Starch Paste Viscosity Research Articles

Diversification of the Waxy Gene is Closely Related to Variations in Rice Eating and Cooking Quality

The Wx gene encoding granule-bound starch synthase is responsible for the biosynthesis of amylose, which plays an important role in determining rice eating and cooking quality. However, the functional evaluation of different Wx alleles remains unclear. In the present study, a set of near-isogenic lines (NILs) carrying four different Wx alleles—Wx a , Wx b , Wx in , and wx—was developed in the genetic background of indica rice cv. Yangfunuo 4 (YFN 4), and designated NIL-Wx a , NIL-Wx b , NIL-Wx in , and NIL-wx, respectively. These NILs show great variations in amylose content (AC), gel consistency (GC), starch viscosity, and thermodynamic property. AC showed the following trend among different NILs: NIL-Wx a > NIL-Wx in > NIL-Wx b > NIL-wx, but the opposite trend for GC. NIL-Wx a and NIL-Wx in had lower starch thermodynamic properties, such as onset temperature, peak temperature, and conclusion temperature, when compared with both NIL-Wx b and NIL-wx. The transcript and protein of Wx gene were not detectable in the NIL-wx line. The accumulation levels of Wx transcript and Wx protein were higher in NIL-Wx a than those in NIL-Wx b and NIL-Wx in . Therefore, Wx gene was closely related to starch quality parameters, such as AC, GC, starch paste viscosity, and starch thermodynamic property. Our results provide a solid foundation for rice grain quality improvement through marker-assistant selection.

Effect of Acid Modification on the Properties of Potato Starch Pastes and Starch Film

The effect of acid modification using 1mol/L HCl on viscosity, thermal properties and mechanical properties of potato starch pastes and starch film were investigated. After acid modification, the surface of starch granules did not show more roughness and viscosity of starch pastes become lower. The results of DSC indicated that acid should act on amorphous region of starch firstly and would act on the crystallization region with the longer treatment time. In the very close viscosity scope, the mechanical properties of starch films were increased obviously after acid modification.

Genetic analysis of starch paste viscosity parameters in glutinous rice (Oryza sativa L.)

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.

CARACTERIZAÇÃO FÍSICA E FÍSICO-QUÍMICA DE RIZOMAS E AMIDO DO LÍRIO-DO-BREJO (Hedychium coronarium)

The objectives of this research were to evaluate the chemical composition of Hedychium coronarium rhizomes and isolate and characterize their starch by conducting physical and physicochemical analyses. The chemical composition of isolated starch granules was also determined, as well as shape, size, particle distribution size by laser diffraction, paste viscosity by rapid visco-analysis, swelling power, water solubility index, thermal property by differential scanning calorimetry, and crystallinity by X-ray diffraction. Rhizomes presented high water content and low lipids, carbohydrates, ash, protein and fiber levels. Due to its low dry matter content (17.3%), with 21.97% of starch, as well as long fibers and latex, which hamper starch extraction, the white ginger lily rhizomes are not interesting as a starch source. The isolated starch showed 99.2% purity, with 37.2% of amylase content. The starch granules presented an irregular polyhedral shape and average size of 38.2 ? m . The crystalline structure of the starch granules was type A, which is maintained by strong internal associative forces that reduce water solubility. The starch gelatinization temperature occurs between 73.1oC and 78.7°C. The starch paste viscosity profile showed high stability at 95°C and high tendency to retrograde, suggesting its use in adhesive and food industries. KEY-WORDS: Hedychium coronarium ; physicochemical and functional properties; paste viscosity; starch thermal property.

Genetic Effect of PUL Allelic Variation on Rice Cooking and Eating Qualities

Pullulanase (PUL) is a type of starch debranching enzymes involved in starch biosynthesis. To test the effect of PUL allelic variation on cooking and eating qualities in rice ( Oryza sativa L.), 2 sets of near-isogenic lines (NILs) for PUL gene were developed by crossing and backcrossing Guichao 2 ( indica) and Suyunuo ( japonica glutinous) and selected with the help of the gene-specific STS marker on PUL gene. The NILs had no significant differences in amylose content, gel consistency, and starch crystalline structure compared with their corresponding recurrent parents. In contrast, the starch paste viscosity and starch thermal property changed obviously between the NILs and their recurrent parents. It was concluded that PUL gene plays an important role in determining rice grain cooking and eating qualities, and functional differentiation occurred at the PUL locus between indica variety Guichao 2 and japonica variety Suyunuo. The gene-specific molecular marker for PUL gene developed on the basis of genomic sequence diversity could be directly applied in rice good quality breeding program.

Viscosity and Thermal Effect of Starch Paste

Viscosity and Thermal Effect of Starch Paste

Detection of quantitative trait loci for paste viscosity characteristics based on the doubled haploid progeny from a cross between two Chinese wheat varieties

In order to understand the genetic basis of starch pasting viscosity characteristics (the RVA profile, which is produced by the Rapid Visco Analyser) of wheat grain samples, a doubled haploid (DH) population (Huapei 3 × Yumai 57; Yumai 57 is superior to Huapei 3 for RVA profile parameters) and a linkage map consisting of 324 marker loci were used to search QTL. This program was based on mixed linear models and allowed simultaneous mapping of additive effect QTL, epistatic QTL, and QTL × environment interactions (QE). Mapping analysis produced a total of 35 QTL for 6 RVA profile parameters with a single QTL explaining 0.91-21.34% of phenotypic variations. The 35 QTL were distributed on 15 chromosomes. The QBd-4A had the most significant additive effect, accounting for 21.34% of the phenotypic variance. Two QTL clusters for RVA profile parameters were located on chromosomes 2A and 4A, respectively. The information obtained in this study should be useful for manipulating the QTL for RVA profiles parameters by molecular assisted selection (MAS) in wheat breeding programs.Key words: Doubled haploid population, paste viscosity characteristics, rapid visco analyser, quantitative trait loci, wheat (Triticum aestivum L.)

Effect of monopalmitin on pasting properties of wheat starches with varying amylose content

The influence of varietal differences among wheat ( Triticum aestivum L.) starches on properties of starch pastes and gels was studied. Wheat varieties with elevated total amylose content within a narrow range (36–43%) displayed widely differing pasting properties in a Rapid Visco Analyser (RVA). The pasting properties of the wheat starches were influenced significantly by the addition of monopalmitin. Increase in final RVA pasting viscosity of starch–monopalmitin mixtures was correlated positively with increasing amylose content. The textural characteristics of the respective retrograded starch gels also differed greatly and were affected by varietal differences between the starches. There was no correlation between textural properties of aged gels with amylose content or the viscoelastic characteristics measured by the RVA. The strength of gels may be affected by subtle differences in starch structure that influence retrogradation, but have only limited effect on starch pasting properties.

酢酸化分級馬鈴薯澱粉の物理化学特性

Physicochemical properties of acetylated fractionated potato starches, prepared using acetic anhydride, were investigated. 1) As levels of acetic anhydride increased, physicochemical properties of acetylated fractionated potato starches changed as follows: (1) Content of acetyl group increased. (2) In distilled water, RVA (Rapid Visco Analyser) characteristics parameters (pasting temperature, peak viscosity and breakdown) and DSC (differential scanning calorimetry) characteristic parameters (onset, peak and conclusion temperatures of gelatinization, and enthalpy change of gelatinization) decreased, but solubility and swelling power increased. (3) Viscoelastic parameters (storage modulus and loss modulus) of starch pastes prepared in distilled water decreased, and their frequency-dependences were observed. Shear stresses of starch pastes at each shear rate decreased, and the extent of thixotropy decreased. (4) Syneresis of 4% starch pastes prepared in 0.1 M NaCl solution decreased. 2) The following differences in physicochemical properties were found among acetylated fractionated potato starches (large, middle and small granules). (1) Acetyl group contents of small granule starches were higher than those of middle and large granule starches. (2) Extent of decrease in RVA peak viscosity measured in distilled water increased with decrease in the starch granule size. Solubility and swelling power in distilled water increased with increase in the starch granule size. (3) In 0.1 M NaCl solution, RVA peak viscosity of starch pastes of small and middle granules increased with the increase in levels of acetic anhydride, and the extent of increase in the viscosity was markedly large for the small granule. (4) Solubility and swelling power in distilled water increased with the increase in the starch granule size. In 0.1 M NaCl solution, with the increase in the starch granule size, solubility increased, but the swelling power decreased. 3) Concerning the effect of 0.1 M NaCl solution on physicochemical properties of acetylated fractionated potato starches, RVA peak viscosity, solubility and swelling power decreased greatly compared with those in distilled water.

Grass pea (Lathyrus sativus L.) starch as an alternative for cereal starches: Rheological properties and retrogradation susceptibility

The study compares selected rheological properties of starch isolated from two cultivars of grass pea with those of wheat and corn starch. The phase transition temperatures on pasting (TO, TP, TE) of both grass pea starches were lower in comparison to normal corn starch, but higher when compared to wheat starch. Pasting temperature of the starch slurries were significantly lower for grass pea as compared to cereals, and paste viscosity of grass pea starch was significantly higher than of wheat starch. Grass pea starches, exhibit much higher values of storage and loss moduli during heating of starch suspensions. Higher values of shear stress as a function of shear rate obtained during the determination of flow curves for grass pea starch pastes are confirmed by high consistency coefficients in the Herschel-Bulkley model. The mechanical spectra of starch gels allow us to state, that grass pea starch gels are characterised by higher values of storage and loss moduli in comparison to cereal starches.

The effect of rice variety and starch isolation method on the pasting and rheological properties of rice starch pastes

The effect of rice variety and starch isolation method on the pasting and rheological properties of rice starches was evaluated. One waxy and three non-waxy rice varieties from California with a range of amylose contents of 1.6–26.5% and four methods of isolation were evaluated. A rotational rheometer (RR) was used to measure the pasting and rheological properties of starch dispersions (8% w/w). The RR pasting curves had similar shapes to those from a rapid visco-analyzer (RVA). The four treatments used for isolating starch were a protease, NaOH (0.1% and 0.4%), or sodium dodecyl sulfate (SDS) (1.0%). The NaOH (0.4%) and SDS treatments were found to reduce the peak pasting temperatures of the non-waxy starches as compared with the protease and NaOH (0.1%) treatments. The same trend of the treatments was found with the elastic moduli, low shear viscosities, and yield stresses of the non-waxy starch pastes measured at 65 °C, immediately after pasting. The elastic moduli of the waxy starch pastes appeared to be least affected by method of starch isolation, but the low shear viscosity and yield stress of the protease starch paste was significantly higher than the paste from the other three treatments. Overall, the method of rice starch isolation was found to affect the gelatinization and rheological characteristics of hot rice starch paste.

Asian noodles: History, classification, raw materials, and processing

Noodles in various contents, formulations, and shapes have been the staple foods for many Asian countries since ancient time. They can be made from wheat, rice, buckwheat, and starches derived from potato, sweet potato, and pulses. Noodles based on wheat are prepared mainly from three basic ingredients; flour, water, and salt. There exist two distinct types of wheat flour noodles based on the presence and absence of alkaline salts, regular salted noodles, and alkaline noodles. The basic process of dough mixing, sheet forming, compounding, sheeting/reduction, and cutting are essentially constant for all machine-made noodles. Noodle strands coming out of cutting rolls can be further processed to produce different types of noodles. This article analyzed all the major processes involved from raw material to finished products in relation to noodle processing properties and cooked noodle texture. Different ingredients and their functionality in noodle processing were discussed as well. Guidelines were provided to select the right ingredients to produce high quality noodle products. Processing properties, appearance, and colour of noodles are the three key criteria used to judge a process and raw material quality. High quality noodles should be bright in colour with very slow discoloration, have an adequate shelf life without visible microbiological deterioration or oxidative rancidity, and have appropriate flavour and textural characteristics which will vary according to the noodle type and region. Flour plays a key role in all aspects of noodle quality. Protein content is positively correlated with noodle firmness and sometimes negatively correlated with elasticity. Therefore, a correct range of protein content is important for textural characteristics. Adequate gluten strength and extensibility is required in all noodle flours. Noodle dough must be strong enough to withstand sheeting, but not so strong as to cause tearing or difficulty in sheet reduction. A good level of dough extensibility ensures that dough sheets do not shrink back during successive roll passes. The importance of the pasting properties of starch to the texture of cooked noodles has been well-documented. The required soft, smooth, and elastic textural properties of certain types of white salted noodles can be best obtained from wheats with high starch paste viscosity and high swelling starch properties. Alkaline noodles do not have the same requirement for high starch swelling properties. Noodles made from flour with high swelling starches have softer texture than those with low swelling starch. Noodles should be bright and slow in discoloration with time after manufacturing. For white salted noodles, a white or creamy white colour is desirable. The level of natural yellow pigment levels (xanthophylls) in flour is highly correlated with noodle colour, and this is wheat variety dependent. For yellow alkaline noodles, a bright yellow colour is required, although the preference for the degree of colour development is regionally based. Noodle darkening increases with the increases of flour extraction rate. This is due to the action of polyphenol oxidase (PPO) enzymes which are largely located in the bran layer. Low flour extraction and ash levels are preferred for the manufacture of noodles with a clean and bright appearance. A relatively fine flour particle size enables even hydration during mixing and optimum, uniform gluten development during sheeting. Increased starch damage, however, is associated with poor noodle colour and undesirable high cooking loss and excessive surface swelling.

The effects of reaction conditions on the production of γ-cyclodextrin from tapioca starch by using a novel recombinant engineered CGTase

A novel mutant enzyme namely H43T CGTase can produce up to 39% γ-cyclodextrin (γ-CD) compared to the native enzyme which produces only 10% γ-CD. The effect of the reaction conditions on γ-CD production was studied using this mutant CGTase. The effects of substrate–buffer combination, starch pretreatment and concentration, pH, additives and finally the use of a debranching enzyme improved the γ-CD ratio further. The tapioca–acetate pair gave the highest conversion (16% conversion) among four types of starch and four buffer system combinations. Gelatinized starch was preferred compared to raw tapioca starch in producing a high percentage of γ-CD and conversion rate. Higher pH especially pH 8–9 led to a higher proportion of γ-CD, and was relatively more apparent when the concentration of starch was increased. Forty-six percent γ-CD was produced using 2.5% gelatinized tapioca starch at pH 8. Pullulanase enzyme was found to be useful in reducing the viscosity of tapioca starch paste thus increasing the efficiency of utilization of starch by CGTase by at least 20- to 30-fold. Up to 48% γ-CD can be produced when 4% pullulanase-pretreated tapioca starch was reacted with the CGTase mutant. It was also found that the supplementation of the reaction mixture with glucose, toluene, or cyclododecanone improved the γ-CD yield by 42.2, 46.4, 43.4, and 43.4%, respectively. All the parameters involved have been shown to affect the product specificity of the mutant H43T CGTase transglycosylation mechanism.

Characterization of indica-type giant embryo mutant rice enriched with nutritional components

Five giant embryo mutants, described as MH-gel, MH-ge2, MH-ge3, MH-ge4 and MH-ge5, which were derived from the same indica rice cv. ‘Minghui 86’ and characterized by 2.0, 1.88, 2.08, 1.93 and 1.88 times enlarged embryo than that of wild type, were selected for the current study. The mutated giant embryos were controlled by a single recessive gene, and except mutated locus with MH-ge1 other four loci were allelic to each other and the previous reported locus ge in japonica rice cv. ‘Kinmaze’. No obvious differences in physicochemical properties such as apparent amylose content (AAC), alkali spreading value (ASV), gel consistency (GC), and starch paste viscosity were observed between giant embryo mutants and wild type. Significant increases in the contents of crude lipid (LC), crude protein (PC), Vitamin B1 (VB1), Vitamin B2 (VB2), Vitamin E (VE), essential amino acids such as Arginine (Arg), Aspartic acid (Asp), Glutamic acid (Glu), Lysine (Lys), Methionine (Met), and mineral elements such as calcium (Ca), iron (Fe), potassium (K), phosphorus (P) and zinc (Zn) were detected in brown rice (BR) of giant embryo mutants. The amounts of gamma aminobutyric acid (GABA), an inhibitory neurotransmitter, were similar in the BR of giant embryo mutants and wild type, and more GABA content was observed in germinated brown rice (GBR) than BR. Significant enrichments were detected in the GBR of giant embryo mutants, basically corresponding to the enlarged embryo.

Analysis of Genotype × Environment Interaction Effects for Starch Pasting Viscosity Characteristics in Indica Rice

Milled rice ( Oryza sativa L.) is composed of approximately 90% starch. The properties of starch have considerable effects on cooked rice palatability and consumer acceptability. Starch pasting viscosity parameters serve as important indices in the estimation of eating, cooking, and processing qualities of rice. In the present study, four cytoplasmic male-sterile (CMS) lines and eight restorer (R) lines have been used in an incomplete diallel cross to analyze seed effects, cytoplasmic effects, maternal gene effects, and their genotype × environment (GE) effects on the following starch pasting viscosity parameters: breakdown (BD), consistency (CS), and setback (SB). The results demonstrated that the total main genetic variances ( V G ) accounted for over 64% of the total genetic variance ( V G + V GE ) for the three traits, indicating that these traits were mainly controlled by the main genetic effects in addition to the GE interaction effects. The estimated total narrow-sense heritability were 67.8%, 79.5%, and 79.5% for BD, CS, and SB, respectively. The general heritability ( h 2 G ) accounted for over 75% of the total heritability ( h 2 G + h 2 GE ), indicating that early selection would be effective for those traits and the selection efficiencies were relatively stable in different environments.

Pasting Properties of Non‐waxy Rice Starch‐Hydrocolloid Mixtures

AbstractThe swelling and pasting properties of non‐waxy rice starch‐hydrocolloid mixtures were investigated using commercial and laboratory‐generated hydrocolloids. The swelling power of the rice starch‐hydrocolloid mixtures was generally depressed at low concentration of hydrocolloids (0–0.05%), but increased directly with increasing hydrocolloid concentrations (0.05–0.1%). In gellan gum dispersion, the swelling power at 100°C was higher than that of control. The rice starch‐hydrocolloids mixtures showed shear‐thinning flow behavior (n = 0.26–0.49). Hydrocolloids except the exopolysaccharide from S. chungbukensis (EPS‐CB) increased apparent viscosity and consistency index (K) of rice starch dispersions, but decreased the n value. Hydrocolloids enhanced the trough and final viscosity of rice starch dispersions but EPS‐CB reduced the viscosity of rice starch pastes. Hydrocolloids lowered peak viscosity but addition of guar gum resulted in high peak viscosity, apparent viscosity, and consistency index of rice starch dispersions. Total setback viscosity appeared to be not affected by hydrocolloids at low concentration (0.05%). The hot and cold paste of the starch‐gellan gum mixture exhibited the highest viscosity values in the Brookfield viscometer.

Starches from different botanical sources II: Contribution of starch structure to swelling and pasting properties

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.

Improvement of the Functional Properties of Sucrose Stearate by Phosphorylation

Phosphorylated sucrose stearate (SE-P) was prepared by dry-heating sucrose stearate (SE) with metaphosphoric acid. The main product was deduced to be a monophosphosucrose monostearate by chemical analysis and mass spectrometry. SE-P exhibited remarkably higher solubility and emulsifying properties than SE, especially in the acidic region and in the presence of NaCl, and SE-P bound Ca2+ at a 1:1 molar ratio (SE-P/Ca2+). SE-P markedly reduced the viscosity of potato starch paste and inhibited retrogradation, whereas SE did not reduce it so much. It is thus expected that phosphorylation would be an appropriate method for improving the functional properties of SE and that SE-P could be used as a novel emulsifier and modifier with Ca2+-binding ability for starchy foods.

EFFECT OF AMYLASE ACTIVITY ON STARCH PASTE VISCOSITY AND ITS IMPLICATIONS FOR FLAVOR PERCEPTION

ABSTRACTThe viscosity of starch pastes prepared from waxy maize and wheat starches was measured as a function of concentration. Concentrations at which the two starches had comparable viscosities were selected and the decrease in viscosity with time on amylase addition was determined at 37C using a rapid viscosity analyzer (RVA). At the same level of enzyme addition the decrease in viscosity with time was much faster for waxy maize starch compared to wheat starch. For the latter, the time for the RVA viscosity to be reduced to half its value was of the order of 10 s. Volatile release was substantially increased with amylase addition. It is suggested that, at comparable initial viscosities, starch‐thickened products have better flavor and taste perception than products prepared with other thickeners because of the in‐mouth viscosity decrease resulting from amylase degradation. This could be explained by a reduction in perceived viscosity, which may enhance flavor perception as a consequence of signal processing within the brain, and/or an increase in the concentrations of volatiles reaching the olfactory receptors.

Functional properties of native, physically and chemically modified breadfruit ( Artocarpus artilis) starch

Starch was isolated from breadfruit ( Artocarpus artilis). It was further modified by oxidation, acetylation, heat–moisture-treatment and annealing. The functional properties of native and modified starches were then studied. Proximate analysis revealed that following modifications, the annealed (BANS), oxidised (BOS) and acetylated (BACS) starches retained higher moisture content compared to native starch (BNS), while heat–moisture treated starch (BHMTS) had lower moisture content. Crude fibre was reduced by following modifications, except that BNS and BANS had the same value (0.42%). Protein and fat contents were also reduced after modifications. Acetylation, oxidation and heat–moisture-treatment improved the swelling power of the native starch. The result indicates that all forms of modification reduced the solubility of native breadfruit starch. For all the starches, replacing the wheat flour by the starch resulted in increased alkaline water retention of the blends. Gelation studies revealed that native breadfruit starch is a better gelating food material than the modified derivatives. All forms of modification reduced pasting temperature, peak viscosity, hot paste viscosity and cold paste viscosity of the native starch, except that heat–moisture-treatment increased the pasting temperature. Setback value reduced after modifications, indicating that modifications would minimize starch retrogradation.