Effect of annealing on the structure and physicochemical properties of barley starches of varying amylose content

Starch from normal (CDC McGwire, SR 93102), waxy (CDC Fibar, HB 364), and High amylose (SB 94897, SB 94893) hull-less barley cultivars was isolated and its structure, morphology, and properties were studied before and after one-step annealing (50 °C for 72 h at a moisture content of 75%). The amylopectin structure of all starches was nearly identical. The X-ray pattern of CDC Fibar, HB 364, and CDC McGwire starches was of the ‘A’-type. Whereas, SR 93102, SB 94897, and SB 94893 starches exhibited a mixed ‘A + B’-type pattern. The relative crystallinity (RC), swelling factor (SF), amylose leaching (AML), gelatinization temperature range (GTR), enthalpy of gelatinization (ΔH), amylose–lipid complex melting temperature (Tp_CX) and the enthalpy of melting of the amylose–lipid complex (ΔH_CX) ranged from, 37.0% to 44.3%, 41.0–54.2% (at 90 °C), 4.0–31.0% (at 90 °C), 11.4–22.5 °C, 6.0–13.0 J/g, 84.9–89.1 °C and 0.4–1.8 J/g, respectively. The RC of CDC Fibar, HB 364, SR 93102 and CDC McGwire starches increased on annealing. Whereas, it remained unchanged in SB 94897 and SB 94893 starches. The ‘A’-type X-ray pattern of CDC Fibar, HB 364, and CDC McGwire starches remained unchanged on annealing. However, the ‘A + B’-type X-ray pattern of SR 93102, SB 94897 and SB 94893 starches resembled more closely the ‘A’-type pattern on annealing. In all starches, the X-ray intensity of the V-amylose–lipid complex peak increased on annealing. Annealing increased the gelatinization transition temperatures and decreased the GTR in all starches. The ΔH of SB 94893 starch increased on annealing, whereas it remained unchanged in the other starches. Tp_CX of SR 93102 and SB 94897 remained unchanged on annealing, whereas Tp_CX of CDC McGwire increased slightly. ΔH_CX of native and annealed CDC McGwire, SR 93102 and SB 94897 were similar. Tp_CX and ΔH_CX were not detectable in annealed SB 94893 starch. In all starches, SF decreased on annealing. Annealing decreased AML in SR 93102, SB 94897 and SB 94893 starches in the temperature range of 50–90 °C, but increased AML in HB 364 and CDC McGwire starches at higher temperatures. The effect of annealing on acid hydrolysis was marginal.     

Physicochemical properties of waxy and normal corn starches treated in different anhydrous alcohols with hydrochloric acid

Corn starches (25 g, d. b.) were treated in anhydrous methanol, ethanol, 2-propanol or 1-butanol (100 ml) with 1 ml 36% hydrochloric acid at 45 °C for 1 h, the molecular weight and chain length distributions of starch were examined by high-performance size-exclusion chromatography (HPSEC), and the granule size, granular structure, λ_max, blue value, solubility and gelatinization thermal properties of starch were also examined. Results showed the recovery yields of the treated starch were higher than 96%, and the granule sizes of treated starches were slightly lower than their counterpart native starch. Starches after acid-alcohol treated showed internal fissures or cavities in some granules, and the number of granule with fissures or cavities increased with the increasing carbon number of alcohol. The weight average degree of polymerization and relative content of F1 fraction of starch after treated profoundly decreased, and the amylose and long chain of amylopectin of starch were preferentially degraded. The degradation extent of molecules after acid-alcohol treatment was found directly related to the alternation of internal structure of starch granule. The λ_max and blue value of both waxy and normal corn starches after treated also obviously decreased with the increasing carbon number of alcohol, while the solubility of starch profoundly increased after treated. The gelatinization onset temperature (T_o) of acid-alcohol treated waxy corn starch decreased with the increasing carbon number of alcohol, but the treated normal corn starches showed similar T_o values. Despite the alcohol used, the solubility of treated waxy corn starch linearly correlated (r²=0.983) with T/T_o value (T was the measuring temperature used for solubility determination). Whereas, normal corn starch treated in different alcohols showed distinct relations between T/T_o and solubility.     

Composition,morphology, molecular structure,and physicochemical properties of starches from newly released chickpea (Cicer arietinum L.) cultivars grown in Canada

Starch from four cultivars (CDC Xena, CDC Flip 97-133C, CDC 418-59, CDC ICC 12512-9) of chickpea (cicer arietinum L.) grown in Saskatchewan, Canada was isolated and variability in composition, morphology, molecular structure and physicochemical properties was evaluated. The yield of starch was in the range 32.0–36.8% on a whole seed basis. The starch granules were oval to spherical with smooth surfaces. The granule size distribution ranged from 5 to 35 μm. The free lipid, bound lipid, total amylose and the amount of amylose complexed with native starch lipids ranged from 0.04% to 0.08%, 0.21% to 0.46%, 33.9% to 40.2% and 9.1% to 15.9%, respectively. There was no significant difference in branch chain length distribution of amylopectin among the starches. The X-ray pattern was of the C-type. The relative crystallinity was in the range 31.3–34.4%. Swelling factor and amylose leaching in the temperature range 50–90 °C ranged from 1.6% to 25.9% and 8.61% to 36.1%, respectively. All four starches exhibited nearly identical gelatinization temperatures. However, the enthalpy of gelatinization was in the range 11.2–13.1 J/g, respectively. The starches differed significantly with respect to peak viscosity (3223–4174 cp), breakdown viscosity (394–1308 cp) and set-back (3110–4281 cp). Starches were hydrolyzed by acid to nearly the same extent. The amount of rapidly digestible, slowly digestible and resistant starch contents ranged from 10.9% to 15.7%, 48.5% to 60.2% and 24.1% to 40.6%, respectively.     

Starch from hull-less barley: II. Thermal,rheological and acid hydrolysis characteristics

Gelatinization, granular swelling, amylose leaching, viscosity and acid susceptibility characteristics of starches isolated from 10 hull-less barley (HB) genotypes [zero amylose (CDC Alamo), waxy (CDC candle, SB 94794, SB 94912, and SB 94917), normal amylose (Phoenix, CDC Dawn, SR 93102, and SB 94860) and high amylose (SB 94893 and SB 94897)] were monitored by differential scanning calorimetry (DSC), swelling power (SP), solubility, Brabender viscoamylography, and reaction with 2.2 N HCl (at 35 °C), respectively. DSC data showed that T_o, T_p, T_c, T_c–T_o, and ΔH ranged from 50.1–56.1, 58.1–64.5, 71.0–75.8, 17.9–24.0 °C and 9.6–14.2 J/g of amylopectin, respectively. In compound waxy (SB 94917) and compound normal (SR 93102 and SB 94860) starches, T_o and T_c–T_o were lower and higher, respectively, than in the other starches. ΔH followed the order: compound normal>waxy>normal≈zero amylose>high amylose>compound waxy. The SP followed the order: zero amylose>waxy>compound normal>normal>high amylose. A rapid increase in solubility occurred at lower temperatures (<70 °C) for zero amylose HB starch, however, this increase was gradual for the other starches. At 90 °C, solubility followed the order: high amylose>compound normal>normal>waxy. Zero amylose and waxy HB starches exhibited lower pasting temperatures, higher peak viscosities, and higher viscosity breakdown than normal HB starches. The extent of acid hydrolysis followed the order: zero amylose>compound waxy>waxy>normal>compound normal>high amylose. High correlations were observed between physicochemical properties and structural characteristics of HB starches.     

Studies on the granular structure of resistant starches (type 4) from normal,high amylose and waxy corn starch citrates

Granular and crystalline structure of starch citrates from normal, high amylose and waxy corn starch were characterized using scanning electron microscopy (SEM), optical microscopy, X-ray diffraction and Fourier transform infrared spectroscopy (FT-IR) in this study. SEM showed that citric acid treatment induced changes in the morphology of starch granules. The granule structure of starch citrates was not collapsed or destroyed even after heating. Normal and high amylose corn starch citrates maintained birefringence but lost it upon heating at 100 °C for 30 min. However, waxy corn starch citrate showed no birefringence, even before heating. Starch citrates showed different X-ray diffraction patterns before and after heating. A new peak at 1724 cm⁻¹ (ester bond) was observed in FT-IR for all starch citrates before and after heating, indicating starch citrates were heat-stable. After the deconvolution of spectra, the intensity ratio of 1016 cm⁻¹/1045 cm⁻¹ was used to calculate the ratio of amorphous to crystalline phase in the starch citrates. The ratio of 1016 cm⁻¹/1045 cm⁻¹ increased with an increase in the degree of substitution.     

Formation and stability of amylose ligand complexes formed by high pressure treatment

Starch can be gelatinized during high pressure processing in the presence of water, but to a greater or lesser extent. Starch gelatinization is often accompanied by the formation of amylose complexes, in particular when a thermal treatment is used. Four different starches were considered in this study: potato, broad bean (Vicia faba), pea and tapioca. A comparison between high pressure-induced starch gelatinization (HPG) and conventional thermal gelatinization (TG) was made. In the case of broad bean starch, selected complexing molecules were considered for both thermal and high pressure treatments. Cross polarization/magic angle spinning (CP/MAS) ¹³C NMR, X-ray diffraction and thermal analysis were used to monitor physico-chemical changes in the structure and microstructure of starch preparations. Decanoic acid and carvacrol were selected as complexing agents to track the formation of amylose ligand complexes. It was observed that B-type starch (potato) was more resistant to pressure than the A-type starches (tapioca, broad bean and pea) considered in this study. The results showed that amylose ligand complexes were formed during high pressure treatment (20 min at 500 MPa at temperatures of 20 °C and 40 °C). Decanoic acid induced the complexing of amylose in the V_6I type whatever the treatment used. On the other hand, the complexation of carvacrol appeared to depend on the temperature used during the high pressure treatment. It is assumed that carvacrol forms amorphous complexes with amylose during high pressure treatment. The amylose complexes were characterized by ¹³C CP/MAS NMR confirming the results obtained by X-ray analysis.Industrial relevanceDevelopment of innovative assembly of amylose + molecules of interest (i.e. antioxidant) using a mild processing (40 °C) instead of 90 °C. At 90 °C, some molecules are damaged or oxidized.The use of high pressure permits the production of larger amount of compounds than using conventional thermal treatment. The main reason is that there is no need to solubilise the molecule of interest.     

Chemical composition,digestibility and emulsification properties of octenyl succinic esters of various starches

Octenyl succinate starches are commonly used as emulsifiers and texturizing agents in many food-systems. Rice, tapioca, corn, wheat and potato starches were modified with octenyl succinic anhydride (OSA) at 3% level. Structural characterization, molecular weight, starch digestibility and physical properties of starch granule stabilized emulsions were studied for modified starches. Modified potato (0.022) and wheat (0.018) starches had the highest and lowest degrees of OSA substitution, respectively. For all starches, amylose and amylopectin molecular mass was significantly (P < 0.05) lower for OSA starches. OSA modification may have hydrolyzed the small amylose and amylopectin chains, or caused rearrangement of the starch molecules. Although the starch modification improved emulsification properties, botanical source showed more influence on this parameter. Overall, botanical source had more influence on functional properties than degree of substitution. Further studies on OSA group distribution and fine molecular structure of amylopectin and relationship with functional properties will be important.     

In vitro digestibility,structural and functional properties of starch from pigeon pea (Cajanus cajan) cultivars grown in India

Starches isolated from two pigeon pea cultivars (AL-15 and AL-201) were evaluated for their in vitro digestibility, structural and functional properties. Both the cultivars exhibited a characteristic C-type diffraction pattern with relative crystallinity values of 31.9% and 34.2%, for AL-15 and AL-201, respectively. The structural characterization obtained using high performance size exclusion column chromatography revealed that molecular weight of amylopectin and amylose was higher for AL-201 (396 and 3.92 × 10⁶ g/mol, respectively) in comparison to AL-15 starch (354 and 3.31 × 10⁶ g/mol, respectively). AL-201 exhibited higher values for transition temperatures, enthalpy of gelatinization, pasting temperature and percentage retrogradation in comparison to AL-15 starch. Slowly digestible starch, readily digestible starch and resistant starch contents of AL-15 and AL-201 cultivars were observed to be 31.0, 8.1 and 60.9% and 29.6, 5.2 and 65.2%, respectively. The hydrolysis index and RS values indicated that pigeon pea starches were highly resistant to digestion.     

Effect of single and dual hydrothermal treatments on the crystalline structure,thermal properties,and nutritional fractions of pea,lentil, and navy bean starches

Pea, lentil and navy bean starches were annealed at 50 °C (70% moisture) for 24 h and heat-moisture treated at 120 °C (30% moisture) for 24 h. These starches were also modified by a combination of annealing (ANN) and heat-moisture treatment (HMT). The impact of single and dual modifications (ANN–HMT and HMT–ANN) on the crystalline structure, thermal properties, and the amounts of rapidly digestible starch (RDS), slowly digestible starch (SDS), and resistant starch (RS) were investigated. Birefringence remained unchanged on ANN but decreased on HMT. Granular swelling and amylose leaching decreased on ANN and HMT. Relative crystallinity, gelatinization enthalpy, and short-range order on the granule surface increased on ANN but decreased on HMT. Gelatinization transition temperatures increased on ANN and HMT. Gelatinization temperature range decreased and increased on ANN and HMT, respectively. ANN and HMT increased SDS and decreased RS levels in all starches. However, RDS levels increased on ANN and HMT in pea and lentil starches but decreased in navy bean starch. In gelatinized starches, ANN and HMT decreased RDS level and increased SDS and RS levels. Changes to crystalline structure, thermal properties and amounts of RDS, SDS, and RS were modified further on ANN–HMT and HMT–ANN.     

Effect of maize type and extrusion‐cooking conditions on starch digestibility profiles

This study aimed at evaluating the influence of screw speed (250–600 rpm), barrel temperature (100–160 °C) and water content (16.4–22.5%) on rapidly digestible (RDS), slowly digestible (SDS) and resistant (RS) starch levels of waxy, normal and high‐amylose maize starches. In native starches, an increase in amylose content was correlated with lower SDS content. After extrusion, this trend was reversed. Both waxy and normal maize starches became rapidly digested. However, for normal maize starch, some SDS fraction remained. In contrast, the high‐amylose maize starch showed a significant increase in digestibility and an increase in SDS content from 20.4% in the native starch up to 27.5% after extrusion. This high level of SDS may be attributed to the presence of some remaining granular structures and formation of crystalline orders, which have slow digestion properties.     

Effect of acid hydrolysis in the presence of anhydrous alcohols on the structure,thermal and pasting properties of normal,waxy and high‐amylose maize starches

Maize starches with different amylose contents (0%, 23% and 55%) were treated in anhydrous methanol, ethanol, 2‐propanol, 1‐butanol with 0.36% HCl at 25 °C for 5 days. Results showed that the extent of change in physicochemical properties increased from methanol to butanol. Treated waxy maize starch showed higher than 65% solubility at above 75 °C. The diffraction peak at 2θ = 5.3° of amylomaize V starch disappeared after treatment in ethanol, 2‐propanol and 1‐butanol. Acid–alcohol treatment decreased the gelatinisation temperature of normal (from 64.5 to 61.9 °C) and waxy maize (from 68.1 to 61.1 °C) starches, while it increased that of amylomaize V (from 68.7 to 72.3 °C) starch. The extent of the decrease in the pasting viscosity followed the following order: amylomaize V < normal maize < waxy maize. This study indicated that acid–alcohol treatment degraded preferentially the amorphous regions and the different changes depended on the crystal structure and amylose content of starch.     

Amylose and β‐Glucan Content of New Waxy Barleys

Starch was isolated from four new waxy barleys and compared with normal and high‐amylose barley starch. The waxy barley samples were selected lines from crosses of Swedish hulled and naked barley cultivars with the cultivar Azhul as donor of the waxy gene. The starches from the waxy barley samples were found to contain 0.7–2.6% amylose when determined iodimetrically by amperometric titration and 0.0–0.9% when determined by size exclusion chromatography after debranching. However, Sepharose CL‐2B elution profiles of the starches detected by iodine staining showed that all four waxy samples were free from detectable amounts of amylose. The amylopectin starches were found to contain a small polysaccharide fraction with molecular size smaller than amylopectin, with an iodine staining λ_max range of 550–600 nm. The water extractable and acid extractable β‐glucan contents in the waxy barley cultivars were generally found to be higher than those in normal barley.     

Thermostabile Bindung von Aromastoffen an Stärke Teil 1: Bindung durch Gefriertrocknen

Thermostable Binding of Aroma Compounds to Starch. Part 1: Binding by Freeze-Drying. By freeze-drying of aqueous emulsions or suspensions of menthol, pyrazine, thymol, vanillin or peppermint oil and solutions of native or modified starches, amylose, amylopectin Or β-cyclodextrin sorbates were prepared. After heating to 180°C the aroma compounds were bound thermostable and in most cases also stable during extrusion. In general the adsorbed amounts decreased in the order cyclodextrin, amylose, potato starch, waxy maize starch, maize or tapioca starch, wheat starch, amylopectin. Some modified maize starches adsorbed greater amounts than native maize starch. Menthol and thymol were better bound to high-amylose starches, vanillin and pyrazine better to high-amylopectin starches, but vanillin best to cyclodextrin and pyrazine to maltodextrin (DE 4–5). The desorption of the aroma compounds during chewing in the mouth was limited after formation of channel inclusion compounds with amylose.     

Effect of pH on aqueous structure of maize starches analyzed by HPSEC-MALLS-RI system

Molecular conformation of maize starches (waxy, normal and high amylose) was examined at different pH values (5–10) using an aqueous medium-pressured size exclusion column chromatography (SEC) connected to multi-angle laser light scattering (MALLS) and refractive index (RI) detectors. The starch molecules were partially degraded at pH 5 and 10, resulting in lower values for molar size and radius of gyration than those in neutral condition. The specific volume data revealed that the structural changes under an alkaline condition such as pH 10 was more significant for amylose than that for amylopectin. Logarithmic ratios between molar size and radius of gyration were similar (0.2–0.3) for the amylopectins in waxy and normal maize starches, but higher (0.4–0.5) for the amylopectin in high amylose starch, indicating that the amylopectins in waxy or normal maize starches had sphere forms whereas that in high amylose starch had a random coil shape.     

Enthalpy–entropy compensation in sorption phenomena of starch materials

The enthalpy–entropy compensation theory was applied to the experimental moisture adsorption and desorption isotherm data (water activity (a_w) range 0.006–0.982) of raw potato, potato starch gel, potato starch powder, highly amylopectin corn starch powder and highly amylose corn starch powder in the temperature range 30–60 °C. A linear relation existed between differential enthalpy (ΔH) and differential entropy (ΔS) for all the experimental data considered, thus satisfying the enthalpy–entropy compensation theory. Further analysis of the data indicated an enthalpy-controlled (isokinetic temperature (T_β) > harmonic mean temperature (T_hm)) and spontaneous (−ΔG) sorption process.     

Steady and oscillatory shear behaviour of semi-concentrated starch suspensions

The viscoelastic moduli G’ and G” of aqueous suspensions with 40% (w/v) normal corn starch (NCS) and waxy corn starch (WCS) were determined by oscillation rheometry. The oscillatory shear flow experiments at heating from 30° to 75 °C and maintaining at this temperature showed changes from a behaviour predominant viscous (G”>>G’) to predominant elastic (G’>G”) for both starches at 60.5 °C for WCS, respectively 70,85 °C for NCS, WCS having higher values of G’ and G” as NCS. After the gelatinisation temperature was attired, NCS showed no significant changes, both moduli remaining relatively constant. Peaks of both moduli G’ and G” were obtained for WCS at its maintaining at 75^oC, these changes being attributed to the changes in the amylopectin structure in the absence of amylose for this starch type. The frequency influenced the results; analysis at constant low frequency (10 s^-1) gave big oscillations during the measurements and made the analysis impossible, whereas frequencies as 50 s^-1 or 100 s^-1 gaves reproducible and similar results. The shear flow measurements realised at angular frequencies ω from10^-1 to 10³s^-1 at 25^oC showed that changes from a behaviour predominant elastic (G’>G”) to predominant viscous (G”>>G’) occurred when ω attired the values 10 s^-1 for WCS and 3 s^-1 for NCS. The calculation of the ‘Power-Law’ parameter B showed that NCS forms a physical gel structure, whereas WCS behaves as a covalent gel in the frequency domain 10^-1 to 10 s^-1 and as physical gel in the frequency domain 10 to 10² s^-1.     

Influence of hydroxypropylation on retrogradation properties of native,defatted and heat-moisture treated potato starches

Recent studies have shown that defatting and heat-moisture treatment cause structural changes within the amorphous and crystalline regions of potato starch. Furthermore, the alkaline reagents (NaOH and Na₂SO₄) used during hydroxypropylation has been shown to cause structural changes within the amorphous and crystalline regions of native, defatted and heat-moisture treated starches. In this study, we have compared (using different techniques) the retrogradation properties of potato starch before and after physical (defatting and heat-moisture treatment), and chemical (alkaline treatment and hydroxypropylation) modification. Turbidity measurements showed that changes in turbidity during storage (4°C for 24 h and then at 40°C for 29 days) of native, defatted and heat-moisture treated gelatinized starch pastes were influenced by the interplay of two factors: (1) interaction between leached starch components (amylose–amylose, amylose–amylopectin, amylose–amylopectin), and (2) interaction between granule remnants and leached amylose and amylopectin. In alkali treated gelatinized native, defatted and heat-moisture treated starch pastes, turbidity changes on storage was influenced by aggregation of granule remnants. Hydroxypropylation decreased the rate and extent of increase in turbidity during storage of native, defatted and heat-moisture treated starches. The change in turbidity during storage of hydroxypropylated starch pastes was influenced by the interplay between: (1) steric effects imposed by hydroxypropyl groups on chain aggregation, (2) aggregation between small granule remnants, and (3) settling of large granule remnants beneath the path of the spectrophotometer beam. Stored gelatinized pastes of native, defatted and heat-moisture treated starches gave a `B' type X-ray pattern. A similar pattern was also observed after alkaline treatment, and hydroxypropylation. However, the X-ray intensity of the strong reflection at 5.2 Å decreased after alkaline treatment and hydroxypropylation. The retrogradation endotherm (monitored by differential scanning calorimetry) occurred after 2 days storage in native, defatted and heat-moisture treated starches. A similar trend was also observed after alkaline treatment. However, the retrogradation endotherm appeared only after 7 days in hydroxypropylated starches. The enthalpy of retrogradation in all starches decreased on alkaline treatment and hydroxypropylation.     

Effect of storage proteins on pasting properties and microstructure of Thai rice

This study investigated the influences of rice storage proteins, in relation to amylose content, on pasting properties of newly harvested Thai rice. The polished rice cultivars investigated included waxy rice SPT1, which contained 1.3% amylose and 8.3% protein; and non-waxy rice, namely PTT1 and LPT123, which contained 14.1% and 28.6% amylose, and 6.7% and 9.6% protein, respectively. The characteristics of protein fractions were altered by accelerated aging at 60 °C and 70% relative humidity (RH) for 5 days, and/or by alkali deproteinisation and cysteine addition during Rapid Visco Analyser (RVA) pasting characterisation. Accelerated aging, deproteinisation and the reduction of disulfide bonds changed the RVA pasting curves of all Thai rice cultivars, particularly the waxy one (p < 0.05). This study has quantified the contribution of protein in relation to amylose on the RVA pasting profiles and demonstrated that protein and starch were in separated phases after heating. The continuity of the protein network in cooked non-waxy rice grains observed under confocal laser scanning microscopy (CLSM) indicated bi-continuous structure of starch and protein phases.     

Amylose Chain Association Based On Differential Scanning Calorimetry

Amylose and lipid depleted starches from amylomaize, pea, maize, wheat, potato, and waxy maize were heated from 20°C to 180°C, cooled to 4°C, and then reheated to 180°C in a differential scanning calorimeter (DSC) in excess water. Cooling curves of the amylose and starch melts showed exothermic transitions (< 70°C) attributed to the mechanism of amylose chain association. Amylose/amylopectin mixtures covering the range 0–95% amylose were similarly heated and cooled. The association of linear amylose chains was restricted by amylopectin.     

Formation of starch spherulites: Role of amylose content and thermal events

Commercial maize starches and potato starches of two cultivars differing in physicochemical composition (granule size distribution; amylose to amylopectin ratio) and crystallinity were heated to 180 °C and then cooled by fast quench using a differential scanning calorimeter (DSC), in order to produce spherulitic starch morphologies. Among the raw maize starches, waxy maize starch had highest relative crystallinity (49%) whereas a lowest crystallinity of 33–39% was calculated for high-amylose maize starches. Potato starches showed a relative crystallinity of 50%. The temperatures and enthalpies of gelatinisation and melting varied among all the starches. High-amylose maize starches showed higher transition temperatures of gelatinisation (T_gel), whereas waxy maize starch had lowest T_gel and enthalpy of gelatinisation (ΔH_gel). Similarly, a considerable variation in parameters related with crystalline melting (T_m1, T_m2 and ΔH_m1, ΔH_m2) was observed for different starches. The superheated gels of different starches treated using DSC were subjected to polarised microscopy, to confirm the formation of spherulites. Both the high-amylose starch gels showed the presence of spherulites exhibiting birefringence and a weak crystalline pattern. No birefringence was observed for waxy maize starch gel, while potato starch gels had some birefringence. The particle size distribution of high-amylose maize starch gels analysed through Zetasizer showed the sizes of spherulitic particles fall in the range of 300 nm–900 nm. The scanning electron micrographs of the dried high-amylose maize starch gels showed the presence of round spherulites consisting of several aggregated spherulitic particles. Amylose content and melting of crystallites during heating play an important role during recrystallisation of amylose (spherulite morphologies).