Hydroxypropyl Starch Research Articles

Preparation and characterization of aminoethyl hydroxypropyl starch modified with collagen peptide

The preparation of aminoethyl hydroxypropyl starch collagen peptide (AEHPS-COP) was via an enzyme-catalyzed reaction between amino groups in aminoethyl hydroxypropyl starch (AEHPS) and γ-carboxamide groups in collagen peptide (COP) by using microbial transglutaminase (MTGase) as biocatalyst. As an intermediate reactant, AEHPS was synthesized from hydroxypropyl starch (HPS) and 2-chloroethylamine hydrochloride (CEH). The chemical structures of HPS, AEHPS and AEHPS-COP were characterized by Fourier transform infrared spectroscopy (FT-IR) and 13C nuclear magnetic resonance (13C NMR). The reaction conditions that influenced the degree of substitution (DS) of AEHPS-COP were optimized, which included the reaction temperature, the reaction time, the mass ratio of collagen peptide to aminoethyl hydroxypropyl starch and the pH value. In addition, in vitro antioxidant activities of AEHPS-COP were evaluated through the scavenging activity of hydroxyl and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical. Furthermore, the methylthiazol tetrazolium (MTT) assay was applied to investigate the cell viability of AEHPS-COP. The results indicated that the AEHPS-COP exhibited better cell viability to L929 mouse fibroblast cells. Therefore, the AEHPS-COP showed a promising potential application in cosmetic, biomedical and pharmaceutical fields.

The influence of rice protein content and mixed stabilizers on textural and rheological properties of jasmine rice pudding

Jasmine rice flour containing unique fragrance is a preferred choice to improve the rice pudding flavor and texture. A substitution of rice grain and egg with the jasmine rice flour (high and low protein content: 7.70% HPJF and 3.54% LPJF, respectively) and with mixed stabilizers, respectively in the pudding was evaluated. Mixed stabilizers (KHPS and KOSA) composed of κ-carrageenan (K) at 0.25, 0.50 and 1.00% with hydroxypropyl starch (HPS) or octenyl succinic anhydride starch (OSA) were used for egg substitution by controlling the total solid content at the same level as in the egg. The puddings were randomly checked for textural and rheological properties at day 0 to day 6. The hardness and stability of all puddings egg-substituted by mixed stabilizers increased significantly when compared with the egg formula. As a function of time, the hardness, gumminess, and chewiness of LPJF-puddings were higher than those of HPJF-puddings, attributed to the protein content and gelation of starch granules in the flour. OSA gave higher values than HPS via a possible electrostatic interaction with K. All puddings behaved like a weak gel with G′ > G″ in all studied frequencies. G′' and G″ of LPJF-puddings increased as the storage time increased while those of HPJF-puddings were constant. The mixed stabilizers and their concentration could enhance the harder texture and more stable structure, especially in the LPJF puddings. The microstructures of LPJF gel were finer and showed a tighter cluster but less void spaces than those of HPJF gel, resulting in the harder texture and more stable structure. Thus, the integrated effect of protein content and the concentration of mixed stabilizers resulted in a different textural and rheological properties of the puddings that could be adopted in the pudding production to achieve the specific attributes.

Controllable biosynthesis and characterization of α-ZnS and β-ZnS quantum dots: Comparing their optical properties

The controllable biosynthesis of α-ZnS and β-ZnS quantum dots by Clostridiaceae sp. using different concentration of hydroxypropyl starch as dispersant are demonstrated. The structure and properties are characterized by XRD, TEM, HRTEM, UV–Vis and fluorescence spectra, and so on. The results indicate that the α-ZnS quantum dots with wurtzite structure and diameter of 8±2nm were attained under low dose of hydroxypropyl starch, while high dose obtained the β-ZnS quantum dots with sphalerite structure and diameter of 4±1nm. The UV–Vis absorption of β-ZnS quantum dots have an evident red shift compared with α-ZnS quantum dots, and the as-biosynthesized β-ZnS quantum dots have a stronger fluorescence activity than α-ZnS quantum dots. This work displays a simple biosynthetic method to control the crystal structure and particle size of metal sulfide nanoparticles under mild conditions.

Effect of film multi-scale structure on the water vapor permeability in hydroxypropyl starch (HPS)/Na-MMT nanocomposites

To improve the water vapor resistance of starch-based films, Na-MMT (Na-montmorillonite) as nanofillers were fabricated into hydroxypropyl starch and the multi-scale structural changes (including intermolecular interaction, short-range conformation, long-range ordered structure and the aggregated structure of the film) were revealed. The elongation of the water vapor molecule pathway by tortuous path is generally recognized as the main reason for the improvement of water resistance. However this study observed the lowest water vapor permeability (WVP) was at the 3% Na-MMT/hydroxypropyl starch (HPS) ratio instead of 5% even nanofillers were partially exfoliated at both ratio. Except for the “tortuous path” caused by nanofillers, this observation proposed that the short-range conformation of HPS chains, long-range ordered structure and the aggregated structure likely influenced the water barrier property. The relationship between WVP and multi-scale structure of the film was investigated. The results suggested that a good balance of short-range conformationin the amorphous region, long-range ordered structure and the aggregated structure of the film was required for the improvement of water vapor barrier property.

Relationship between morphologies and mechanical properties of hydroxypropyl methylcellulose/hydroxypropyl starch blends

Edible films from the blending hydroxypropyl methylcellulose (HPMC) with hydroxypropyl starch (HPS) have been developed. This work focuses on the relationship between morphologies and mechanical properties of such systems. To aid understanding of blend morphology, a new technique used to identify the two phases through dying of the HPS by iodine has been developed, which provided a simple and convenient way to clearly distinguish between HPMC and HPS phases. It was found that the blend system is immiscible and there is phase transition point depending on blending ratio and solution concentration. The lower transparency point of the blend and phase transition reign of HPMC from continuous phase to separated phase correspond with the variation of tensile modulus. The modulus and elongation decreased with increased solution concentration, which is correlatable with the morphologies present, where it was found that the HPMC gradually changed from a continuous phase to a distinct phase.

Morphology and properties of thermal/cooling-gel bi-phasic systems based on hydroxypropyl methylcellulose and hydroxypropyl starch

The miscibility between two gels with largely different gelation behaviors is an interesting topic both scientifically and practically. This paper reports a novel bi-phasic system based on two natural polymers, hydroxypropyl methylcellulose (HPMC) which has a thermal gelation behavior, and hydroxypropyl starch (HPS) which has a cooling gelation property. While both biopolymers have the same glucose unit grafted with propylene oxide, and are compatible to a certain degree, they were observed immiscible because of their different gelation behaviors. The immiscibility of these two compatible polymers could result in special structures leading to different blend film properties. Regarding this, the morphology, thermal transition, mechanical properties and oxygen barrier property could be well tailored by the ratio of two biopolymers and the environmental conditions. The knowledge obtained from this work could be useful for understanding other similar systems with desirable structure and properties.

Interaction of starch and casein

Starch was commonly used to improve the stability of set yogurt. In this research, casein and modified starches were placed in a simulated yoghurt system giving the advantage of a low variation in the environment parameters compared to a natural yoghurt system. The interactions between modified starches (phosphate starch, hydroxypropyl starch and starch ester of octenyl succinic) and casein were investigated with several independed types of measurements methods. The combination of zeta potential and fluorescence micrograph were used to research the interactions between modified starches and casein. And the results proved that modified starches not only absorbed with casein via electrostatic forces, but also had steric stabilization. Besides this, fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC) were used to investigate the role of hydrogen bonds between modified starches and casein. It could be deduced that the interactions of modified starches and casein included electrostatic adhesion, steric stabilization and hydrogen bond. At the same time, electrostatic adhesion was the main interaction between phosphate starch and casein. The main role of the interactions between starch ester of octenyl succinic and casein should be steric stabilization.

Effect of dual modification with hydroxypropylation and cross-linking on physicochemical properties of taro starch

Dual modification of taro starch by hydroxypropylation and cross-linking was carried out and the properties of the modified starches were investigated. Two different levels of hydroxypropylation (5 and 10%) and cross-linking (0.05 and 0.10%) were used in different sequences. The amylose contents of the starch decreased due to single and dual modification. For the dual-modified starches, the swelling, solubility and clarity was found to increase with level of hydroxypropylation and decrease with level of cross-linking. The freeze-thaw stability of the dual-modified starches was also affected by the sequence of modification. The viscosities of the cross-linked and dual-modified starches were more than native and hydroxypropylated starches. The firmness of the dual-modified starches was also higher than native and single modified starches. The dual-modified starches have benefits of both type of modifications and could be used for specific purposes e.g. food products requiring high viscosity as well as freeze-thaw stability.

Plasma Concentrations of GLP-1 and PYY in Rats Fed Dietary Fiber Depend on the Fermentability of Dietary Fiber and Respond to an Altered Diet

Background: It was reported to be associated with intake of dietary fiber and gut hormone. We compared the effect of dietary fiber on the plasma concentration of glucagon-like peptide-1 (GLP-1) and peptide YY (PYY). Methods: Firstly, male Wistar rats (10 wk old) were fed a fiber-free diet (FF diet, AIN-93G-based diet without cellulose) or one of nine FF diets with 5% dietary fiber for 21 days. Cellulose, guar gam (GG), partially hydrolyzed guar gum (PHGG), sugar beet fiber (BF), konjac mannnan (KM), raffinose (RF), hydroxypropyl starch (HPS), hydroxypropyl distarch phosphate (HPDP) and Akamoku (AK) were used as dietary fiber sources. Secondly, we then determined whether the concentrations of GLP-1 and PYY in portal and aorta plasma and microbiota in cecal contents responded to an altered diet. Male Wistar rats (10 wk old) were fed the PHGG diet for 20 days before being changed to the FF diet. Results: The amount of short chain fatty acids (SCFA) in the cecal contents markedly increased in rats fed the GG, PHGG, BF, KM, RF, HPS or HPDP diets compared with SCFA in rats fed the FF, CL or AK diets. The concentrations of GLP-1 and PYY in portal plasma positively correlated with the concentration of SCFA in the cecal contents and cecal tissue weight. The concentrations of GLP-1 and PYY, in the altered diet group decreased to the same concentration as that measured in the FF group. However, it was low the similarities in the cecal bacteria population. Conclusion: The plasma concentrations of GLP-1 and PYY increased with increasing the amounts of SCFA, the products of DF fermentation, in the cecal contents. GLP-1 and PYY plasma concentrations and SCFA concentrations in the cecal contents rapidly responded to the altered diet, but the cecal bacteria population did not.

Conformational Changes and Kinetic Study of Actomyosin from Silver Carp Surimi with Modified Starch–Sucrose Mixtures during Frozen Storage

AbstractThe cryoprotective effects of modified starch–sucrose mixtures on silver carp surimi were compared with commercial cryoprotectant using the changes in gel strength and actomyosin conformation during frozen storage. Acetic acid esterification starch (AAES)‐sucrose maintained the maximum gel strength and Ca2+–ATPase activity throughout the frozen storage (P < 0.05). Hydroxypropylated starch (HS)‐sucrose showed a similar retention of Ca2+–ATPase activity (39.34%) and salt‐soluble protein (SSP) content (60.20%) to that of AAES–sucrose (40.14%, 63.89%, respectively) after 91 days of storage (P > 0.05). AAES–sucrose and HS–sucrose separately showed the best effect on depressing loss of total sulfhydryl content in the early 28 days and later 63 days. Therefore, they protected actomyosin structure more effectively than commercial cryoprotectant. The relationship of Ca2+–ATPase activity and SSP content with respect to storage time could be fitted with a first‐order model to predict the changes in fish protein structure during frozen storage (R2 > 0.99).Practical ApplicationsModified starch–sucrose mixtures tended to improve gel strength of frozen surimi, as well as effectively prevent conformational changes of actomyosin during long period of frozen storage at −20C. The effectiveness of acetic acid esterification starch (AAES)‐sucrose and hydroxypropylated starch (HS)‐sucrose seemed to be slightly evident than commercial cryoprotectant. Therefore, the application of AAES‐sucrose or HS‐sucrose in frozen surimi products could be popularized at reduced cost and more healthy quality.

Comparative optimization study for chemical synthesis of hydroxypropyl starch from native corn and taro starch through evolutionary operation (EVOP) factorial design technique

Modification of native starch is aimed at tailor‐making functional properties of starch to overcome its inherent shortcomings which will enhance its versatility for different food‐uses. Optimization of chemical synthesis of hydroxypropyl starch from two native starch sources, corn and taro, was explored through application of evolutionary operation (EVOP) factorial design technique. Concentrations of starch slurry, propylene oxide, and sodium sulfate were considered as process variables and these were optimized in order to maximize swelling power of hydroxypropyl starch. EVOP factorial designing technique was applied consecutively and the results were analyzed statistically. Maximization of swelling power was achieved by corn starch after two sets of experiments of EVOP and the maximum value obtained was 36.17 at 20% sodium sulfate, 50% starch slurry, and 3.2% propylene oxide concentrations. The highest value of swelling power for hydroxypropyl taro starch was measured to be 62.33 after two sets of experiments and there was still scope for increasing its value in further set of experiments. Final conditions for taro starch were found to be optimum at 30% sodium sulfate, 40% starch slurry, and 5.6% propylene oxide concentrations, evaluated through EVOP method.

Rheological and gel properties of hydroxypropyl methylcellulose/hydroxypropyl starch blends

This work focuses on the study of rheological and gel properties of hydroxypropyl methylcellulose (HPMC)/hydroxypropyl starch (HPS) blends. It was found that both rheological properties in solution and gel behaviors in hydrogel of the blends depended on polymer/solvent concentration, HPMC/HPS ratio, and temperature. At higher temperature, all the blending samples showed hydrogel behavior, while at lower temperature, the suspensions with higher HPS ratio displayed hydrogel-like behavior but the gels were able to be destroyed at higher frequencies. With an increase of the HPS ratio, the fluid behavior index deceases, meaning the solution shows more obvious pseudoplastic behavior. However, the fluid consistency index increases, meaning that viscosity increases with increase of HPS content. The strength of HPMC gel was weakened by additional of HPS at higher temperature, while the HPS gel was weakened by addition of HPMC at lower temperatures. Viscosities of both HPMC and HPS were balanced by the blending at different temperatures since one is thermal and other is cool gel, which improves the processability for many applications.

Properties of starch–hydroxypropyl methylcellulose based films obtained by compression molding

Corn starch–glycerol (1:0.3) films, containing or not citric acid (1g/100g starch) and HPMC (10 and 20g/100g starch), are obtained by compression molding. The microstructure of the films, the thermal behavior, the X-ray diffraction spectra and the physical properties (mechanical, barrier and optical) were analyzed after 1 and 5 storage weeks at 25°C and 53% relative humidity. The bonded citric acid and film solubility were also determined. Starch–HPMC blend films showed a dispersed phase of HPMC in a continuous, starch-rich phase with lower glass transition than HPMC-free films. The addition of citric acid also provoked a decrease in glass transition in line with the partial hydrolysis of starch chains. Both components implied a decrease in the water vapour permeability while the oxygen permeability slightly increased. Although citric acid only provoked a small hardening effect in the films, it greatly decreased their extensibility (weak cross-linking effect), which seems to increase during film storage. Starch crystallization during storage was inhibited by both citric acid and HPMC.

Evaluation of a PEG/hydroxypropyl starch aqueous two‐phase system for the separation of monoclonal antibodies from cell culture supernatant

In this study, an aqueous two-phase system (ATPS) with PEG and hydroxypropyl starch (HPS) was used to separate monoclonal antibody (mAb) from Chinese hamster ovary cell culture supernatant. The phase diagram of the PEG/HPS ATPS was determined, and the effects of NaCl addition were investigated. The results showed that NaCl addition could lead to a shift of the binodal curve and that phase separation would occur at higher PEG and HPS concentrations. The effects of NaCl addition, pH, and the load of cell supernatant on the partitioning of mAb in a PEG/HPS ATPS were investigated. It was found that with 6% cell supernatant and 15% NaCl addition at pH 6.0, the yield of mAb in the upper phase was 96.7% with a purity of 96.0%. The back-extraction of mAb with a PEG/phosphate ATPS were also studied, and the results showed that after the two-step extraction with ATPSs the purity of mAb could reach 97.6 ± 0.5% with a yield of 86.8 ± 1.0%, which was comparable to the purification with Protein A chromatography. These results indicate that the two-step extraction with PEG/HPS and PEG/phosphate ATPSs might be a promising alternative for the separation of mAb from cell culture supernatant.

Synthesis, Characterization and Utilization of Starch Hydroxypropyl Sulphate for Cationic Dye Removal

The best conditions for synthesis of starch hydroxypropyl sulphate as per the dry method were firstly established. This was done through a thorough investigation into factors affecting the synthesis including concentrations of both the NaOH catalyst and the 2-hydroxy-3-chloropropyl sulphate along with duration and temperature of the reaction. The resultant newly synthesized 2-hydroxy-3-chloropropyl sulphate was then reacted with starch to obtain starch hydroxypropyl sulphate ultimately. After being characterized by making use of IR spectroscopy analysis and scanning electronic microscope, the starch hydroxypropyl sulphate samples were submitted to evaluation for cationic dye removal using Methylene Blue (MB). Cationic dye removal was studied under a variety of conditions. Factors involved encompass initial dye concentration, duration, sulphur %, pH and adsorbent dose. 100% dye removal could be achieved under certain conditions which were described in the text.

Synthesis and Evaluation of New Environment-Friendly Starch Hydroxypropyl Phosphate as Flocculant

Synthesis and Evaluation of New Environment-Friendly Starch Hydroxypropyl Phosphate as Flocculant

Investigation into The Synthesis and Characterization of Silver Nanoparticles

Hydroxypropyl starch (HPS) is synthesized by using maize starch and different concentrations of both propylene oxide )PO) and sodium hydroxide (NaOH) with the intent to obtain HPS products which can better serve as a reducing and stabilizing agent during the preparation of silver nanoparticles. Such a preparation is carried out under a variety of conditions which include: pH, temperature, duration of the reaction medium, molar substitution (MS) of HPS, and concentration of both HPS and silver nitrate (AgNO3). The yield of silver nanoparticle colloids is monitored via color and ultraviolet (UV) visible spectral analyses whereas their evaluation is performed by making use of a transmission electron microscopy (TEM) to determine size and size distribution. The results obtained conclude that the optimum conditions for preparation of silver nanoparticle colloids with excellent size and size distribution which range from 6-8 nm could be produced by using 0.9 gm of HPS (MS = .84), 0.425 gm of AgNO3, a pH of 12, and temperature of 70°C for 15 minutes. Furthermore, the silver nanoparticle colloid solution prepared under these conditions is stable and remains without aggregation for more than six months. Thus preparation of a well stabilized silver nanoparticle solution with a concentration of 1608 ppm and a diameter of 9-18 nm can be achieved. A silver nanoparticle solution with these unique characteristics may be suitable for industrial applications.

Developing hydroxypropyl methylcellulose/hydroxypropyl starch blends for use as capsule materials

Blends of hydroxypropyl methylcellulose (HPMC) with up to 70% hydroxypropyl starch (HPS) were developed for use as hard capsule materials. Polyethylene glycol (PEG) was used as both a plasticizer and a compatibilizer in the blends. In order to prepare hard capsules for pharmaceutical application using the well-established method of dipping stainless steel mold pins into solution then drying at certain temperature, equilibrated solutions with higher solids concentration (20%) were investigated and developed. The solutions, films and capsules of the different HPMC/HPS blends were characterized by viscosity, transparency, tensile testing, water contact angle, SEM, as well as FTIR. The results showed that the blend system is immiscible but compatible in certain degree, especially after adding PEG. The hydroxypropylene groups grafted onto both cellulose and starch improved the compatibility between the HPMC and the modified starch. The higher viscosity of starch at lower temperature improved the viscosity balance of the system, which enlarged the operation window for the dipping–drying technique. The PEG increased the transparency and toughness of the various blends. By optimizing temperature and incubation time to control viscosity, capsules of various blends were successfully developed.

Hydroxypropyl derivatives of legume starches: Functional, rheological and thermal properties

AbstractHydroxypropyl derivatives were prepared from the native starches isolated from lima bean and jack bean. Both native and hydroxypropylated starches were evaluated for functional, rheological and thermal properties. Molar substitution (MS) value ranged from 0.24 to 0.37 while degree of substitution (DS) from 0.02 to 0.04. The values of swelling power, solubility and pasting parameters of the native starches were significantly different from the hydroxypropyl derivatives with deviations of insignificant difference obtained for lima bean starches. Non‐Newtonian shear‐thinning behaviour was exhibited by all the samples. Their viscosity consistency, K, deduced from Herschel–Bulkley model, increased progressively with MS. Starches at low‐substitution possessed high shear viscosities compared to the native and high‐substituted starches. Increase in yield stress (σo) was observed at low‐substitution level and decrease at high‐substitution level of hydroxypropylation. Upon hydroxypropylation, enthalpies of gelatinisation (ΔHgel) increased whereas the transition gelatinisation temperatures (To, Tp and Tc) decreased. Comparatively, lower values of transition temperature and enthalpy were obtained for retrograded starch gels than the gelatinised gels. Upon hydroxypropylation, native starches experienced increase in MW and polydispersity index (PDI). All the native starches exhibited type‐A XRD patterns, which remained unchanged after hydroxypropylation.

Evaluation of poly(ethylene glycol)/hydroxypropyl starch aqueous two-phase system for immunoglobulin G extraction

The aqueous two-phase system (ATPS) with polyethylene glycol (PEG) and hydroxypropyl starch (HPS) was evaluated for the extraction of human immunoglobulin G (IgG) from human serum albumin (HSA). The partitions of IgG in PEG/sulphate, PEG/phosphate, PEG/Dextran and PEG/HPS ATPSs were compared, and the results indicated that PEG/HPS system was most suitable for IgG extraction. The effects of the concentrations of PEG, HPS and NaCl addition and pH on the partition of IgG and HSA in PEG/HPS ATPS were investigated. It was found that with 15% NaCl addition at pH 8.0 IgG could be largely recovered in the top PEG-rich phase and most of HSA kept in the bottom phase. In addition, the response surface methodology (RSM) was used to optimize the extraction of IgG from the protein mixture of IgG and HSA. The optimal conditions were obtained as 12% (w/w) PEG 4000, 18% (w/w) HPS and 10% (w/w) NaCl at pH 8.0. The extraction yield of IgG in the top phase was 99.2% and the purification factor could reach 5.28. The back extractions of IgG into a phosphate-rich bottom phase were also studied. The total purification factor was 5.73 with the yield of 84.0%. The results indicated that PEG/HPS ATPS might be a promising alternative for the primary recovery of IgG from the complicated feedstock.