Surface Of Starch Granules Research Articles

Morphological, functional and thermal characteristics of hydroxypropylated-crosslinked barley starches

The present study investigated effects of three different levels of crosslinking using a mixture of sodium trimetaphosphate (STMP) and sodium tripolyphosphate (STPP) on hydroxypropylated barley starches. Hydroxypropylated barley starches crosslinked with 1%, 1.5% and 2% mixture of STMP and STPP were coded as HPCL(1), HPCL(1.5) and HPCL(2.0), respectively. However, the level of hydroxypropylation employed was same for all the modifications i.e. 6%. The results showed that increase in level of crosslinking increased swelling power, solubility and water holding capacity of starches. HPCL(2.0) starch demonstrated noticeably lower percent transmittance, higher percent retrogradation and elevated peak viscosity. Harder gels were produced by dual modified barley starches. A decline was observed in thermal transition temperatures after dual modification. FTIR was unable to detect much difference among different samples. However, peak at 1414 cm−1 associated with hydroxypropylation was detected. Hydroxypropylation followed by crosslinking led to roughness and grooves formation on the surface of barley starch granules.

Dual modification of achira (Canna indica L) starch and the effect on its physicochemical properties for possible food applications.

The aim of this study was to evaluate the effect of acid hydrolysis and succination upon single and a combination of both of them as a dual modification on the morphological, structural, thermal, and pasting profile of the achira starch in order to expand its potential food applications. The surface of achira starch granules was eroded with acid hydrolysis, while the succination resulted in the formation of pores or cavities, having a slight impact on the crystallinity and the gelatinization enthalpy. Succinated starch presented the lowest transition temperatures (To = 60.29°C, Tp = 65.03°C and Te = 69.86°C) compared to other starches in this study. The succination increased the final viscosity (3808 cp) when compared with the native starch (3114 cp), while acid hydrolysis resulted in a decreased value (735 cp). These are desirable properties for its possible use as an additive in bakery industry processes.

Amylose-lipid complex formation from extruded maize starch mixed with fatty acids

Functional modifications of starch, such as paste properties, retrogradation, water absorption indexes, solubility, and swelling capacity, are induced by the amylose-lipid complex. This research comprehends the study of functional properties of extruded maize starch mixed with fatty acids (stearic acid, oleic acid, and maize oil) and the formation of amylose-lipid complexes. Maize starch with lipids (5 or 10 %), moisture (35 %) was extruded (single screw). Starch granule was modified by extrusion, to a lesser extent at 10 % of lipids, especially stearic acid, which covers starch granule surface. Viscosity decreased meaningfully with stearic acid addition. DSC showed both starch gelatinization enthalpy and amylose-lipid complex enthalpy for stearic or oleic acid, but it was just the first enthalpy for maize oil. X-ray diffraction showed orthorhombic crystals with or without the presence of lipids. Our results indicated that stearic acid yielded the highest amount of amylose-lipid complexes.

Effect of porous waxy rice starch addition on acid milk gels: Structural and physicochemical functionality

Waxy rice starch granules were digested by amyloglucosidase at 50 °C for up to 24 h. Granular and lamellar structures of the digested starch granules were studied using particle sizing, scanning electron microscopy (SEM), ultra-small angle neutron scattering (USANS), and small-angle X-ray scattering (SAXS). The appearance of spherical pores on the starch granule surface upon enzymatic digestion is identified by SEM. USANS was able to monitor changes in the pore polydispersity as digestion progressed. The size of the digested starch granules decreased with digestion time up to 8 h owing to enzymatic degradation. Excessive digestion (15 h and 24 h) resulted in a slight increase in apparent starch granule diameter, suggesting that the particles might be swollen or aggregated. Thermal (50 °C) and enzymatic treatments of the starch granules induced a destruction of the starch internal lamellar structures, with enzymatic digestion showing a more prominent effect. Incorporation of the digested starch granules into acid milk gels in a pasted form resulted in a decrease in elasticity, while their incorporation in a granular form resulted in a marked (nearly 3-fold) increase in the elasticity of the acid milk gels.

Removal of starch granule-associated proteins promotes α-amylase hydrolysis of rice starch granule.

Starch granule-surface proteins (SGSPs) and granule-channel proteins (SGCPs) are granule-associated proteins (SGAPs), which have been found to be distributed on the surface and channels of starch granules, respectively. To investigate the impacts of SGAPs on α-amylase hydrolysis of starch, SGCPs or SGAPs of waxy, low and high amylose rice starches were removed. Removal of SGAPs or SGCPs greatly increased hydrolysis rate of rice starches. Meanwhile, these granules incurred a greater number and size of pores on their surfaces during hydrolysis. Compared to low and high amylose starches, waxy starch before and after removing SGAPs exhibited a higher hydrolysis rate. Rice starch hydrolysis began with enlargement of cavity and channels both horizontally and vertically. XRD analysis revealed that removal of SGAPs decreased relative crystallinity (RC) of starch and advanced changes in RC during hydrolysis process. This study provides new information about the role of SGAPs in the mechanisms of α-amylase hydrolysis.

Effect of natural fermentation on milled rice grains: Physicochemical and functional properties of rice flour

This study examined the effects of natural fermentation on rice components to understand how fermentation affects the physicochemical and functional properties of rice flour. We found that natural fermentation for 72 h had almost no effect on the structural properties of rice starch and slightly affected the protein content and composition. The charged amino acid content of rice flour decreased after fermentation, while the surface hydrophobicity increased. The surface charge of rice flour increased from −12.7 mV before fermentation to +7.06 mV after 72 h of fermentation. The reduced protein content in fermented rice flour increased the gelatinization enthalpy of rice flour to a level similar to that of starch, and enhanced starch granule expansion, resulting in an increased peak viscosity and granule breakdown, but decreased final viscosity, setback, and pasting temperature. Differences in the protein composition, surface hydrophobicity, and surface charge between fermented and non-fermented rice flour explained the greater hardness of fermented rice flour. We conclude that natural fermentation can improve the functional properties of rice flour through protein modification on the starch granule surface.

Structural, rheological, pasting and textural properties of granular cold water swelling maize starch: Effect of NaCl and CaCl2

In this study granular cold water swelling (GCWS) starches were subjected to 0, 50, 100, 150 and 200 mM NaCl and CaCl2 and their effects on microstructure, rheological, pasting, and textural properties were determined. SEM images revealed that NaCl decreased the thickness of GCWS starch paste cell walls while, CaCl2 resulted in formation of denser and more homogenous pastes. The atomic force microscopy (AFM) results showed that NaCl increased the surface wrinkles of starch granules but CaCl2 reduced the roughness of starch granule surface. Zeta potential measurements showed both salts reduced the negative values and CaCl2 was more effective than NaCl. The steady shear measurements showed the shear thinning behavior of the samples. Starch pastes incorporated with NaCl had lower consistency coefficient (K) and apparent viscosity. However, the CaCl2 containing samples were more viscous. The pasting and textural parameters were increased by the increase of CaCl2 but decreased with NaCl.

Effects of nitrogen fertilizer on structure and physicochemical properties of ‘super’ rice starch

Nitrogen fertilizer is an essential nutrient for rice (Oryza sativa L.), especially, for newly bred ‘super’ rice cultivars with great yield potential. The effects of nitrogen fertilizer (0, 100, 200, 300, 400 kg N ha−1) on the physicochemical properties of two high yielding ‘super’ rice Yongyou 2640 and Lianjing 7 were investigated in this study. The application of nitrogen fertilizer affects the structure of rice starch, thus changing its functional properties, which ultimately leads to a change in the quality of both rice cultivars. There were dose effects of nitrogen fertilizer on grain quality. Grain quality was improved under moderate nitrogen inputs (100 & 200 kg N ha−1), but deteriorated at excessive nitrogen levels (300 & 400 kg N ha−1). With moderate N application, starch granule size increased and the surface of starch granule became smoother; there were higher proportion of short branch-chain of amylopectin and lower proportion of long branch-chain of amylopectin with low relative crystallinity, lower degree of order of structure and higher content of amorphous structure at the outer region of the starch granules; peak viscosity, hot viscosity, breakdown value were increased while setback and pasting temperature were decreased; gelatinization temperature, gelatinization enthalpy, retrogradation enthalpy, retrogradation percentage, hardness were decreased while viscosity were increased. At excessive nitrogen inputs, the grain quality was deteriorated and the opposite results of structure and physicochemical properties of rice starch were observed. These results indicate that nitrogen fertilizer significantly affected the structure and physicochemical properties of rice starch, and appropriate fertilization would improve rice grain quality.

Effect of heat-moisture treatment on the in vitro digestibility and physicochemical properties of starch-hydrocolloid complexes

The effect of heat-moisture treatment (HMT) on the in vitro digestibility and physicochemical properties of starch-hydrocolloid complexes of various structures was investigated, employing Gum Arabic, Xanthan Gum, and Guar Gum. HMT was performed at 120 °C for 4 h with a starch moisture content of 20%. HMT was shown to increase the slowly digestible starch content from 6.89% to 11.41%, and that of resistant starch from 7.02% to 18.04%. After blending with hydrocolloids, digestibility can be further reduced, with a Guar Gum-starch complex (1:40 ratio) showing the lowest rate of digestion. Scanning electron microscopy (SEM) and particle size analysis revealed that starch granules aggregated due to hydrogen bond interactions. Starch granules formed larger aggregates in the presence of Xanthan Gum or Guar Gum than Gum Arabic. SEM also demonstrated that the surface of starch granules became smoother after HMT. Rapid viscosity analysis and differential scanning calorimetry revealed that HMT significantly reduced the peak viscosity and setback of starch and significantly delayed gelatinization onset, peak, and conclusion temperatures. Finally, X-ray diffraction revealed that the A-type crystal form of the complexes was unaltered, but the relative crystallinity decreased. Overall, this study provides useful information for the development of healthful, low-GI, functional foods.

Repeated Heat-Moisture Treatment: a more EffectiveWay for Structural and Physicochemical Modification of Mung Bean Starch Compared with Continuous Way

Effects of repeated heat-moisture treatment (RHM) and continuous heat-moisture treatment (CHM) on structural, physicochemical, and digestibility properties of mung bean starch were investigated. Rupture and scallops appeared on the surface of starch granules and some polarization cross disappeared after CHM and RHM. Besides, CHM starch exhibited severe rupture than RHM with the same treatment time. Crystal type of CHM and RHM starch maintained A-type while crystallinity decreased first but then increased as treating time increased. Besides, the relative crystallinity, transition temperatures, ΔH, and slowly digestible starch and rapidly digestible starch content of RHM were significantly higher than CHM whereas solubility, swelling power, and pasting viscosities of RHM samples were lower than CHM under the same treating time. Overall, RHM measures have more advantages than CHM in the modification of the structural, physicochemical, and digestibility properties of starch.

Gaseous Ozonation at Low Concentration Modifies Functional, Pasting, and Thermal Properties of Arrowroot Starch (Maranta arundinaceae)

AbstractGaseous ozone at 13 parts per million (ppm) is applied repeatedly (10–30 cycles) to oxidize dry arrowroot starch. The ozonation increases carboxyl content of the starch by 0.13–0.52%. The starch granule surface becomes rougher and it exhibits a presence of fissure particularly at 30 cycles. Crystallinity decreases with the increase of ozonation cycle but the A‐type pattern of the native starch remains unchanged. Swelling volume, solubility, water absorption capacity, and gel strength of the native starch increases following ozonation particularly at 30 cycles. Freeze–thaw stability is also augmented as indicated by a decrease in syneresis. The ozonation at 10, 20 and 30 cycles remarkably decreases the syneresis of native starch (5.24%) to 0.02%, 0.002% and 0.001% respectively. No effect of ozonation on pasting point is observed but an increase of values of the other pasting properties is noted. Regarding thermal properties, the ozonation increases T0 of the arrowroot starch. The decrease in ΔT, along with the increase in ΔH of the ozonated starch, suggests that the ozonation leads to the formation of more homogenous and stronger crystallites. Overall, the effectiveness of gaseous ozonation at low concentration on modifying starch properties is dependent on the number of ozonation cycles.

Effect of hydrophobized starch granules on cereal foods - Importance of wheat starch granule surface protein

Effect of hydrophobized starch granules on cereal foods - Importance of wheat starch granule surface protein

Impact of maltogenic α-amylase on the structure of potato starch and its retrogradation properties

Structural modification of starch using efficient α-amylases to improve its properties is an established method in the starch industry. In our previous research, the novel maltogenic α-amylase CoMA that catalyzes multi-molecular reactions has been identified. In this study, the impact of CoMA on the structure and retrogradation properties of potato starch was evaluated. CoMA cleaves internal starch chains to change the proportion of amylose and amylopectin in starch. Following treatment, visible pores and microporous on the surface of starch granules were observed from SEM analysis. CoMA modification led to increased insoluble blue complex formation and hydrolysis to shorten the outer chains, which was found to reduce the development rate of starch according to network interactions from the dynamic rheological analysis. Furthermore, maltose accumulation with water competition was also deduced to be involved in the inhibition of retrogradation. Its activities in the cleavage of internal starch granules, shortening of outer chains of starch, and maltose formation make CoMA a powerful agent for the inhibition of starch retrogradation with a very low effective dose of 0.5 mg/kg, which may find potential applications in the starch processing industry.

Synthesis and characterization of lactic acid esterified starch by an in-situ solid phase method

To improve the hydrophobicity and thermoplastic processability of starch, lactic acid esterified starch (LA-e-starch) was prepared by in-situ solid phase esterification with corn starch as the raw material and LA as the esterifying agent. Fourier transform infrared spectroscopy confirmed that the esterification reaction was successful. The optimal esterification efficiency of LA-e-starch was obtained when the LA proportion was 20% by mass, catalyst ratio at 3%, reaction temperature 80 °C and reaction time 2.5 h. LA-e-starch was characterized by scanning electron microscopy (SEM), contact angle (CA) analysis, X-ray diffractometry (XRD), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA) as well as its water absorption rate evaluated. Results showed that in-situ solid phase esterification mainly occurred on starch granule surfaces and did not destroy the starch granularity. LA-e-starch surfaces were covered with a layer of polylactic acid resin, which caused starch granules to stick together. The initial contact angle of LA-e-starch was clearly larger than that of native starch and the water absorption rate lower than native starch in a 168 h test time, which showed that esterification effectively improved the hydrophobicity of starch. This esterification destroyed the crystalline structure of starch to some extent, resulting in a crystallinity reduction to 25.16%. In addition, the gelatinization temperature and enthalpy were lower than those of native starch. XRD and DSC analyses indicated that esterification modification increased starch thermoplasticity. Also, LA-e-starch exhibited better thermal stability than native starch, from which it was inferred that this application of esterification could improve the thermoplastic processability of starch modify the interfacial compatibility between starch and polymer resins.

Effect of pulsed electric field on properties and multi-scale structure of japonica rice starch

Rice accounts for more than half the global population as staple food with starch predominating the major component. The effect of pulsed electric field (PEF) on thermal, paste and digestible properties, morphology, and hierarchical structure of rice starch in solid state was investigated. Upon PEF treatment, the gelatinization enthalpy (ΔΗ) of starch decreased, the retrogradation value of starch paste decreased slightly; and the rapid digestible starch (RDS) increased, the slowly digestible starch (SDS) decreased and the resistant starch (RS) changed slightly. PEF might act on the outer structure of starch granules, slightly changed the molecular structure of rice starch by rearranging the short-range structure and damaging the amorphous and crystalline structure. Pearson correlation analysis suggested that molecular weight of amylopectin, ΔΗ and digestibility were strongly dependent on the electric field strength; the changes in multi-scale structure was closely related to those in properties of PEF. The improvement of digestibility of rice starch might be attributed to the disruption of starch granule surface as evidenced by SEM observation and the rearrangement of multi-scale structures of rice starch induced by PEF.

Effects of high-voltage electric field treatment on physicochemical properties of potato starch

The application of a high-voltage electric field (HVEF) is a novel method for starch. First, potato starch slurry (20%, w/w) were subject to HVEF treatment at 10, 20, 30 and 40 kV, and the treatment time was 10, 20, 30, 40, 50 min respectively. Then, the modified starch was characterized by using X-ray diffraction (XRD), Fourier transformation infrared (FT-IR) spectroscopy, pasting behavior, water absorption capacity (WAC), light transmission and scanning electron microscopy (SEM). The results showed that HVEF caused a shift in the gelatinization range to lower temperatures, and a decrease in solubility, swelling power and crystallinity. HVEF was evidenced to change WAC and Light transmittance, with a tendence firstly increase and then decrease with the increasing of the treatment time. The SEM micrographs demonstrated that some roughness or damages emerged on the surface of potato starch granules after HVEF treatments. The X-ray diffraction showed that the decrease of crystallinity during the HVEF treatment. It was concluded that HVEF destroyed amorphous area and surface crystalline zone of starch.

LIKE SEX4 1 Acts as a β-Amylase-Binding Scaffold on Starch Granules during Starch Degradation.

In Arabidopsis (Arabidopsis thaliana) leaves, starch is synthesized during the day and degraded at night to fuel growth and metabolism. Starch is degraded primarily by β-amylases, liberating maltose, but this activity is preceded by glucan phosphorylation and is accompanied by dephosphorylation. A glucan phosphatase family member, LIKE SEX4 1 (LSF1), binds starch and is required for normal starch degradation, but its exact role is unclear. Here, we show that LSF1 does not dephosphorylate glucans. The recombinant dual specificity phosphatase (DSP) domain of LSF1 had no detectable phosphatase activity. Furthermore, a variant of LSF1 mutated in the catalytic cysteine of the DSP domain complemented the starch-excess phenotype of the lsf1 mutant. By contrast, a variant of LSF1 with mutations in the carbohydrate binding module did not complement lsf1 Thus, glucan binding, but not phosphatase activity, is required for the function of LSF1 in starch degradation. LSF1 interacts with the β-amylases BAM1 and BAM3, and the BAM1-LSF1 complex shows amylolytic but not glucan phosphatase activity. Nighttime maltose levels are reduced in lsf1, and genetic analysis indicated that the starch-excess phenotype of lsf1 is dependent on bam1 and bam3 We propose that LSF1 binds β-amylases at the starch granule surface, thereby promoting starch degradation.

Effects of debranching and repeated heat-moisture treatments on structure, physicochemical properties and in vitro digestibility of wheat starch

In this study, wheat starch (WS) was firstly debranched with pullulanase (PUL) and then subjected to repeated heat-moisture treatments (RHMT). The effects of PUL and RHMT on the structure, physicochemical properties and in vitro digestibility of WS were investigated. The proton nuclear magnetic resonance spectroscopy confirmed that the ratio of α-1,6 glycosidic linkage decreased. Raman and Fourier transform-infrared spectroscopy demonstrated that more ordered structure of starch was formed. Differential scanning calorimetry and X-ray diffraction analysis revealed that RHMT could enhance thermal stability and degree of crystal perfection of PUL-WS sample. Scanning electron microscopy results showed that more agglomerates appeared on the surfaces of RHMT starch granules. The swelling power and solubility significantly decreased after HMT. Additionally, the resistant starch (RS) content of RHMT samples significantly increased. These results suggest that debranching and RHMT can significantly change the physicochemical properties and digestibility of WS, and it’s beneficial to the RS formation.

Structural, Physicochemical, and Functional Properties of Electrolyzed Cassava Starch.

Cassava starch was oxidized using the electrolysis system. Sodium chloride was added to this system at various concentrations from 0.5 to 5.0 % (w/v). The whiteness of modified starches proportionally increased based on the NaCl concentration and human eyes could recognize the difference of color. Under treatment, dents occurred on the surface of starch granule. Concentration of carbonyl and carboxyl groups was increased compared to native starch. Based on X-ray diffraction pattern, oxidized starch kept its A-type. Besides, the ratios of alpha-helix/amorphous regions remained indicating oxidation reaction mainly subjected on amorphous region. Intrinsic viscosity was used to indirectly calculate the average molecular weight of sample. Furthermore, results showed that average molecular weight was significantly reduced (from 2.09-fold to 13.22-fold) based on the reacting NaCl concentration. The increase of NaCl content related to the increase of retrogradation of treated starches. At various temperatures (30-95°C), swelling factor and clarity reflected negative and positive correlations to NaCl concentration.

Effect of natural fermentation on the structure and physicochemical properties of wheat starch

In this study, the effects of natural fermentation on the multi-scale structure and physicochemical properties of wheat starch were investigated. The results showed that fermentation reduced weight-average molecular weight (Mw) and slightly eroded the starch granule surface. An obvious increase in relative crystallinity from X-ray diffraction was observed in all fermented starch (39.38–42.27%) when compared with native starch (37.15%). Data from small angle X-ray scattering revealed that fermentation increased the crystalline layer and decreased the amorphous region of the starch granules. The intensity of absorption related to hydrogen bonding by FT-IR (3000–3600 cm−1) also increased in fermented starch. The rapid viscosity analysis results showed that fermented starch had a lower peak viscosity and final viscosity, and a lower setback value than native starch. The present results reveal that fermentation is an effective method to modify wheat starch and suggest its potential to improve the quality of starch-based foods.