Rheological Properties Of Starch Research Articles

The Effects of Naematelia aurantialba on the Pasting and Rheological Properties of Starch and the Research and Development of Soft Candy.

To study the effects of Naematelia aurantialba (NA) on the rheological and gelatinization properties of starch, the processing methods of NA were diversified. In this study, the gelatinization and rheological properties of corn starch (CS) and edible cassava starch (ECS) were investigated by adding NA with different mass fractions. Starch soft candy was prepared using NA, CS, and ECS as the main raw materials. Rheological studies showed that both CS-NA and ECS-NA exhibited elastic modulus (G') > viscosity modulus (G″), implying elastic behavior. G' was such that CS+1%NA > CS+5%NA > CS+3%NA > CS > CS+2%NA > CS+4%NA > ECS+4%NA > ECS+3%NA > ECS+5%NA > ECS+2%NA > ECS+1%NA > ECS. The gelatinization implied showed that after adding NA, the pasting temperature of CS-NA and ECS-NA increased by 1.33 °C and decreased by 2.46 °C, while their breakdown values decreased by 442.35 cP and 866.98 cP, respectively. Through a single-factor test and orthogonal test, the best formula of starch soft candy was as follows: 0.4 f of NA, 10 g of white granulated sugar, a mass ratio of ECS to CS of 20:1 (g:g), 0.12 g of citric acid, 1 g of red date power, and 16 mL of water. The soft candy was stable when stored for two days. This study offers a new direction for the research and development of NA starch foods.

Preparation and Characterization of Extruded Yam Starch-Soy Protein Isolate Complexes and Their Effects on the Quality of Dough.

Extrusion is a method of processing that changes the physicochemical and rheological properties of starch and protein under specific temperature and pressure conditions. In this study, twin-screw extrusion technology was employed to prepare yam starch-soy protein isolate complexes. The structure and properties of the complexes and their effects on the quality of dough were studied. The results showed changes in the X-ray diffraction, rheology, and in vitro digestibility of the complexes. The extruded starch-protein complex formed an A+V-type crystal structure with the addition of soy protein isolate. A small amount of soy protein isolate could improve the complex's viscoelasticity. As the content of soy protein isolate increased, the content of slow-digesting starch and resistant starch in the complexes increased, and the digestibility decreased. The microstructure of the dough indicated that the network structure of the puffed yam starch-protein complex dough was more uniform than that of the same amount of puffed yam starch. The moisture distribution of the dough showed that with the addition of extruded flour, the closely bound water content of the dough increased, and the weakly bound water content decreased. The hardness, gumminess, chewiness, and resilience of the dough decreased. In conclusion, extruded starch-protein complexes can improve dough quality and provide technical support for the broad application of yam.

Pasting and Rheological Properties of Starch Paste/Gels in a Sugar-Acid System.

This study was to investigate the impact of granule size, amylose content, and starch molecular characteristics on pasting and rheological properties of starch paste/gels in neutral (water) and sugar-acid systems. Normal rice starch (RS), waxy rice starch (WRS), normal tapioca starch (TS), and waxy tapioca starch (WTS) representing small-granule starches and intermediate-granule starches respectively, were used in the study. Impacts of granule size, AM content, and their synergistic effects resulted in different starch susceptibility to acid hydrolysis and interactions between starch and sucrose-water, yielding different paste viscosities in both systems. The high molecular weight (Mw¯) and linearity of amylopectin and amylose molecules increased the consistency of starch pastes. RS produced a stronger and more brittle gel than other starch gels in both neutral and sugar-acid systems. The results indicated the impact of the effect of granule size and amylose content on starch gel behaviors. Properties of waxy starch gels were mainly governed by amylopectin molecular characteristics, especially in the sugar-acid system. Adding sugar and acid had minor impacts on starch gel behaviors in the linear viscoelastic (LVE) region but were most evident in the nonlinear response regime of starch gels as shown in the Lissajous curves at large oscillatory strain.

Effect of molecular structure changes during starch gelatinization on its rheological and 3D printing properties

Although the changes in molecular structure during starch gelatinization has been intensively investigated, how a relationship between starch rheological properties, printability, and starch molecular structure changes during starch gelatinization remains unclear. This research is focused on the molecular structure changes of corn starch (CS) gels caused by different treatment temperatures and their effects on CS gel rheological and 3D printing properties. With increasing treatment temperature, the leached amylose content and short linear chains (DP 6–12) of CS increase, whereas the contents of long linear chains (DP > 12) decrease, which influences the rheological and 3D printing properties of starch. Due to the presence of the original granules and crystalline structure, the CS-65 starch gel presented a poor storage modulus (G′), indicating poor 3D printing performance. The leaching of amylose induced the formation of new crystal and cross-linked network structures, which is beneficial for increasing its G′. However, the increase in short amylopectin linear chains (DP 6–12) reduced the degree of short-range order and hydrogen bonding interactions, which was detrimental to its G′ and yield stress (τf). CS-80 starch gel exhibited the largest G′ and shear recovery rate, showing the highest self-supporting properties and printing precision. Extremely high temperatures contributed to the densification of the starch gel structure, which led to an increase in τf and difficult extrusion. Overall, molecular structural changes caused by starch gelatinization are critical to its ideal rheological properties for 3D printing.

Removal of starch granule associated proteins affects annealing of normal and waxy maize starches

The effects of starch granule associated proteins (SGAPs) removal on the annealing of waxy and normal maize starch were investigated. Annealing significantly decreased the crystallinity, pasting viscosity, gelatinization temperature range, pseudoplasticity, and thixotropy of waxy and normal maize starches. Annealing little affected digestibility of the starches. Removal of SGAPs reduced the stability of starch granules, but significantly increased pasting viscosity, pseudoplasticity and thixotropy. Both annealing and SGAPs removal decreased the G′ and G″ of normal maize starch in dynamic rheological testing, but had little effect on waxy maize starch. Removal of SGAPs increased rapidly digestible starch (RDS) but reduced resistant starch (RS) for in vitro digestibility. SGAPs removal changed the effect of annealing on starches, and annealing showed different effect on waxy and normal maize starch with SGAPs removal. Annealing increased gelatinization enthalpy and RS of both normal and waxy maize starches after SGAPs removal, and decreased their pasting viscosities and RDS. The rheological properties of starches with SGAPs removal prior to annealing were impacted by amylose content. Annealing decreased pseudoplastic and thixotropy of waxy maize starch with SGAPs removal while increasing dynamic rheological properties of normal maize starch with SGAPs removal. • Annealing reduced crystallinity, pasting viscosity, and pseudoplasticity of starch. • SGAPs removal reduced the stability of starch granules. • Effect of SGAPs removal on starch properties was greater than that of annealing. • Effect of annealing and SGAPs removal depended on amylose content. • SGAPs removal inhibited annealing of normal amylose maize starch.

Morphological, Thermal, and Rheological Properties of Starch from Brown Rice and Germinated Brown Rice from Different Cultivars

AbstractMorphological, thermal, functional, pasting, and rheological properties of starch from BR (Brown rice) and GBR (Germinated brown rice) (PB1, PS44, PB1509, PB1121, PS5) are investigated. Scanning electron microscopy shows the presence of rougher and slightly eroded pits starch granules after germination. Starch from both the BR and GBR has the highest proportion of granules of 5–10 µm size and the lowest of 20–60 µm size. Starch from GBR shows lower gelatinization temperatures and enthalpy of gelatinization. GBR starch has a higher amount of long side chains and lower short side chains of amylopectin as compared to BR starch. Starches from BR show higher moduli as compared to their counterpart starches from GBR. GBR starch from different rice cultivars shows different amylopectin molecular structures, crystallinity, and thermal properties than BR starch. The lower paste viscosities and transition temperatures of GBR starch make it more suitable for the formulation of food products where a higher amount of starch is required without a rise in viscosity.

Morphological, Thermal, and Rheological Properties of Starch from Potatoes Grown in Mexico

AbstractThe morphological, thermal, and rheological properties of potato starch from three cultivars in the State of Sonora, Mexico, are evaluated. Content of starch, moisture, purity, and amylose vary from 11.8% to 14%, 9.2% to 11.2%, 78.2% to 83.0%, and 20.0% to 29.9%, respectively. The size and shape of the starch granules are similar among the cultivars. The granules show birefringence, which indicates the presence of a structural arrangement of their components (amylose and amylopectin). The highest peak temperature is observed in “Fiana” starch (67.0 ± 0.3 °C), even though gelatinization enthalpy is similar for the three starch sources (9.1 to 10.1 J g−1), indicating a similar arrangement of the double helixes of the amylopectin. The percentage of retrogradation is highest in “Vivaldi” starch (38.2%), which is similar to “Atlantic” (32.1%). Regarding the pasta profiles, the highest viscosity is as found in “Vivaldi” starch (95.1 mPa s−1). Due to its physicochemical properties, isolated starches produced from potatoes grown in Mexico have the potential to be used in industrial applications.

Pasting and Rheological Properties of Different Starches Using Starch Cell of Discovery Hybrid Rheometer

The study was conducted to evaluate the pasting and rheological measurements of four different starches (wheat, rice, corn and chickpea) using starch pasting cell of the hybrid rheometer. The experiment was planned to initially record the pasting behavior of starches in the starch cell using heating, holding and cooling program. The cooked gels were then subjected to steady shear and dynamic rheological measurements in the same cell. The highest peak and the final and setback viscosities were recorded for chickpea starch while the lowest values were obtained for the rice starch. The pasting curves of different starches represented the typical curve as observed using the traditional visco-analyzer or visco-amylograph. All the studied starches represented shear-thinning non-Newtonian behavior (n was less than 1) when studied for their steady shear properties. The starches could be classified from less to more pseudoplastic as rice>corn>wheat>chickpea. The activation energy of rice starch was highest (142719 J/mol) while the activation energy of chickpea starch was lowest among all the starches (13291 J/mol). The storage moduli, loss moduli and tan ? were increased with increasing the frequency, and the crossover was also observed in corn, rice and wheat starch at the higher frequency. It is well evident from all the studied parameters that starch cell can be conveniently used to study the pasting and rheological properties of starches.

Structure and properties of soft rice starch

Pasting and rheological properties of starch from soft rice and two traditional rice varieties were analyzed. Soft rice starch was found to have a low pasting temperature of 67.2 °C, with a high system viscosity, including peak and trough viscosity. The storage modulus and loss modulus of soft rice starch were high and showed good viscoelasticity. The amylose content of soft rice starch was found to be 11.3%, classifying it was low amylose content type. Compared with japonica rice starch, soft rice starch had lower solubility but higher swelling power, gel consistency, and water binding capacity. The medium particle size and volume mean particle size of soft rice starch were the highest. The average molecular weight of soft rice starch was 5.4 × 107. The molecular density and proportion of short amylopectin side chains, with a range of 6–12, were the highest among all varieties tested. These findings provide a theoretical basis for the processing of soft rice starch and breeding of high-quality rice.

Prediction of swelling behavior of crosslinked maize starch suspensions

Rheological properties of starch are affected by swelling of the granules that is in turn controlled by the degree of crosslinking. A previously developed model for swelling of starch granules was extended to account for electrostatic interactions. Maize starch was crosslinked with sodium trimetaphosphate. Granule swelling of 8% suspension of crosslinked maize starch when subjected to heating to 70,75,80,85 and 90 °C was more pronounced at higher temperatures eventually approaching equilibrium with the swelling ratio decreasing with increase in extent of crosslink. The number of crosslinks in the starch network was inferred from equilibrium swelling and related to peak viscosity and zeta potential. Chemical potential profile as well as the temperature profile within the granule at different times were predicted which were then employed to evaluate the evolution of granule size. The proposed model is able to describe the effect of crosslinking on swelling behavior.

Physicochemical, rheological, morphological, and in vitro digestibility properties of cross-linked starch from pearl millet cultivars

ABSTRACTThe effect of epichlorohydrin (0.5%) as a cross-linking agent on physicochemical, rheological, morphological, and in vitro digestion properties of pearl millet starches from different cultivars was studied. Degree of cross-linking (DC) ranged between 40.61% and 89.75%, lower values of DC were observed for cv.HC-10 and cv.HHB-67 whereas higher values were observed for cv.HHB-223 and cv.GHB-732. Cross-linked starch from cv.GHB-732 showed the lowest amylose content, swelling power, and solubility as compared to other cultivars. Rheological properties of starches during heating showed their elastic behaviour. G′ value was much higher than the G′′ value at all frequency values for starch pastes. Plots of shear stress (σ) versus shear rate (γ̇) data for cross-linked starch pastes were fitted to Herschel-Bulkley model and yield stress (σo), flow behaviour index (n), and consistency index (K) were evaluated. Scanning electron micrographs (SEM) investigations revealed that cross-linked starch granules had slightly rough surfaceand grooves with slight fragmentations. Readily digestible starch (RDS) of cross-linked starches varied from 46.1% to 50.6%, cv.GHB-732 had the lowest value. Slowly digestible starch (SDS) and resistant starch (RS) content of cross-linked starches ranged from 34.5% to 36.4% and 13.6% to 19.4%, respectively. cv.HC-10 had the highest value for SDS content while the highest RS content was observed for cv.GHB-732. In comparison to native starches, cross-linked modification decreased SDS and RDS content whereas RS content was increased.

Online Research on Plasticizing Process of Starch Under Superimposed Vibration Field

ABSTRACTA novel testing machine, integrating plastic vibration processing with molding, based on a multipass rheometer, was used to investigate the effect of the complex force field on plasticization of taro and wheat thermoplastic starch (TPS) melts. Various kinds of continuous vibration fields could be tested by controlling the movement of pistons. A superimposed vibration field, combining the effects of vibration and shear, was obtained by adding a high-frequency low-amplitude oscillation on a low-frequency high-amplitude oscillation. The rheological properties of starch were directly monitored during and after the plasticization process without removing the starch melts out of the testing machine. The apparent viscosity of the TPS melts were obtained for different high-frequency oscillation conditions by monitoring the pressure difference in the cavity. The plasticization preparation time was used to characterize the benefit provided by the superimposed vibration field. The results showed the decrease of the percentage of the average plasticizing preparation time for taro starch was 3.4%, while that for wheat starch was 1.6% compared to single, low-frequency, high-amplitude oscillation. Comparison of the plasticizing preparation time under different vibration frequencies showed that the plasticization was promoted by applying the superposed vibration field, and the effective degree was related to the vibration frequency and starch type. Both TPS exhibited shear-thinning behavior after the plasticization, and samples of both types of starch which were plasticized under higher vibration frequency presented lower apparent viscosities at certain shear rates.

Effect of frying on the pasting and rheological properties of normal maize starch

Normal maize starch (NMS) with various water content was subjected to high temperature in the oil phase to mimic the frying process. The structure and physicochemical properties of the fried starchy samples were investigated. Frying induced the reduction in the swelling power, solubility, the amount of leached amylose, and the molecular weight of starch. Rapid visco-analysis (RVA) revealed the partial gelatinization and limited swelling of starch granules after frying treatment. The effect of frying on the pasting properties of starch was dependent on the water content. Creep curves were fitted with the Burgers model and results showed that the fried samples exhibited higher values of instantaneous creep compliance (J0) and viscoelastic creep compliance (Jm), whereas lower values of zero-shear viscosity (η0) as compared with those of native NMS. The low storage modulus (G′) and low loss modulus (G″) form dynamic viscoelasticity measurements indicated that the fried starch pastes exhibited viscoelastic properties that are inferior to those of native NMS paste. Flow state tests showed that fried starch pastes were less thixotropic than was native NMS. Present work confirmed the inhibitory effect of frying on starch granule swelling and starch molecules leaching. The formation of gelatinization layer near the surface of starch granules and the possible molecular degradation during frying were hypothesized to be responsible for the alterations of the pasting and rheological properties of starch.

Investigation of rheological properties and conformation of cassava starch in zinc chloride solution

Zinc chloride aqueous solution is a non-derivatizing solvent for starch, and can be used as a media for homogeneous starch modification. Here, the rheological properties of starch in ZnCl aqueous solution under different conditions are considered. Specifically, a large number (120) of viscosity–shear-rate curves for starch–ZnCl solutions with different starch contents, ZnCl concentrations, and temperatures were obtained and modeled using a master curve method. In particular, the power-law index (n) from the modeling could accurately classify the starch molecules in ZnCl aqueous solutions into an insoluble state, a dilute state, a semi-dilute state, and a sticky state, reflecting the different degrees of chain interactions in the solution. In particular, the sticky state would be mostly likely be controlled by the zinc–starch complex, which made the rheological behavior entirely different from that at low ZnCl concentrations. The knowledge obtained from this study can be used to guide the homogeneous modification of starch and the fabrication of starch-based materials using green solvents such as aqueous ZnCl with desired properties.

Preparation and rheological properties of starch- g -poly(butyl acrylate) catalyzed by horseradish peroxidase

This work was financially supported by the National NaturalScience Foundation of China (21674043, 31401647), the Pro-gram for Changjiang Scholars and Innovative Research Team inUniversity (IRT-15R26), the Creative Fund of the Cooperationof Industry, Education and Academy of Jiangsu Province, China(BY2014023-05) and Fundamental Research Funds for the CentralUniversities(JUSRP51717A).

Morphological, Thermal, and Rheological Properties of Starches from Maize Mutants Deficient in Starch Synthase III.

Morphological, thermal, and rheological properties of starches from maize mutants deficient in starch synthase III (SSIII) with a common genetic background (W64A) were studied and compared with the wild type. SSIII deficiency reduced granule size of the starches from 16.7 to ∼11 μm (volume-weighted mean). Thermal analysis showed that SSIII deficiency decreased the enthalpy change of starch during gelatinization. Steady shear analysis showed that SSIII deficiency decreased the consistency coefficient and yield stress during steady shearing, whereas additional deficiency in granule-bound starch synthase (GBSS) increased these values. Dynamic oscillatory analysis showed that SSIII deficiency decreased G' at 90 °C during heating and increased it when the paste was cooled to 25 °C at 40 Hz during a frequency sweep. Additional GBSS deficiency further decreased the G'. Structural and compositional bases responsible for these changes in physical properties of the starches are discussed. This study highlighted the relationship between SSIII and some physicochemical properties of maize starch.

Physicochemical and rheological characterization of Andean tuber starches: Potato (Solanum tuberosum ssp. Andigenum), Oca (Oxalis tuberosa Molina) and Papalisa (Ullucus tuberosus Caldas)

The physicochemical and rheological properties of starches from four land races of Andean potato (Cuarentona, Rosadita, Imilla, and Waycha), and Oca and Papalisa tubers were investigated and compared against conventional potato starch. Proximate composition studies showed that the protein content in the studied starches varied between 0.29 and 1.18% w/w, the ash content between 0.24 and 1.14% w/w, and the lipid content between 0.14 and 0.34% w/w. Scanning electron microscopy investigations showed differences in shape of the granules of Andean potatoes and Oca and Papalisa. The mean size D[4,3] of the granules ranged between 23.3 and 48.11 µm. Papalisa was the starch with the lowest AM content (20.4%, w/w) and Rosadita had the greatest (28.03%, w/w). The gelatinization enthalpy ranged from 18.7 to 14.8 J/g and the gelatinization temperature between 65.5 and 60.8°C. Viscograms of starch pastes showed that Cuarentona was the sample with the greatest peak viscosity (3152 cP) and presented the greatest final viscosity (3222 cP). The Andean potato and tuber starches exhibited low breakdown values. The relationship between the physicochemical and rheological properties was analyzed by principal component analysis (PCA). The results indicated that Oca and Papalisa starches were different from the Andean potato starches. Cuarentona starch showed the greatest consistency coefficient (Pa · s−n) (K), storage modulus (Pa) (G′), peak viscosity, final viscosity, and Oca starch the lowest ones. The protein content affected the peak viscosity and setback of the samples. The results suggest that these starches have similar properties to those of conventional potato starch.

Effect of ultrasonic treatment on the morphological, physicochemical, functional, and rheological properties of starches with different granule size

Effect of ultrasonic treatment on the morphological, physicochemical, functional, and rheological properties of starches with different granule size

Physicochemical and rheological properties of starch and flour from different durum wheat varieties and their relationships with noodle quality.

Starch and flour properties of different Indian durum wheat varieties were evaluated and related to noodle-making properties. Flours were evaluated for pasting properties, protein characteristics (extractable as well as unextractable monomeric and polymeric proteins) and dough rheology (farinographic properties), while starches were evaluated for granule size, thermal, pasting, and rheological properties. Flour peak and final viscosities related negatively to the proportion of monomeric proteins but positively to that of polymeric proteins whereas opposite relations were observed for dough rheological properties (dough-development time and stability). Starches from varieties with higher proportion of large granules showed the presence of less stable amylose-lipids and had more swelling power, peak viscosity and breakdown viscosity than those with greater proportion of small granules. Noodle-cooking time related positively to the proportion of monomeric proteins and starch gelatinization temperatures but negatively to that of polymeric proteins and amylose content. Varieties with more proteins resulted in firmer noodles. Noodle-cohesiveness related positively to the proportion of polymeric proteins and amylose-lipids complexes whereas springiness correlated negatively to amylose content and retrogradation tendency of starches.

Structural characteristics and rheological properties of plasma-treated starch

Abstract Corn starch was treated by a dielectric barrier discharge plasma, and the changes in the granule morphology, crystalline structure, and molecular structure, as well as the rheological properties, were investigated using diverse techniques. Dielectric barrier discharge plasma could change not only the granule surface but also the internal structures of the starch granule through its pinholes. Specifically, after the plasma treatment, as the pinhole diameter increased, the relative degree of crystallinity decreased, accompanied by molecular chain oxidation, i.e., the generation of carboxyl groups, and degradation, i.e., molecular weight reduction. Therefore, the rheological behavior changed from pseudo-plastic to Newtonian with a decrease in the paste viscosity. The results indicate that dielectric barrier plasma could be used to produce modified starch with low viscosity at a high concentration for food and non-food applications. Industrial relevance As an eco-friendly and non-thermal physical technique, dielectric barrier discharge plasma has attracted great attention in polymer modification due to the interest in reducing generated wastes during modification and producing polymer products with high safety. Starch is traditionally a main material for foods and has been widely used in food and non-food industries. For improving the properties of starch and thus widening its industrial applications using a specific technique, it is indispensible to understand how the technique affects starch's structure and property. The present work revealed that not only was the surface of starch granules altered by the dielectric barrier discharge plasma but also the internal structure was affected, since the pinholes promoted the penetration of the plasma into granule interior. In particular, along with a reduced degree of crystallinity, molecular chain oxidation and degradation occurred, as confirmed by the generation of carboxyl groups and the molecular weight reduction. Then, the rheological behavior of starch paste changed from pseudo-plastic to non-Newtonian, together with a decreased paste viscosity. These results have demonstrated that dielectric barrier discharge plasma could be used as a new physical method to modulate the structure and rheological properties of starch, for the production of starchy food products with relatively low viscosity at a high concentration.