Papers by Keyword: Modified Starch

Abstract: Thermoplastic starch bio-composite compound of cross-linked cassava starch has been produced by a twin screw extruder. Rice husk powder, bacterial cellulose fiber and glycerol were incorporated into the starch at various compositions. Bio-composite compounds were thermally compressed into a mechanical test specimen. Influences of reinforcing materials and plasticizer contents were investigated. An extrusion (160°C) and compression (200°C) at higher temperature produced a greater structural deformation of the cross-linked starch than a processing at lower temperature. Morphology of the bio-composite showed a homogeneous distribution of reinforcement in the matrix at high temperature processing and showed good adhesion between rice husk particle, bacterial cellulose fiber and starch matrix. Flexural and tensile mechanical properties of the bio-composite significantly improve with only 0.71%wt bacterial cellulose incorporation.

Abstract: The objective of this study was to investigate the effect of modified hydroxypropyl tapioca starch (HPTS) and % drug loading on physical property of tablet. Paracetamol was used as model drug because of its poor compressibility. The filler ability of modified HPTS such as hydroxyl propyl oxidized tapioca starch (HPOTS), hydroxyl propyl crosslinked tapioca starch (HPCTS) and pregelatinized tapioca starch (PTS) were evaluated and compared with the commercial starch (Starch 1500^®). Tablets were prepared by direct compression method and the percent drug loading were 15, 30, 45, 60, 75%. For modified HPTS, the hardness of the tablets tended to decrease when the concentration of paracetamol increased. At drug concentrations of 15-30%, HPOTS exhibited good performance of tablet as indicated by the high hardness, low friability and acceptable disintegration time. The obtained results were better than HPTS and comparable to Starch 1500^®. Moreover, the results revealed that tablet containing PTS provided the highest hardness and prolonged disintegration time (>30 min) while tablet containing HPCTS showed rapid disintegration time (<2 min). Therefore, modified HPTS disclosed promising properties for application as tablet filler

Abstract: This is a preliminary study for hardness removal via modified starch combined with an ultrafiltration process that provides on high effluence quality and low cost, footprint and environmental impact treatment. This studied on potential of chemisorption process using modified starch as absorbents for hardness removal. Four modified tapioca starches were selected for evaluation that includes of oxidize starch, di-starch phosphate, hydroxyphophyl starch and phosphate monoester as well as non-modified tapioca starch too. Phosphate monoester starch achieved the highest efficiency about 98.2% of hardness removal within the adsorption capacity about 18 mg-hardness removed/g-starch. The modified starch had capable to reduced total hardness from 350.5 mg/L as CaCO₃ to 6.3 mg/L as CaCO₃ from water. However, the modified starch is an organic matter its can be contaminates in water. Then, a coagulation-flocculation processes were applied for starch colloidal destabilization and flocs by aluminum chloride (PAC) and cationic polymer for starch separation. After that process, turbidity was less than 1 NTU in the effluents. However, the total dissolved solids were increased that may be cause of some starch was solutes. These should be having a future treatment for particulate removal and cutoff the soluble starch in water likes an ultrafiltration process.

Abstract: For the principle of green sizing, the key research on sizing technology which reduce the degree of COD in wastewater of sizing was carried out. PVA and modified starch slurry was gradually replaced by hemp pole cellulose ether and modified starch slurry, and the original formula was optimized. After valuing viscosity and COD of the slurry, several suitable formulas were chosen. Then experiments on the same batch of hemp/cotton blended yarn sizing were carried out, and the sizing enhancement rate, stretching rate and the increasing grinding rate were tested. Through the comparative analysis, the COD of hemp pole cellulose ether slurry with modified starch is lower than that of PVA slurry with modified starch. Meanwhile, with the certain compound rate, the former sizing performance is better than the later.

Abstract: Fluorocarbons were added into the mixture of modified starch and sodium alginate to get uniform coating solution, and the solution was then coated on the surface of transparent paper. The color as well as grease barrier property of paper at different coating weight were studied. The results showed that color under different coating weights were not significantly different from base paper. The scanning electron microscopy (SEM) diagram showed the surface of paper became smoother and more homogeneous as the coating weight increased. The grease barrier property of coated papers were significantly improved compared with base paper according to Tappi-559 kit test. A highest grease rating number of 12 was obtained when the coating weight became 3.3 g/m². The dynamic changes in contact angle studies revealed that the contact angle of the base paper was continuously decreased from 29.41 °minutes to 23.46 °within 20, the contact angles of coated papers were significantly increased, and reaching a steady state within 2min with the maximum rate of contact angle change was of merely 0.06 ° / min.

Abstract: The effect of physical aging on the properties of starch is important to understand structural relaxation and to control the physicochemical changes after pregelatinization which induced by aging. In this study, the effect of physical aging on the physicochemical properties of pregelatinized tapioca starch was investigated. The tapioca starch was pregelatinized by either heating at 80°C or using high power (400 W) ultrasonic treatment. After pregelatinization, dextrose equivalent (DE), viscosity, turbidity, swelling power and solubility were determined and compared with native tapioca starch. Compared to fresh tapioca starch, the aged starch exhibited an increase in DE, turbidity and solubility. The viscosity and swelling power were decreased after storage. Similar results were found for both tapioca starches pregelatinized by heat and ultrasonic treatments. The results of the physicochemical properties of pregelatinized starches obtained from ultrasonic treatment related to the formation of low molecular weight components that aging starch are easily changed by disruption of molecular structure within the starch granule.

Abstract: A new processing method for the production of modified starch, high power ultrasonic treatment (400 W), was applied to native tapioca starch. The effect of processing parameters such as ultrasound amplitude (50 and 100%) and sonication time (10, 20 and 30 minutes) on the properties of the modified starches was investigated. Starch granule morphology observed by scanning electron microscopy (SEM), swelling power, solubility and powder x-ray diffractometry (PXRD) of the obtained ultrasonically treated tapioca starch were determined and compared with native as well as heat-treated tapioca starches. The results from SEM and PXRD showed that the ultrasonic treatment of tapioca starch distorted the crystalline region in starch granules, especially at higher amplitude or sonication time. The swelling power of the tapioca starch increased after treatment with both heat and ultrasound, in which the swelling power of ultrasonically treated starch was higher than that of heat-treated starch. It was found that tapioca starch treated by ultrasound for a certain period of time has an increase in solubility. The increase in the swelling power is associated with water absorption capacity and starch granules solubility.

Abstract: soflavones, a special phenolic group found in soybean, have been found to act as antioxidant and are widely used in pharmaceutics and nutraceuticals. Due to the storage and handling problem, the extract has been prepared in dry form by spray drying technique. The condition of extract solution prior to spray drying has been reported to affect the property of dried powder. The aim of this work was to evaluate the effect of diluents on the physical properties of soybean extracted powder. The experiment was carried out by a Büchi B-290 Mini Spray Dryer. Four types of diluents were applied, they weremannitol, maltrodextrin, and 2 types of modified starch The comparison was then made among those with diluents and without diluent as a carrier. The physicochemical property was then characterized for flowability, moisture content, morphology, particle size and X-ray diffraction. From the results, the addition of all diluents could improve the physicochemical properties of soybean extracted powder indicating the improvement in morphology and hence the better flow property .The types of diluent also had the effect on the extracted powder. Maltodextrin and modified starch exhibited the best carrier in term of improvement of flow property. Therefore, the spray drying technique was successfully used to prepare microparticles of soybean extracted powder and by taking into consideration of the selection of suitable diluents, the good quality of soybean extracted powder could be achieved.

Abstract: Properties of thermoplastic starch (TPS) produced from commercial-grade modified cassava starches were investigated in a pilot scale for future practical production in plastic industry. Five types of commercial cassava starches including native, oxidized, acetylated, octenyl succinate and pregelatinized starches were transformed into TPS by extrusion. The morphology implied that degree of destructuration could be manipulated by adjusting amount of glycerol of the starch melt. All types of TPS exhibited strong water sensitivity especially when exposed to humid atmosphere (>0.75 water activity). Compared among these selected five commercial cassava starches, there were no significant differences in sorption properties. Tensile strength of the thermoplastic starches increased with increasing starch content, and a drastic gain was recorded for 80% starch content for all types of starches. The elongation at break seemed to reach a maximum value for native TPS and pregelatinized TPS when composition of starch was 70%. The concavity of elongation at break of both TPS’s could arise from greater mobility of starch molecules during deformation due to the presence of glycerol and water, so that the properties shifted from glassy to more fluid-like. When compared among the types of modification, pregelatinized starch produced a highly elongated TPS with lowest strength due to its complete destructuration of starch granules, and the octenyl succinate starch yielded the highest strength and most brittle TPS. This study proved that cassava starch had a considerable potential to further developed for biodegradable applications but higher degree of modification than these of common commercial grade was required to improve water resistance of its thermoplastic starch.

Abstract: In order to reduce the emission of volatile organic compounds (VOCs) and save the non-renewable resource, a novel interior wall coating with high bond strength based on metakaolin and modified starch was developed. The process on researches includes three steps. Firstly, cassava starch was reformed including etherification, oxidation, conjugate crosslinking and drying to gain natural polymer glue powder which can be used as forming agent, and a dispensation in producing environment friendly paint for interior wall coating was preliminarily obtained. The dispensation consists of forming agent, calcium carbonate, French chalk, chitosan and mildew preventive. Secondly, the process on metakaolin was studied. Metakaolin shows hydration Characteristics and can make interior wall coating have bond strength and resistance to water. At last, the dispensations and processes in obtaining starch glue, metakaolin and paint powder were decided respectively, and the data in gauging bonding force, resistance to water and the performance of interior wall coating were gained. The research on forming agent was as following: the mixture of cassava starch and NaOH was stirred, and pulverized to be sieved by100 mesh. After reacted stirringly with chloroacetic acid for 1.5h at room temperature, the mixture was oxidized by oxidant for 2h and crosslinked by crosslinking agent for 1h respectively to obtain forming agent. The mass fraction of NaOH, chloroacetic acid, oxidant and crosslinking agent to cassava starch were 6%, 5%, 6% and 0.8%, respectively. The Kaolin selected must contain high percents of Al₂O₃ and SiO₂ , and was calcined at 700°C for 5h to have metakaolin as additive for interior wall coating to improve bond strength and resistance to water. The composition of interior wall coating optimized by orthogonal test is about: 4% of starch glue, 6% of metakaolin, 80% of calcium carbonate, 9.7% of French chalk, 0.1% of chitosan and 0.2% of mildew preventive. The interior wall coating is environmental benign material in building industry.