Waxy Maize Starch Research Articles

Position of modifying groups on starch chains of octenylsuccinic anhydride-modified waxy maize starch

Octenylsuccinic anhydride (OSA)-modified starches with a low (0.018) and high (0.092) degree of substitution (DS) were prepared from granular native waxy maize starch in aqueous slurry. The position of OS substituents along the starch chains was investigated by enzyme hydrolysis followed by chromatographic analysis. Native starch and two OS starches with a low and high DS had β-limit values of 55.9%, 52.8%, and 34.4%, respectively. The weight-average molecular weight of the β-limit dextrin from the OS starch with a low DS was close to that of the β-limit dextrin from native starch but lower than that of the β-limit dextrin from the OS starch with a high DS. Debranching of OS starches was incomplete compared with native starch. OS groups in the OS starch with a low DS were located on the repeat units near the branching points, whereas the OS substituents in the OS starch with a high DS occurred both near the branching points and the non-reducing ends.

Structure and physicochemical properties of octenyl succinic esters of sugary maize soluble starch and waxy maize starch

The structure and physicochemical properties of octenyl succinic anhydride (OSA) starches prepared from sugary maize (SMSS) and waxy maize (WMS) were studied and compared. The degree of substitution (DS) increased linearly with the amount of OSA, while the DS of OSA-SMSS was higher than that of OSA-WMS using equivalent modification conditions. FT-IR analysis indicated that two characteristic peaks, at 1725 and 1570cm−1, were observed for OSA-starch. The weight-average of the molar mass (Mw) and z-root mean square radius of gyration (Rz) of SMSS increased with increased OSA esterification substitutions, whereas Mw was reduced and Rz was nearly constant for WMS. The zeta-potential and emulsifying activity increased with DS for starch modified with OSA. OSA-SMSS (DS of 0.0192) was the best material for stable oil-in-water emulsion preparation. The increase of DS in OSA-starch resulted in a substantial reduction of RDS content with an accompanying increase of SDS and RS. This study revealed the potential application of OSA-SMSS as a particle stabilizer of oil-in-water emulsion, which would allow encapsulate and protect functional food components.

Effect of microwave thawing on microstructure and physicochemical stability of low fat white sauces made with soy protein

The microstructural and physicochemical stability of white sauces made with soy protein and modified waxy maize starch was evaluated after subjecting them to a freezing-thawing process in a conventional or microwave oven. The microstructure of sauces revealed a structured matrix of soy protein and starch polymers where fat globules and swollen starch granules remain dispersed. Both thawing methods affected the fat globule size and morphology but they did not affect the starch granules. The SDS-PAGE analysis did not show any apparent changes between sauces thawed by both methods. Moreover, a similar pattern was found in the soy protein isolate used as a raw material indicating that this type of protein was also stable to the cooking process. There were no significant differences (P > 0.05) in the reducing power of the sauces regardless of the thawing method used. However, the acidity index and the k<sub>232</sub> parameter were significantly higher (P < 0.05) in conventionally thawed sauces. Finally, syneresis was negligible and no significant differences (P > 0.05) were found among different frozen storage periods. In conclusion, the formulation of the sauce is appropriate to develop low fat, vegetarian meals which can be subjected to frozen storage and microwave reheating.

Long-term stability of waxy maize starch/xanthan gum mixtures prepared at a temperature within the gelatinization range

The retrogradation behavior of waxy maize starch pastes with added xanthan gum was investigated. The pastes were prepared with or without added xanthan gum at two starch concentrations (5:100 and 7:100), at two temperatures within the gelatinization range (70°C or 72°C) and at acid or neutral pH. The evolution of the macrostructure (texture, flow behavior and syneresis), microstructure (oscillation rheology) and molecular aggregation (pulsed-field NMR) of the pastes was followed up in an 8week period during cold storage (7°C). Heating temperature was found to have a profound effect on the long-term stability of the pastes. Pastes prepared at 70°C behaved as flocculated dispersions of largely intact, swollen granules which resulted in stable structural properties during the preservation period. At 72°C, a higher degree of gelatinization and degradation was observed, resulting in structurally unstable systems due to association and crystallization of amylopectin. Especially for these systems, xanthan gum was found to enhance the gelation process, probably due to phase separation. Although xanthan gum may restrict the granule disruption during preparation, this beneficial effect on the freshly prepared pastes did not result in an improved stability during storage.

Analysis of a preferential action of α-amylase from B. licheniformis towards amorphous regions of waxy maize starch

Waxy maize starch was subjected to α-amylase (Bacillus licheniformis) hydrolysis in buffered medium to determine the evolution of reaction in quantitative terms and also in terms of the morphology and crystallinity of the partially hydrolyzed starch granules. Gathered data allowed studying the pattern of action of this α-amylase over waxy maize starch granules, with particular focus on a preferential hydrolysis of the amorphous regions of starch. Results showed that waxy maize starch hydrolysis followed a two-stage kinetic profile with an initial stage characterized by high reaction rate, followed by a slower second stage. The change of hydrolysis rate occurred at approximately 6h of reaction, a time for which X-ray diffraction data quantitatively analyzed by three different techniques showed a maximum of crystallinity in partially hydrolyzed granules. Scanning electron microscopy images illustrated the action of α-amylases which implied the exoerosion of the granules surface, the entry of α-amylases into the granules through radial channels, their endoerosion towards the granule exterior, and their fragmentation. Fragmentation of waxy maize starch granules revealed internal layered structures of starch which were interpreted as hydrolyzed/non-hydrolyzed growth rings. Under the conditions chosen, kinetic, electron microscopy and X-ray data all gave evidence of a preferential action of α-amylase from Bacillus licheniformis towards the less ordered regions of waxy maize starch. Results showed that, provided the proper hydrolysis time is chosen, starch granules with increased crystallinity can be obtained by a pure enzymatic treatment.

Self-Assembly of Short Linear Chains to A- and B-Type Starch Spherulites and Their Enzymatic Digestibility

A novel process combining enzymatic debranching, melting, and crystallization was developed to produce spherulites from short linear α-1,4-linked glucans (short-chain amylose, SCA) with controlled enzyme digestibility. SCA was obtained by completely debranching waxy maize starch at 50 °C and 25% solids in 0.01 M sodium acetate buffer. The mixture was then heated to 180 °C followed by cooling and crystallization to form well-developed spherulites. Multiple analytical techniques including light microscopy, scanning electron microscopy, differential scanning calorimetry, wide-angle X-ray diffraction, and synchrotron small-angle X-ray scattering (SAXS) covered over 5 orders of length scale and were applied to study the morphology and structure of the spherulites. Spherulites crystallized at low temperatures (4 and 25 °C) had a large size (5-10 μm), a B-type starch X-ray diffraction pattern, a lower melting temperature (70-110 °C), and a higher digestibility (Englyst method) compared to the spherulites crystallized at 50 °C, which had a small size (1-5 μm), an A-type diffraction pattern, a higher melting temperature (100-140 °C), and a lower digestibility. Intact spherulites along with small fragments were observed after digestion with a mixture of α-amyase and amyloglucosidase, indicating that digestion was not homogeneous and preferentially occurred in weak spherulites. A second exposure of the undigested residues to the amylases showed a similar digestive pattern as with the parent spherulites, suggesting that the spherulites were hydrolyzed by enzymes at essentially a constant digestion rate between 20 min and 3 h.

Effect of defatting on acid hydrolysis rate of maize starch with different amylose contents

The effect of defatting on the physiochemical properties and the acid hydrolysis rate of maize starch with different amylose contents was evaluated in this study. The increase in the number of pores and the stripping of starch surface layers were observed after defatting by scanning electron microscopy. X-ray diffraction spectrum showed that the peaks attributing to the amylose–lipid complex disappeared. The relative crystallinity increased by 19% for high-amylose maize starch (HMS) on defatting, while the other tested starches virtually unchanged. Differential scanning calorimetry study indicated an increase in the thermal stability for the defatted starches. Compared with native waxy maize starch, the acid hydrolysis rate of the defatted one increased by 6% after 10 days. For normal maize starch (NMS) and HMS, the higher rate of hydrolysis was observed during the first 5 days. Thereafter, the hydrolysis rate was lower than that of their native counterpart. The increase in susceptibility to acid hydrolysis (in the first 5 days) was mainly attributed to the defective and porous structures formed during defatting process, while the decrease of hydrolysis rate for NMS and HMS samples (after the first 5 days) probably resulted from the increase in the relative crystallinity.

Effects of pregelatinized waxy maize starch on the physicochemical properties and stability of model low-fat oil-in-water food emulsions

The effects of pregelatinized waxy maize starch (WMS) concentration (0.0–5.0 wt%) on the physicochemical properties and stability of model low-fat (20.0 wt% rapeseed oil) oil-in-water emulsions, made with dried egg yolk or sodium caseinate (2.0 wt%) were explored. All samples exhibited shear-thinning flow behavior, and the detected from Herschel–Bulkley's model parameters: yield stress (τ0), consistency coefficient (K), and flow behavior index (n) were highly affected (p < 0.001) by WMS addition. Oscillatory test data revealed that the structure of emulsions changed from liquid (≤2 wt% WMS) to gel-like (≥3 wt% WMS). The storage (G′) and loss (G″) moduli were modeled as a power function of oscillatory frequency. WMS concentration had a significant (p < 0.001) impact on the emulsions stability with respect to creaming and fat holding capacity. Positive correlation values were found between Bohlin's and stability parameters of emulsions. The obtained results can be exploited for the development of low-fat health-oriented food emulsions.

Cross-Linked Waxy Maize Starch-Based “Green” Composites

In this research, “green” composites were fabricated by blending waxy maize starch (WMS) with micro/nanofibrillated cellulose (MFC). Further, an environmentally friendly, sustainable, and water-soluble cross-linker, 1,2,3,4-butane tetracarboxylic acid (BTCA), was used to cross-link WMS to fabricate cross-linked starch-based composites. The method described here provides a benign and convenient way to produce cross-linked starch-based composite films (≈ 300 μm in thickness), comparable to commercially available plastic sheets. The process can be easily scaled up for commercial production. Industrially pregelatinized WMS was used to obtain smooth, transparent, and defect-free films. Cross-linking helped in reducing the moisture absorption as well as made the films and composites insoluble in water. MFC (15% MFC)-cross-linked WMS composite films exhibited excellent tensile properties with a Young’s modulus of over 2.3 GPa, fracture strain of 3.1%, and fracture stress of 39 MPa, as a result of MFC incorporati...

Starch/carrageenan/milk proteins interactions studied using multiple staining and Confocal Laser Scanning Microscopy

This study focused on the effects of the interactions between modified waxy maize starch, kappa carrageenan and skim milk on the microstructure of their mixed systems using Confocal Laser Scanning Microscopy (CLSM). A multiple staining of the components was set up with a view to improving starch covalent staining. In starch/carrageenan pasted mixtures, carrageenan was found to adsorb on and penetrate slightly into the starch granules, whereas no interactions were observed between starch and milk proteins. In ternary mixtures, interactions between starch granules and carrageenan were no longer observed, even when milk proteins were added after starch swelling in the carrageenan solution, thus showing preferential interactions between carrageenan/milk proteins in comparison to carrageenan/starch granules. Modifying the blending order of the components led to microstructure differences depending on several parameters such as starch/carrageenan interactions, carrageenan/milk proteins network structure, level of starch granules disruption and amylopectin contribution to the microstructure.

Interactions between modified starch and carrageenan during pasting

This study focused on starch/carrageenan blends. Its aim was to develop a method to evaluate if carrageenan was trapped or excluded by starch granules during pasting, and quantify the amount of interacting polysaccharide in the case of trapping. Four carrageenan samples and a modified waxy maize starch were used, where starch was pasted in carrageenan solutions. The set up method permitted, using an indirect titration, to evaluate the concentration of carrageenan in the supernatants of those ‘pasted blends’. The quantity of carrageenan trapped by starch granules could then be obtained. The percentage of trapped kappa-carrageenan was higher than for iota-carrageenan. Increasing the rigidity of kappa-carrageenan chains decreases the amount of trapped carrageenan. To the contrary, decreasing the molecular weight leads to an increase in carrageenan trapping.

Reaction of octenylsuccinic anhydride with a mixture of granular starch and soluble maltodextrin

The reaction of octenylsuccinic anhydride (OSA) with a mixture of granular waxy maize starch and soluble maltodextrin was investigated. OSA was reacted with a 1:1 (w/w) mixture of the granular starch and maltodextrin at OSA levels of 1.5, 3, 9, and 15% (wt% based on starch weight). After the first 0.5h of the reaction, degree of substitution (DS) on maltodextrin reached 0.021, 0.030, 0.080, and 0.10 for 1.5, 3, 9, and 15% OSA, respectively, whereas DS for granular starch was only 0.0020, 0.0087, 0.014, and 0.016. At 2h of the reaction, the bound OS ratio of maltodextrin to granular starch was 10.8 when OSA concentration was 1.5% and the ratio decreased to ca. 5 at higher OSA concentrations. OSA preferred to react with maltodextrin than semi-crystalline granular starch when both existed in the system. OSA reacted with maltodextrin at a much faster rate and to a greater extent than with granular starch, but a significant amount of OSA reacted with granular starch at 3–15% OSA concentrations.

Starch/carrageenan mixed systems: Penetration in, adsorption on or exclusion of carrageenan chains by granules?

This study focused on the understanding of starch/carrageenan interactions. Seven carrageenan samples and a modified waxy maize starch were used. Two types of blends were made: starch was pasted in carrageenan solutions or swelled starch granules were mixed with carrageenan solutions. For each blend, the carrageenan concentration in the continuous phase was determined by indirect titration that permitted to evaluate the percentages of carrageenan trapped by starch granules. The presence of carrageenan in the continuous phase was shown to impact the swollen starch granules' sizes and characteristics. The level of viscosity in the continuous phase was shown to depend on the starch/carrageenan interactions but also on the released amylopectin concentration. Starch pasting was shown to be unnecessary to promote interactions as the same percentage of trapped carrageenan was found when put into contact with starch granules either before or after swelling. Carrageenans were found to be both excluded and adsorbed on starch granules. The level of adsorption of carrageenan on starch granules seemed to be promoted by low-negatively-charged carrageenan and by low-molecular-weight carrageenan.

Effects of balanced hydroxyethyl starch solutions on gut mucosal microcirculation and exhaled nitric oxide in septic rats

Balanced hydroxyethyl starch (HES) solutions with a molecular weight of 130 kDa (tetrastarches) are frequently used in clinical practice. These solutions are derived either from waxy maize or potato starch and they are not bioequivalent. Investigation of the effects of waxy maize-derived and potato-derived starches on intestinal microcirculation and pulmonary inflammation in experimental sepsis. A randomised (three groups), blinded animal study. Animal experimental facility in a university hospital. Twenty-one male Sprague-Dawley rats weighing 275 to 300 g. Sepsis was induced by caecal ligation and puncture. Animals received balanced crystalloid infusion (6 ml kg h) for 23 h followed by randomised 1 h bolus infusion (30 ml kg h) of crystalloid: balanced crystalloid solution or waxy maize starch: 6% wt/vol HES 130/0.4 or potato starch: 6% wt/vol HES 130/0.42. Results are presented as median (interquartiles). Using intravital microscopy, mucosal perfusion was assessed by intercapillary area (ICA) between all perfused capillaries (ICAtotal) and continuously perfused capillaries only (ICAcont). Mucosal blood flow was calculated from arteriolar diameter and red blood cell velocity. Intestinal wall 3-nitrotyrosine (3-NTint) content and exhaled nitric oxide (exNO), to indicate pulmonary inflammation, were measured. Both tetrastarches improved capillary perfusion compared to the crystalloid group, as indicated by reduced ICAtotal [crystalloid 1054 (905 to 1211) μm; waxy maize starch 789 (744 to 940) μm, P <0.05; potato starch 674 (536 to 693) μm, P < 0.05] and reduced ICAcont [crystalloid 1060 (996 to 1340) μm; waxy maize starch 860 (793 to 975) μm, P <0.05; potato starch 701 (558 to 728) μm, P <0.05]. Mucosal blood flow and systemic blood pressure did not differ significantly between groups. 3-NTint was comparable among all groups. exNO was significantly reduced from 11.1 (5.0 to 16.5) ppb to 4.2 (4.0 to 4.8) ppb in the waxy maize group, whereas no significant difference was detected in the potato starch group 6.2 (4.8 to 10.5). Bolus infusion of balanced 6% wt/vol tetrastarches augments mucosal capillary perfusion. Pulmonary inflammation in sepsis is differentially influenced by tetrastarches produced from different raw materials.

Effects of waxy maize and potato starches on the stability and physicochemical properties of model sauces prepared with fresh beef meat

SummaryStability and physicochemical properties of model sauces containing 2.5 wt% fresh beef meat (related to raw material), 30 wt% rapeseed oil and native waxy maize starch (WMS) or potato starch (PS) at concentrations ranged from 0.5 to 4.0 wt% were assessed. Sauces thickened with WMS showed a significantly (P &lt; 0.05) higher stability than respective ones made with PS. All studied systems exhibited non‐Newtonian, pseudoplastic behaviour. The Ostwald–de Waele and Herschel–Bulkley models were used to describe the flow properties of model sauces. In comparison with control sample (prepared without starch), addition of this polysaccharide (WMS or PS) increased consistency index, yield stress and apparent viscosity and decreased flow behaviour index of model sauces. The Arrhenius equation was used to determine the effects of temperature (20–50 °C) on the apparent viscosity. The activation energy values were in ranges 7.66–10.59 kJ mol−1 and 8.87–11.82 kJ mol−1 in sauces prepared with WMS and PS, respectively. The instrumentally detected changes in consistency and whiteness of model sauces were found, which may be used as the good predictors of the perceived sensory consistency and whiteness.

Effects of heat stress during grain filling on the structure and thermal properties of waxy maize starch

Clarifying the waxy maize starch physicochemical characteristics response to heat stress could modify starch quality. The effects of heat stress during grain filling (1–40day after pollination) on starch structure and thermal properties of four waxy maize varieties were investigated. The mean day/night temperature during grain filling for heat stress and control treatments was 35.2/16.1°C and 27.4/15.6°C, respectively. Heat stress during grain filling increased the starch average granule size and the proportion of long chains in amylopectin. Starch granules under heat stress presented more pitting or uneven surfaces. X-ray peak intensities in response to heat stress were variety dependent. Heat stress during grain filling decreased the swelling power and increased the gelatinization temperature and retrogradation percentage, while the gelatinization enthalpy was not affected. In conclusion, heat stress during grain filling significantly affected structural characteristics of waxy maize starch and consequently, changed its swelling and thermal properties.

Guar and xanthan gum differentially affect shear induced breakdown of native waxy maize starch

Starches and non-starch hydrocolloids or gums are used very often as texturizers in the food industry. The aim of this work was to investigate the effects of guar gum and xanthan gum on the mild temperature pasting behavior of waxy maize starch. Waxy maize starch dispersions containing either guar, xanthan or no gum were pasted at temperatures (70 and 72.5 °C) close to the gelatinization temperature by means of the starch pasting cell mounted on the rheometer. Different shear conditions were imposed (no shear, 50 s−1 and 150 s−1). Along with the pasting behavior, the particle size distribution of the swollen granules was derived by means of laser light scattering and the rheological behavior of the cooled pastes was determined to characterize the samples. Finally, confocal laser scanning microscopy was used to locate the fluorescently labeled gums in the swollen starch dispersions. Under the given conditions, both gums differently affected the starch during the heating steps. While xanthan gum lowered the shear induced breakdown of the granules, guar gum did not show this specific property. Consequently, guar gum primarily modified the rheological properties of the pastes by its presence in the continuous phase, whereas xanthan gum also induced indirect effects by better preserving the granular structure.

Modeling and Validation of the Mechanism of Pulsed Flow Cleaning

The enhancement of the cleaning efficiency of cleaning-in-place (CIP) systems is playing a key role in improving food production. Cleaning models based on computational fluid dynamics (CFD) can be a tool that enables identifying locations in a plant that are difficult to clean and enhances the cleaning efficiency by appropriate fluid dynamics, that is, the application of transient flow. A CFD cleaning model was developed that is based on the assumption of a mass transfer controlled cleaning process. The physical basis of the model is the analogy between heat and mass transfer. A validation of the cleaning mechanism, using experimental data of local cleaning times in several complex geometries with varied static and transient flow velocities, was carried out. A modified waxy maize starch with phosphorescent tracers was used as model food soil. The received results show a good agreement between the measured and simulated cleaning times. The cleaning model is suitable for the calculation of the cleaning progress for all fouling systems, where the cleaning mechanism is mass transfer controlled. It is now possible to visualize the effect of complex pipe geometries or inappropriate hygienic design on the overall cleaning time. Especially in locations difficult to reach with steady flow, the application of pulsed flow shows a shorter cleaning time. Based on the presented new CFD model the local cleaning efficiency can be predicted.

Preparation of crystalline starch nanoparticles using cold acid hydrolysis and ultrasonication

Waxy maize starch in an aqueous sulfuric acid solution (3.16M, 14.7% solids) was hydrolyzed for 2–6 days, either isothermally at 40°C or 4°C, or at cycled temperatures of 4 and 40°C (1 day each). The starch hydrolyzates were recovered as precipitates after centrifuging the dispersion (10,000rpm, 10min). The yield of starch hydrolyzates depended on the hydrolysis temperature and time, which varied from 6.8% to 78%. The starch hydrolyzed at 40°C or 4/40°C exhibited increased crystallinity determined by X-ray diffraction analysis, but melted in broader temperature range (from 60°C to 110°C). However, the starch hydrolyzed at 4°C displayed the crystallinity and melting endotherm similar to those of native starch. The starch hydrolyzates recovered by centrifugation were re-dispersed in water (15% solids), and the dispersion was treated by an ultrasonic treatment (60% amplitude, 3min). The ultrasonication effectively fragmented the starch hydrolyzates to nanoparticles. The hydrolyzates obtained after 6 days of hydrolysis were more resistant to the ultrasonication than those after 2 or 4 days, regardless of hydrolysis temperatures. The starch nanoparticles could be prepared with high yield (78%) and crystallinity by 4°C hydrolysis for 6 days followed by ultrasonication. Scanning electron microscopy revealed that the starch nanoparticles had globular shapes with diameters ranging from 50 to 90nm.

Stabilization of aqueous dispersion of CoQ10 nanoparticles using maize starches

Aqueous coenzyme Q10 (CoQ10) dispersions were prepared by blending CoQ10 (60 mg) in aqueous maize starch dispersion (300 mg in 30 mL water) at 60–100 °C for up to 6 h. The CoQ10 agglomerates were removed by centrifugation (5000 × g, 30 min) and filtration through a glass filter. As the temperature increased, the amount of CoQ10 which was stably dispersed increased. Normal maize starch was more effective in dispersing the CoQ10 (57.3%) than waxy and high-amylose maize starches (9.8% and 21.9%, respectively). A light scattering analysis revealed that ultrasonication during cooling was effective in preventing the formation of CoQ10 agglomerates. The average particle size of dispersed CoQ10 was <150 nm. Differential scanning calorimetry and X-ray diffraction analysis revealed that dispersed CoQ10 particles had no amylose complex crystals. The CoQ10 dispersion, however, remained homogeneous without forming precipitates during ambient storage for 2 weeks.