Preparation Of Starch Research Articles

Starch/silver nanocomposite: Effect of thermal treatment temperature on the morphology, oxygen and water transport properties

The present work reports a strategy involving the preparation of nanostructured starch based film containing silver nanoparticles (AgNPs) using a completely green chemistry process. The nanocomposite films were prepared by solution cast process. The AgNPs were in situ generated inside the polymer film by thermal treatment at different temperatures (25, 40 and 85°C). The influence of the presence and the amount of reducing agent (glucose) were also investigated. For all nanocomposite films, the AgNPs were spherical with a diameter less than 15nm. Contrary to the presence of glucose, thermal treatment condition was a key factor for the AgNPs structure. Crystalline AgNPs were obtained only after thermal treatment at 85°C. Improvements of water and oxygen barrier properties near to one decade were observed in this last case and were explained by the formation of crystalline AgNPs associated to the establishment of strong interactions between AgNPs and starch polymer matrix.

Aerogels as drug delivery systems: In vitro and in vivo evaluations

The research was oriented toward the preparation of silica aerogels and starch and sodium alginate aerogels, using supercritical fluid technology with potential applications as carriers for oral drug delivery.A supercritical adsorption process was used to obtain drug-loaded aerogels. In-vitro dissolution test were performed. Release behavior was evaluated in different pH media (pH 1.2 and 6.8). Results showed that the release rate increased for certain pharmaceutical ingredients. Time was required to release and dissolve 50% of the active drug from drug-loaded aerogels, reduced in comparison with pure active drugs. The primary in-vivo studies were performed to determine the bioavailability of the active substance loaded into the aerogel in comparison with the pure active drug. Results showed that bioavailability values for drug-loaded samples are higher than that of pure active drugs.Obtained results provide insight into the application of aerogels as a drug delivery system to improve pharmacokinetic properties of active drugs.

Characterization and Preparation of Sago Starch (SS) Based Reinforced with Silver Nanoparticle (SNP)

This paper reported on the properties of sago starch (SS) films impregnated with different concentration of sliver nanoparticles (SNP) of 100, 2000, 5000 rpm with weight ratio of 1% and 10% to be used as wound healing material. The SS films were prepared through film moulding technique by mixing aqueous SNP with SS, glycerol and water at weight percentage of 6.5:3.5:90. The performance of SS-SNP films produced is studied. The morphology study shows the existence of SNP embedded in the SS particles. SNP with 2000ppm has the biggest particle width but small in particle sizes, which make the SS-SNP film of 2000ppm is superior in thickness, denser and has lower moisture content compared to other SS-SNP film with different composition. The highest water absorption occurred in the SS-SNP of 100ppm, due to the high existence of pores in the network of amylose content in starch. SNP act as particulate reinforcement in the SS film meaning higher number of ppm made the film more brittle and easy to rupture. Thus, the SS-SNP film of 5000ppm has the lowest tensile strength and modulus for tensile strength and modulus. It can be concluded that the SS-SNP film of 2000ppm is suitable to be used as wound healing material, as the addition of 2000ppm SNP inside the SS films help in improving the properties of SS-SNP film produced.

Preparation of CMC-PVA/PAN-FePc(COOH)8/CS-PVA Bipolar Membrane and its Application in Electro-Oxidized Synthesis of Dialdehydle Starch

The polyacrylonitrile (PAN)-iron octocarboxyphthalocyanine (FePc(COOH)8) nanofibers were prepared using electrospinning technique and introduced into the interlayer of a carboxymethyl cellulose (CMC)-polyvinyl alcohol (PVA)/chitosan (CS)-polyvinyl alcohol bipolar membrane (BPM), which was characterized using SEM, contact angle measurement, current-voltage characteristics, AC impedance spectroscopy and so on. The experimental results showed that after modification by PAN-FePc(COOH)8 nanofibers, the membrane impedance of the BPM and its cell voltage were decreased. That indicated that the water splitting efficiency in the interlayer of the BPM was increased. Then the prepared CMC-PVA/PAN-FePc(COOH)8/CS-PVA BPM was used in the electro-oxidized preparation of dialdehydle starch (DAS). The experimental results indicated that a current density of 20mA·cm-2 was suitable to obtain high current efficiency. When the electrolysis time was 3h at a current density of 20 mA·cm-2 , the current efficiency of the CMC-PVA/PAN-FePc(COOH)8/CS-PVA BPM-equipped cell was as high as 67%.

Preparation, health benefits and applications of resistant starch—a review

Resistant starch (RS) encompasses those forms of starch, which are not accessible to human digestive enzymes and are fermented in the colon producing short chain fatty acids. Because of its unique physicochemical and functional properties resistant starch finds use in wide range of food products and yields high quality products. It has recently gained substantial importance due to its positive impact on health. Among the health benefits include improvement of colonic health and microflora, management of diabetes, lower glycemic index and blood cholesterol levels, reduced bilestone formation, increased mineral absorption, and potential to modify fat oxidation. Technically RS can be produced by different physical, enzymatic and chemical modifications. This article reviews about types of resistant starch, sources, preparation, health benefits, and applications of resistant starch.

Preparation and characterization of protein resistant zwitterionic starches: The effect of substitution degrees

Zwitterionic polymers are known to possess excellent protein resistance due to high hydration capacity of their zwitterionic moieties. In this study, polysaccharide‐based zwitterionic polymers 3‐dimethyl(propyl) ammonium propanesulfonate starches (Z‐starches) with different degrees of substitution of the zwitterionic moieties (DSZM) were synthesized successfully. The value of DSZM can be controlled exactly in the range of 0–0.46. The cytotoxicity of Z‐starches with different DSZM was evaluated by an MTT assay, and the Z‐starch with DSZM of 0.26 promoted cell proliferation when the concentration of this polymer solution was 1–25 mg/mL. The protein resistance and cell adhesion of Z‐starch hydrogels were evaluated, and the amount of protein adsorption or cell adhesion on Z‐starch hydrogels was decreased as the DSZM increased. The preliminary protein resistance and cell adhesion tests suggest that the Z‐starches have potential applications in drug delivery carriers and coatings of implanted sensors where protein resistance is needed.

Efficiency of high hydrostatic pressure in preparing amorphous granular starches

To investigate the possibility of amorphous granular starch (AGS) preparation from corn, tapioca, potato, sweet potato, waxy rice, and normal rice starches with non‐thermal HHP treatment, all starches were treated at 20°C for 30 min at 550 MPa. Ethanol (EtOH) and distilled water) were used to wash the high hydrostatic pressure (HHP)‐treated starches, and the microscopic and macroscopic properties of the resultant starches were investigated. EtOH washing after HHP treatment allowed HHP‐treated starch to retain the granular shape similar to that of its native form. HHP‐treated corn, tapioca, and normal rice starches completely gelatinized but maintained granular structures, successfully achieving AGSs. Although HHP‐treated potato and sweet potato starches exhibited their granular structures, gelatinization became incomplete. Waxy rice starch no longer exhibited its granular structure after HHP treatment. HHP‐treated starches (forming AGSs) from corn, tapioca, and normal rice exhibited different microscopic and macroscopic properties compared to their respective native ones and non‐AGSs.

Update of use of hydroxyethyl starches in surgery and trauma

Update of use of hydroxyethyl starches in surgery and trauma

To use or not to use hydroxyethyl starch in intraoperative care: are we ready to answer the 'Gretchen question'?

The decision of the European Medicines Agency (EMA) against the use of hydroxyethyl starch (HES)-based volume replacement solutions in critically ill patients has led to a general uncertainty when dealing with HES-based solutions, even though HES-containing solutions can still be used for the treatment of hypovolaemia caused by acute (sudden) blood loss. This review discusses current evidence of the intraoperative use of HES-based solutions. HES solutions are often criticized for possible side-effects on the kidney, the coagulation system or tissue storage. Relevant differences exist between modern 6% HES 130/0.4 and older generation of starches. Because of pathophysiological differences between elective surgery and critical illness, the evidence on renal injury and coagulation impairment with HES administration cannot be generalized. Current data suggest that there is no clinically relevant impact of 6% HES 130/0.4 administration on perioperative renal function and coagulation. Over-resuscitation is a frequent problem associated with adverse outcomes. Due to the higher volume effect, fluid overload with HES is probably more harmful than with crystalloids, whereas goal-directed use of HES may be able to reduce intraoperative fluid accumulation and overload. The use of 6% HES 130/0.4 in elective surgery patients is associated with reduced fluid accumulation and no clinically relevant difference in bleeding or the rate of acute kidney injury as compared with crystalloid use alone. Current data do not allow a conclusion on mortality. As they provide no benefit, older starch preparations should not be used.

Novel hydrophilic carboxymethyl starch/montmorillonite nanocomposite films

Preparation of novel carboxymethyl starch (CMS)-based biodegradable films with calcium montmorillonite has been described. The biocomposites were obtained by casting method, glycerol and citric acid were used as plasticizer and crosslinking agent, respectively. The effect of calcium montmorillonite (MMT-Ca) on hydrophilicity (moisture absorption, solubility in water as well as contact angle measurements) was evaluated. Moreover, thermomechanical and mechanical properties of nanocomposites were determined. For all the systems tested intercalated structure of MMT-Ca was revealed, however the most efficient clay platelets dispersion was noted for film containing 5wt.% MMT-Ca. Such biodegradable CMS/MMT-Ca films exhibiting relatively good mechanical properties could find application in controlled delivery systems as well as in agriculture for seed tapes production where hydrophilicity of polymer carrier is strongly advantageous.

Physicochemical Characterization of an Exopolysaccharide Produced by a Newly Isolated Weissella cibaria

A high molecular weight (3037 kDa) dextran-like polysaccharide was purified from the culture broth of a probiotic Weissella cibaria. Dry weight of the exopolysaccharides (EPS) obtained after ethanol precipitation was 6.35 g/L by using sucrose as carbon source and was further purified by phenol:chloroform:isoamyl alcohol (25:24:1) extraction and acetone precipitation to white powder with 52% recovery. Rheological characterization revealed that it has a pseudoplastic behaviour and showed a temperature tolerance of up to 280 °C in thermogravimetric analysis. Fourier transform infrared (FTIR) spectra showed the characteristic peaks of polysaccharide such as hydroxyl group, α-pyranose, asymmetrical C-H stretching vibration of methyl group and carbonyl hydrogens of D-glucopyranose. The (1)H nuclear magnetic resonance (NMR) spectrum showed resonances of hydrogen corresponding to the glucosyl residue, a repeat unit of the biopolymer. The cell viability analysis of normal L6 cells treated with the Weissella EPS showed that it is noncytotoxic even up to the 500-μg/mL level. A 0.2% (w/v) supplementation of EPS in 2% (w/v) wheat starch preparation could reduce the degree of syneresis up to 45% and up to 75% with 1% EPS.

Thermoplastic starch prepared with different plasticizers: Relation between degree of plasticization and properties

Ethylene glycol, glycerol, sorbitol, formamide, and urea were used as plasticizers for the preparation of thermoplastic starch (TPS) from corn starch. The properties of TPS were tested by analysis method. The results showed that TPSs were more highly plasticized with amines than alcohols. For the same type of plasticizer, the degree of plasticization decreased as the molecular weight of plasticizer increased. The relationship between plasticization degree and TPS properties was characterized and described by mechanical properties and water absorption. The experimental results showed that when the degree of plasticization increased, the tensile strength decreased and the elongation at breakage and water absorption increased.

Preparation and characterization of thermoplastic starches and their blends with poly(lactic acid)

Two different thermoplastic starches (TPS), namely maleic anhydride grafted starch (MA-g-starch) and epoxidized cardanol grafted starch (Epicard-g-starch), were successfully prepared by chemical modification without the addition of any plasticizer. The structure and properties were characterized by nuclear magnetic resonance (NMR), X-ray diffraction (XRD), hot press testing, scanning electron microscopy (SEM) and contact angle meter, respectively. Results from XRD showed that the highly crystalline structure of native starch was destroyed after modification. Continuous phase was obtained from both of the chemically modified starches after hot pressing at 130°C, indicating that they have good thermoplasticity. Subsequently, they were melt-blended with PLA. It was found that the Epicard-g-starch had a much finer dispersed phase size than MA-g-starch in PLA matrix due to its better hydrophobicity. As a result, the mechanical properties of PLA/Epicard-g-starch blend were superior to those of PLA/MA-g-starch blend.

Blood loss in obstetrics, hemorrhagic shock: obstetricians and gynecologists tactics

The key aspects of diagnostics and treatment of obstetric hemorrhage and hemorrhagic shock are present in this article. Treatment of obstetric hemorrhage, including hemorrhagic shock is more effective if the infusion therapy initiated as early as possible. The basic aims of infusion therapy are support of systemic circulation and recovery of tissue perfusion. Crystalloids, colloids and blood preparations are used as an infusion-transfusion therapy. To date, there is a great experience with colloidal preparations, among which the most widely used drugs are hydroxyethylated starch and gelatin preparations.

Preparation and Properties of Cross-Linked Starch Nanocrystals/Polylactic Acid Nanocomposites

Cross-linked starch nanocrystals (CStN)/polylactic acid (PLA) nanocomposites were prepared by blending CStN and PLA, wherein CStN were homogeneously dispersed in the nanocomposites. The structure and morphology of the nanocomposites were studied through FTIR, XRD, and SEM. The results of mechanical test showed that the strength and toughness of the nanocomposites could be improved when the additive amount of hydrophobic CStN was 3% (weight ratio). Meanwhile, the microstructures of tensile fracture surface showed that CStN were uniformly dispersed in PLA matrix, and the tensile fracture surface was presented as ductile fracture. Moreover, water vapor permeability experiments illustrated that the addition of CStN reduced the water vapor permeability of PLA nanocomposites, so CStN have some resistance to water vapor. Those above indicated that CStN have functions of reinforcement and toughness in PLA matrix; therefore, they are expected to be used as functional additives in polymer matrix such as PLA, polycaprolactone (PCL), and polybutylene succinate (PBS).

Preparation and characterization of a dialdehyde starch crosslinked feather keratin film for food packaging application

Crosslink effects of dialdehyde starch on the mechanical properties, water-resistance, compatability, micromorphology, and water vapor barrier property of feather keratin films.

Studies on Preparation and Characterization of Carboxymethyl high Amylose Starch: As a Novel Polymeric Carrier in Oral Controlled Drug Delivery

The present study involved the use of old biomaterial starch as excipient for oral controlled drug delivery in which the properties of starch are tailored by chemical modification. Among the various commercially available starches, high amylose starch (HAS) was chosen and chemically modified by reaction with monochloro acetic acid in the presence of sodiumhydroxide to carboxymethyl high amylose starch (CM HAS). The starch derivative was synthesized with three different degree of substitution (CM HAS 1(DS 0.63), CM HAS 2(DS 0.35) and CM HAS 3(DS 0.21)) by varying the molar concentration of monochloro acetic acid in non-aqueous medium (organic solvent method). The prepared polymeric excipients were characterized by FT IR, DSC, 1H NMR, acute toxicity studies and solubility studies. The CM HAS matrix tablets (F1-F18) were formulated using nimodipine as model drug with different polymer concentrations by direct compression method and the physicochemical parameters were evaluated. The in vitro release profile showed a low drug release in acid pH followed by controlled drug release in phosphate buffer pH 6.8 and best fit to zero order release kinetics. The mechanism of drug release followed was found to be supercase II transport release mechanism. The absence of immediate and fast disintegration of the CM HAS matrix tablets proved as a promising new excipient for the development oral controlled drug delivery system. It was concluded that CM HAS with higher DS (0.35 and 0.63) at above 40% concentration were able to control drug release up to 12hrs.

Preparation and characterization of pullulanase debranched starches and their properties for drug controlled-release

Linear short amylose and glucan tend to align and aggregate to form hydrogels that hold less water. The drug release properties of debranched starch based tablets can be controlled by the pullulanase modification conditions.

Effect of Acetylated Retrograded Starch (Resistant Starch RS4) On the Nutritional Value and Microstructure of the Crumb (SEM) of Wheat Bread

The objective of this study was to evaluate nutritional value and the microstructure of crumb of bread baked with three types of wheat flour with acetylated retrograded resistant starch preparation (RS4) obtained in the laboratory. The research material was three wheat flour type 550, 750 and 2000 incorporated with acetylated retrograded starch obtained in the laboratory with a degree of substitution DS = 0,16. Content of RS4 preparations in the achieved flour samples was 10, 20, 30and 40%. The control sample was wheat flour without additives (0%). The study assessed the nutritional value of bread on the basis of energy value, the total amount of digested starch (TDS) and total dietary fiber (TDF). Also carried pictures of bread crumb investigated using scanning electron microscopy (SEM). Breads baked with whole meal flour type 2000 were characterized by higher energy than breads made from flour lower type. Increasing the type of wheat flour resulted in a gradual decrease in the total amount of digested starch (TDS) in the breads. The consequence of increasing the share of resistant starch in the samples was a gradual increase in total dietary fiber (TDF). With the increase in the share of resistant starch in the samples were reduced energy value, and the total amount of digested starch (TDS). In the photograph of the control bread crumb made using a scanning electron microscope is shown forming the gluten network of pores of medium and large.

Fluid resuscitation in acute medicine: what is the current situation?

The administration of intravenous fluids for resuscitation is the most common intervention in acute medicine. There is increasing evidence that the type of fluid may directly affect patient-centred outcomes. There is a lack of evidence that colloids confer clinical benefit over crystalloids and they may be associated with harm. Hydroxyethyl starch preparations are associated with increased mortality and use of renal replacement therapy in critically ill patients, particularly those with sepsis; albumin is associated with increased mortality in patients with severe traumatic brain injury. Crystalloids, such as saline or balanced salt solutions, are increasingly recommended as first-line resuscitation fluids for the majority of patients with hypovolaemia. There is emerging evidence that saline may be associated with adverse outcomes due to the development of hyperchloraemic metabolic acidosis, although the safety of balanced salt solutions has not been established. Fluid requirements vary over the course of critical illness. The excessive use of fluids during the resuscitative period is associated with increased cumulative fluid balance and adverse outcomes in critically ill patients. The selection of fluid depends on the clinical context in which it is administered and requires careful consideration of the dose and potential for toxicity. There is an urgent need to conduct further high-quality randomized controlled trials of currently available fluid therapy in patients with critical illness.