Corn Starch Granules Research Articles

Encapsulation of lutein into swelled cornstarch granules: Structure, stability and in vitro digestion

Swelled cornstarch granules incubated at different incubation temperatures was prepared as a complexation matrix to encapsulate lutein. Increasing incubation temperature (55–70 °C) induced the gelatinization of cornstarch, resulting in enhancement of swelling power (1.67–6.26 g/g) and lutein content (0.78–4.86 mg/g). A decreased (double helix of amylopectin) and an increased (single helix of V-amylose) enthalpy change were associated with the increased incubation temperature. The retention index of lutein in the composites incubated at 65 °C and 70 °C could achieve 76% after 21 days of storage. Less than 30% of lutein in the composites was released after incubating for 120 min under stomach conditions. Fast lutein release was observed during the first 20 min intestinal digestion, consistent with starch hydrolysis data. This study opens a promising pathway for swelled cornstarch granules as delivery carriers of bioactive ingredients, which are of vital importance for their potential use in the sensitive food supplement.

Alumina Ceramics Fabricated by in-situ Consolidation of Pre-gelling Starch

An in-situ consolidation method was developed and optimized to successfully fabricate alumina ceramics using pre-gelling starch. Our results showed that the obtained ceramics have more homogeneous microstructure, higher density, higher flexural strength, and favorable biocompatibility compared to the regular one. During the process, cornstarch granules swelled and deformed but no fracture was observed. After the cornstarch granules bursted, alumina particles were suspended uniformly in the three-dimensional network structure to generate a much smoother surface. Below 0.5 wt% higher cornstarch content increased the flexural strength of prepared ceramics, while above 0.5 wt% the mechanical properties were compromised. Therefore the cornstarch content of 0.5% was the optimal concentration to achieve the highest mechanical strength of the prepared ceramics, with a measured flexural strength of 341 MPa, and a relative density of 96.01%.

Comparative study on the interaction between native corn starch and different hydrocolloids during gelatinization

The effect of hydrocolloids (Arabic gum, guar gum, xanthan gum) on the thermal, rheological, and microstructural changes of corn starch during gelatinization was studied by combining multiple analytical techniques. Arabic gum located in the continuous phase had no significant delaying effect on starch gelatinization. A two phase system could be directly observed by scanning electron microscopy. The analysis of variance suggested that xanthan gum could restrict the swelling of starch granules and the destruction of granule structure more effectively than other hydrocolloids tested. Morphologies of corn starch granules formed with hydrocolloids showed that xanthan gum promoted the association between starch granules. Compared to xanthan gum, starch granules were more swollen in the presence of guar gum during heating, thus the increase in hydrocolloid concentration in the continuous phase results from an excluded volume effect was more pronounced. Overall, the results suggest that hydrocolloids could effectively restrict the swelling of starch granules, depending on hydrocolloid type, owing to the efficient thickening property. A synergistic increase in paste viscosity occurred as a result of a combination of intermolecular interactions and phase separations. These findings may thus provide a useful basis for the study of other types of starch/hydrocolloid mixtures and concentrations.

Development and characterization of irradiated-corn-starch films

The effect of 60Co gamma ray irradiation on the physicochemical and crystalline properties of native corn starch were investigated. Fourier transform infrared spectroscopy and X-ray diffraction showed that irradiation had a slight effect on the molecular structure of corn starch with crystallinity decreasing with increasing irradiation dose. Particle size analysis showed that 59.1% of native corn starch granules had sizes of ≥8 μm, which decreased to only 24.1% after treatment with an irradiation dose of 40 kGy. Irradiated-corn-starch films were prepared by casting gelatinized irradiated-corn-starch solutions. An increased irradiation dose was found to increase the tensile strength of the resultant films, but caused a significant decrease in water vapor permeability. The irradiated-corn-starch films showed potential for the development of biodegradable starch films with improved properties.

Production of Thermal-Resistant Cornstarch-Alginate Beads by Dripping Agglomeration

Abstract This work investigated the agglomeration of native cornstarch and production of microcapsules by dripping of sodium alginate suspensions into calcium chloride solution. The crosslinking reaction formed a calcium alginate that worked as an encapsulation matrix and coated the cornstarch granules. The spherical beads produced were rigid and compact, and resistant to mechanical handling. The differential scanning calorimetry (DSC) computed the thermal resistance of the cornstarch-alginate beads. Particles containing 50 % w/w calcium alginate showed an increased gelatinization peak compared to particles with a higher starch content. The increase in alginate fraction resulted in beads with a higher particle density. Scanning electron micrographs showed the coating of cornstarch by the calcium alginate matrix. The beads were compact and with no superficial pores. DSC thermograms of native cornstarch showed a gelatinization temperature of 70.0 °C, and the gelatinization range was 64.6–80.4 °C, while beads containing 50 % alginate had an increased peak at 79.5 °C and the gelatinization interval was 71.0–90.2 °C. When compared with the native cornstarch, cornstarch-alginate beads had a lower water absorption, and the gelatinization occurred at a higher temperature and over a wider temperature range.

CAMBIOS FISICOQUÍMICOS DE ALMIDÓN DE MAÍZ DURANTE LA FERMENTACIÓN ACIDO LÁCTICA CON Lactobacillus bulgaricus

Lactic acid fermentation with L. bulgaricus induced large changes in the morphology of corn starch granules. The production of amylolytic enzymes as well as lactic acid produced fractures along the granule hilum, which led to disintegration of starch granules at long fermentation times. On the other hand, lactic acid fermentation increased crystallinity and double-helices structures, which led to increased susceptibility to acidic hydrolysis. In fact, thermal analysis results indicated than an improved internal organization of granule residues occurred. In general, the results showed that the fermentation time can be considered as a suitable parameter for modulating the physicochemical properties of corn starch granules. Additionally, it can be postulated that lactic acid fermentation of starchy food matrices has a positive effect on the acidic digestibility of starch granules, by improving the content of resistant starch fractions

Production of Cornstarch Granules Enriched with Quercetin Liposomes by Aggregation of Particulate Binary Mixtures Using High Shear Process.

This study is an unprecedent association of 2 technologies, nanoencapsulation and wet agglomeration, here used together to enrich cornstarch with quercetin. The agglomeration process was used to obtain granules of cornstarch, an ingredient extremely used in the food industry, enriched with quercetin-loaded lyophilized liposomes. The goals were both the improvement of the nutritional quality and the increase of the added value of the cornstarch.

Investigation of glycerol concentration on corn starch morphologies and gelatinization behaviours during heat treatment

The effects of various glycerol concentrations (0%, 5%, 10%, 20%, and 50%, w/w) on the morphologies and gelatinization behaviours of corn starch were evaluated by confocal laser scanning microscopy (CLSM), scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and rapid visco-analyzer (RVA). When corn starch granules with no added glycerol were treated at 65°C, the granules of corn starch were almost completely broken and tightly connected, and the characteristic birefringence of the starch granules disappeared. Various microscopic techniques revealed that starch gelatinization was delayed to higher temperatures as the glycerol concentration increased. In the presence of glycerol-water systems (5%, 10%, 20%, and 50%, w/w), the peak temperatures of corn starch increased by 1.6°C, 7.4°C, 10.7°C, and 19.7°C, respectively, compared to corn starch in water. The RVA pasting profiles showed that the gelatinization temperature increased as the glycerol concentration increased, which was consistent with polarized light microscope observations and DSC tests.

Influence of corn variety, drying temperature, and moisture content at harvest on the saccharides released during an in vitro pepsin‐pancreatin digestion

High‐performance anion‐exchange chromatography coupled with pulsed amperometric detection (HPAEC‐PAD) was used to quantify and to determine the nature of saccharides released after the digestion of two corn grains submitted to different drying and harvesting protocols. Five saccharides were quantified: glucose, maltose, isomaltose, maltotriose, and glucosyl‐maltotriose. After a subsequent hydrolysis with amyloglucosidase of the released saccharides, the amount of total glucose recovered increased with the increase in drying temperature and the moisture content of grain at harvest. These results suggest that structural changes induced within corn starch granules during drying affect their hydrolysis by amylases. These changes may lead to different pathways of sugar absorption in the small intestine of monogastrics. Thus, corn grains with a similar composition may lead to different levels of metabolizable energy upon gastro‐intestinal digestion.

Physical structure and absorption properties of tailor-made porous starch granules produced by selected amylolytic enzymes.

Porous starch granules (PSGs) with various pores and cavity sizes were prepared by amylolysis enzymes. The greatest hydrolysis rate on corn starch granule was observed with α-amylase, followed by gluco- and β-amylases. Temperature increase enhanced glucoamylase reaction rate more drastically than other enzyme treatments. Final hydrolysis level with glucoamylase reached to 66.9%, close to 67.5% of α-amylolysis. The α-amylase-treated PSGs displayed the greatest pore size and ratio of cavity-to-granule diameters. Gelatinization onset temperatures of PSGs increased to 72.1 (α-), 68.7 (β-), and 68.1°C (gluco-amylolysis) after 8 h; enthalpy changes of β- and gluco-amylase-treated PSGs increased to 13.4, and 13.1 J/g but α-amylase-treated one showed slightly reduced value of 8.5 J/g. Water holding capacities of PSGs were 209.7 (α-), 94.6 (β-), and 133.8% (gluco-amylolysis), and the untreated control had 89.1%; oil holding capacities of them showed 304.5, 182.7, and 211.5%, respectively, while the untreated control had 161.8%. Thus, enzyme types and their reaction conditions can be applied to generate desirable cavity and pore sizes in starch granules. This biocatalytic approach could contribute to develop tailor-made PSGs with distinct internal structure for specific uses in wide range of food, pharmaceutical and other industrial applications.

Structural properties of waxy corn and potato starch blends in excess water

The structural properties of blends of waxy corn starch and potato starch at different proportions were evaluated at 20% solids content. The results from differential scanning calorimetry, wide-angle X-ray scattering, and small-angle X-ray scattering of the starch blends indicated that each starch gelatinized completely and independently. The setback viscosity values were higher in the blends compared with native starches, which suggested that the granular interactions had an important effect. The presence of waxy corn starch granules could have reinforced the network formed by amylose leached from potato starch granules. The intrinsic characteristics of waxy corn starch and potato starch determined the type of granular and molecular interactions that could be carried out during the processes of gelatinization and gel formation in starch blends.

Effects of microwave-discharged cold plasma on synthesis and characteristics of citrate derivatives of corn starch granules.

The objectives of this study were to identify the potential function of microwave-discharged cold plasma (MCP) treatment in preparing starch citrate (SC) non-thermally and to investigate the physicochemical properties of MCP-induced starch citrates. SCs were prepared by either dry heating in a convection oven (as a reaction control; COV) or MCP treatment using N2 (N2-MCP) and N2-O2 (N2/O2-MCP). Fourier transform-infrared spectra of the MCP-induced SCs revealed new peaks indicating ester bonds. The molar degree of substation was 0.013-0.015 depending on the reaction conditions. The plasma-formed dents were observed more on the surfaces of granular starch citrates (GSCs) treated with N2/O2-MCP than N2-MCP. Relative to COV, MCP-induced GSCs possessed lower resistant starch content, solubility, and gelatinization temperatures and higher swelling power. The pasting viscosities were higher with N2-MCP GSCs and lower with N2/O2-MCP GSCs. The results suggest that MCP can be used as a novel catalyst for non-thermal starch citration.

Co-encapsulation of amyloglucosidase with starch and Saccharomyces cerevisiae as basis for a long-lasting CO2 release.

CO2 is known as a major attractant for many arthropod pests which can be exploited for pest control within novel attract-and-kill strategies. This study reports on the development of a slow-release system for CO2 based on calcium alginate beads containing granular corn starch, amyloglucosidase and Saccharomyces cerevisiae. Our aim was to evaluate the conditions which influence the CO2 release and to clarify the biochemical reactions taking place within the beads. The amyloglucosidase was immobilized with a high encapsulation efficiency of 87% in Ca-alginate beads supplemented with corn starch and S. cerevisiae biomass. The CO2 release from the beads was shown to be significantly affected by the concentration of amyloglucosidase and corn starch within the beads as well as by the incubation temperature. Beads prepared with 0.1 amyloglucosidase units/g matrix solution led to a long-lasting CO2 emission at temperatures between 6 and 25 °C. Starch degradation data correlated well with the CO2 release from beads during incubation and scanning electron microscopy micrographs visualized the degradation of corn starch granules by the co-encapsulated amyloglucosidase. By implementing MALDI-ToF mass spectrometry imaging for the analysis of Ca-alginate beads, we verified that the encapsulated amyloglucosidase converts starch into glucose which is immediately consumed by S. cerevisiae cells. When applied into the soil, the beads increased the CO2 concentration in soil significantly. Finally, we demonstrated that dried beads showed a CO2 production in soil comparable to the moist beads. The long-lasting CO2-releasing beads will pave the way towards novel attract-and-kill strategies in pest control.

Effects of solid‐state fermentation (Aspergillus oryzae var. oryzae) on the physicochemical properties of corn starch

The physicochemical transformations suffered by corn starch granules under the solid‐state fermentative action of Aspergillus oryzae var. oryzae were studied. Light microscopy images showed that the starch granules became increasingly fractured and broke‐down as fermentation time was longer. SEM micrographs showed that the mean particle diameter decreased linearly with the fermentation time, indicating a zeroth‐order hydrolysis kinetics. The crystallinity content of fermented corn starch achieved a maximum value (39.72 ± 1.02) after 100 h followed by a reduction at longer fermentation times. The short‐range ordering monitored by the absorbance ratio 1047/1022 from FTIR increased during the first 100 h, suggesting the formation of double‐helix structures as long chains was hydrolyzed. DSC analysis showed the deterioration of the internal ordering of starch granules for long fermentation times, reflecting an extensive disruption of the granule integrity. Overall, the results showed that starch granules underwent strong, although slow, physicochemical changes as the solid‐state fermentation evolved. Specifically, crystallinity increased about 25% and viscosity of 5% w/w gelatinized starch dispersion decreased about 85% in the first 100 h of fermentation. In addition, the gelatinization enthalpy decreased about 60.0% and the ζ‐potential doubled during the fermentation process.

Ultrasonic modification of starch – Impact on granules porosity

Rice, corn, wheat, and potato starch granules suspended in water or ethanol were treated with ultrasounds at frequency of 20kHz and power 170W for 30min. Porosity of starch was investigated in terms of specific surface area (SBET), average pore size and pore size distribution using low-temperature nitrogen adsorption method. The significant increase of SBET was noted for all the studied starches sonicated in water and for potato starch modified in ethanol. Ultrasonic treatment influenced the average diameter of mesopores (2nm<width<50nm) differently. The significant increase of this parameter was noted for wheat and rice starches suspended in ethanol and for potato starch granules suspended in water, but in the case of corn starch, the obtained value was slightly lower after sonication in water. Modification of starch with ultrasounds resulted in the formation of new pores in the studied range of diameter.

Effect of High Hydrostatic Pressure, alkaline and combined treatments on corn starch granules metal binding: Structure, swelling behavior and thermal properties assessment

Modification of corn starch granules to transform them into carriers for molecules of nutritional interest was assayed by alkaline and high pressure treatments. Changes in the granular structure of starches were revealed by porosimetry and swelling power studies, while confocal microscopy evaluated the mode of disruption of the granules. Both alkali and high pressure treatments increased the number of pores in the granules while the combined procedures led to a central disruption and an increased deep pore number. The high pore volume found in alkali treated starches resulted in a high swelling power and created more binding sites to load high amounts of minerals, such as zinc and magnesium, as determined by atomic emission spectrometry. The extent of gelatinization process was affected differently in treated starches. The reduction in temperature and enthalpy, associated to high pressure granular starch suspensions, was moderated by the creation of new charged interactions due to alkali addition.

A morfologia dos vasos Jê na produção de cauim de milho em Vereda III: uma proposição

A análise arqueobotânica focada em grânulos de amido extraídos de vasos cerâmicos e um artefato lítico exumados em Vereda III, MG revelou a presença generalizada do milho (Zea mays sp). Um estudo prévio realizado com os artefatos havia detectado marcas de uso típicas da fermentação em alguns vasos, assim, levantou-se a possibilidade de que mais vasos teriam sido utilizados na produção de cauim de milho. Tratou-se de compreender a produção dessa bebida/alimento nas suas múltiplas possibilidades através de relatos históricos, etnografias, informações tecnológicas e testes com fermentação. Os efeitos tafonômicos das distintas etapas do processo sobre os grânulos de amido de milho foram pesquisados em literatura e através de testes. Faz-se aqui uma proposição quanto à morfologia dos vasos Jê utilizados na elaboração do cauim de milho, pensada a partir do cruzamento de 2 tipos de evidências: o estudo dos microvestígios contidos nos artefatos arqueológicos e as marcas de uso nos vasos.

Thermal, rheological, and mechanical properties of normal corn and potato starch blends

ABSTRACTNative corn and potato starches were mixed in different proportions. Blends presented similar values to potato starch at onset temperature and at ending temperature to corn starch. CS20PS80 blend had the highest values for hardness between blends due to the formation of a three-dimensional network with corn starch granules that act as composite material. Some blends exhibited higher recovery viscosity than native starches, possibly due to interactions. Gelatinization temperature, swelling power, phosphorous content, granule size, and x-ray pattern played an important role in the resulting properties, however, the amylose content did not show influence due to both starches having a similar content.

Flow Behavior of Native Corn and Potato Starch Granules in Aqueous Suspensions

The flow behavior of native corn and potato starch granule suspensions prepared in a concentrated sucrose solution has been investigated. Measurements were performed using a rotational rheometer with a concentric cylinder geometry. Starch suspensions were dilute to semi-concentrated (1 % to 25 % by volume). Shear and dynamic viscosity were measured by shear flow and dynamic oscillatory testing at 20, 50 and 80 °C. The starch suspensions exhibited essentially Newtonian behavior at all solid contents, although at higher solid volume fractions there was evidence of slight shear thickening. The relative viscosity of suspensions increased with increasing starch granule content, and the data conformed well to Maron-Pierce’s equation. An increase in maximum packing fraction and gravitational depletion of the starch granules with increasing temperature resulted in lower relative viscosities at higher temperatures. Also, the relative viscosities of potato starch granule suspensions with bigger, more oval and anisometric particles were lower than those of corn starch suspensions where granules were closer to sphericity but were angular in shape. Oscillatory shear testing results showed the presence of viscoelastic properties at intermediate solid volume fractions at low frequencies; in addition, the relative shear viscosity was higher than the relative dynamic viscosity, probably due to the formation of shear-induced structures during the shear flow test.

Coaggregation of mineral filler particles and starch granules as a basis for improving filler-fiber interaction in paper production

The sustainable, efficient use of renewable bio-based additives in the production of various materials fits well into the concept of sustainability. Here, the concept of coaggregation of mineral filler particles and starch granules for improving filler-fiber interaction in paper-based cellulosic networks is presented. Coaggregation of precipitated calcium carbonate filler particles and uncooked, unmodified corn starch granules by cationic polyacrylamide (a cationic high molecular weight polymer flocculant) in combination with bentonite (an anionic microparticle) prior to addition to cellulosic fiber slurry delivered enhanced filler bondability with cellulosic fibers. For instance, under the conditions studied, preaggregation resulted in an increase in filler bondability factor from 9.24 to 15.21 at starch dosage of 1% (on the basis of the dry weight of papermaking stock). The swelling and gelatinization of the starch granules in starch-filler preaggregates or hybrids enabled the “bridging” of the gaps in cellulosic networks, leading to structural consolidation and strength enhancement.