Waxy Starch Research Articles

Paste viscosity of rice starches of different amylose content and carboxymethylcellulose formed by dry heating and the physical properties of their films

Starch modified by combination with sodium carboxymethylcellulose (CMC) has been reported to have improved film properties. In this study, rice starches with different amylose content were heat-treated in a dry state after being impregnated with low or medium-viscosity CMC. Noticeable change was found in pasting properties of the starches after dry heat treatment with CMC. It indicated that crosslinkage occurred between the starch and CMC. The waxy starch showed significant change in viscosity throughout pasting after dry heating with CMC, suggesting that the ester bonds were mostly formed between the hydroxyl groups in amylopectin branches of rice starch and carboxylate acid groups of CMC. Particle size also increased after heat treatment with CMC. The modified starch-based films showed improvement in the tensile strength. Both water vapor and oxygen permeability reduced for the modified starch-based films. Dynamic mechanical analysis (DMA) study showed that the values of G′ of modified starch-based film were higher than those of native starch-based film over the temperature range −40 to 60 °C. The heating process with CMC could be used as a modification method for starch and provide desirable properties of starch-based films.

Characteristics of French Bread Baked from Wheat Flours of Reduced Starch Amylose Content

ABSTRACTWheat genotypes of wild type, partial waxy, and waxy starch were used to determine the influence of starch amylose content on French bread making quality of wheat flour. Starch amylose content and protein content of flours were 25.0–25.4% and 14.3–16.9% for wild type; 21.2 and 14.9% for single null partial waxy; 15.4–17.1% and 13.2–17.6% for double null partial waxy; and 1.8 and 19.3% for waxy starch, respectively. Wheat flours of double null partial waxy starch produced smaller or comparable loaf volume of bread than wheat flours of wild type and single null partial waxy starch. Waxy wheat flour, despite its high protein content, generally produced smaller volume of bread with highly porous, glutinous, and weak crumb than wheat flours of wild type and partial waxy starch. French bread baked from a flour of double null partial waxy starch using the sponge‐and‐dough method maintained greater crumb moisture content for 24 hr and softer crumb texture for 48 hr of storage compared with bread baked from a flour of wild type starch. In French bread baked using the straight‐dough method, double null partial waxy wheat flours with protein content >14.3% exhibited comparable or greater moisture content of bread crumb during 48 hr of storage than wheat flours of wild type starch. While the crumb firmness of bread stored for 48 hr was >11.4 N in wheat flours of wild type starch, it was <10.6 N in single or double null partial waxy flours. Wheat flours of reduced starch amylose content could be desirable for production of French bread with better retained crumb moisture and softness during storage.

A comparison of native and oxidized normal and waxy corn starches: Physicochemical, thermal, morphological and pasting properties

The effect of sodium hypochlorite on the physicochemical and functional properties of normal and waxy corn starches was investigated in this study. It was found that both carboxyl and carbonyl contents of oxidized starches from normal corn were higher than those of waxy corn. The introduction of carboxyl and carbonyl groups resulted in lower amylose content and swelling power. Both amylose and amylopectin were oxidized and degraded during oxidation but amylose was more susceptible to oxidation. Studies conducted on paste clarity revealed that the percentage transmittance increased after oxidation. The morphology of the starches was not altered after oxidation. Thermal properties measured by differential scanning calorimeter, showed that oxidation reduced transition temperatures (onset temperature, T o; peak temperature, T p; and conclusion temperature, T c), gelatinization and retrogradation enthalpies of both normal and waxy corn starches. The retrogradation tendency was reduced after oxidation both in normal and waxy corn starches. Oxidation produced waxy starch with significantly higher peak ( P V), trough ( T V), breakdown ( B V), final ( F V), and setback viscosity ( S V) as demonstrated by using a rapid visco analyzer. Oxidation reduced the pasting temperature of both normal and waxy corn starches. Also, the principal component analysis (PCA) study was conducted to find the overall variations among the oxidized starches studied. Together, the first two components represent 88.7 g/100 g of the total variability.

Characteristics of imitation cheese containing native or modified rice starches

Imitation cheese provides a useful model system to examine starch–protein interactions from a rheological and microstructural perspective. Imitation cheeses containing 3% native (amylose levels of 2.5%, 15% or 28%), pre-gelatinised, cross-linked or cross-linked and stabilised rice starch were manufactured and compared with a control (0% starch) imitation cheese. Scanning electron microscopy images showed smaller (more emulsified) fat globules in products containing 15% amylose starch or cross-linked starch compared with the control, while those containing 2.5% amylose starch or pre-gelatinised starch appeared less emulsified. Products containing waxy or cross-linked acetylated waxy starch had large starch particles within the protein matrix, indicating high degrees of starch hydration. The other starch-containing products contained starch particles that were generally smaller and more compact, indicating less hydration and disruption of the protein network. With the exception of cross-linked starch, starches reduced imitation cheese hardness, particularly with decreasing amylose content. The storage modulus of imitation cheese was significantly increased at all examined temperatures (22–80 °C) with the inclusion of native starch with 28% amylose levels, native cross-linked starch or cross-linked and stabilised starch. All starches significantly reduced imitation cheese meltability and peak tan δ values relative to the control, with cross-linked starches causing the greatest reduction, while the 2.5% amylose starch resulted in the best melting products. Amylose content of native rice starch and cross-linking or gelatinisation of starch influenced the elasticity and thermo-reversibility of imitation cheese.

Influence of protein level and starch type on an extrusion‐expanded whey product

SummaryA whey‐based puffed snack food was produced on a twin‐screw extruder to determine the effect of varying starch type (normal corn and pregelatinised waxy), protein type (regular and instantised whey protein concentrate) and protein concentration (16%, 32% and 40%) on the physical and chemical characteristics of an extruded‐expanded snack food. Increasing protein concentration and normal cornstarch significantly reduced extrudate expansion ratio, air cell size, water solubility index and increased extrudate density, and breaking force. Protein concentration and starch type significantly affected the water absorption index and water‐soluble carbohydrate. Total soluble protein was influenced by protein concentration and the interaction of starch type and protein type. With normal corn starch, a covalent complex between amylose and protein was likely formed while protein:protein interactions were favoured with low pregalatinised waxy starch concentrations.

Effect of granular characteristics on the viscoelastic properties of composites of amylose and waxy starches

For elucidating the influence of granular properties on the viscoelastic characteristics of starch gel, in this study waxy corn and waxy rice starches pre-heated at different temperatures were mixed with amylose isolated from normal corn starch to form amylose–waxy starch composites. Rheological properties of the amylose, the waxy starches and the composites during aging at 25 °C were determined and compared. Results showed that the storage modulus ( G′) of amylose solution (2%, w/w) during aging was lower than 48 Pa, and the rheological properties during aging of waxy starches pre-heated at 60 °C were too weak to be detected. The G′ of waxy starches during aging decreased with increasing pre-heating temperature from 70 to 90 °C, and the decrement on G′ value was more obvious for waxy corn starch. The amylose–waxy starch composites had higher gel strength than that of amylose or waxy starch alone. The G′ of amylose–waxy corn starch composite increased with increasing pre-heating temperature from 60 to 80 °C and then decreased at 90 °C, however, the G′ of amylose–waxy rice starch composite increased with increasing pre-heating temperature from 60 to 90 °C. Waxy corn starch had lower hot paste and final viscosities, but higher breakdown than waxy rice starch. Waxy corn starch also showed a rapid increase on the swelling power at temperature above 70 °C, while waxy rice starch increased slowly. The rigidity and integrity of waxy corn starch granules was found lower than waxy rice starch at 90 °C. Results indicate that granule properties and interaction occurred between amylose and starch granules play important roles during gelation of starch.

Preparation and Properties of High Degree Substituted Acetylated Rice Starches and Preparation of Their Films Part 1

Starches from three varieties of rice of high amylose (indica), intermediate amylose (japonica) and almost negligible amylose (japonica waxy) were isolated. They were acetylated by using four times their weight of acetic anhydride (11% sodium hydroxide as 50% aqueous solution as catalyst) for 15, 30 and 60 min.The acetyl content varied from 30 to 41% and degree of substitution (DS) from 1.63 to 2.55. Under similar conditions of acetylation, waxy rice starch showed highest acetyl content and highest DS. Dimethyl formamide was the solvent used for dispersing these modified starches. Films of indica modified starch of 30% acetyl content and 1.63 DS showed highest strength compared to other varieties of modified starch. Glass transition temperature (Tg) was highest in waxy rice starch (~ 232°C) followed by japonica non-waxy and indica rice starch. After acetylation, the Tg values increased in waxy modified ones, remained almost same in indica modified ones, decreased to some extent in japonica non-waxy modified ones compared to their respective native starches. Difference in specific heat capacity between starting and ending of glass transition point of indica and its modified ones remained almost same, increased in japonica and its derivatized ones, decreased in waxy modified one compared to their respective native starches. Among the native starches, melting point was highest in waxy starch. Modification increased this property in all the starches under all periods of acetylation. Increment was highest in japonica waxy acetylated ones. Degradation or decomposition of these starches occurred at 3-10°C higher than their respective melting points. Heat evolution was very high in japonica native (~ 203 mJ mg-1) and heat absorption was highest in indica 15 min modified one (~ 265 mJ mg-1). Difficulties encountered while determining the dynamic viscosity using the equipment of the synthetic polymer have been explained

Effect of high-pressure treatment on various starch-in-water suspensions

This study investigated the high-pressure-induced gelatinization of different starches, namely normal rice, waxy rice, normal corn, waxy corn, tapioca and potato starches. The high-pressure-treated starch solutions were characterized by pasting behaviour, degree of swelling and changes in birefringence. Potato starch was found to be less affected by pressure treatment than the other starches, as it retained birefringence after a pressure treatment of 600 MPa for 30 min. Waxy and tapioca starches showed complete gelatinization after the same treatment, whereas normal starches were only partially gelatinized. The pasting curves of the normal starches showed an increase in the initial viscosity after pressure treatment, whereas the initial viscosities of the waxy starches after the 600 MPa for 30 min treatment were already equal to their respective peak viscosities.

A comparison of native and acid thinned normal and waxy corn starches: Physicochemical, thermal, morphological and pasting properties

The starches isolated from normal and waxy corn varieties were hydrolyzed with hydrochloric acid (0.14 mol equivalent/L) and evaluated for physicochemical and functional properties. Acid thinning decreased the amylose content and swelling power but increased the solubility. The light transmittance of acid thinned (AT) starch pastes was higher than those of their native starches after similar storage intervals. The scanning electron microscopic observation demonstrated that the acid thinning did not cause any disruption of the granular crystalline structure. Native normal corn starches showed lower onset temperature ( T o) and peak temperature ( T p) as compared to their counterpart AT starches, whereas the reverse was observed for waxy corn starch. Enthalpy of gelatinization (Δ H gel) was lower in AT normal and waxy starches as compared to their native starches. The percentage of retrogradation (% R) was significantly higher for native corn starches as compared to their AT starches. A significant reduction in peak—( P V), trough—( T V), breakdown—( B V), final—( F V), and setback viscosity ( S V) was observed by acid thinning, and the reduction was more pronounced in AT waxy starches. Among AT starches, AT waxy starch showed the lowest values of P V, T V, B V, F V and S V.

Comparison of the physicochemical properties of barley starches after partial α-amylolysis and acid/alcohol hydrolysis

Zero amylose waxy (CDC Alamo), normal (Falcon), and high amylose (CDC 92-55-06-48) hull-less barley starches were isolated and subjected to α-amylase ( Bacillus licheniformis) hydrolysis (24 and 48 h; 50 and 500 U/g) and acid hydrolysis (2% HCl, 10 and 96 h) in different alcohol media (methanol, ethanol, and 1-butanol) to determine the molecular characteristics of the starch material remaining in the granules after treatments. The greatest yield of α-amylase-treated starches was obtained for the high amylose (79.9–86.6% w/w) followed by normal (61.1–76.1% w/w), and zero amylose waxy starch (44.2–64.5% w/w). Very little solubilization of starches occurred during acid/alcohol hydrolysis, and very high yields of treated starches were obtained (91–99%). Relatively small decreases in the average molecular weights ( M w) of starch components were observed after α-amylolysis; the extensive hydrolysis of the zero amylose starch (56% solubilization) caused only a threefold decrease in the M w of amylopectin. The M w of starch fractions after acid/alcohol hydrolysis was affected by the hydrolysis time and alcohol but not by the amount of amylose in the native starches; the M w and the mode of distribution of various M w species can be tailored to specific needs by choosing appropriate hydrolysis conditions. The partially enzyme-hydrolyzed normal and high amylose starches formed stronger gels (40% w/w) than their native counterparts, but waxy starch showed no evidence of network development during storage (20 h, 5 °C). The partially acid-hydrolyzed high amylose starch (2% HCl/MeOH, 10 h) showed significantly higher values of G′ compared to the native sample upon storage, whereas the partially hydrolyzed normal starch exhibited the G′ values similar to its native counterpart. Both normal and high amylose starches, hydrolyzed for 96 h, exhibited a rapid rise in G′ upon cooling but very little network development thereafter.

Rheological Properties of Starch Gels from Wheat Mutants with Reduced Amylose Content

ABSTRACTWheat lines with reduced amylose content were recently produced by single and double mutation from a low‐amylose line, Kanto 107. They are appropriate for clarifying the influence of amylose content on starch gel properties because of their similar genetic background. When measured using the concanavalin A method (ConA), the total amylose content of isolated starches from Kanto 107 and three mutants (K107Afpp4, Tanikei A6599‐4, K107Wx2) was 24.8, 18.5, 7.1, and 1.7%, respectively. Results of differential scanning calorimetry (DSC) showed that the difference in amylose content strongly affected gelatinization conclusion temperature and enthalpy. We prepared 30 and 40% starch gels and measured their dynamic shear viscoelasticity using a rheometer with parallel plate geometry. Compressive and creep‐recovery tests were conducted under uniaxial compression. The storage shear modulus correlated highly with the amylose content of starch in 30 and 40% starch gels. The creep‐recovery test showed a clear distinction in creep curves among starch samples. When the compressive force required for 50, 80, and 95% strains was compared, starch gels with lower amylose content showed lower compressive force at 50% strain. Waxy starch gel (K107Wx2) showed higher compressive force at strain >80% than other samples due to its sticky property.

Accumulation and Degradation of Two Functional Constituents, GABA and .BETA.-Glucan, and Their Varietal Differences in Germinated Barley Grains

The changes in the contents of two functional constituents, γ-aminobutyric acid (GABA) and (1→3)(1→4)-β-D-glucans (β-glucan), during germination were investigated in two malting barley varieties in order to determine the optimal conditions for accumulation and degradation of these constituents in dried barley grains after germination treatment. A time-course analysis during germination treatment revealed that the content of GABA remarkably increased in the 48 hour imbibition process and decreased in the subsequent germination process. On the other hand, β-glucan, which is known to be decomposed during malting, did not undergo substantial degradation after the 48 hour imbibition process. These findings thus indicated that it is possible to produce germinated barley grains containing these functional constituents at high levels by optimal germination treatment. A total of 43 barley varieties were surveyed for the GABA and β-glucan contents in germinated grains. Our results also indicated that there were varietal differences in the content of each ingredient. A waxy starch variety in which the contents of both β-glucan and GABA were higher than those in the other barley varieties tested, could become a promising source of the two functional constituents.

Two high-amylose maize starches with different amounts of resistant starch vary in their effects on fermentation, tissue and digesta mass accretion, and bacterial populations in the large bowel of pigs

Four groups of young pigs (n 6) were fed a diet containing 50% maize starch as either a highly digestible waxy starch (control; 0% amylose) or one of three resistant starch (RS) diets, namely a high-amylose maize starch (HAMS; 85% amylose), this starch subjected to hydrothermal treatment (HTHAMS; 85% amylose), or a blend of HAMS and HTHAMS included in equal amounts, for 21 d. Food intake and live weight at the end of the study were similar among the four groups. Ileal starch digestibility was lower in pigs fed the three RS diets but was greater for HAMS(88%) than for HTHAMS (70%; P<0.05). Faecal output and large bowel digesta mass, and concentrations and pools of individual and total SCFA were higher (by about two- to threefold; all P<0.05) and digesta pH lower (by about 1 unit, all P<0.001) in pigs fed either HAMS or HTHAMS compared to the controls. These differences in biomarkers were seen along the length of the large bowel. Colon length was 0.5-0.9 m longer (19-35%) in pigs fed the high-RS diets relative to those fed the highly digestible starch diet (P<0.05). Faecal and proximal colonic lactobacilli and bifidobacteria numbers were higher (by 1 and 3 log units; P< 0.05) in pigs fed the HAMS or HTHAMS diets. Although both high-amylose starches promoted fermentation throughout the large bowel, the data suggest that the effects of HTHAMS may be more pronounced in the distal region compared to those of HAMS.

Effect of high pressure on binding aroma compounds by maize starches with different amylose content

Hylon VII, waxy maize starch and their mixtures were subjected to high pressure treatment (650 MPa/9 min). To obtain starch-odorants products: (i) the pressurised and native starches were incubated with odorants; and (ii) the native starches mixed with odorants were treated under high pressure (650 MPa/9 min). The sorption capacity of odorants by investigated starches was studied using capillary gas chromatography. The sorption capacity of odorants by native starches was found to stronger depend on hydrophobicity and molecular structure of odorants rather than the starch botanical origin. The highest sorption was observed for polar hydrophobic compounds (hydrocarbons) and for aliphatic esters, whereas the lower one—for guaiacol and methyl anthranilate. The high pressure-treated Hylon VII demonstrated slight changes in melting enthalpy and degree of gelatinisation compared to other starches and it showed the highest sorption capacity of the majority of odorants. The treatment of a starch with odorant under 650 MPa for 9 min resulted in a diminished average sorption of the aroma compounds. However hexanol, guaiacol and methyl antrinilate, that were slightly or not sorbed by native and high pressure-treated starches, demonstrated the highest degree of binding with waxy starch and its mixtures under high pressure conditions.

Surface properties of water soluble maltodextrin, starch acetates and starch acetates/alkenylsuccinates

Surface and interfacial tensions with hexadecane were measured for water soluble maltodextrin and starch ester solutions in order to determine their potential as stabilizers or emulsifiers. The surface tension for an acid hydrolysed starch (maltodextrin) initially declined with concentration and then reached an equilibrium value of 56 mN/m at 20–40 wt.%, suggesting that hydrated starch has this surface energy. Surface and interfacial tensions of starch acetates decreased more rapidly with concentration reaching values of 41–44 and 11–13 mN/m, respectively, at 40 wt.%. There was little dependence of surface or interfacial tensions on degree of substitution between 0.3 and 0.8 and amylose content of starch acetates. Surface and interfacial tensions for starch acetate/alkenylsuccinates were lower than those for starch acetates, particularly at low concentrations. Emulsions of soybean oil/water mixtures were stabilized for >1 day by waxy starch acetate/octenylsuccinate and acetate/dodecenylsuccinate but not starch acetates. In summary, these starch esters may represent biodegradable, economical alternatives to some emulsifiers and coating polymers currently in use.

Impact of Waxy, Partial Waxy, and Wildtype Wheat Starch Fraction Properties on Hearth Bread Characteristics

ABSTRACTThirteen different wheat cultivars were selected to represent GBSS mutations: three each of wildtype, axnull, and bxnull, and two each of 2xnull and waxy. Starch and A‐ and B‐granules were purified from wheat flour. Hearth bread loaves were produced from the flours using a small‐scale baking method. A‐granules purified from wildtype and partial waxy (axnull, bxnull, and 2xnull) starches have significantly higher gelatinization enthalpy and peak viscosity compared with B‐granules. A‐ and B‐granules from waxy starch do not differ in gelatinization, pasting, and gelation properties. A‐ and B‐granules from waxy starch have the highest enthalpy, peak temperature, peak viscosity, breakdown, and lowest pasting peak time and pasting temperature compared with A‐ and B‐granules from partial waxy and wildtype starch. Waxy wheat flour has much higher water absorption compared with partial waxy and wildtype flour. No significant difference in hearth bread baking performance was observed between wildype and partial waxy wheat flour. Waxy wheat flour produced hearth bread with significantly lower form ratio, weight, a more open pore structure, and a bad overall appearance. Baking with waxy, partial waxy, and wildtype wheat flour had no significant effect on loaf volume.

Properties of Cross‐Linked Starch from Waxy Mutant Wheat Tanikei A6599‐4

ABSTRACTNative starch from waxy mutant wheat Tanikei A6599‐4 is known to exhibit more stable hot paste viscosity than a typical waxy wheat (Tanikei H1881) and waxy corn. The objective of this study was to investigate the starch paste properties of Tanikei A6599‐4 after cross‐linking and compare with Tanikei H1881 and waxy corn. As an example of cross‐linking, the reaction (at 30, 60, 120, and 360 min) with sodium trimetaphosphate was used. In Rapid Visco Analyser (RVA) measurement, the unique characteristic was maintained in Tanikei A6599‐4 starch cross‐linked at low reaction time (&lt;120 min) levels. Cross‐linking at a high reaction time (360 min) level suppressed the swelling of both Tanikei A6599‐4 and Tanikei H1881 starches but not waxy corn starch. Although unmodified Tanikei A6599‐4 starch showed the lowest paste clarity among unmodified waxy starches, this defect became unremarkable when starch was cross‐linked for ≥120 min. In gel‐dispersed dynamic viscoelasticity measurement, the order of G′ and G″ values was always Tanikei A6599‐4 &gt; Tanikei H1881 &gt; waxy corn. This indicates that cross‐linked Tanikei A6599‐4 and Tanikei H1881 starches have different starch properties and that swollen Tanikei A6599‐4 starch granules are more rigid than swollen Tanikei H1881 starch granules.

Effects of molecular size and structure of amylopectin on the retrogradation thermal properties of waxy rice and waxy cornstarches

Starches from waxy rice and waxy corn were treated in anhydrous methanol with 0.36% HCl at 25 °C for 1–15 days to obtain starches with different molecular weights. The retrogradation thermal properties of the HCl–methanol-treated starches, after gelatinized and stored at 4 °C for 7 days, were determined by using differential scanning calorimetry, and effects of molecular size and structure of amylopectin on the retrogradation thermal properties were elucidated. Results indicated that the degree of retrogradation (DR%) of waxy starches increased with decreasing molecular weight. The DR% of waxy starches was found negatively correlated with the logarithmic value of its weight-average degree of polymerization (DP w ) ( r 2=0.847 for waxy rice and 0.951 for waxy corn). The increment of DR% with the decreasing DP w of waxy cornstarch (slope=−13.98) was profoundly lower than that of waxy rice starch (slope=−25.42). In spite of the botanical source of starch, the DR% and the melting temperature of retrograded waxy starch depended on not only the molecular size, but also the molecular structure such as average chain length and chain length distributions of amylopectin branch chains and its subfractions.

Composition and Properties of A‐ and B‐type Starch Granules of Wild‐Type, Partial Waxy, and Waxy Soft Wheat

ABSTRACTStarch A‐ and B‐type granules were isolated from soft wheat (Triticum aestivum L.) genotypes representing the four granule bound starch synthase I (GBSSI) classes, and characterized according to composition and properties. While total (TAM) and apparent (AAM) amylose contents of both granule fractions decreased as starch waxy character increased, the A‐type granules possessed higher TAM and AAM contents than B‐type granules for a given genotype. From wild‐type to waxy, a general transition was observed from B‐ to A‐type starch granule fractions with higher levels of lipid‐complexed amylose (LAM) and phospholipid. Within a genotype, A‐type (relative to B‐type) granules possessed higher gelatinization enthalpies, while B‐type granules exhibited higher gelatinization peak and completion temperatures (broader gelatinization ranges) than A‐type granules. Normal (wild‐type) and waxy A‐ and B‐type starch granule pasting rates were affected by starch granule lipids; the granule type within a genotype with the lowest LAM and phospholipid levels generally exhibited the shortest time to pasting. For normal and waxy starches, A‐type granules exhibited higher pasting viscosities than B‐type granules throughout the pasting profile. Thus, the A:B‐type granule ratio is important to understanding overall wheat starch composition and behavior.

Gelatinization of Starch in Excess Water: Beyond the Melting of Lamellar Crystallites. A Combined Wide- and Small-Angle X-ray Scattering Study

The gelatinization of waxy rice, regular rice, and potato starch suspensions (66% w/w moisture) was investigated by real-time small-angle X-ray scattering (SAXS) and wide-angle X-ray diffraction (WAXD) during heating and by fast ramp differential scanning calorimetry (DSC). The high-angle tail of the SAXS patterns suggested the transition from surface to mass fractal structures in the DSC gelatinization range. Amylose plays a major role in determining the dimensions of the self-similar structures that develop during this process as the characteristic power-law scattering behavior extends to lower scattering angles for regular than for waxy starches. Crystallinity of A-type starches is lost in the temperature region roughly corresponding to the DSC gelatinization range. At the end of the gelatinization endotherm, the B-type potato starch showed residual crystallinity (WAXD), while SAXS-patterns exhibited features of remaining lamellar stacks. Results indicate that the melting of amylopectin crystallites during gelatinization is accompanied by the (exothermic) formation of amorphous networks.