starches reduced syneresis and no water weeping was observed in custard sample incorporating hydroxypropylated starch (HPC) even after 7days of cold storage. Viscoamylographic analysis revealed that custard containing succinylated starch (SUC) had the highest peak viscosity (108.8 BU), whereas HPC showed the least set back viscosity (19.0 BU). Sensory results suggested that assessors preferred HPC over other custards. Custards are preferred for their chewy semi-solid texture. Incorporation of hydroxypropylated starch (HPS) increased hardness, gumminess and chewiness which subsequently led to higher sensory scores during subjective analysis. Also, no retrogradation peak was observed for HPS and acetylated starch (ACS) when rescanned after 14 days. Thus, it could be concluded that HPS could be used in custards to confer low temperature stability by reducing syneresis.

Controlled extracellular biosynthesis of ZnS quantum dots by sulphate reduction bacteria in the presence of hydroxypropyl starch as a mediator

Metal sulphide quantum dots (QDs) have broad applications. Sulphate-reducing bacteria (SRB) have been recognized as synthesizers of metal sulphides, with the characteristics of a high-production efficiency and easy product harvest. However, SRB are incapable of synthesizing metal sulphide QDs. In the present study, cheap hydroxypropyl starch (HPS) was used to assist SRB in manufacturing the ZnS QDs. The results exhibited that the HPS accelerated the growth of SRB and reduction of SO4 2+ into S2−, while it blocked the precipitation between S2− and Zn2+ to control the nucleation and growth of ZnS, resulting in the formation of ZnS QDs. When the HPS concentration increased from 0.2 to 1.6 g/L, the average crystal size (ACS) of ZnS QDs dropped from 5.95 to 3.34 nm, demonstrating the controlled biosynthesis of ZnS QDs. The ZnS QDs were coated or adhered to by both HPS and proteins, which played an important role in the controlled biosynthesis of ZnS QDs. The remarkable blue shift of the narrow UV absorption peak was due to the quantum confinement effect. The sequential variation in the colour of the photoluminescence spectrum (PL) from red to yellow suggested a tunable PL of the ZnS QDs. The current work demonstrated that SRB can fabricate the formation of ZnS QDs with a controlled size and tunable PL at a high-production rate of approximately 8.7 g/(L × week) through the simple mediation of HPS, with the yield being 7.46 times the highest yield in previously reported studies. The current work is of great importance to the commercialization of the biosynthesis of ZnS QDs.

Effect of processing conditions on microstructures and properties of hydroxypropyl methylcellulose/hydroxypropyl starch blends

Since hydroxypropyl methylcellulose (HPMC) is a thermal gel while hydroxypropyl starch (HPS) is a cool gel, their blends show some unique and interesting behaviors of phase transitions and microstructures, which control their performances. This work focused on the effect of processing conditions on the microstructure and mechanical properties of these blends with various ratios of HPMC/HPS, in particular for incubation and drying conditions. To clearly identify the changes of starch phase in such blending system, the technique of dyeing HPS with iodine was developed and used. Rheometer, small angel X-ray scattering (SAXS), X-ray diffraction (XRD), dynamic mechanical analysis (DMA) and mechanical testing apparatus were used to study the changes of microstructure and the relative properties of the blending gels and dried films incubated at different temperatures. It was found that the higher incubation temperature resulted in higher storage modulus, more solid-like behavior and more compact self-similar structure of the blending gel. Moreover, the films prepared from the gels dried at high temperature showed higher crystalline degree and more compact amorphous structure, and therefore result in increasing tensile strength and modulus but decreasing elongation.