Comparison of Functional Properties between Native and Chemically Modified Starches from Acha (<i>Digitaria</i>Stapf) Grains

Acha grain (Digitariaexilis) starch was isolated and subjected to chemical modifications by acetylation, benzylation, succinylation, carboxymethylation and acid-thining. Functional properties (swelling, solubility, gelation, oil and water absorption capacities, alkaline water retention) and rheological properties of the native and modified starches were determined. Swelling power and solubility of the starch samples increased with increase in temperature. Swelling power and solubility were pH dependent, with maximum values obtained at pH 12 in both native and modified starches. Increasing degree of alkalinity increased both solubility and swelling capacity. Water absorption capacities of chemically modified starches decreased, but acetylated starch, ATAS showed higher value compared to the native and also chemically modified starches improved oil absorption capacity of the native starch. The modified starches showed increase in alkaline water retention. Gelation studies revealed that ACAS had higher LGC than the native while some chemically modified starches did not alter the gelation capacity of the native starch except for BAS and ACAS with LGC of 10% and 16% v/w. There were significant differences in functional properties between native and chemically modified starches from acha, so chemical modification improved functional properties. Chemical modifications increased pasting temperature except for ATAS and BAS. Set-back values were reduced after modifications, indicating that modification would minimize starch retrogradation.

DEGREE OF SUBSTITUTION OF THE IONIZED STARCHES AND THEIR ADHESIVE CAPACITY TO POLYESTER / COTTON FIBERS

Adhesive capacity of quaternary ammonium starch and starch phosphate to the polyester / cotton fibers was studied by means roving method for the purpose of improving the sizing performance and decreasing the cost. By introducing different amount of quaternary ammonium or phosphate groups onto starch molecules, the modified starch with a series of defferent degree of substitution was prepared. Therefore the regularity of adhesive capacity, extended property and size-absorbing ability with the change in degree of substitution (DS) was obtained through the researches. The experiments demonstrate that the DS of the two modified starches show a marked influence upon the properties mentioned above. The starch phosphate is superior to quaternary ammonium starch as warp size for polyester / cotton yarns from the viewpoint of adhesive capacity and cost, although both of them are better than natural one. To improve the adhesive capacity to polyester / cotton fibers, DS≥0.027 is necessary for quaternary ammonium

Effect of modified starches on depression of diaspore

Four modified starches with selected charge characteristics including cationic starch(CAS),carboxymethyl starch(CMS),amphoteric starch(AMS) and soluble starch(SS) were investigated as depressants for diaspore in reverse flotation test using cationic collector(dodecylamine).Adsorption examination,Zeta potential measurement and Fourier transform infrared(FTIR) spectroscopy were used to clarify the role of the surface charge characteristics of starches in determining the adsorption behavior and depression performance as well as the mineral-starch interaction.Results show that the positively charged starches(CAS and AMS) display higher adsorption amounts and also better depression performance compared with the non-ionic(SS) and anionic starch(CMS),benefiting from the favorable electrostatic attraction with diaspore and also electrostatic repulsion with collector.FTIR spectroscopy proves the presence of hydrogen bonds and chemical complexation between mineral and starches in an integrated manner.

SYNTHESIS AND SIZING PROPERTIES OF GRAFT STARCHES AS WARP SIZING MATERIALS FOR POLYESTER/COTTON BLEND SPUN YARN

Grafting a number of monomers such as acrylic acid, acrylamide, methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, butyl methacrylate and vinyl acetate onto granular corn starch was carried out respectively in aqueous dispersion by using cerie ammonium nitrate as an initiator under nitrogen atmosphere. Conversion of monomer, grafting ratio and grafting efficiency were measured by the method of combining the chemical quantitative analysis with the weight. The adhesive power of the starch graft copolymers to polyester/cotton fiber was evaluated by measuring the breaking strength and elongation of the roving impregnated with the paste. The viscosity change of the size paste before and after grafting was studied. The mechanical properties of polyester/cotton fibre yarn sized by the graft starch were tested. The main conclusions are as follows: (1) monomers which were graft coplymerized onto starch have a significant influence upon the viscosity of the size paste; (2) the adhesive power

Physicochemical and structural properties of starches from non-traditional sources in China

In this study,we isolated starches from non-traditional sources,including quinoa,lentil,arrowhead,gorgon fruit,sorghum,chickpea,proso millet,and purple potato and investigated their morphology,physicochemical,and functional properties.Significant differences in starch particle morphology,swelling power,solubility,syneresis,crystalline pattern,and pasting viscosity were observed among the starches from these nontraditional sources.Further,all these isolated starches had unique properties because of their characteristic distinct granules when seen under scanning electron microscopy(SEM).The amylose content of the isolated starches shown significant difference(P<0.05),and the values ranged between 11.46%and 37.61%.Results demonstrated that the isolated starches contained between 79.82%to 86.56%starch,indicating that the isolated starches had high purity.X-ray diffraction(XRD)patterns of starches isolated from sorghum,proso millet,quinoa,purple potato,and gorgon fruit presented A-type diffraction pattern;while lentil seeds,arrowhead,and chickpea starches presented C-type diffraction pattern.Overall,these results will promote the development of products based on starch isolated from non-traditional starches.

Structure, Physico-chemical and Microbiological Properties of Ozone-oxidized Wheat, Corn, Potato and Rice Starches

A limited number of studies have been conducted on the effects of ozone use on cereal and its components. Starch, an important natural macromolecule, is an essential component of cereals. In present study, the effects of ozone on the structure, physico-chemical and microbiological properties of wheat, corn, potato and rice starches were investigated. Wheat starch, corn starch, potato starch and rice starch water mixtures were prepared in the ratio of 1：9 （dry sample to water ratio） and treated with ozone at a rate of 60 g/h for 1 hour, while unozonated samples were used as controls. Light microscopy represented that the structures of corn and potato starch samples were affected by 1 hr ozonation rather than the structures of wheat and rice starch samples. Colour of ozone-oxidized wheat, corn and potato starch samples could meet the consumer preference due to the higher lightness, higher whiteness and lower chroma value. However, high chroma, high yellownes and low whiteness values of ozonated rice starch is not adequate for consumer desire. Microbiological analysis showed that 1 hr ozonation reduced the total bacteria and mould/yeast counts significantly for all wheat, corn, potato and rice starch samples （P 〈 0.05） due to most probably the reduced pH of samples. Ozonation can be an alternative modification technique, but further research is needed to understand the certain benefits and limitations of ozone applications on starch oxidation for human safety and health.

Characterization and Utilization of Starches Extracted from Florencia and Waxy Maize Hybrids for Tablet Formulation: Compaction Behaviour and Tablet Properties

The aim of this work is to analyze the particle characteristics, such as shape, roundness and size, of starches extracted from Florencia and waxy maize hybrids. The micromeritics and structural properties of the samples were examined. The evaluation of flow properties, densification and compression behaviour of the powders was carried out. Physical parameters and swelling characteristics of tablets containing Florencia and waxy maize starch were also studied. Starch samples were compared with respect to their applicability as excipients in tablet formulation. The samples exhibited identical structure and similar particle characteristics. Maize starch extracted from the Florencia dent hybrid showed better flowability and compressibility in tableting experiments, which resulted in better mechanical tablet properties. With regard to utilization as a disintegrant, Florencia starch indicated rapid and intensive swelling and proved to act more effectively in the swelling process than waxy maize starch.

Morphological and Physicochemical Properties of Water Chestnut Starches: a Comparative Analysis of Three Varieties

Water chestnut(Eleocharis dulcis) is widely cultivated in many countries for its edible and starchy corms. In this study, starches were separated from Guangxi biqi, Hubei biqi and Anhui biqi, and the morphological and physicochemical characteristics of the starches were systematically investigated. There were significant differences in granule size, total starch and amylose contents among starches from the three water chestnuts which present similar X-ray diffraction patterns and Fourier transform infrared spectroscopy. The starch of Guangxi biqi exhibited higher swelling power and solubility than that of Hubei biqi and Anhui biqi. Thermal and pasting properties of starch were different among the three water chestnuts. When hydrolyzed by porcine pancreatic α-amylase(PPA), starches from Hubei biqi and Anhui biqi had higher hydrolysis degree. The starches from the three water chestnut varieties differed significantly in morphological and physicochemical properties, and these studies may provide useful information for future exploitation and application of water chestnut starch in food and non-food industries.

Insights into the relations between cell wall integrity and in vitro digestion properties of granular starches in pulse cotyledon cells after dry heat treatment

Natural foods,such as whole pulses,are recommended in the dietary guidelines of the US and China.The plant cell wall structure in whole pulses has important implications for the nutritional functionalities of starch.In this study,garbanzo bean cells with varying degrees of cell wall integrity were subjected to dry heat treatment(DHT)and used to elucidate the food structure-starch digestion properties of pulse food.The morphological features suggested that all cell samples do not exhibit remarkable changes after being subjected to DHT.Molecular rearrangement and the crystallite disruption of starch granules entrapped in cells occurred during DHT as assessed by the crystal structure and thermal properties.DHT decreased the inhibitory effects of enzymes of both the soluble and insoluble components,but the digestion rate and extent of slightly and highly damaged cell samples did not exhibit significant differences compared with their native counterparts.We concluded that the starch digestion of pulse cotyledon cells is primarily determined by the intactness of the cellular structure.This study reveals the role of food structure on the ability to retain the desirable nutritional properties of starch after subjection to physical modification.

Influence of ginger and banana starches on the mechanical and disintegration properties of chloroquine phosphate tablets

Objective:The influence of two experimental starches - ginger starch obtained from Zingiber officinale and banana starch from Musa sapientum - on the mechanical and disintegration properties of chloroquine tablets have been studied in comparison with the influence of official corn starch.Methods:Chloroquine tablets were formulated using various concentarions of the starches as binding agent.The mechanical properties of the tablets were assessed in terms of crushing strength and friability and the crushing strength-friability ratio(CSFR) while drug release properties were evaluated based on disintegration and the time of tablets.Results:The ranking for crushing strength and CSFR was corn】banana】ginger starch while the ranking was reverse for friability.The disintegration time increased with packing fraction and starch concentration in the rank order of formulations containing corn】banana】ginger starch.The CSFR/DT values increased with concentration of starch binder indicating an improved balance between binding and disintegrant properties of the starches.Statistical analysis showed that there were significant(P【0.001) difference in the CSFR/DT for tablets containing the various starch binders.Conclusion:The mechanical and disintegration properties of the experimental starches compared favorably with those of corn starch and ginger starch could be more useful when faster tablet disintegration is desired.

Effect of thermal and chemical modifications on the mechanical and release properties of paracetamol tablet formulations containing corn, cassava and sweet potato starches as filler-binders

Objective: To investigate the effects of acetylation and pregelatinization of cassava and sweet potato starches on the mechanical and release properties of directly compressed paracetamol tablet formulations in comparison with official corn starch.Methods: The native starches were modified by acetylation and pregelatinization. The tablets were assessed using friability(Fr), crushing strength(Cs), disintegration time(Dt) and dissolution parameters. Results: Starch acetylation produced paracetamol tablets that were stronger and had the best balance of mechanical and disintegration properties, while pregelatinization produced tablets that were more friable but had a better overall strength in relation to disintegration than formulations made from natural starches. Correlations mainly existed between Dt and the dissolution parameters t80, t2 and k1 in the formulations. Conclusions: Modification of the experimental starches improved the mechanical and release properties of directly compressed paracetamol tablet formulations. Thus, they can be developed for use as pharmaceutical excipients in specific formulations.

Formulation factors affecting the binding properties of Chinese yam(Dioscorea oppositifolia) and corn starches

Objective:The quantitative effects of formulation and processing variables affecting the binding properties of Chinese yam starch（Dioscorea oppositifolia） in chloroquine phosphate tablet formulations have been investigated in comparison with corn starch using a 23 factorial experimental design.Methods:Chinese yam starch,representing the "low" level,and corn starch,representing the "high" level were used as binders at concentrations of 2.5%w/w and 10%w/w in chloroquine phosphate tablet formulations.The mechanical properties of the tablets,measured by the tensile strength（T） and brittle fracture index（BFI） as well as the release properties measured by the disintegration time（DT） and dissolution time(t80- time for 80%drug release),were used as assessment parameters.Results:The ranking of the individual coefficient values for the formulations on T was D 】 N 】】C,on BFI was N 】 D 】】C,on DT was D 】 N 】 C and on t80 was C 】 N 】 D while the ranking of the interaction coefficient on T was N-D 】 C-D 】】 N-C,on BFI was N-D 】 N-C = C-D,on DT and t80 was N-C 】 N-D 】 C-D.Changing the binding agent from Chinese to corn starch,led to a decrease in T,DT and t80 but increase in BFI of the tablets.There were significant（P 【 0.001 ） interactions between the nature of binder,N and the other two variables,C and D.Conclusion:The result showed that Chinese yam possessed stronger binding capacity than corn starch and could be useful as an alternative binder when tablets with high mechanical strength with minimal problems of lamination,and slow release are required.

Morphological and Rheological Properties of Starches Separated from Cultivars of Rice (<i>Oryza sativa</i>L.) from North East India

Starch granules isolated from different accessions of rice from North East India showed a typical polygonal morphology with size ranging from 3.4 ± 0.8 μm to 6.4 ± 1.2 μm. The apparent amylose content (AAC) of the granules varied from 1.9% to 28.33%. Our results identify starch from IC-583088 as “waxy” and IC-583085, IC-583038, DPRR-168 as “very low” amylo-. The coefficient of resistance to flow (n) for starch pastes from the varieties of rice studied in the present investigation recorded a value of <1.0. The observed “n” value deviates from the Newtonian flow indicating the pseudoplastic nature of starches isolated from these varieties. While starch pastes from the accession IC-583088 recorded the highest ‘‘n’’ value of 0.6, that from the accession IC-545197 showed the lowest value of 0.03. The variations in coefficient of resistance to flow clearly revealed a higher ‘‘n’’ value for starch pastes from the “waxy” and ‘‘low” amylo-cultivars than the “intermediate” or ‘‘high” amylo-cultivars. Our results clearly established characteristic rheological properties for starches from the accessions SKY-AK-1608, IC-583035, YS-RC-219, IC-564939 and IC-332963, which exhibited greater resistance to thinning and shearing than other varieties.

Effects of Agrobacterial<i>rol</i>-Genes on the Thermodynamic and Structural Features of Starches Extracted from Potato Microtubers

Wild-type potato (Solanum tuberosum L.) plants and their transformants harboring agrobacterial rolB or rolC genes under control of the patatin class I promoter were cultured in vitro. These plants were used as a source of single-node stem cuttings. The structure of native starch in tubers formed on cuttings was determined using methods of X-ray scattering and differential scanning microcalorimetry (DSC). It was found that in starch from tubers of rolB plants the melting temperature of crystalline lamella was lower and their thickness was less than that in wild-type potato. In tubers of rolC plants starch differed from starch in wild-type plants by a higher melting temperature, reduced melting enthalpy, and a greater thickness of crystalline lamellae. The melting of starch from tubers of rolC plants proceeded as the melting of two independent crystalline structures with melting temperatures of 338.0°K and 342.8°K. Overall data show that starches of different structure can be obtained by using transgenic approach.

Morphological and Thermal Properties of Starches Isolated from White and Pigmented Sorghum Landraces Grown in Hyper Arid Regions

The starches were isolated by alkaline extraction from white and red sorghum, predominant cultivars in the Sahara of Algeria. Morphological, thermal properties and amylose content of isolated starches were examined. The starches of two sorghum landraces of white and pigmented kernels growing in hyper arid environmental conditions showed significant differences in granule size, amylose content and thermal behavior which ultimately affect the physicochemical and functional properties. When observed using environmental scanning electron microscopy （ESEM）. The starch granules showed polyhedral shape. Some of them showed pinholes. The granular size ranged between 6.325-39.905 μm and 7.096-44.774 μm, respectively for white and red sorghum starches. The granule size distribution was unimodal. The amylose content in white sorghum starch （27.1%） was higher than that in red sorghum （24.8%）. Differential scanning calorimetry （DSC） analysis revealed that sorghum starches present higher temperatures at the peak （70.60℃ and 72.28℃ for white and red sorghum starches, respectively） and lower gelatinization enthalpies （9.087 J/g and 8.270 J/g for white and red sorghum starches, respectively） than other cereal starches. The determination of these properties is relevant to the comprehension of starch and starch-based foods digestibility in order to direct them towards the specific applications in food and nonfood sectors.

Influence of Gum Arabic from <i>Acacia Senegal</i>var. <i>kerensis</i>on the Modifications of Pasting and Textural Properties of Cassava and Corn Starches

The use of hydrocolloids to modify the properties of native starches has been on the rise in the recent times due to the market demand for natural, safe and economical food ingredients. The objective of this study was to investigate the effect of gum Arabic from Acacia senegal var. kerensis to modify pasting and textural properties of corn and cassava starches, as an alternative to chemical and enzymatic modification. Blends were prepared by substituting the starches with gum at different levels (0%, 0.5%, 2.0%, 4.0%, 6.0% and 8.0%), whereas native corn and cassava starches were used as control. The pasting properties of the starch-gum mixed systems were determined using the Brabender viscograph while the textural properties (firmness, consistency, cohesiveness and work of cohesion) were determined using Texture Analyzer. Results showed that the gum Arabic significantly decreased all the viscosity parameters (peak viscosity, final viscosity, break down and setback values) of both starches at all levels of substitution. However, there was no significant effect of gum Arabic on the pasting temperature (72.05°C - 71.85°C) for corn starch and (68.90°C - 68.65°C) for cassava starch. The degree of gel firmness and consistency was higher in corn starch than in cassava starch and the effect of gum addition differed with each starch. The findings from this study indicate that gum Arabic significantly modified the pasting and textural properties of corn and cassava starches due to strong interaction between the gum and the starches. Hence, this property of gum Arabic could be useful in controlling starch retrogradation and determining starch end use functionality.

Effects of extrusion and enzymatic debranching on the structural characteristics and digestibility of corn and potato starches

Amylose content has a profound impact on the contents of slowly digestible starch and resistant starch.Enzymatic debranching is a safe method to increase the amylose content,however,the lower substrate concentration and high viscosity of fully gelatinized starch limit the efficiency and yield of this method.This paper aims to explore the effects of extrusion and enzymatic debranching on increasing the amylose content thereby increasing slowly digestible starch and resistant starch contents.Different starch concentrations (10%,15%,and 20%) of extruded corn starch (ECS) and extruded potato starch (EPS) were used to debranch.Both debranched ECS and debranched EPS showed high amylose content of approximately 90%,indicating that all samples with different starch concentrations achieved high-efficiency enzymatic debranching.The high-performance liquid chromatograph results indicated that the samples were mainly short amylose.The samples exhibit a typical B-type crystalline structure and the relative crystallinity of them exceeds 37%.The short amylose exhibited rapid rearrangement ability,with the gelatinization temperature range of rescanning determined as 80–125℃,this will facilitate the formation of slowly digestible starch and resistant starch.The slowly digestible starch and resistant starch contents of the samples (debranched ECS and debranched EPS) were between 23% and 30% and between 31% and 37%,respectively.These results indicate that the extrusion and enzymatic debranching of a high substrate concentration can efficiently increase the amylose content,thereby significantly reducing the digestibility of starch,and has broad prospects of the actual production of slowly digestible starch and resistant starch.

The granule characteristics of yam,sweet potato and tapioca starches determined by gravitational field-flow fractionation

To study the characteristics of tuber starchgranules,firstly,three kinds of common tuber starches were separated and characterized by gravitational field-flow fractionation(GrFFF)instrument,and the ratios of large and small starch granules A/B were calculated.Then,the liquid of peak A and peak B was collected and observed by scanning electron microscope(SEM)to verify the separation result of GrFFF.Secondly,the particle size distribution and crystal characteristics were characterized by particle size analyser,X-ray diffraction(X-ray)and fourier transform infrared spectroscopy(FT-IR).Three kinds of tuber starches all had the bimodal distribution in GrFFF.Peak A contained large particles,and peak B contained small particles.For yam starch,the ratio of starch granules A/B was much higher than 1;for sweet potato starch the ratio was approximately equal to 1;for tapioca starch,the ratio was much lower than 1.Moreover,the starch granules of sweet potato and tapioca were both A-type crystallinity,while yam starch granules were C-type crystallinity.GrFFF could be used to characterize and separate large and small granules of tuber starches and estimate the ratio of starch granules A/B.Yam starch was suitable for the development of slowly digestible starch(one kind of functional food),which could delay the occurrence of metabolic syndrome,diabetes and cardiovascular diseases.Tapioca starch was suitable for plant capsules,which were safer than gelatin capsule and could prevent the"poison capsule"incident from happening.

Enhancing I^(0)/I^(-)Conversion Efficiency by Starch Confinement in Zinc-lodine Battery

The redox couple of I^(0)/I^(-)in aqueous rechargeable iodine–zinc(I^(2)-Zn)batteries is a promising energy storage resource since it is safe and cost-effective,and provides steady output voltage.However,the cycle life and efficiency of these batteries remain unsatisfactory due to the uncontrolled shuttling of polyiodide(I_(3)^(-)and I_(5)^(-))and side reactions on the Zn anode.Starch is a very low-cost and widely sourced food used daily around the world.“Starch turns blue when it encounters iodine”is a classic chemical reaction,which results from the unique structure of the helix starch molecule–iodine complex.Inspired by this,we employ starch to confine the shuttling of polyiodide,and thus,the I^(0)/I^(-)conversion efficiency of an I^(2)-Zn battery is clearly enhanced.According to the detailed characterizations and theoretical DFT calculation results,the enhancement of I^(0)/I^(-)conversion efficiency is mainly originated from the strong bonding between the charged products of I_(3)^(-)and I_(5)^(-)and the rich hydroxyl groups in starch.This work provides inspiration for the rational design of high-performance and low-cost I^(2)-Zn in AZIBs.

Irrigation regimes modulate non-structural carbohydrate remobilization and improve grain filling in rice(Oryza sativa L.)by regulating starch metabolism

Recently developed ‘super’ rice cultivars with greater yield potentials often suffer from the problem of poor grain filling, especially in inferior spikelets. Here, we studied the activities of enzymes related to starch metabolism in rice stems and grains, and the microstructures related to carbohydrate accumulation and transportation to investigate the effects of different water regimes on grain filling. Two ‘super’ rice cultivars were grown under two irrigation regimes of well-watered(WW) and alternate wetting and moderate soil drying(AWMD). Compared with the WW treatment,the activities of ADP glucose pyrophosphorylase(AGPase), starch synthase(StSase) and starch branching enzyme(SBE), and the accumulation of non-structural carbohydrates(NSCs) in the stems before heading were significantly improved, and more starch granules were stored in the stems in the AWMD treatment. After heading, the activities of α-amylase, β-amylase, sucrose phosphate synthase(SPS) and sucrose synthase in the synthetic direction(SSs)were increased in the stems to promote the remobilization of NSCs for grain filling under AWMD. During grain filling, the enzymatic activities of sucrose synthase in the cleavage direction(SSc), AGPase, StSase and SBE in the inferior spikelets were increased, which promoted grain filling, especially for the inferior spikelets under AWMD.However, there were no significant differences in vascular microstructures. The grain yield and grain weight could be improved by 13.1 and 7.5%, respectively, by optimizing of the irrigation regime. We concluded that the low activities of key enzymes in carbon metabolism is the key limitation for the poor grain filling, as opposed to the vascular microstructures, and AWMD can increase the amount of NSC accumulation in the stems before heading, improve the utilization rate of NSCs after heading, and increase the grain filling, especially in the inferior spikelets, by altering the activities of key enzymes in carbon metabolism.