Physical Properties Of Starch Research Articles

Effects of Different Processing Techniques and Sol-Gel Coating on Physical Properties of Starch and Clay-Based Biocomposite Material

This study investigated the effects of different processing techniques and sol-gel coating on the physical properties of biocomposite material. Two dispersion series from corn starch, clay, and sorbitol were prepared by conventional and microwave-assisted processing, and casting technique. One film from each series was sol-gel coated by immersion. All the samples were subjected to moisture content (MC), water solubility (WS), water absorption (WA), FT-IR, DSC, and SEM/digital microscopy tests. The results showed that the coated films contained higher MC (11.5±0.5%) than the non-coated films (5.3±0.6%) and absorbed less water (44.7±12.4%), compared to the non-coated ones (166.3±2.5%). Non-coated films exhibited less solubility in water (26.1±0.2%) than the coated ones (51.0±0.7%). FT-IR test detected cross-linking (1723 cm-1 ester) in the microwave-assisted coated film. The sol-gel coating increased the latent heat of melting and specific heat values by 14.9% and 19.4% for conventionally fabricated samples, and 22.3% and 25.3% for microwaved films, respectively, whereas it reduced the temperature of melting by 23.1% for conventionally fabricated ones, and 6.6% for microwaved ones. Microscopic tests revealed that microwaved compact morphology indicated better gelatinization of starch. Overall, microwaving and sol-gel coating need further investigation to improve the physical properties of biocomposite materials for food packaging.

Effect of improved extrusion cooking technology (IECT) on structure, physical properties and in vitro digestibility of starch

Extrusion can modify the structure and physical properties of starch, while the extent of improved extrusion cooking technology (IECT) affects the starch with high moisture content and different crystal types remaining unclear. Therefore, the influence of IECT at different screw speeds on the structure, physical properties and in vitro digestibility of corn (A-type), potato (B-type) and pea (C-type) starches with high moisture content (42 %) was explored. Results indicated that IECT treatment caused similar variations on structure, physical properties, and in vitro digestibility of the 3 types of starches. The contents of slowly digestible starch (SDS) and resistant starch (RS) decreased by IECT treatment, accompanied by a reduction of crystallinity, enthalpy of gelatinization, gelatinization temperature and viscosity, while the content of rapidly digestible starch (RDS) and the ratio of bound water increased. And the changes in in vitro digestibility of starch were closely related to the damage to starch structure caused by IECT. Furthermore, most of starch granules were in the agglomeration stage by appropriate IECT treatment, which induced the exposure of a great quantity of enzyme binding sites to enhance the in vitro digestibility.

Efficient Accumulation of Amylopectin and Its Molecular Mechanism in the Submerged Duckweed Mutant.

Large-scale use of fossil fuels has brought about increasingly serious problems of environmental pollution, development and utilization of renewable energy is one of the effective solutions. Duckweed has the advantages of fast growth, high starch content and no occupation of arable land, so it is a promising starchy energy plant. A new submerged duckweed mutant (sub-1) with abundant starch accumulation was obtained, whose content of amylopectin accounts for 84.04% of the starch granules. Compared with the wild type (Lemna aequinoctialis), the branching degree of starch in sub-1 mutant was significantly increased by 19.6%. Chain length DP 6-12, DP 25-36 and DP > 36 of amylopectin significantly decreased, while chain length DP 13-24 significantly increased. Average chain length of wild-type and sub-1 mutant starches were greater than DP 22. Moreover, the crystal structure and physical properties of starch have changed markedly in sub-1 mutant. For example, the starch crystallinity of sub-1 mutant was only 8.94%, while that of wild-type was 22.3%. Compared with wild type, water solubility of starch was significantly reduced by 29.42%, whereas swelling power significantly increased by 97.07% in sub-1 mutant. In order to further analyze the molecular mechanism of efficient accumulation of amylopectin in sub-1 mutant, metabolome and transcriptome were performed. The results showed that glucose accumulated in sub-1 mutant, then degradation of starch to glucose mainly depends on α-amylase. At night, the down-regulated β-amylase gene resulted in the inhibition of starch degradation. The starch and sucrose metabolism pathways were significantly enriched. Up-regulated expression of SUS, AGPase2, AGPase3, PYG, GPI and GYS provide sufficient substrate for starch synthesis in sub-1 mutant. From the 0H to 16H light treatment, granule-bound starch synthase (GBSS1) gene was inhibited, on the contrary, the starch branching enzyme (SBE) gene was induced. Differential expression of GBSS1 and SBE may be an important reason for the decrease ratio of amylose/amylopectin in sub-1 mutant. Taken together, our results indicated that the sub-1 mutant can accumulate the amylopectin efficiently, potentially through altering the differential expression of AGPase, GBSS1, SBE, and BAM. This study also provides theoretical guidance for creating crop germplasm with high amylopectin by means of synthetic biology in the future.

Uji Modifikasi Lemari Pengering Pati Talas Kimpul (Xanthosoma sagittifolium) sebagai Eksipien dalam Formulasi Tablet Terhadap Lama Pengeringan

The physical properties of excipients are very important to know for the manufacture of good tablets. Starch or amylum is an additional material that is often used in the manufacture of tablets. The physical properties of starch or powder that are good for tablets can give the desired effect if they have good quality. Unmodified starch does not have good compressibility and has great friability, and capping will occur in the tablet. Taro taro as a potential starch can be used as an excipient in the manufacture of tablets because it has a high starch content. Taro taro used as an excipient needs to be modified physically and chemically to produce derivatives that have better and more specific pharmaceutical characteristics, especially for the manufacture of tablets. The purpose of this study was to determine whether the physical properties of taro starch matched the parameters of good physical properties. Tests carried out included organoleptic tests which obtained powder like flour, had no odor, had no taste and had a white color, Knowledge test obtained dark blue in modified taro starch solution after being given iodine, Microscopic tests obtained taro starch results which had the arrangement is clustered with the hilus located in the middle, the shape of the hilus is in the form of a point, a straight line. The water content test obtained the water content value of each modified starch based on the length of drying time using a drying cabinet of 9.40% for drying for 24 hours, 8.42 % for drying for 48 hours, and 7.9% for drying for 72 hours and pH Test Produces a pH value of 6.52 for drying for 24 hours, 6.22 for drying for 48 hours and 5.92 for drying for 72 hours.

Rice starch accumulation at different endosperm regions and physical properties under nitrogen treatment at panicle initiation stage

The quality of rice grain is characterized by the component, structure and physicochemical properties of starch accumulated in endosperm cell. Nitrogen uptake strongly affects rice growth and starch development. In this study, Nangeng 9108 was used to investigated the accumulation of starch in different positions of the endosperm and physical properties of starch under nitrogen treatment of panicle initiation (PI) stage. Compared with the control group (CG), nitrogen treatment group (NTG) featured a higher number of grains per panicle and 1000-grain weight. Nitrogen treatment significantly increased starch accumulation among different regions during endosperm development, which was expressed as central endosperm cells > sub-aleurone cells of abdominal endosperm > sub-aleurone cells of dorsal endosperm. The amyloplast increased by constricting and budding-type division, generated a bead-like structure and derived some vesicles. The particle size of the starch granules obtained from the NTG was smaller and the apparent amylose content was lower than those of the CG, resulting in higher relative crystallinity. Nitrogen treatment promoted double helical components and provided a higher degree of order at short-rang scale for the starch granules. This study indicated that nitrogen significantly affected the accumulation and physicochemical properties of starch in the endosperm.

STUDY PENGARUH KANDUNGAN AMILOSA DAN AMILOPEKTIN UMBI-UMBIAN TERHADAP KARAKTERISTIK FISIK PLASTIK BIODEGRADABLE DENGAN Plastizicer GLISEROL

Amylose and Amylopectin is the material on starch which is the raw material of making Biodegradable plastic, but easy to tear (brittle), so need addition of plasticizer. In this study using Glycerol as plasticizer. This research was conducted at Polymer Chemical Laboratory of University of Sumatera Utara and Physics Laboratory of FMIPA and Universitas Syahkuala with the aim to make Biodegradable plastic and know physical characteristics of three types of tuber starch with addition of glycerol plasticizer. The experiment was compiled using a complete randomized factorial design with three replications. Factors are the types of starch (sago starch, arrowroot, and cassava). Observations include chemical and physical properties of starches and physical properties of biodegradable plastics. Data obtained for Amylose and Amylopectin content are the biggest Sagu starch (21.7% - 62.51%), starch (19.4% - 59.35%) and wood starch (18.0% 60,15%. The result showed that Amilosa and Amilopectin content highly influenced tensile strength and elongation of Biodegradable plastic. The higher the Amylose value, the value of tensile strength and elongation of Biodegradable plastic increasingly but for sago starch has elongation value and strength of tensile strength (97,83 kgf / mm2 - 4,83%) for starch (98,97 kgf / mm2 - 3,38%) and cassava starch (89.83 kgf / mm2 - 2.26%), this occurs because of the impurity and error factor in the thickness measurement of Biodegradable plastic.

Generation of High-Amylose Rice through CRISPR/Cas9-Mediated Targeted Mutagenesis of Starch Branching Enzymes.

Cereals high in amylose content (AC) and resistant starch (RS) offer potential health benefits. Previous studies using chemical mutagenesis or RNA interference have demonstrated that starch branching enzyme (SBE) plays a major role in determining the fine structure and physical properties of starch. However, it remains a challenge to control starch branching in commercial lines. Here, we use CRISPR/Cas9 technology to generate targeted mutagenesis in SBEI and SBEIIb in rice. The frequencies of obtained homozygous or bi-allelic mutant lines with indels in SBEI and SBEIIb in T0 generation were from 26.7 to 40%. Mutations in the homozygous T0 lines stably transmitted to the T1 generation and those in the bi-allelic lines segregated in a Mendelian fashion. Transgene-free plants carrying only the frame-shifted mutagenesis were recovered in T1 generation following segregation. Whereas no obvious differences were observed between the sbeI mutants and wild type, sbeII mutants showed higher proportion of long chains presented in debranched amylopectin, significantly increased AC and RS content to as higher as 25.0 and 9.8%, respectively, and thus altered fine structure and nutritional properties of starch. Taken together, our results demonstrated for the first time the feasibility to create high-amylose rice through CRISPR/Cas9-mediated editing of SBEIIb.

Effect of A- and B-type granules on the physical properties of starch from six wheat varieties

Six wheat varieties (3 hard and 3 soft genotypes) produced in China were selected to study the effect of granule types on physical properties of starch. Difference in freeze-thaw stability, solubility, gelatinisation, pasting and swelling properties were compared. The results demonstrated that the pasting properties were directly correlated with the granule type of starch, and the A-type granules of starch showed the highest peak viscosity, trough viscosity, final viscosity and breakdown viscosity. The B-type starch displayed poor pasting and textural properties, however, its freeze-thaw stability was satisfactory. Furthermore, the solubility (5.20-29.06) and swelling power (6.31-9.27) of starches also depended on the starch types and wheat varieties. Results revealed that an appropriate wheat and starch type choice would provide the basis for desired starch-based production.

The Effect of Tribomechanical Micronization and Activation on Rheological, Thermophysical, and Some Physical Properties of Tapioca Starch

The aim of this research was to investigate the effect of tribomechanical treatments on rheological, thermophysical, and some physical properties of tapioca starch. Samples of tapioca starch were treated using laboratory equipment for tribomechanical micronization and activation (TMA equipment). Before and after the TMA treatment, analysis of the particle size and particle size distribution was carried out, in addition to scanning electron micrography in tapioca starch. Scanning electron micrography showed that tribomechanical processing of tapioca starch resulted in breaking accumulations of starch granules in the form of granules. Pasting parameters have shown that maximal viscosities of model starch suspension have been decreasing after tribomechanical treatment. On the basis of gelatinization curves, it can be concluded that there are changes in the gelatinization point after treatment, and there is decrease in enthalpy of gelatinization for model suspension. After tribomechanical treatment, changes in physical properties of starch suspensions were determined, as well as specific swelling capacity, solubility index, and turbidity of tapioca starch suspensions.

Effects of lipids on enzymatic hydrolysis and physical properties of starch

This study aimed to understand effects of lipids, including corn oil (CO), soy lecithin (SL), palmitic acid (PA), stearic acid (SA), oleic acid (OA), and linoleic acid (LA), on the enzymatic hydrolysis and physical properties of normal corn (NCS), tapioca (TPS), waxy corn (WCS), and high-amylose corn (HA7) starch, and to elucidate mechanisms of interactions between the starches and lipids. After cooking with the lipids (10%, w/w, dsb), NCS, TPS, and HA7 showed significant decreases in enzymatic hydrolysis, and their DSC thermograms displayed amylose–lipid-complex dissociation peaks except with the CO. 13C NMR spectra of amylodextrin with CO showed downfield changes in the chemical shifts of carbons 1 and 4 of the anhydroglucose unit, indicating helical complex formation. Generally, free fatty acids (FFAs) reduced, but SL increased the peak viscosities of starches. FFAs and SL decreased, but CO increased the gel strength of NCS. These lipids displayed little impacts on the enzymatic hydrolysis and physical properties of WCS because it lacked amylose.

Effect of Coloring Agents on Starch Properties: In Powder and Paste Form

The aim of this study was focusing on the excipients interaction especially between coloring agents and diluents. There were two coloring agents with different charges ; methylene blue(M) showing positive charge while amaranth(A) giving negative charge but all having same concentration of 0.1% w/w in each mixing batch. There are five types of starch using as diluents; arrowroot starch (W), rice starch (R), cassava starch (S), corn starch (C) and lesser yam starch (l). The physical properties of starch powder and paste (5%w/v) were evaluated as angle of repose and viscosity respectively. While the concentration of both coloring agents were determined by either UV spectroscopy or eye observation. The storage conditions of all samples were kept in both light and dark area for 7 weeks. It was found in powder form that C gave the most stable of M while R gave the worst for m in both light and dark condition. M showed less influences on flow properties of starches than a in a powder state. The flow of C with M gave the best results. The W paste was shown to be the most stable physical properties. M was suitable for S paste in a dark condition. While A was suitable for C, R and W paste in a light condition. The charges of coloring agents might not be a major influence on some physical properties of starch in both powder and paste form.

Effect of gamma irradiation on the thermal and rheological properties of grain amaranth starch

Physical properties of starch from two cultivars of gamma-irradiated grain amaranth with different amylose content were investigated. Pasting viscosities decreased continuously with the increase in dosages of irradiation. Furthermore, different irradiation dosages resulted in modification of the thermal properties and crystallinity of starch. Dynamic oscillation on shear was also employed, temperature and frequency sweeps showed that changes in storage modulus and loss modulus were significant, with Tibet Yellow producing more elastic gels as compared to Hy030 at different irradiation dosages.

Starch noodles: History, classification, materials, processing, structure, nutrition, quality evaluating and improving

Starch noodles, produced from purified starch of various plant sources, are a major category of Asian noodles. This review summarizes the current knowledge on: (1) Definition, naming, history and categories of starch noodles. (2) The morphological, physico-chemical, thermal, rheological characteristics and molecular structure of materials including mung bean starch, pea starch, sweet potato starch, potato starch and corn starch. (3) Processing technology of starch noodles including dropping, extruding and cutting. (4) Structure of starch noodles: it is composed of hydrolysis-resistant crystalline zone, network-like framework and filler mass. (5) Nutrition of starch noodles: it could be evaluated by the digestibility of starch, hydrolysis properties of gelatinized and retrograded starches, hydrolysis property of starch noodles. (6) Quality evaluating of starch noodles: it includes sensory, cooking and texture property. Correlation between the physical properties of starch, processing variables and the sensory, cooking and texture property of starch noodles are summarized. (7) Quality improving for non-mung bean starch noodles: (a) using other materials such as red bean starch, pigeonpea starch, potato starch, sweet potato starch, corn starch, to substitute totally or partly mung bean starch; (b) adding chemically modified starch; (c) adding physically modified starch; (d) biologically treating starch; (e) using additives such as chitosan, polysaccharide gums.

Evaluation of Starch Noodles Made from Three Typical Chinese Sweet‐potato Starches

ABSTRACT: The physical properties of starches from 3 typical Chinese sweet potato varieties (SuShu2, SuShu8, and XuShu18) were studied in relation to their noodle‐making performance. The starch gel properties of SuShu2 differed from those of SuShu8 and XuShu18. As determined by both instrumental and sensory analysis the use of SuShu8 starch resulted in better noodle quality compared to XuShu18 and SuShu2 starches. The gel properties and noodle quality of the 3 sweet‐potato starches were clearly different from those of mung‐bean starch. Correlation between starch noodle quality and gel properties of the original starches was established. Keywords: sweet potato, starch, gel, noodle

EFFECT OF CHEMICAL AGENTS ON PHYSICAL AND RHEOLOGICAL PROPERTI ES OF STARCH-GUAR GUM EXTRUDATES

ABSTRACT A mixture of starch and guar gum was extruded with citric acid, sodium stearoyl-2-lactylate (SSL) and diacetyl tartaric acid ester of monoglyceride (DATEM). Water solubility, blue value, extrudate expansion and viscosity were measured for the different additives. Incorporation of hydrocolloids caused a synergistic increase in viscosity indicating a strong interaction between starch amylose and gums. Extrusion with chemical agent affected the physical properties of starch. Citric acid decreased viscosity and increased water solubility and expansion volume. Sodium stearoyl-2-lactylate and diacetyl tartaric acid ester of monoglyceride increased viscosity while reducing expansion and water solubility. This indicated that even at extrusion temperatures, these surfactants maintained their complexing power. Analysis of variance showed that addition of chemical agents significantly affected the physical and rheological properties of the extrudates.

The Effects of Environmental Conditions on the Structural Features and Physico-chemical Properties of Starches

The effects of environmental factors on the structural features and physico-chemical properties of starch (from various botanical sources) have been investigated over many decades. A close study of published data on the effects of environmental factors, especially growth temperature, reveals discrepancies with regard to its effects on the composition and properties of the major components of starch, namely amylose and amylopectin. These discrepancies can in part be explained on the basis of the different experimental protocols used by the various investigators to provide environmental variation although it is clear that environmental factors do influence the deposition and composition of starch granules. However, the effects of environmental conditions on the physical properties of starches are more easily reproduced and are consequently better understood. This review is an up to date survey of current knowledge in this area and draws extensively on the authors' own research.

Effects of moisture content and heat treatment on the physical properties of starch and poly(lactic acid) blends

AbstractStarch, a hydrophilic renewable polymer, has been used as a filler for environmentally friendly plastics for about 2 decades. Starch granules become swollen and gelatinized when water is added or when they are heated, and water is often used as a plasticizer to obtain desirable product properties. The objective of this research was to characterize blends from starch and poly(lactic acid) (PLA) in the presence of various water contents. The effects of processing procedures on the properties of the blends were also studied. Blends were prepared with a lab‐scale twin‐screw extruder, and tensile bars for mechanical testing were prepared with both compression and injection molding. Thermal and mechanical properties of the blends were analyzed, and the morphology and water absorption of the blends were evaluated. The initial moisture content (MC) of the starch had no significant effects on its mechanical properties but had a significant effect on the water absorption of the blends. The thermal and crystallization properties of PLA in the blend were not affected by MC. The blends prepared by compression molding had higher crystallinities than those prepared by injection molding. However, the blends prepared by injection molding had higher tensile strengths and elongations and lower water absorption values than those made by compression molding. The crystallinities of the blends increased greatly with annealing treatment at the PLA second crystallization temperature (155°C). The decomposition of PLA indicated that PLA was slightly degraded in the presence of water under the processing temperatures used. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 3069–3082, 2001

Composition and physical properties of starch in microgravity-grown plants.

The effect of spaceflight on starch development in soybean (Glycine max L., BRIC-03) and potato (Solanum tuberosum, Astroculture-05) was compared with ground controls by biophysical and biochemical measurements. Starch grains from plants from both flights were on average 20-50% smaller in diameter than ground controls. The ratio delta X/delta rho (delta X --difference of magnetic susceptibilities, delta rho--difference of densities between starch and water) of starch grains was ca. 15% and 4% higher for space-grown soybean cotyledons and potato tubers, respectively, than in corresponding ground controls. Since the densities of particles were similar for all samples (1.36 to 1.38 g/cm3), the observed difference in delta X/delta rho was due to different magnetic susceptibilities and indicates modified composition of starch grains. In starch preparations from soybean cotyledons (BRIC-03) subjected to controlled enzymatic degradation with alpha-amylase for 24 hours, 77 +/- 6% of the starch from the flight cotyledons was degraded compared to 58 +/- 12% in ground controls. The amylose content in starch was also higher in space-grown tissues. The good correlation between the amylose content and delta X/delta rho suggests, that the magnetic susceptibility of starch grains is related to their amylose content. Since the seedlings from the BRIC-03 experiment showed elevated post-flight ethylene levels, material from another flight experiment (GENEX) which had normal levels of ethylene was examined and showed no difference to ground controls in size distribution, density, delta X/delta rho and amylose content. Therefore the role of ethylene appears to be more important for changes in starch metabolism than microgravity.

Side-Chain Liquid-Crystalline Model for Starch

A chiral side-chain liquid-crystalline polymeric model for the structure and physical properties of starch was reviewed and extended [1—6]. The lamellae in starch are considered in terms of three components: backbone, side-chains and double helices. It is the degree of mobility of these three components, coupled with the helix-coil transition, which gives starch its distinctive properties. The model is used to help explain phenomena involved during hydration, gelatinisation, plasticisation, freezing, and morphogenesis. The new technique of scanning microfocus X-ray diffraction is used to study double helix orientation and the tilt of the lamellae. Using integration of the double helix orientation along closed contours in single potato granules it is shown that they conain a “+1” hedgehog disclination. The effect of the chirality of the double helices on the phase behaviour is highlighted.

Understanding and Influencing Starch Biochemistry

Starch is one of the most important products synthesized by plants that is used in industrial processes. If it were possible to increase production or modify starches in vivo, using combinations or either genetically altered or mutant plants, it may make them cheaper for use by industry, or open up new markets for the modified starches. The conversion of sucrose to starch in storage organs is, therefore, discussed. In particular the roles of the different enzymes directly involved in synthesizing the starch molecules on altering starch structure are reviewed, as well as the different models for the production of the fine structure of amylopectin. In addition, the process of starch phosphorylation, which is also important in determining the physical properties of starches, is reviewed. It is hoped that detailed knowledge of these processes will lead to the rational design of tailored starches. Starch degradation is also an important process, for example, in the cold-sweetening of potato tubers, but outside of cereal endosperm little is known about the processes involved. The enzymes thought to be involved and the evidence for this are discussed.