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The object of research is the technologies for the production of puree soups using modified starches of the «Gelamil» series. One of the main requirements for the quality of the technology of puree soups is the creation of a fluid, uniform, finely ground texture, which plays a special role in the organoleptic characteristics of this type of product. The texture of the product can be adjusted by adding liquid boiling modified starches. Starches of the «Gelamil» series are represented by potato starch with a reduced viscosity and are characterized as air-flowing gelling potato starch, that is, starch, the solution of which gives a low viscosity at high temperatures, and when solidified – a dense gel. Hydrodynamic changes in the parameters of starch paste based on starches of the «Gelamil» series, depending on the temperature and type of starch, have been established. It was determined that starch paste based on starches of the «Gelamil» series, in comparison with native potato starch, have a low temperature of maximum viscosity from 47±2°C to 57±2°C, and thus form a paste with a viscous-flowing texture. The effective viscosity of starch paste was investigated depending on the starch content. It has been experimentally established that regulation of the starch content makes it possible to create starch paste according to different textural properties. For viscous-thinned dispersions, the starch concentration is from 1.0 to 3.0%. For viscous-flowing dispersions having a long texture, the starch concentration is 3.5 to 5.0%. For viscous-flowing dispersions having a short texture, the starch concentration is 5.5 to 7.0%. For the content of native potato starch in the system of more than 5.0%, a dense paste with a short texture is formed. It was found that for a starch paste based on starches of the «Gelamil» series, the separation of the liquid phase occurs due to 2:00 in an insignificant amount. A lot of components and model systems based on vegetable, legume purees and starch paste have been investigated. It has been determined that, depending on the type of vegetable and legume raw materials, the use of starches of the «Gelamil» series of different types and concentrations depends.

Gelatinized starch paste was prepared by gelatinizing rice starch at 95 °C in a water bath. Then, the rice starch (both normal rice starch and waxy rice starch) paste was subjected to high-pressure homogenization at homogenizing pressure of 20, 40, 60, 80 MPa. The rheological properties (including shear stress versus shear rate, apparent viscosity versus shear rate and thixotropy) of starch paste were studied. The high-pressure homogenization was able to improve the flow properties of starch paste. The shear stress increased with the increasing shear rate, and the Power law equation was capable of fitting the shear stress versus shear rate quite precisely. High-pressure homogenization treatment sharply decreased the thixotropy of starch paste, and the thixotropy of rice starch (both NRS and WRS) paste decreased with the increasing homogenous pressure.

Understanding how starch constituent in frozen dough affected bread quality would be valuable for contributing to the frozen products with better quality. To elucidate the underlying mechanism, starch was fractionated from multiple freezing-thawing (F/T) treated dough and reconstituted with gluten. Results showed that F/T treatment destructed the molecular and supramolecular structures of starch, which were more severe as the F/T cycle increasing. These structural disorganizations made water molecules easier to permeate into the interior of starch granules and form hydrogen bonds with starch molecular chains, which elevated the peak, breakdown, setback and final viscosity of starch paste. In addition, F/T treatment resulted in decreased specific volume (from 1.54 to 0.90 × 103 m3/Kg) and increased hardness (from 42.98 to 52.31 N) for steamed bread. We propose the strengthened water absorption ability and accelerated intra- and inter-molecular rearrangement of starch molecules and weak stability of “starch-gluten matrices” would allow interpreting deteriorated bread quality.

Fil: Trela, Valeria Daiana. Universidad Nacional de Misiones. Instituto de Materiales de Misiones; Argentina. Fil: Trela, Valeria Daiana. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Materiales de Misiones; Argentina. Fil: Trela, Valeria Daiana. Universidad Nacional de Misiones. Facultad de Ciencias Exactas, Químicas y Naturales; Argentina. Fil: Ramallo, Ana Laura. Universidad Nacional de Misiones. Instituto de Materiales de Misiones; Argentina. Fil: Ramallo, Ana Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Materiales de Misiones; Argentina. Fil: Ramallo, Ana Laura. Universidad Nacional de Misiones. Facultad de Ciencias Exactas, Químicas y Naturales; Argentina. Fil: Albani, Oscar Alfredo. Universidad Nacional de Misiones. Instituto de Materiales de Misiones; Argentina. Fil: Albani, Oscar Alfredo. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Materiales de Misiones; Argentina. Fil: Albani, Oscar Alfredo. Universidad Nacional de Misiones. Facultad de Ciencias Exactas, Químicas y Naturales; Argentina. Acetylated cassava starch with low and medium degrees of substitution (DS) were synthesized. Also, the effect of DS on swelling power, solubility, morphological properties, gelatinization temperature, paste clarity and moisture sorption were studied. Swelling power and solubility in water between 50oC and 90°C were determined. Acetylated cassava starches with low DS showed an increased in both parameters, while at higher DS values a reduction of them was observed. Maximum swelling power values were measured in acetylated starch with DS of 0.2 and maximum solubility was registered at DS of 0.72. Equilibrium moisture content values from sorption isotherms presented a good fit using the GAB model (R2>0.96). SEM micrographs showed that as acetyl groups are incorporated the granules suffer surface changes and eventually lose their structure at DS of 1.5. Clarity of acetylated starch pastes with low DS was lighter than native starch paste. In addition, the increase in DS produced a reduction in gelatinization temperature.

In recent times, the use of natural and harmless products for the environment and restorer is taking place in the field of Cultural Heritage restoration. In this sense, wheat, rice and corn starches as adhesives, have suitable characteristics without toxicity risks. A new starch in this field, is the Kudzu, an almost pure compound (99.5% starch) that is processed by a natural way from a plant called Pueraria lobata. This is a preliminary study of the potential use of Kudzu starch for the restoration of Cultural Heritage, focusing, firstly, in its capacity as adhesive through a comparative evaluation with common starches. The accelerated aging process carried out proved that Kudzu ensures optimal chromatic behaviour. On the other hand, the main problem in starch paste is the biological colonization. The daidzein, a natural antimicrobial compound implicit in Kudzu starch, confirmed the resistance to microorganism in this preliminary approach. The evaluation of the adhesive capacity, and the reversibility of the starches, suggest that Kudzu starch is a valid adhesive in the field of paper restoration. Thus, the potential of this starch in the conservation of Cultural Heritage is evidenced and its use as cleaner, resistance to biological colonization and consolidant is promising. This work has been supported by the MADyLIN project (Grant No. BIA2017-87063-P) funded by the Spanish Agency for Research AEI (MINEICO/FEDER-UE). The author wishes to acknowledge professional support of the Interdisciplinary Thematic Platform from CSIC Open Heritage: Research and Society (PTI-PAIS). Technical and human support provided Macroconduct, Mesostructure and Nanotechnology by SGIker (UPV/EHU, MICINN, GV/EJ, ERDF and ESF) are also gratefully acknowledged

Native starch is an important raw material used in the industry. Rheological, pasting, and textural properties of starch are the major functional properties to determine its applications. Key rheological properties of starch include rheology of starch during heating, viscosity of starch paste, and rheological features of starch gel. The pasting properties of starch are commonly quantified by measuring changes in viscosity during the heating and cooling of starch dispersions. The textural characteristics of starch gels have an important role in the classification of sensory and quality of foods. In this this chapter, the rheological, pasting, and textural properties of starch from different botanical sources are compared, and the impacts of other ingredients (sugars, salts and lipids) on the properties are summarized. The relationship of starch functionalities with food quality is also summarized. The information provided will be useful for the applications of starch in the industry.

When a starch paste stretches and breaks during dropping under gravity, the length of fully stretched paste drop is considered as an important flowing characteristic of starch. The length of paste drop (LPD) often determines eating quality of the starch-containing foods. The relationship between pasting parameters measured using a rapid visco-analyzer and LPD of various starches from different botanical sources was investigated at different starch concentrations (50, 70 & 90 g/kg). Starch content in the paste mainly affected the single pasting parameters (p

Pongamia pinnata seed (PPS) starch was studied for its physicochemical, thermal, rheological and morphological properties. As PPS starch is a novel starch, it was compared with corn, mung bean, potato, pearl millet and mango kernel starches. Peak, trough and final viscosity of PPS starch was found the lowest as compared to other starches. Plots of shear stress versus shear rate for starch pastes were plotted and fitted to Herschel-Bulkley model. Yield stress and consistency index value of starch pastes varied between 6.5 and 58.9 Pa and 1.4–10.6 Pa s, respectively. During frequency sweep testing, G′ and G′′ values of starch pastes varied between 33 and 484 Pa and 18–71 Pa, PPS starch paste had the lowest values. Transition temperatures (Tο, Tp, Tc) for PPS starch was 61.5, 72.1 and 82.9 °C, respectively. Scanning electron microscopy of PPS starch showed small to large and round to oval shape starch granules with small pitches on their surface.

We present a methodology to predict the storage modulus ( G ’ ) of starch paste due to granule swelling, given the physical properties of the starch granule and temperature history. This was tested on experimental measurements of granule size distribution and G ’ for 8% w/w suspensions of waxy maize, normal maize, waxy rice, normal rice, and cross linked normal maize – all heated to different temperatures (65–90 °C) with holding times between 2 and 60 min. Experimental data of storage modulus G ′ vs volume fraction φ fall onto a master curve when G ′ is normalized by a multiple of γ / R ‾ , where γ is the granule-solvent interfacial energy, and R ‾ is the average granule size. We show that one can combine this master curve with starch swelling theories to forecast the time-dependent rheology of starches. This work also demonstrates that granule-solvent interfacial energy is a key physical parameter in controlling starch rheology.

In this study, we aimed to examine the effects of different low concentrations of alcohol solution (5%–20%) on the gelatinization and pasting properties of pea starch. A rapid visco analyzer revealed that when the starch concentration was fixed, the viscosity of the starch paste decreased with increasing alcohol concentration. In addition, the texture analyzer results showed that compared to the hydrogel formed in water, the hardness of the gel formed by 15% starch in 10% alcohol increased approximately 2-fold (1696.4 g versus 928.1 g). Furthermore, the rheological results showed that the tan δ value of the gel formed under this condition was second only to that of 20% starch in water, which indicated the gel had a strong network structure. X-ray diffraction analysis showed an increased relative crystallinity of 15% starch gels formed in 10% alcohol (13.2%) compared to the hydrogel formed in water (12.2%). Our study will expand the knowledge of the gelatinization properties of starch in low concentrations of alcohol.

Materials used in this research were residual oat flour and starch isolated from it, and wheat flour and starch were used as reference. Pasting temperature of the starch present in flour or isolated starch increased with increasing syrup concentration, depending on material and syrup concentration. The maximum values of oat flour and starch paste viscosity were achieved at 30–40% syrup concentration, and at 50% for wheat pastes. Oat flour and starch pastes were pseudoplastic shear thinning fluids. In presence of syrup they revealed lesser deviation from Newtonian properties. Mechanical spectrum analysis of oat flour and starch pastes revealed stronger elastic than viscous properties. The hardness of flour gels prepared in syrup was higher than aqueous ones, and was increasing with increasing syrup concentration. It was stable during 7 days of storage. Adhesiveness of oat flour gels with syrup were lower than aqueous ones, reverse situation was observed for wheat flour gels. During storage, oat gels showed an increase of adhesiveness, in contrast to wheat gels, that were characterized by only initial increase of adhesiveness.

Selected physicochemical properties of native and modified water chestnut starch (Trapabispinosa) were studied. Single- and dual-modifications were carried out by pregelatinization, acetylation and acid-thinning methods. Chemical modification created unevenness on the surface of starch granule. Swelling power, solubility, and water retention capacity were improved by all modification techniques used. The peak viscosity was reduced in all modified starches as compared to native water chestnut starch. The setback value which is an indication of retrogradation (re-association of starch molecules) tendency in the starch paste was reduced after pregelatinization and acid-thinning but increased by acetylation.

Improving the stickiness of non-glutinous rice is an important strategy in scaling out the applications of rice foods, e.g. Sushi, Zongzi etc. In this study, the effect of HPH treatments on the transparency and molecular structure of starch and the stickiness of cooked non-glutinous rice were investigated by cooking rice with high-pressure homogenization (HPH) thinned starch paste. HPH treatments significantly increased the light transmittance of starch paste from 7.6% to 81.3% (p

This study aimed at exploring the effects of exogenous seed crystals on the starch recrystallization. A-type and B-type seed crystals from rice starch were added to rice starch paste during cooling to analyze the changes in retrogradation process. DSC results indicated that B-type seed improved the uniformity of crystal size and the degree of crystal perfection; it also affected the nucleation mode of retrograded starches at 4 °C, while A-type seed did not affect these properties. The XRD showed that the unit cell was compact, and the crystal grain became larger upon the introduction of B-type seed, while A-type seemed to loosen the cell. The SAXS reflected that B-type seed increased the thickness of the imperfect lamellar structure formed during recrystallization, while A-type seed decreased it. These findings might be due to the molecular segment arrangement on the nuclei growth surface affecting the arrangement of starch molecular segments approaching the nuclei.

The novel hyperbranched poly(trimellitic glyceride) (PTG) starch plasticizer synthesized in our previous study was neutralized with different alkaline metal hydroxides. Mixed with starch, the effects of different alkaline metal cations, M+, on gelatinization of starch suspensions and thermal behaviors of the films were analyzed using RVA and DMA, respectively. The structures of the starch suspensions, films and freeze-dried samples (S/PTG-M) were investigated using DSC, XRD and FTIR spectroscopy, respectively. M+ increased the gelatinization temperature of starch suspensions in the order of S/PTG-Li > S/PTG-Na > S/PTG-K. The formation of a complex between M+ and starch in the films observed using FTIR spectroscopy improved the stability of the starch paste and gel, and increased the gel temperature of starch dispersions. The corresponding starch gel was relatively thermostable, but not shear-resistant. PTG decreased the Tg of starch films with different paired M+. PTG-Li and PTG-K, but not PTG-Na, strengthened the mechanical properties of starch films.

Wheat with a low falling number (FN) has been particularly prevalent in recent years and has resulted in a loss of more than $140 million in a single year in the wheat industry in the Pacific Northwest of the United States. FN measurement is a standard method for the evaluation of grain α-amylase activity, and a low FN indicates a reduction in hot wholemeal paste viscosity due to sprouting damage. Recent studies show that a low FN may result from a developmental change of starch and adverse effects of non-α-amylase macromolecules on wheat. In this review, we describe the principles of FN measurement and the relationship between FN and α-amylase. We also discuss the isozymes, locations, and inhibitors of wheat α-amylase. The effects of various aspects of starch, which is the substrate of α-amylase, on wheat FN are also discussed, including starch structural characteristics (for example, starch granule architecture), starch susceptibility to α-amylase, and the interaction between starch and nonstarch macromolecules (for example, lipids). Studies on the effects of planting environments (for example, temperature) and agronomic practices (for example, irrigation and fertilization) on both starch paste viscosity and FN are also reviewed. This paper highlights the importance of considering the impacts of starch and the interactions of starch and other macromolecules, including wheat α-amylase, on wheat FN, which is important for developing strategies to solve the low FN problem.

The oldest use of enzymes in the pulp and paper industry is in the modification of starches for surface sizing and coating. This practice dates back to the early 1970s and is now carried out more frequently within the paper mills. Starch imparts many beneficial properties to paper, including strength, stiffness, and erasability. Properly controlled enzymatic modification of starch provides the papermaker ample opportunities to get uniform quality of starch paste, to produce starch paste as per requirement, and to produce quality surface sized papers with the minimum cost of the starch component. Starch modified with alpha-amylase enzyme meets almost all the properties required for surface sizing of writing and printing grades of paper. It does not require much capital investment to switch over from oxidized starch to in situ modification of native starch with enzyme. The process of enzyme modification is applicable to different types of starches although the operating conditions in terms of enzyme dose and reaction time may vary. Enzyme-modified starch is available from starch producers or can be produced on-site at the paper mill using a batch or continuous process.

Starch retrogradation is a process in which disaggregated amylose and amylopectin chains in a gelatinized starch paste reassociate to form more ordered structures. Starch retrogradation has been the subject of intensive research over the last 50 years, mainly due to its detrimental effect on the sensory and storage qualities of many starchy foods. However, starch retrogadation is desirable for some starchy food products in terms of textural and nutritional properties. To better understand the effect of starch retrogradation on the quality of starchy foods, measurement methods of starch retrogradation and factors that influence starch retrogradation have been studied extensively. This article provides a comprehensive review of starch retrogradation including the definition of the process, molecular mechanisms of how it occurs, and measurement methods and factors that influence starch retrogradation. The review also discusses the effect of retrogradation on the in vitro enzyme digestibility of starch. Spectroscopic methods such as FTIR and Raman are considered to be very promising in characterizing starch retrogradation at a molecular level, although more studies are needed in the future.

Native and modified starches are important raw materials used in the industry. Gelatinization and rheological properties of starch are primary physicochemical properties to determine its applications. Starch gelatinization refers to a process that starch loses the native order and crystalline structure of the granules and becomes amorphous. Key rheological properties of starch include pasting property, viscosity of starch paste, and rheological features of starch gel. In this review, gelatinization and rheological properties of native starches from different botanical sources are compared and impacts of other ingredients, including sugars, salts, and lipids, on the properties are summarized. The review also covers current understandings of the gelatinization and rheological properties of modified starches with different structures. The information provided will be useful for the applications of starch in the industry as well as fundamental research in this field.

Cooked paste of smoked-dried flour of retted cassava is the staple food of million people in West and Central Africa. The present study investigates the dynamics of combined smoking and drying on some physicochemical and functional properties of the flour and its derived starch. Fresh cassava tubers (variety 4115) were trimmed, retted, wrung, crushed, put into balls and then dried using three processes: traditional combined smoking and drying, electrical combined smoking and drying, and oven-drying. The drying processes did not significantly modify (p > 0.05) the proximate composition of samples neither their drying rates (0.19 h−1

BACKGROUND Functional properties of wheat starches with different particle size distribution were investigated. RESULTS A-granules displayed a disc shape and B-granules displayed a spherical shape. A-granules had the highest conclusion temperature (Tc, 80.28 °C) and gelatinisation enthalpy (3.268 J g−1) and B-granules had the highest peak temperature (Tp, 66.00 °C) and the lowest gelatinisation enthalpy (2.237 J g−1). The gelatinisation onset temperature (To), the peak temperature (Tp), Tc and retrogradation of mixed starches increased with the increase of the ratio of B-granules, while the enthalpy, all the viscosity parameters and syneresis of mixed starches decreased with the increase of the ratio of B granules. B-granules had a higher pasting temperature. The sample of B/A = 0.5/10 had the highest peak, breakdown and final viscosity. The percentage of water separated from B-granule gels was minimal, indicated that B-type gels were more stable than other samples. The ΔH2 of A-granules was obviously higher than that of B-granules. However, during storage, the ΔH2 of the starch paste was dramatically increased and the ΔH2 of B-granules was obviously higher than that of A-granules. CONCLUSION B-granules were easier to age than A-granules and most of the properties of wheat starches varied significantly with the ratio of B-granules. The relationship between structure and functionality of wheat starch received further verification. © 2013 Society of Chemical Industry

The objectives of this work were to determine the gelatinization temperature of jackfruit starch and to compare the effect of pH on the viscosity and density of different botanical sources of starch pastes. The study was conducted according to a three × four factorial design with three repetitions, being three levels for the starch paste (jackfruit seed, corn and cassava) and four levels for pH (3.4; 4.4; 5.4 and 7.0). The results showed a gelatinization temperature (GT) of jackfruit seed starch ranging from 75 to 80 °C, superior to GT range of common starch sources. Density of all starch pastes increased with pH. The effect of the kind of starch was not significant (P > 0.05). Viscosity of corn and cassava starch pastes varied with pH according to quadratic models. The viscosity of seed starch paste from jackfruit did not significantly vary with pH, indicating acid resistance.

Cassava starch is used as the main ingredient in the production of biscuits and Brazilian cheese bread. The processing and sale of sour cassava starch - an artisanal product with no established standard of quality - is marked by hygiene problems and its commercial availability is uncertain. The purpose of this study was to characterize native and modified cassava starches and test them in cheese bread and cassava starch biscuit recipes. The main characteristics that differentiate sour starch from native cassava starch are its acidity, degree of expansion, viscosity, clarity of the starch paste, freeze-thaw stability and reducing power. Four different starches were used in the production of baked products: native cassava starch, sour cassava starch, starch modified with hydrogen peroxide and a commercial modified starch named Expandex® 160003. The baked products were evaluated to determine their physicochemical properties and to assess how the different starches affected the products’ internal and external characteristics and flavor. The baked samples were subjected to a sensory analysis of acceptability on a nine-point hedonic scale by untrained tasters. The cheese bread samples containing modified starch oxidized with hydrogen peroxide showed the best results. In the case of the cassava starch biscuits, those made with sour cassava starch and Expandex® 160003 showed the best results, which did not differ statistically.

An attempt on starch modification has been made to increase the paste concentration of potato starch for reducing the energy consumption required for the encapsulation of herbicide within starch matrix by encapsulating 2, 4-D as model herbicide. The matrix behaviors were evaluated in terms of the herbicide content, capability of swelling in water, encapsulation efficiency, and the rate of herbicide released from the matrix. To increase paste concentration of starch for decreasing the energy consumption in dry process, potato starch was acidified before the encapsulation. However, the matrix prepared in such a way showed that it weakened the control to the herbicide encapsulated, which increased the rate of herbicide released from the matrix. By introducing covalent bonds among starch molecules, the problem with the control and release rate can be completely solved. Moreover, the effects of formaldehyde amount, medium pH, herbicide content, and particle size on the matrix behaviors and release rate were also investigated. The newly developed matrix shows low capability of swelling and slow release, and reduces water evaporation in dry process by about 40% during matrix preparation.

This study was designed to investigate the effect of a thermostable α-glucanotransferase (TSαGT) originated from Thermus scotoductus on the rheological properties, molecular weight distribution, thermo-reversibility, and freeze-thaw stability of rice starch paste. Rice starch paste samples (5%) were incubated at 70 °C with TSαGT and a commercial α-amylase, respectively, until reduction of moduli leveled off. The TSαGT-modified rice starch paste showed a yield stress. After the enzymatic treatment, both enzyme-treated pastes showed considerably low moduli with higher G ″ than G ′, indicating a significant liquefaction. However, when stored at 4 °C, both moduli of a TSαGT-treated sample dramatically increased with significantly higher G ′ than G ″, confirming that a solid gel structure formed. This transition was found to be reversible, when temperature fluctuated between 70 and 4 °C. The control starch gel did not show thermo-reversibility, and α-amylase-treated starch paste was incapable of forming a solid gel. The size distribution of the starch polymers, as measured by MALLS, revealed that average M w reduced to about 5×10 5 after the TSαGT treatment, which was a significant decrease, but possibly high enough to form a solid gel matrix at low temperatures. The TsαGT-treated gel demonstrated highly improved freeze-thaw stability.

Swelling and pasting properties of 15 starches from different plant origins were studied to elucidate their relationship with structural features using simple and multiple regression analyses. Avoidance of additional effects of starch minor components showed that swelling power and pasting parameters were associated with the ratio of the relative molar distribution of amylopectin branch-chains with a degree of polymerization (DP) of 6–12 to that of chains with DP 6–24 (amylopectin unit-chain (APC) ratio). Swelling power of starch granules increased with APC ratio. Multiple regression analysis revealed that the peak viscosity (PkV) of starch paste increased with low APC ratio, low amylose content (AC) and large average granule size (AGS). At a high starch concentration, pasting temperature (PT) was reduced by a high APC ratio and large AGS. Peak time (PkT) decreased with increasing APC ratio and AC. Percentage of breakdown viscosity (BD%) and setback viscosity (SB) were primarily affected by APC ratio. At a low concentration, AC and AGS had more profound effects on BD%. SB was also reduced by higher AC. Models of pasting profile, which is influenced by individual factors, were also proposed.

A model for dough is proposed in which the distribution of water between hydrated gluten and starch paste explains a number of practical observations such as 1) the extreme sensitivity of the consistency of dough to the amount of water in the recipe, and 2) the fact that working of the material results in an increase in consistency. The model assumes dough to be a composite material consisting of a starch paste and gluten filaments. During kneading, the starch granule paste in dough dries to become a phase with a yield stress as a result of the uptake of water by the stretching gluten filaments. This study focused on one particular aspect of this model: the osmotic properties of gluten during stretching. The results suggest that gluten can be hydrated more efficiently in the stretched state than in an unstretched conformation. Gluten hydration tends to change slowly over a period of weeks, which is accompanied by water expulsion or uptake, depending on the osmotic properties of the solvent. The r...

The usefulness of (CT) n microsatellite markers of Wx gene in rice starch quality improvement is demonstrated in this paper with 36 F 2 plants derived from the cross between Longtefu A (Wx 1 1 Wx 1 1 ) and 371 (Wx 1 8 Wx 1 8 ). The F 2 plants could be divided into three groups according to the microsatellite marker, i.e. that of Wx 1 1 Wx 1 1 group, Wx 1 1 Wx 1 8 group and Wx 1 8 Wx 1 8 group. The F 3 seeds with the same Wx alleles were bulked to test the starch quality parameters which implied that only the Wx allele was different among the bulked samples while the genetic background was identical. Results indicated that all the starch quality parameters including amylose content (AC), gelatinization temperature (GT), gel consistency (GC) and starch paste viscosity parameters were related significantly to the Wx alleles. However, the amylopectin structure of each group had no relation to the Wx allele. This study indicated that early selections in rice breeding based on Wx microsatellite marker would improve the starch quality.

Ten rice starches with a fairly narrow range of amylose content, but wide variation in RVA pasting curves, were selected to study a possible relationship between amylopectin fine structure and RVA paste viscosity parameters. Amylopectin fine structure was found to significantly correlate with paste breakdown. Proportion of long chains of amylopectin (FrI) was negatively correlated (r=0·84, p

The mechanical behavior of cowpea starch gels (10%, w/v) at small and large deformations were investigated in comparison with acorn, corn, and potato starches in storage at 4°C for seven days. The rapid viscograms of starch paste (7%, w/v) revealed that cowpea starch had a larger setback (1,135 cP) than other starches (465–830 cP), although peak viscosity (1,723 cP) and pasting temperature (76°C) were between those of corn and potato starches. Texture profile analysis of cowpea starch gel showed exceptionally higher values for hardness, gumminess, chewiness and initial modulus than other starch gels. Cowpea starch gel also exhibited higher G′ and smaller tan δ compared with other starch gels, regardless of the storage time. A creep test revealed that the cowpea starch gel could remain highly resistant to stress, showing the least deformation among the tested starch gels during storage up to seven days. The overall results disclosed that cowpea starch was capable of forming exceptionally strong an...

Heat-Moisture-Treatment (HMT) was originated by V.L. Sair in 1944. It is a very interesting method to modify the structures and functions of starches. HMT is carried out by heating starch at 100-125°C under 100% relative humidity. Recently, much attention has been paid to HMT as a suitable method for modifying starch instead of chemical methods, from the viewpoint of health for uses for foods. However, it was not possible to produce commercially, because of difficulty in ob-taining a uniform product by partial gelatinization. We have solved this problem by introducing a new device suitable for both laboratory and industrial uses. The device consists of a combination of vacuum evacuation of a vessel containing starch and subsequent heating of the starch by introduc-ing live steam. This device provides a good uniform product in shorter time than conventional methods. We called it "reduced-pressurized heat-moisture treatment." Using this treatment (USP 5362329 (1994)), HMT has been recognized as one of the useful means of modifying starch, espe-cially for food uses. Heat-Moisture-Treated Starch (HMTS) swells but retains granular shape with-out dissolving by heating above 100°C in the presence of water. HMT increases the stability for acid and mechanical agitation in pasting. HMT increases hydrophiricity and decreases hydrophobic-ity of starch granules. On the contrary, HMT decreases hydrophiricity and increases hydrophobicity of starch paste. HMTS appears to be a suitable material for the production of retort foods, dress-ings, noodles, baked foods, batter products, confections, dairy products, creams, fat minetics and resistant starches.

Alternative sources from different botanical origin were used for starch isolation. Chemical analysis and functional properties were studied in amaranth seed and banana fruit starches. Chemical composition in both starches was different; banana starch presented higher protein, fat and ash levels than that from amaranth. Botanical origin of these starches contributes notably in their chemical composition. Blue value and λmax gave information on starch components: amaranth starch is classified as waxy type and banana starch as normal. Functional properties were evaluated; amaranth starch was more soluble than banana starch, but at higher temperatures amaranth showed lower swelling values than banana starch. The results of freeze-thaw stability suggest that amaranth starch can be used in frozen products. Apparent viscosity studies showed that amaranth starch paste has higher viscosity than banana starch, but the former starch presented higher stability during the 30-min test.

Triticum turgidum var. polonicum has been one of the primitive wheats for traditional agriculture. It is the genetic resource of several traits, such as earliness, long vitreous kernels and tolerance to high temperature during grain-filling period to improve durum wheat cultivars. T. polonicum is characterized by a long, empty outer glume controlled by P gene, which is located on chromosome 7A. The aim of this study was to assess the effect of P gene on the starch pasting properties of tetraploid and hexaploid wheat using near-isogenic lines. It was confirmed that P gene strikingly contributed to increase starch pasting properties. If it was widely confirmed that T. polonicum carries the gene to modifying starch paste viscosity, this species would be one of the potential genetic resource to develop improved cultivars.

High pressure processing is a promising non-thermal technology for the development of fresh-like, shelf-stable foods. The effect of high pressure on starch has been explored by many researchers using a wide range of techniques. In general, heat and pressure have similar effects: if sufficiently high, they both induce gelatinization of starch in excess water, resulting in a transition of the native granular structure to a starch paste or gel. However, there are significant differences in the structural and rheological properties between heated and pressurized starches. These differences offer benefits with respect to new product development. However, in order to implement high-pressure technology to starch and starch-containing products, a good understanding of the mechanism of pressure-induced gelatinization is necessary. Studies that are published in this area are reviewed, and the similarities and differences between starches gelatinized by pressure and by temperature are summarized.

A NUMBER of methods are available for the separation of the unbranched (amylose) and branched (amylopectin) components of starch. Of these methods, that of T. Schoch1 has been generally useful but presents certain disadvantages as a routine method inasmuch as it consists in a relatively high-temperature treatment, under pressure, of starch paste with butanol and isoamyl alcohol, and this treatment is known to cause some hydrolytic degradation of starch. The amylose component forms a Complex with butanol which is insoluble in water, whereas amylopectin either does not form such a complex or, more probably, forms a complex which is soluble in water.

Starch paste viscosity plays an important role in estimating the cooking, eating, and processing quality of rice. The inheritance of starch paste viscosity in glutinous rice remains undefined. In the present study, 118 glutinous rice accessions were collected, and the genotypes of 17 starch synthesis-related genes (SSRG) were analyzed by using 43 gene-specific molecular markers. Association analysis indicated that 10 of 17 SSRGs were involved in controlling the rapid visco analyzer (RVA) profile parameters. Among these, the PUL gene was identified to play an important role in control of peak viscosity (PKV), hot paste viscosity (HPV), cool paste viscosity (CPV), breakdown viscosity (BDV), peak time (PeT), and paste temperature (PaT) in glutinous rice. Other SSRGs involved only a few RVA profile parameters. Furthermore, interactions between SSRGs were found being responsible for PeT, PaT, and BDV. Some of the RVA parameters, including PKV, HPV, CPV, CSV, and PaT, were mainly governed by single SSRG, whereas other parameters, such as BDV, SBV, and PeT, were controlled by a few SSRGs, functioning cooperatively. Further, three near-isogenic lines (NIL) of a japonica glutinous cv. Suyunuo as genetic background, with PUL, SSIII-1, and SSIII-2 alleles replaced with those of indica cv. Guichao 2, were employed to verify the genetic effects of the various genes, and the results were consistent with those obtained from the association analysis. These findings indicated that starch paste viscosity in glutinous rice had a complex genetic system, and the PUL gene played an important role in determining the RVA profile parameters in glutinous rice. These results provide important information for potentially improving the quality of glutinous rice.

Indica rice starch and japonica rice starch were used in the study. The protein contents of the two rice variety were respectively 0.43%, 0.62%, 0.84%, 1.08%, 1.25%. The pasting and rheological properties of samples were determined with Rapid Visco Analyzer and dynamic rheometer. The results indicated that, with the increase of protein content, the peak viscosity, breakdown viscosity and final viscosity of rice starch paste decreased, the setback viscosity increased and the pasting temperature did not change significantly. With the increase of protein content, the consistency coefficient of starch decreased, the corresponding yield stress also decreased, however, the flow behavior index increased with the decrease of consistency coefficient. At same temperature, the storage modulus G’ was greater when the protein content was higher.

Two methods are described for storing starch paste adhesive that allow it tobe kept mold-free for up to six months at room temperature without fungicidal additives. The preferred method, using sterile syringes, has the further advantage that small quantities of starch paste can be used without opening the container and risking contamination with microorganisms. Paste stored in a syringe for eight weeks is smooth, free of lumps, and ideal for use when extruded from the syringe. An alternative method for inhibiting fungal growth in paste pots without the use of chemical fungicides involves exposing the starch paste to ultraviolet light. The gelatinization process of starch as it relates to paste preparation and storage is discussed, as is the microwave oven method of preparing starch paste.

Different types of Crosslinked waxy-corn starches and pregelatinized-crosslinked waxy-corn starches were evaluated for potential use as a binding agent in a conventional wet granulation process. Lactose granules were prepared by granulation in a planetary mixer using starch as a binding agent in either the dry or paste form. The granules, prepared with dry starch or starch paste, showed no difference in size distribution and average size of granules. The pregelatinized starch used in the paste form gave coarser granules with a greater average size in comparison to other starch modifications. In general, the friability of granules prepared by using dry starch is higher than that when using starch paste. Nevertheless, starches that were only pregelatinized or pregelatinized and crosslinked yielded granules having a similar friability by using either a dry starch or starch paste. The lactose granules prepared by using a paste of pregelatinized-crosslinked starch provided more friable granules with greater friability as compared to only pregelatinized starch paste. No difference in friability was observed between granules prepared with different types of pregelatinized-crosslinked (phosphate and adipate) starches. There was no difference in moisture content between all granules prepared in this study. The pregelatinized starch and pregelatinized-crosslinked starches showed potential use as a binding agent in the conventional wet granulation process. The starches that were Crosslinked only showed no advantage in binding properties over native corn starch or waxy-corn starch.

Rheological properties of pastes of glutinous rice, waxy corn, and cassava starch were mea-sured with rheometers. The temperature at which viscosity increased was observed on viscogram to be highest for waxy corn starch, followed by cassava starch, and glutinous rice starch. Waxy corn starch showed the highest maximum viscosity, while cassava starch showed the largest setback upon cooling. Changes in degree of gelatinization of various starch samples, which had been stored at 5 and -20°C for 72 hr, were very small. This fact suggests that these materials would hard-ly suffer from retrogradation. The spinning distance of a starch paste increased with an increase in concentration. The increasing ratio of glutinous rice starch was the highest, followed by cassava starch and waxy corn starch. Cassava starch had the highest elastic modulus and viscosity. The apparent activation energy of glutinous rice, waxy corn, and cassava starch was 38. 60, 28. 30, and 76.35 kJ/mol, respectively. Though dynamic modulus and the dynamic loss of each starch paste increased with an in-crease in frequency, cassava showed significantly high values, compared with those of glutinous rice and waxy corn. The tanδ of waxy corn and cassava starch increased with an increase in frequency, while glutinous rice starch was scarcely changeable. Cassava starch showed the smallest tanδ.

Remusatia vivipara is a common herbaceous belongs to the family of Araceae. Tubers of plant contain mucilage hence attempt to evaluate the tubers for suitability as tablet binder is considered and the present investigation repots the isolation of mucilage of Remusatia vivipara tubers. The DSC and FTIR thermograms of drug and mucilage indicated no chemical interaction. Phytochemical and Physiochemical characteristics of mucilage were studied which confirmed the mucilage nature. The mucilage was evaluated for its granulating and binding properties in compressed tablet using Metformin HCl as model drug. The granules prepared by mucilage with different concentration such as 1%, 3%, 5% and 10% were compared with starch paste, which was used as standard binder. The tablets had good physiochemical properties and the drug release was more than 95% within 24hr. It was observed that decreasing the concentration of mucilage increases hardness and the disintegration time. The tablet prepared using 1% and 3% shows drug release rate in sustained manner and that of standard binder 10% starch paste used for comparison. Remusatia vivipara mucilage could be used as a good binding agent at very low concentrations. This can be used for sustaining the drug release from tablets, since the prepared tablets produced a sticky film of hydration on the surface, which ultimately reduces drug release rate and hence it can be evaluated for its efficacy to sustain the drug release.

An Onlator[○!R], a heat exchanger, was utilized as a continuous starch paste supplier for a fluidized-bed granulator. Ascorbic acid was used as a model drug substance and cornstarch as the binder. To control the temperature of cooking starch paste, modes of proportional control (P control) and proportional integral deviation (PID control) were used to distinguish their respective effects on the tablet properties. It was shown that the PID control caused less variation in the temperature of cooking starch paste and, in accordance with this, that variation in disintegration time for the resultant tablets was less. there was, however, little difference in tablet hardness between these two modes of control.

International audience; The retention of three aroma compounds-isoamyl acetate, ethyl hexanoate, and linalool--from starch-containing model food matrices was measured by headspace analysis, under equilibrium conditions. We studied systems containing standard or waxy corn starch with one or two aroma compounds. The three studied aroma compounds interact differently: ethyl hexanoate and linalool form complexes with amylose, and isoamyl acetate cannot. However, in systems containing one aroma compound, we observed with both starches a significant retention of the three molecules. These results indicate that amylopectin could play a role in the retention of aroma. In systems containing two aroma compounds in a blend, the retentions measured for isoamyl acetate and for linalool were either equal to or less than those in systems where they were added alone. This phenomenon was attributed to competition between aroma compounds to bind with starch. The retention of aroma compounds blended in starch-based systems gave us additional information which confirmed that interactions occur not only with amylose but also with amylopectin.

A wide range of variation was found in the properties tested among Amaranthus species and among genotypes within the same species. It was generally found that the amylose content of cultivated genotypes of Amaranthus was lower than that of non-cultivated genotypes; starch of cultivated genotypes had more stable pasting properties (i. e. higher peak viscosity, lower viscosity drop during shear thinning and lower retrogradation) than noncultivated genotypes; starch of cultivated genotypes had lower TP and higher ΔH than non-cultivated genotypes; the starch pastes of cultivated genotypes were stable during cold storage, i. e. hardness, cohesiveness and modulus of cultivated starch pastes were lower, and adhesiveness was higher, compared to non-cultivated genotypes. The values for pasting, functional, and thermal properties of Amaranthus starch were highly correlated, especially the pasting and functional properties. Amylose content was closely related to the physical and functional properties of Amaranthus starch. The environmental effect on the properties of Amaranthus starch was different for different species. Compared to the reference corn, rice, potato and wheat starches, Amaranthus starch tended to have more stable paste, i. e. lower shear thinning and lower retrogradation, and higher Tp and ΔH; Amaranthus starch paste was more resistant to cold storage. Generally, many Amaranthus starches would be good thickeners and stabilizers in food processing. The wide genetic diversity necessitates specific choices for specific uses.

In cooking, the functional properties of food hydrocolloids are a valuable means of evaluating the quality of the cooked food and detecting the changes caused in the food properties during the cooking process. The fundamental properties and structure of the hydrocolloid sols and gels are reflected, both directly and indirectly, in the cooking properties. This study focuses mainly on the roles played by various hydrocolloids in cooking. Furthermore, the cooking properties of starch are examined in detail as an example. The subjects of (i) the thermal insulating property of starch paste; (ii) transitions in the properties during the gelation process; and (iii) transitions in the properties of blancmange caused by cooking, etc. are reviewed through rheological experiments and sensory evaluations.

The detrogradation or the setback of starch paste has come into question with an increase in the use of starch. In this paper, the detrogradation was reviewed and illustrated on the basis of chemical and morphological structure of starch. Some suggestions were given about the method for the prevention.

Unmodified cassava starch paste was characterized on the basis of its paste viscosity as affected by drying, cooking, and paste temperatures at different paste concentrations The paste exhibited plastic fluid flow with high hot-paste peak viscosity. The temperature of the peak viscosity decreased with increasing concentration. Drying temperature had statistically significant effects on the paste viscosity; the higher the temperature at which the starch was dried, the lower was the paste viscosity over the levels of concentration and cooking temperature. Starch drying temperature and paste concentration significantly affected the paste stability as measured by freeze-thaw tests and paste retrogradation tendencies.

Raw Chinese noodles were made from a number of experimentally-milled flours. The principal factors governing the eating quality of the noodles when boiled were protein content, dough strength and starch paste viscosity. In each case there was an optimum range outside which quality declined. Noodle brightness was related inversely to protein content and to flour colour grade.

The mechanism of the separating effect of fatty acid ester (FAE) has been studied in frozen starch noodles (FSN). This was examined by FAE adsorption on the starch surface and by FAE effects on viscosity, adhesive force, syneresis and iodine-affinity of starch paste. The present and previous results indicate that separating effect of FAE has a close relationship to the interaction of FAE with starch. The following factors are at least important in the separating effect of FAE; (a) adsorption of FAE on starch surface and (b) the subsequent action of FAE to reduce the viscosity and adhesive force of starch paste. The reason for FAE, especially sorbitan sterate or glycerin sterate, being effective in the separating action of FSN probably lies in the FAE ability to satisfy the above requirements.

The dynamic mechanical behaviour of starch pastes has been investigated over a frequency range of 0.02 to 5.0 radian sec−1. The influence of concentration of starch, source of starch and method of paste preparation on rheological properties have been studied. The results suggest that under the conditions examined differences in the dynamic rigidity and viscosity of pastes may be attributed to differences in the number fraction of large granules and the volume fraction of swollen starch particles they contain.