bluuebunny/crossref_metadata_2025_split huggingface dataset:
Oxidized banana starch–polyvinyl alcohol film: Partial characterization
Authors: Palma‐Rodríguez Heidi M. , Aguirre‐Álvarez Gabriel , Chavarría‐Hernández Norberto , Rodríguez‐Hernández Adriana I. , Bello‐Pérez Luis A. , Vargas‐Torres Apolonio 
Published: October 2014

AbstractComposites of polyvinyl alcohol, native banana starch, oxidized banana starch using glycerol like plasticizer, were studied by mechanical tests (MT), scanning electronic microscopy (SEM), differential scanning calorimetry (DSC) and solubility in water. The oxidized banana starch showed higher level of carboxyl groups than of carbonyl groups. Composites of native banana starch/polyvinyl alcohol and oxidized banana starch/polyvinyl alcohol showed irregularities, indicating incomplete dispersion of the polymers. However, the film elaborated with the blend oxidized banana starch/polyvinyl alcohol showed the highest mechanical properties and the melting temperature of the first transition, as well as the lowest water vapor permeability, indicating higher interaction between both polymers. The composite oxidized banana starch/polyvinyl alcohol showed higher water solubility than the one of its counterpart with native banana starch at 25°C, and similar values were obtained for both films at 60°C. The oxidation of banana starch in order to elaborate a film blended with polyvinyl alcohol improved some mechanical and barrier properties, and this composite could be used for specific applications in the packing of food.
Effects of protein removal on the physicochemical properties of waxy maize flours
Authors: Lu Dalei , Lu Weiping 
Published: October 2014

AbstractThe effects of protein removal on the physicochemical properties of waxy maize flours were investigated. Protein removal caused significant reduction in the P and S contents of starches. Starch granules had a smoother surface and low protein content (<6 g/kg) compared with the flours. Both flours and starches had a typical A‐type X‐ray diffraction pattern, with a crystallinity range of 29.8–32.2% and 27.7–30.6%, respectively. Flours had higher swelling power and solubility, and lower light transmittance than starches. The gelatinization enthalpy and onset temperature of starches were higher compared with those of their counterpart flours. The retrogradation of flours was significantly greater compared with that of starches. Protein removal increased the peak viscosity, trough viscosity, final viscosity, and breakdown, whereas it decreased the setback and pasting temperature. Genotypic differences in those maize were related to the physicochemical characteristics of the flours and starches.
A facile approach for controlled synthesis of hydrophilic starch‐based nanoparticles from native sago starch
Authors: Tay Soon Hiang , Pang Suh Cem , Chin Suk Fun 
Published: October 2014

AbstractA facile approach for the preparation of hydrophilic starch‐based spherical nanoparticles from native sago (Metroxylon sagu) starch using the drop‐wise solvent exchange method was reported. Starch‐maleate monoester (SM) was initially synthesized from native sago starch and maleic anhydride in an aqueous medium, and SM nanoparticles was subsequently precipitated in absolute ethanol under controlled conditions. The present study was focused mainly on modulating of the solvent and non‐solvent systems to prepare SM nanoparticles of different morphologies. The pH of the solvent system and the nature of surfactants being added into the solvent system could influence the morphology of regenerated SM nanoparticles. SM nanoparticles of discrete and spherical shape were regenerated from a basic SM sample solution, or an acidic sample solution in the presence of an appropriate surfactant. SM nanoparticles with mean diameter of about 250 nm was obtained by precipitation in absolute ethanol in the presence of Brij 35 as the surfactant.
Selective degradation, oxidation, and characterization of hydroxyethyl starch for potential use as a drug carrier
Authors: Abbas Muhammad Azhar , Hameed Shahid , Kressler Joerg 
Published: October 2014

AbstractThe selective degradation, oxidation, and characterization of hydroxyethyl starch (HES) was successfully carried out. Different mass fractions of HES were obtained through degradation either using acidic (hydrochloric acid) or enzymatic (α‐amylase) hydrolysis under controlled pH, temperature, and concentration. The degraded samples were successfully oxidized using sodium hypochlorite solution to convert cyclic ether into carboxylic acid group. The degraded and oxidized samples were tested for their molar masses and structural properties using different techniques. The samples were further characterized using FTIR, and 1H NMR spectroscopy. The solubility check was also performed and a significant enhancement in water solubility of the degraded products of HES was observed which increased further on oxidation. This increased solubility may be utilized to enhance the water solubility of the drugs through coupling with degraded and oxidized HES.
Characterization of glucoamylase immobilized on magnetic nanoparticles
Authors: Panek Anna , Pietrow Olga , Synowiecki Józef 
Published: October 2014

AbstractMagnetic support was prepared by precipitation from an alkaline solution of divalent and trivalent iron ions and subsequently was modified with 3‐aminopropyltriethoxysilane. FTIR analysis showed existence of a new Si–O–Fe bond in obtained particles. Scanning electronic microscopy images shows that the nanoparticles of all samples have particle size below 30 nm. Glucoamylase AMG 300L was immobilized onto the modified magnetic support using glutaraldehyde as a coupling agent. Obtained preparations had specific activity of 148 U/g of the support when measured at 55°C using maltose as substrate. The immobilized enzyme exhibited mass transfer limitation as reflected by a higher apparent Km value and a lower energy of activation. The immobilization was almost completely terminated after 30 min of the reaction at 30°C. The highest immobilization yield of the enzyme was achieved at glutaraldehyde concentration of 10 mM. The immobilization did not influence considerably on optimum pH and temperature of substrate hydrolysis catalyzed by investigated enzyme (55°C, pH 4.5). Moreover, immobilized glucoamylase was easily separated from the reaction medium by an external magnetic field and retained about 60% of initial activity after nine repeated cycles of enzyme reaction followed by magnetic separation.
Xylanase immobilization on functionalized polyaniline support by covalent attachment
Authors: Madakbaş Seyfullah , Danış Özkan , Demir Serap , Kahraman Memet Vezir 
Published: October 2014

AbstractChemically synthesized polyaniline (PANI) was used as polymeric support for xylanase immobilization. The polymer was first activated with glutaraldehyde and then xylanase was successfully immobilized. Xylanase bound polymer was characterized using FTIR. The optimum pH of the immobilized enzyme was at pH 5, which was shifted 1.0 pH unit to the acidic region when compared to the free enzyme. Thermal stability of the xylanase was improved with the immobilization. The characteristic properties of the immobilized and native enzyme, such as kinetic activity, reusability and storage stability were also studied at optimum pH and temperature. Immobilized enzyme exhibited better reusability and storage stability than the free one. Vmax values for the free and immobilized enzymes were calculated as 1.44 and 0.44 mg/mL/min, respectively. The Km values for the immobilized xylanase were found to be lower.
Rheological, thermal properties, and gelatinization kinetics of tapioca starch–trehalose blends studied by non‐isothermal DSC technology
Authors: Zhang Xiaoyu , Zhu Wenxue , Tong Qunyi , Ren Fei 
Published: October 2014

AbstractIn this paper, we studied the effects of trehalose on the rheological and thermal properties of tapioca starch (TS). Temperature sweep experiments showed that trehalose shifted the peak gelatinization temperature (TG′max) to higher value. Rheological features calculated from the power law model indicated that trehalose addition increased the consistency and decreased the thixotropy of TS gels. DSC experiments showed that trehalose retarded the gelatinization of TS–trehalose blends reflected in the increase of gelatinization temperature. The gelatinization kinetics was evaluated by a non‐isothermal technique based on the DSC endotherms. Kinetics analysis showed the addition of trehalose increased the activation energy and decreased the rate constants of TS–trehalose blends, indicating the same sugar effect as the rheological and DSC experiments. The work demonstrated that kinetics analysis could provide new evidences for the influence of trehalose on starch gelatinization.
Current advances of chemical and physical starch‐based hydrogels
Authors: Xiao Congming 
Published: October 2014

AbstractStarch is a natural polymer, which has many unique properties. It has been utilized to prepare hydrogels and received growing attention. Starch‐based hydrogels (SH) are attractive and widely applied in a variety of fields such as biomedical, food packing, and others. In this article, the developments of physical and chemical SHs in the last decade are summarized. The common approaches to prepare hydrogels are briefly elucidated. Subsequently, the SHs obtained by chemical and physical cross‐linking methods are described. Then, the characteristics and potential applications of the SHs are introduced and correlated. Finally, suggestions about the future directions of developing SHs are presented.
Perspectives on the history of research on starch Part II: On the discovery of the constitution of diastase
Authors: Seetharaman Koushik , Bertoft Eric 
Published: October 2014

AbstractStarch has been used over several millennia for a number of different applications. However, research on understanding this substance only spans about three centuries starting with Leeuwenhoek who observed it in 1716. This story of discovery of the molecular structure and architectural makeup of starch is chronicled in a series of six essays of which this is the second with a focus on diastase. Malted barley has been used in the brewing industry for millennia. However, it was not until 1833 that the active substance was identified and called diastase. Much of the research on diastase, interestingly, developed in the context of improving beer production efficiency and quality. Research in this area has given us the terms maltose, dextrin, and maltodextrin, which are still in use today. It was only in 1886 that the active substance was identified as a protein and soon thereafter as two distinct proteins. Finally, it was around mid 1900s that it was recognized that diastase contained several isoforms of the enzymes. This review on diastase spans over a period of 130 years.
Effect of amylopectin long chains on measured amylose content and their correlation with pasting properties
Authors: Park Inmyoung , Kim Seung‐Hyun , Chung Ill‐Min , Shoemaker Charles F. 
Published: October 2014

AbstractThis paper describes how long chains of AP affect the measurement of AM content and also investigates the rheological properties of purified starches from 14 rice cultivars. The AM content of each rice starch was determined by two different methods: the colorimetric iodine method and the Concanavalin A method. A high‐performance size exclusion chromatograph equipped with multi‐angle laser‐light scattering and RI detectors was used to determine the molecular weight of long chains of AP. Iodine blue values overestimated the AM content because iodine interacts with long chains of AP. However, long chains of AP with molecular weight under 0.89 × 104 g/mol (Calmochi101) did not affect the measurement of AM content by the iodine calorimetric method. Peak temperature correlated positively with AM content and negatively with the number of long chains of AP. Peak viscosity correlated negatively with AM content and molecular weight of long chains of AP. The difference between final viscosity and peak viscosity was larger in long, medium, and short grain rice varieties than in wx grain varieties.
The effect of xanthan on short and long‐term retrogradation of rice starch
Authors: Tang Minmin , Hong Yan , Gu Zhengbiao , Zhang Yayuan , Cai Xuran 
Published: October 2014

AbstractThe short‐term retrogradation of the rice starch (RS)/xanthan (Xan) mixtures was investigated by Brabender‐E viscograph and dynamic rheometer while the long‐term retrogradation was investigated by DSC and pulsed NMR (PNMR), respectively. RS and 0, 2.5, 5, and 10% Xan (based on RS weight) were prepared into RS/Xan mixtures at the ratios of 100:0, 40:1, 20:1, and 10:1 w/w, respectively. With increasing Xan concentration, the reduced setback (SB) value suggests the decrease of short‐term retrogradation. The gelation rate constant (k) of the mixtures increased during the storage at 4°C for 5 h due to phase separation. The endothermic enthalpy of the pastes of RS/Xan mixture after being stored at 4°C for 1, 3, 5, 7, 14, and 21 days were lower than the native starch stored for the same days. The spin–spin relaxation time (T2) indicating the water mobility of starch gels was detected. T2 decreased gradually with extending storage time, which may be attributed to the retrogradation of RS. T2 of the system with xanthan was apparently higher than that without. The overall results demonstrate the remarkable inhibitory effects of Xan on the retrogradation of RS.
Influence of storage temperature and autoclaving cycles on slowly digestible and resistant starch (RS) formation from partially debranched rice starch
Authors: Lee Kwang Yeon , Lee Suyong , Lee Hyeon Gyu 
Published: October 2014

AbstractIn this study, optimum conditions to produce slowly digestible starch (SDS) and RS from rice starch were investigated as a function of pullulanase concentrations, storage temperature, and autoclaving‐cooling cycles. Then, the physicochemical properties of the rice starches obtained were compared with native rice starch. Response surface methodology (RSM) was used to evaluate the effects of independent variables, namely the enzyme (pullulanase) concentration (X1), storage temperature (X2), and autoclaving‐cooling cycle (X3) on the production of SDS and RS fraction. The optimum conditions for SDS and RS occurred in the treatment with application of pullulanase at 482 and 610 µL, and storage temperature at 36 and 63°C with autoclaving cycles of three times, respectively. SDS and RS obtained through optimum conditions showed higher amylose content and water solubility index as compared to native starch. While the SF and water absorption index were lower than native starch. The extent of hydrolysis α‐amylose decreased in the order cooked starch>SDS>RS>native starch. SDS and RS had lower RVA parameters (except pasting temperatures) than native starch.
The effect of drying and whole grain content on the pasting, physicochemical and qualitative properties of pasta
Authors: West Ryan , Duizer Lisa , Seetharaman Koushik 
Published: October 2014

AbstractDrying is one of the most important stages in pasta production because of its influence on texture and colour. Whole grain pasta has been associated with greater cooking loss and softer texture. The objective of this research was to examine the impact of the drying profile and whole grain content on pasting and physicochemical properties of starch in macaroni and see how the qualitative properties of macaroni are affected. A flour × drying interaction was detected in pasting properties of the samples with differences observed in peak viscosity, peak time and final viscosity in whole grains following drying. Hot stage microscopy showed restricted granule swelling following treatment, reducing amylose leaching, which partly governs viscosity. DSC showed a significant increase in ALC formation upon treatment, which can also reduce leaching. While the interaction between these main effects was significant for cooking loss, firmness and adhesiveness measured instrumentally, differences between drying conditions for either textural attribute could not be detected using a trained panel.
From native to multifunctional starch‐based excipients designed for direct compression formulation
Authors: Rashid Iyad , Al Omari Mahmoud M. H. , Badwan Adnan A. 
Published: October 2014

AbstractThe development of new materials, processes and in machinery plays an important role in pharmaceutical industry. This allows the solid dosage form manufacturers to improve and develop their processes toward the exploitation of direct compression and dry granulation (e.g., roll compaction) leading to relatively fast process and low cost. This review outlines a comprehensive understanding on the physico‐chemical and compaction properties of native and modified starches. The physical modification of native starch has been given a technical focus along with an understanding on the impact of their modified powder/tablet properties on direct compression attributes. All processes involved on starch modifications have been confined herein to the production of direct compression excipients with multifunctional purposes as most chemical modifications exhibit limited applications.
Influence of starch acetylation on selected rheological properties of pastes
Authors: Żmudziński Daniel , Ptaszek Anna , Grzesik Mirosław , Kruk Joanna , Kaczmarczyk Kacper , Liszka‐Skoczylas Marta 
Published: October 2014

AbstractSelected rheological properties of acetylated starch pastes of different amylose content were discussed in the study. The rheological studies were carried out immediately after the preparation of the pastes as well as after 1 and 7 days of storage. For the paste of acetylated potato starch (P‐A), a phenomenon of oscillatory changes of viscosity with time was observed. The pastes of the acetylated amylostarch (AMY‐A) and acetylated waxy potato starch (AP‐A) exhibited the phenomenon of thixotropy. Based on the flow curves, the distribution of the time constants of the exponential rheological equation of state has been determined. They served to describe the contributions forming rheological properties. It has been noticed that during shear the phenomenon of the energy dissipation is predominant in AMY‐A (rheological characteristic time of 0.3 s) and AP‐A, whereas the elastic contributions are specific for the paste of acetylated potato starch (rheological characteristic time of 10−6 s). In order to describe the structural changes of AMY‐A and AP‐A pastes during flow, i.e. for the systems exhibiting frictional properties, the Cheng and Evans viscous structural theory has been applied. The rheological properties were then interpreted in light of the results of chromatographic and osmometric analyses.
Cross‐link copolymerization of cationic starch by gamma irradiation and its swelling‐shrinking and flocculating behaviors
Authors: Song Weiqiang , Guo Zhengchao , Yao Yiming , Zheng Hongjuan , Zhao Zhiwei 
Published: October 2014

AbstractCationic starch‐based hydrogels were synthesized by simultaneously irradiating starch, acrylamide (AM), dimethyldiallylammonium chloride (DMDAAC), and N,N′‐methylenebisacrylamide (MBA) in aqueous solution. A mechanism for hydrogel formation was proposed, and the product was characterized by NMR spectroscopy. Results showed that a minimum amount of AM and a maximum amount of DMDAAC were grafted onto the starch backbone at an absorbed dose of 4 kGy and a starch/AM/DMDAAC weight ratio of 6:9.8:4.2, while NDMDAAC/NAM reached its maximum value of 0.17. The equilibrium swelling ratio (Se) of the hydrogels progressively decreased with increased absorbed dose at a fixed starch/AM/DMDAAC/MBA ratio of 6:9.8:4.2:1.6, but the swelling rate parameter (τ) initially decreased up to 3 kGy and then increased. Meanwhile, the hydrogels showed similar shrinking behaviors with increased absorbed dose. At a fixed starch/AM/DMDAAC weight ratio of 6:9.8:4.2 and fixed gamma irradiation of 3 kGy, Se and τ decreased with increased MBA and solvent volume, but both water‐loss rate (Rloss) and minimum mass maintenance ratio (Rm0) progressively increased at 60°C. At a constant starch:AM:DMDAAC:MBA wt. ratio of 6:9.8:4.2:1.6, the flocculating activity of SADM decreased with absorbed dose increasing. The optimal flocculant concentration was 4 mg/L for SADMs synthesized at 1 and 2 kGy.
Enzymatic synthesis of epoxy fatty acid starch ester in ionic liquid–organic solvent mixture from vernonia oil
Authors: Desalegn Tegene , Garcia Ignacio J. Villar , Titman Jeremy , Licence Peter , Diaz Isabel , Chebude Yonas 
Published: October 2014

AbstractIn this study, epoxy fatty acid esters of cassava starch were synthesized by reacting cassava starch with vernonia oil methyl ester (epoxy ester) using 1‐butyl‐3‐methylimidazolium hexafluorophosphate, [C4C1Im][PF6] ionic liquid (IL) as a reaction medium and DMSO as co‐solvent. Lipase Candida antarctica fraction B (Novozyme 435) was used as a catalyst for the esterification reaction. In the optimized reaction conditions, a degree of substitution (DS) of 0.95 was achieved, at a reaction temperature of 40°C within 72 h of reaction time. The new cassava starch esters were characterized by infrared (FTIR), solid state NMR (CP/MAS 13C NMR), SEM, XRD, thermogravimetric analysis (TGA), and DSC. FTIR and NMR spectroscopy analyses confirmed the successful esterification of starch and the DS was calculated to be 0.95 by titration methods. SEM and XRD studies showed that the morphology and crystallinity of native cassava starch were significantly changed upon esterification producing a continuous and amorphous material. Finally, the thermal behavior of the native and the starch vernolate was investigated using TGA and DSC techniques. The results revealed a change in the characteristic melting point and decomposition pattern of the new polymer. The onset decomposition temperature of the new starch vernolate is similar to the native form.
Characterizing the chemical features of lipid and protein in sweet potato and maize starches
Authors: Xijun Lian , Haibo Sun , Lin Li , Hong Wu , Nan Zhang 
Published: October 2014

AbstractThe chemical features of lipid and protein in sweet potato and maize starches were investigated by comparing their IR and NMR spectra before and after hydrolysis by lipase or alkali protease. The results showed that the absence of C–H stretching vibration near 2930 cm−1 in IR spectra of sweet potato and maize starches hydrolyzed by lipase or protease was probably due to an interaction of amylose and amylopectin without lipid or protein. The results of 13C NMR showed that the lipid and protein were attached to each other in those two starches and both connected with maize starch, but only lipid connected directly with sweet potato starch. Lipid in starch probably inhibits crystal formation of starches, but protein in starch promotes the process. The characteristic fatty acids for sweet potato starch were CH3(CH2)13COOH + Lys + Glucose (G) and CH3(CHCH)4(CH2)4COOH + G, for maize starch, CH3(CHCH)6(CH2)29COOH. The typical peptides for sweet potato starch might be Lys + Phe + Ala + G + G and Leu + Lys + Leu + G, for maize starch, they were Asp + Val + Leu + Val and Asp + Glu + Leu + Glu.