Maximum Degree Of Substitution Research Articles

Esterified wheat bran: Physicochemical properties, structure and quality improvement of Chinese steamed bread during refrigerated storage

To develop the application of wheat bran and improve the nutrition and anti-staling capacity of Chinese steamed bread (CSB), oleic acid-esterified wheat bran (OWB) was prepared by esterification of wheat bran with oleic acid, and its physicochemical properties, structure, and quality improvement for CSB during refrigerated storage were investigated. The hydrophilic-lipophilic balance value of OWB was 16.0, the maximum degree of substitution was 0.146, and its emulsifying capacity was similar to that of glycerol monostearate. The starch gelatinization degree of CSB containing 3 % OWB and the control decreased by 19.55 % and 27.12 % within 7 days of refrigerated storage, respectively, while the hardness of CSB with OWB was lower than that with wheat bran. OWB inhibited starch recrystallization and increased bound water in the corresponding CSB, which effectively delayed starch retrogradation. OWB had a positive emulsifying capacity and showed potential as a functional material for preventing retrogradation of starch-based foods.

Optimization of preparation conditions of medium and highly substituted carboxymethyl inulin through response surface methodology

This article introduces the synthesis optimization of carboxymethyl inulin using response surface methodology. The important factors affecting the degree of substitution (DS) were determined by Plackett-Burman design, including sodium hydroxide concentration, monochloroacetic concentration, and etherification temperature. Further optimization was conducted using the Box-Behnken response surface design. The coefficient of determination (R2) of the response surface model was 0.9827, and the adjusted R2 value was 0.9516, which proved the significance of the model. The optimized results of the predicted response showed that the molar ratios of sodium hydroxide to monochloroacetic acid and fructose to furan were 3.67 and 2.21, respectively. The maximum DS of 1.67 was obtained at 30 °C alkalization for 30 min and 50.30 °C etherification for 4 h, and the reaction efficiency (RE) reached 76.01 %. Under the optimized conditions, the Experimental DS was 1.68, suggesting that the experimental and predicted values of DS were in good agreement. The characterization results confirmed the synthesis of CMI. In this work, we have provided an effective method for the preparation of moderately to highly substituted CMI in 95 % ethanol.

A novel efficient wet process for preparing cross-linked starch: Impact of urea on cross-linking performance

Although wet processes are promising for preparing cross-linked starch, they are currently challenged by lower cross-linking efficiency and the requirement of large amounts of salts. Herein, an efficient and greener wet process was proposed, in which the cross-linking performance between sodium hexametaphosphate (SHMP) and starch was enhanced with the aid of urea. The maximum degree of substitution (DS) of the urea-phosphorylated cross-linked starch (UPCS) was 0.040 at 35 °C, while that of the conventional phosphorylated cross-linked starch (CPCS) was 0.031 at 45 °C. Compared with CPCS, the maximum DS of UPCS was elevated by 29.03 %, but its optimum cross-linking temperature was reduced by 10 °C, indicating that the cross-linking efficiency of this novel wet process was greatly improved by urea. The structural difference between UPCS and CPCS was confirmed by using a series of techniques including 31P NMR and 13C NMR. Zeta potential results suggested that urea may promote starch cross-linking by preventing the closure of active sites through hydrophobic interactions. Due to the structural reinforcement of starch by urea, UPCS showed better thermal stability, water resistance, acid and alkali resistance, and steady shear tolerance properties. This study provides a facile wet process for the fabrication and application of cross-linked starch materials.

Preparation, characterization and biological activity of phosphorylated surface deacetylated chitin nanofibers

Phosphorylation is a key route to achieve varieties of biological activities for polysaccharides. Here, we report the phosphorylated surface deacetylated chitin nanofibers (PS-ChNFs) using the sodium tripolyphosphate/sodium trimetaphosphate (STPP/STMP) method. Response surface methodology (RSM) was employed to optimize in this study. Under optimal conditions, a maximum degree of substitution (DS) of 0.13 was obtained. In addition, the structures of PS-ChNFs were investigated by Fourier transform infrared spectroscopy (FT-IR), Nuclear Magnetic Resonance spectra (NMR), X-ray photoelectron spectroscopy (XPS), Scanning electron microscope (SEM) and (Energy Dispersive Spectroscopy-mapping) EDS-mapping. The findings revealed that the FT-IR spectroscopy and XPS analysis confirmed the appearance of phosphate groups in PS-ChNFs. The 31P NMR results indicate that the PS-ChNFs structure has characteristic peaks of P elements. SEM images showed that PS-ChNFs had a rough surface with many cavities, but the P elements on the surface of the EDS-mapping are uniformly distributed throughout the sample without any enrichment. Antioxidant and antibacterial test showed that PS-ChNFs had significant scavenging effect on free radicals and antibacterial effect. The above results indicate that the chemical modification of PS-ChNFs was successful.

The effect of freezing-assisted cross-linking on structural and rheological properties of potato starch

In order to achieve preparation of cross-linked (CL) potato starch with the maximum degree of substitution, freezing pre-treatment (FS) in different modes as three days freezing (3D), two freezing-thawing cycles (3D + 3D) and 6 days freezing (6D) were conducted. Thereafter, native, frozen and cross-linked starches were characterized for morphological, structural and pasting properties as well as alkaline and intrinsic viscosity. Regarding obtained result, freezing pre-treatment as 3D + 3D was found to be an efficient method to achieve high level of cross-linking than native and other modes of freezing pre-treatments when exposed to POCl3 reagent. The crystallinity (%) and ratio of 1047/1022 cm−1 increased from 38.6 % and 1.112 (native potato starch; NPS) to 41.6 % and 1.269 (cross-linked native potato starch; CL) and 41.3 and 1.292 (cross-linked freeze- thawed starch 3D + 3D + CL) after being treated with POCl3. Data obtained by intrinsic viscosity was in line with the power-law model. Cross-linked starch with POCl3 exhibited the lowest k value and the highest n value, implying lower shear-thinning behavior of cross-linked starch after freezing pre-treatment than CL native starch. To sum up, low peak viscosity (determined by RVA) and intrinsic viscosity (by U-tube viscometer) could also explain the high level of cross-linking and low swelling power of 3D + 3D + CL.

Synthesis and Performance of a Novel Cotton Linter Based Cellulose Derivatives Dispersant for Coal-Water Slurries.

A novel sulfonic-cellulose succinate half ester (S-CSHE) dispersant for coal–water slurry (CWS) was successfully synthesized using cotton linters, sulfamic acid and succinic anhydride in DMF by a one-pot synthesis. The effects of the synthetic condition of S-CSHE as a dispersant for CWS were studied. An S-CSHE with a maximum degree of substitution of 0.98 was obtained under these optimized conditions. The synthesized samples were characterized by GPC, FT-IR spectroscopy, 13C-NMR, and SEM. The molecular weight was from 2.2 × 103 to 1.2 × 104, revealed by GPC; FT-IR spectra analysis revealed characteristic absorptions of the sulfonic-cellulose succinate half ester; SEM images showed smooth cellulose structures, while the S-CSHE had a compact surface. Effects of S-CSHE on the fluidity of application as the dispersants for the CWS prepared from Chinese Zhundong coal were studied further. The CWS application performance investigations showed that S-CSHE can most effectively reduce CWS viscosity, and perform excellent dispersity and stability. When the dosage of S-CSHE was up to 0.5 wt.%, the maximum coal content of CWS may reach 70 wt.%, and the apparent viscosity of CWS was 487 mPa·s. The CWS prepared using S-CSHE (0.38 wt.%) for Zhundong coal showed the rheological characteristics of shear-thinning, and is consistent with the Herschel–Bulkley model. This work found a new route for utilizing cotton linters cellulose and enlarged the selecting range of the dispersant for CWS. It has a positive significance for efficient and clean utilization of Xinjiang Zhundong coal.

OBTAINING MONO-SUBSTITUTED SORBITAN ESTERS

Polyol esters have recently been widely used in various fields: medicine, cosmetics, food industry, sanitation, science and technology. This is ensured by the specific physical and chemical properties of this group of substances. Polyols are polyhydric alcohols obtained by hydrogenation of monosaccharides. These compounds are found in natural sugars and are used in food and as dietary sweeteners. Esters of polyols with carboxylic acids are functionally divided into several groups. Thus, esters of saturated carboxylic acids С12-С18 - with a degree of substitution from 4:1 to 6:1 are mainly thick and hard artificial oils and, accordingly, are used in medicine, pharmacy and cosmetology. In engineering, polyol esters are mainly used in the machine tool, automotive and aviation industries as high temperature lubricating oils. Polyol esters containing C4-C12 carboxylic acids or unsaturated carboxylic acids are generally liquid or soft oils for use in ointments, cosmetic preparations, and the like. A variety of polyol esters with a degree of substitution from 1:1 to 3:1 are particularly widely used as emulsifiers, stabilizers, defoamers, dispersants and detergents. Our previous studies have focused on obtaining oil-like esters with the maximum degree of substitution. Using the examples of mannitol, sorbitol, xylitol, and erythritol, numerous samples of esters were obtained and the optimal conditions for esterification reactions, isolation, and analysis of the obtained products were worked out. In this work, we set a goal to study the patterns of obtaining monosubstituted esters of sorbitol and sorbitan, which are of interest as nonionic emulsifiers and detergents. In particular, the technical regulations of the Eurasian Economic Community allow the use of emulsifiers: E491 – sorbitan monostearate, E492 – sorbitan tristearate, E493 – sorbitan monolaurate, E494 sorbitan monooleate, E495 sorbitan monopalmite. Sorbitan monopalmitate or span 40 emulsifier is a flaky yellowish brown wax. It consists of a mixture of mono- and dianhydrides of sorbitan. Its liquid crystal structure is similar to the natural structure of the skin, easily absorbs water and effectively moisturizes the skin, transfers nutrients and medicinal substances deep into the skin.

Facile Post-Carboxymethylation of Cellulose Nanofiber Surfaces for Enhanced Water Dispersibility.

To improve the water dispersibility of cellulose nanofibers without deteriorating the physical properties, it is necessary to develop methods that can selectively modify fiber surfaces. Herein, the reaction conditions for carboxymethylation of the surface of nanofibrillated bacterial cellulose were optimized using chloroacetic acid as an etherification agent. Carboxymethylation in a high-concentration alkaline solution (>5 wt %) in the presence of isopropanol caused the mercerization and carboxymethylation of not only the nanofiber surface but also the cellulose crystals within the nanofiber, resulting in nanofiber swelling and an increase in fiber width. In contrast, with a dilute alkaline aqueous solution (3 wt %), the nanofiber surface was successfully carboxymethylated without changing the inner structure. Furthermore, the morphology was not affected by the carboxymethylation reaction, and no fiber swelling occurred under these reaction conditions. When the substitution reaction proceeded only on the nanofiber surface, the maximum degree of substitution (i.e., the average number of carboxymethyl groups substituted per anhydroglucose residue in cellulose) was 0.091. After surface modification, the nanofibers became more negatively charged, which improved the dispersibility in water through electrostatic repulsion, resulting in a drastic increase in the transparency of the nanofiber dispersion. This method provides a general approach for the surface modification of cellulose nanofibers to increase water dispersibility.

Biocatalytic Synthesis and Characterization of Starch Ferulate Based on Ultrasonic Pretreatment of Substrate

To improve the hydrophobicity and biological activity of corn starch, starch ferulate was prepared by Novozym 435 lipase catalyzed transesterification of ultrasonic pretreated corn starch and ethyl ferulate. The ferulic acylation of starch was confirmed by UV and Fourier transform infrared spectroscopy (FT-IR). Starch ferulate was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and differential scanning calorimeter (DSC). In addition, the hygroscopicity and free radical scavenging ability of esterified starch (ES) were evaluated. In the results, the maximum degree of substitution (DS) of ES was 0.0728 under the optimal ultrasonic pretreatment conditions, which was much higher than that of 0.0142 without ultrasonic pretreatment. The XRD and DSC analysis showed that ferulic acylation destroyed the crystalline structure of corn starch to a certain extent. Moreover, ferulic acylation can improve the hydrophobicity and free radical scavenging ability of starch. In conclusion, ES obtained with ultrasonic pretreatment followed by enzyme catalysis can improve physical and chemical properties of starch. Ultrasonic provides an effective method for synthesizing high-quality modified starch and lays a theoretical foundation for expanding the application of corn starch.

Synthesis and Characterization of Carboxymethyl Cellulose Derived from Empty Fruit Bunch

Oil palm empty fruit bunch (EFB), a cellulose rich lignocellulosic biomass has huge potential to be utilised as a raw material for the synthesis of carboxymethyl cellulose (CMC). In this study, CMC was synthesised from EFB extracted cellulose at the optimum carboxymethylation reaction conditions. The extracted cellulose yield obtained by alkaline treatment followed by bleaching with hydrogen peroxide was 45.5 wt.%. The cellulose structure was elucidated using thermogravimetric analysis (TGA), Fourier-transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) patterns. Meanwhile, the synthesised CMC was characterised with FT-IR, XRD and scanning electron microscopy (SEM). The maximum degree of substitution (DS) obtained was 1.30 with the yield of 177.51 wt.% and purity 89% determined using chemical methods at the optimum conditions of 30 wt.% of NaOH, 18 g of SMCA, 65 °C, 3 h reaction time and less than 75 μm of EFB-cellulose particle size. XRD analysis inferred low crystallinity while FTIR spectra verified the CMC structure and presence of different functional groups. The results for DS and EFB CMC yield obtained from this work were considerably higher than those reported in the literature. The synthesised EFB CMC can be further utilised in various industries such as detergent, mining, flotation, and oil and gas drilling muds applications.

Optimization of synthesis conditions for carboxymethyl cellulose from pineapple leaf waste using microwave-assisted heating and its application as a food thickener

Pineapple leaf waste, with its high cellulose content, can serve as alternative starting material for the production of carboxymethyl cellulose (CMC). In this study, synthesis conditions of CMC from pineapple leaves via the use of microwave heating were optimized. Box-Behnken design and response surface methodology were applied to schedule the experiments and to optimize the synthesis condition, respectively. Preparation of CMC was investigated by varying three factors, namely, sodium hydroxide (NaOH) concentration, monochloroacetic acid (MCA) dose, and etherification time. The process of carboxymethylation was optimized to produce CMC with high degree of substitution (DS). Optimal condition for CMC synthesis was noted to be 50% (w/v) NaOH solution, 8 g of MCA/g cellulose, and etherification time of 16 min; such optimal condition resulted in the maximum DS of 0.78. Synthesized CMC was utilized as a thickener for liquid foods (water, orange juice, milk, and mushroom cream soup) where 2% (w/v) as-synthesized CMC increased the viscosity of the foods and changed their characteristics from thin to nectar-like liquids.

Optimization of synthesis conditions for carboxymethyl cellulose from pineapple leaf waste using microwave-assisted heating and its application as a food thickener

Pineapple leaf waste, with its high cellulose content, can serve as alternative starting material for the production of carboxymethyl cellulose (CMC). In this study, synthesis conditions of CMC from pineapple leaves via the use of microwave heating were optimized. Box-Behnken design and response surface methodology were applied to schedule the experiments and to optimize the synthesis condition, respectively. Preparation of CMC was investigated by varying three factors, namely, sodium hydroxide (NaOH) concentration, monochloroacetic acid (MCA) dose, and etherification time. The process of carboxymethylation was optimized to produce CMC with high degree of substitution (DS). Optimal condition for CMC synthesis was noted to be 50% (w/v) NaOH solution, 8 g of MCA/g cellulose, and etherification time of 16 min; such optimal condition resulted in the maximum DS of 0.78. Synthesized CMC was utilized as a thickener for liquid foods (water, orange juice, milk, and mushroom cream soup) where 2% (w/v) as-synthesized CMC increased the viscosity of the foods and changed their characteristics from thin to nectar-like liquids.

Synthesis and Biological Evaluation of a Novel Glycidyl Metharcylate/Phaytic Acid-Based on Bagasse Xylan Composite Derivative.

The development of natural biomass materials with excellent properties is an attractive way to improve the application range of natural polysaccharides. Bagasse Xylan (BX) is a natural polysaccharide with various biological activities, such as antitumor, antioxidant, etc. Its physic-chemical and biological properties can be improved by functionalization. For this purpose, a novel glycidyl metharcylate/phytic acid based on a BX composite derivative was synthesized by a free radical polymerization technique with glycidyl metharcylate (GMA; GMABX) and further esterification with phytic acid (PA; GMABX-PA) in ionic liquid. The effects of the reaction conditions (i.e., temperature, time, initiator concentration, catalyst concentration, GMA concentration, PA concentration, mass of ionic liquid) on grafting rate(G), conversion rate(C) and degree of substitution(DS) are discussed. The structure of the composite material structure was confirmed by FTIR, 1H NMR and XRD. SEM confirmed the particle morphology of the composite derivative. The thermal stability of GMABX-PA was determined by TG-DTG. Molecular docking was further performed to study the combination mode of the GMABX-PA into the active site of two lung cancer proteins (5XNV, 2EB2) and a blood cancer protein (2M6N). In addition, tumor cell proliferation inhibition assays for BX, GMABX-PA were carried out using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetraz -olium bromide (MTT) method. The results showed that various reaction conditions exhibited favorable gradient curves, and that a maximum G of 56% for the graft copolymerization and a maximum DS of 0.267 can be achieved. The thermal stability was significantly improved, as demonstrated by the fact that there was still 60% residual at 800 °C. The molecular docking software generated satisfactory results with regard to the evaluated binding energy and combining sites. The inhibition ratio of GMABX-PA on NCI-H460 (lung cancer cells) reached 29.68% ± 4.45%, which is five times higher than that of BX. Therefore, the material was shown to be a potential candidate for biomedical applications as well as for use as a heat resistant material.

Effect of strontium atoms substitution on the features of two-slab structure of Sr1-xCaxLa2Sc2O7 scandates

Effects of substitution of the Strontium atoms with smaller Calcium atoms on the structural features of the Ruddlesden-Popper SrLa2Sc2O7 two-slab compound is established. The crystal structure of orthorhombic Sr0.85Ca0.15La2Sc2O7 phase with maximum degree of substitution was determined by the Rietveld method (Fmmm space group, a = 0.5766(2) nm, b = 0.5743(2) nm, c = 2.0522(7) nm). Comparison of the structural features of SrLa2Sc2O7 and Sr0.85Ca0.15La2Sc2O7 shows that such type of substitution leads to a decrease in the (La,Sr)2 - О2 interblock bond length (from 0.222 (2) nm at x = 0 to 0.215 (1) nm at x = 0.15). The decrease in interblock bond length brings the constitution of the two-dimensional structure Sr1-хCaxLa2Sc2O7 closer to the structure of the three-dimensional perovskite, leads to its instability at х > 0.15 and gives a reason to conclude that this factor causes a limitation of region of the Sr1-хCaxLa2Sc2O7 solid solutions with a slab perovskite-like structure. Presence of such structure changes is the precondition for regulation of structural-dependent features of the materials on the base of scandates alkaline-earth and rare earth metals.

Preparation of alpha cellulose from sugarcane bagasse and its cationization: Synthesis, characterization, validation and application as wet-end additive

Paper industry uses cationic polymers for imparting strong bonds with pulp furnish to enhance strength properties. Due to environmental reasons, emphasis is on utilization of biobased polymers in place of synthetic. Sugarcane bagasse, an agro-industrial waste, was processed for extraction of alpha cellulose and preparation of cationic derivative. Reaction conditions were optimized to achieve highly substituted cationic derivative with insertion of 2-hydroxy-3-(trimethylammonium) propyl group. Artificial neural network (ANN) was applied to analyze the experimental data for cationization modeling. Maximum degree of substitution 0.66, was achieved at 5.0 M NaOH/anhydro glucose unit (AGU), 20 °C alkalization temperature, 8 min alkalization time, 3.5 M/AGU etherification agent concentration, 45 min time and 60 °C etherification reaction temperature. The experimental results showed that mean square error values for input parameters were significantly low. The ANN based regression values of the output, and computed values of target were close to unity. ANN based fitting indicates better performance level to predict the degree of substitution. The synthesized cationic cellulose was characterized through FTIR, XRD, NMR, FESEM and TGA. The activity of cationized cellulose as wet-end additive was tested for bagasse, wheat straw and recycled pulps due to their shorten fiber and feeble pulp characters than wood pulp.

Octenyl succinylation of kefiran: Preparation, characterization and functional properties

In this study, kefiran was esterified with octenyl succinic anhydride (OSA). The esterification reaction variables including pH (8.5), kefiran concentration (5% (w/w)), OSA concentration (12% (w/w)), temperature (~38 °C) and reaction time (~80 min) were found as optimum points to achieve the maximum degree of substitution (DS) (0.041 ± 0.002). Kefiran-OSA samples with DS of 0.021 (FDA suggested DS) and 0.041 (maximum DS) were prepared and compared with unmodified kefiran in all experiments. FTIR and 1H NMR spectroscopies proved the grafting of OSA on kefiran structure. XRD analysis revealed that with increase in DS, the physical state of kefiran to be more amorphous. In addition, the esterification modification led to a decrease in the degradation temperature and an increase in the apparent viscosity based on the obtained data from thermal analysis and viscosity measurement. The results of the foaming and emulsifying properties confirmed the improvement in surface properties of the modified kefiran. The frequency sweep test illustrated that with an increase in DS, the viscoelastic behavior of the kefiran cryogels to be more viscous. It can finally be stated that the modification with OSA was a high potential strategy to extend the industrial applications of the kefiran.

Synthesis and characterization of citric acid esterified canna starch (RS4) by semi-dry method using vacuum-microwave-infrared assistance

In this study, citric acid (CA) esterified canna starch was firstly synthesized with the aid of vacuum, microwave and infrared radiation treatment. The changes in structural, physicochemical properties and in vitro digestibility of the modified starch were then investigated. The maximum degree of substitution (DS) reached 0.273 and the maximum thermo-stable resistant starch (RS) content reached 86.5 %. FT-IR confirmed the esterification reaction had successfully occurred, XRD and DSC results revealed that the crystalline and endothermic peaks of the samples disappeared after CA-treated, and TGA showed that the thermal degradation temperatures were above 280 °C. SEM showed the destroyed surface of the starch granules. All modified samples were lighter and generally whiter than native canna starch in color. These results suggest that the aid of vacuum treatment, microwave and infrared radiations for CA esterified of canna starch is an effective method for preparing high content of thermally stable RS4.

Chemical modification of pullulan exopolysaccharide by octenyl succinic anhydride: Optimization, physicochemical, structural and functional properties

Pullulan (PU) is an exo-polysaccharide used in the food and pharmaceutical industries. However, the use of PU in different industries is limited due to its highly hydrophilic nature and consequently weakness in surface properties which can be remedied by its chemical modification with octenyl succinic anhydride (OSA). For this purpose, PU modification with OSA was optimized and the results showed that the maximum degree of substitution (0.061 ± 0.003) was obtained under pH of 9.0, pullulan concentration of 40% (w/w), temperature of ~40.90 °C, reaction time of ~101.21 min and OSA concentration of 14.96% (w/w). Also, the grafting of OSA on pullulan structure was confirmed by FTIR, 1H NMR and zeta-potential analyzes. Although this modification had no significant effect on the amorphousity of pullulan, it led to an increase in viscosity and a decrease in decomposition temperature and surface tension. Improvement of emulsifying properties of PU-OSA sample was proved by the evaluation of emulsifying capacity of un- and modified samples and also, zeta-potential, particle size and viscosity of the prepared emulsions. In line with surface characteristic results, an increase in foam capacity of modified samples was observed with decreasing the interfacial tension.

Acetylated debranched starch micelles as a promising nanocarrier for curcumin

Natural amphiphilic polymer micelles are of great interest as a carrier of hydrophobic functional ingredients due to their relatively easy synthesis, biocompatibility, and extensive sources. This study modified debranched starch (DBS) with acetic anhydride to introduce the hydrophobic acetyl group, and micelles were then obtained through the self-assembly of acetylated debranched starch (ADBS). The degree of substitution (DS) and the structural and thermal properties of ADBS were systematically investigated; the maximum DS value was 0.17. Proton nuclear magnetic resonance spectra of ADBS confirmed the presence of acetyl methyl protons, and Fourier transform infrared spectra exhibited a new absorption band of carbonyl C = O vibration at 1730 cm−1 due to the introduction of acetyl. The developed micelles were mostly spherical, and the particle size was about 50–100 nm. The critical micelle concentration was 0.45 mg/mL. Curcumin was incorporated into the micelles successfully, and the curcumin-loaded micelles exhibited sustained release properties in simulated gastric and intestinal fluids.

Structure and properties of cationic starches synthesized by using 3-chloro-2-hydroxypropyltrimethylammonium chloride

Cationic starches (CS) with preserved microgranular structure were prepared from potato starch, with 3-chloro-2-hydroxypropyltrimethyl ammonium chloride as cationic reagent. CS with degree of substitution (DS) and reaction efficiency (RE) ranging from 0.05 to 0.84 and from 47.1% to 99.6%, respectively, were obtained by semidry cationization. The influence of the composition of reaction mixture on RE was investigated. CS with highest DS of 0.84 were obtained by using CaO additive. Meanwhile, without addition of CaO cationic starches with maximum DS of 0.28 were synthesized. Modified starches were characterized by means of Fourier transform infrared and X-ray powder diffraction spectroscopy, scanning electron microscopy, histological examination, Brabender viscoamilography, and solubility studies. It was confirmed that by addition of CaO into reaction mixture, the cationization proceeded in the deeper layers of the granules and attached cationic groups were more evenly distributed in the granule volume. Consequently, CS with high DS and cold water solubility were obtained.