Starch Complex Research Articles

Adsorption of paper strength additives to hardwood fibres with different surface charges and their effect on paper strength

Light-weight paper products that contain less fibres, but with a maintained bulk and improved strength properties, are highly desirable due to the low cost of raw materials and improved logistics of packaged goods. In this respect, the adsorption capacity of dry strength additives onto fibres, which is affected by the surface charge of said fibres, is very important for the development of these mechanically robust paper products. The influence of the surface charge on the adsorption of strength additives was investigated for, dissolving grade fibres, kraft fibres and kraft fibres modified with carboxymethyl cellulose (CMC) with different surface charge densities, but the same fibre dimensions. The strength additives investigated were cationic starch (CS), anionic polyacrylamide (APAM) and polyelectrolyte complexes (PECs), containing CS and APAM. A linear relationship was found between the surface charge of the fibres and the saturated adsorbed amount of CS. However, when either APAM or PECs adsorbed as secondary layers onto the CS, no correlation between cellulose charge and the saturation adsorption could be observed. The adsorption of APAM was dramatically affected by the pre-adsorbed amount of CS, whereas PECs were less influenced. Moreover, the additives improved the tensile strength (60%) and strain at break (> 100%) of handsheets formed with the kraft fibres and adsorbed APAM. It was also found that CS/APAM increased the sheet density while CS/PECs lowered it. In conclusion, the gained fundamental understanding of these adsorption of additives is of significant importance to facilitate the industrial development of sustainable low-cost high-end packaging products.Graphical abstract

Insights into the formation and digestive properties of lotus seed starch–glycerin monostearate complexes formed by freeze–thaw pretreatment and microfluidization

The objective of this paper was to investigate the formation and digestive properties of lotus seed starch–glycerin monostearate complexes (LSG) formed by freeze–thaw pretreatment and microfluidization. The results showed that the preparation of LSG with six freeze–thaw cycles at 60 MPa had the highest complex index (69.92%). The formation of LSG led to the conversion of the crystalline pattern of lotus seed starch from C-type to V-type and increased the proportion of the microcrystalline region. In addition, the digestive results indicated that LSG had a high resistance to digestive enzymes, which was conducive to increasing the content of resistant starch. Based on the above investigation, the formation and digestive properties showed that the appropriate number of freeze–thaw cycles of pretreatment could facilitate the complexation of starch and lipid under low-pressure microfluidization, which made for the directional regulation of helical conformation and anti-digestion.

Effect of freezing-assisted treatment on the formation of stable VII -type complex of fried sweet potato starch and its mechanism.

To comprehensively understand the effect of freezing-assisted treatment on the physicochemical properties of the fried sweet potato starch, the structural changes at granular and crystalline level were investigated. The results suggested that the freezing temperature exerted a significant effect on the interactions between sweet potato starch (SPS) and fried oil. With decreasing the freezing-assisted temperature, the gelatinization enthalpy of the fried frozen SPS remarkably increased by 1.5-4.9 J·g-1 and the transition temperatures of the second peak were elevated from 132.5°C to 136.5-141.1°C compared to that of native SPS, which suggested that more stable VII -type starch-lipid complexes were formed during frying. This finding was consistent with the results of the X-ray diffractometer that the intensity of the diffraction peak at 20.1° for V-type complex increased sharply as the temperature decreased from 20°C to -80°C, and the corresponding relative crystallinity and R1047/1022 values were increased from 16.5% and 0.35 to 26.4% and 0.45, respectively. The scanning electron microscopy revealed that the lower freezing-assisted temperature before frying promoted a membrane-like material covered on surfaces. The results showed that decreasing the freezing temperature promoted the formation of stable VII -type complex during frying. PRACTICAL APPLICATION: The purpose of this study was to comprehensively understand the effect of freezing-assisted treatment on the physicochemical properties of the fried sweet potato starch. These results provided useful information and effective method for producing fried starch-based foods with low digestibility.

MORPHOLIGICAL AND MOLECULAR DOCKING STUDIES ON THE FORTIFICATION OF STARCH FROM MAIZE WITH ISOLATED AND CHARACTERIZED DEFATTED SOYBEAN GLOBULINS POWDER

Fortification of indigenous infant weaning meal with protein from leguminous plants such as soybean can actually improve its nutritive value. This study investigates the stability and composition of soy-based formulations with maize starch and determines the nature of intermolecular interaction between the protein and the starch molecules. Dry protein powders were isolated from the legumes and the percentage crude protein was confirmed by proximate analysis. Scanning Electron Microscope (SEM) was used to visualize the surface morphology of the defatted soybean, starch, dry protein powders and protein–starch composite. Molecular docking was used to investigate the nature of the binding and interaction between the 7S and 11S globulin storage protein in soybean and the Cyclo-Amylose and amylopectin present in starch. The results reveal that the blending of maize starch with the dry protein powders yielded a uniformly mixed protein–starch gel in all proportions with the best binding pose of the amylopectin with the 11S and 7S globulins having binding affinity energies of -11.0 and -10.8 kcalmol-1 respectively, while for the amylose, the binding affinity energies are -3.8 and -3.7 kcalmol-1 for the 11S and 7S globulins respectively. These results indicate higher propensity of amylopectin in the formation of protein–starch complex.

Ordered structure of preformed V-amylose inclusion complex with 5-heptadecylresorcinol

5-Heptadecylresorcinol (ARs-17) is an amphiphilic phenolic lipid in grain bran with multiple bioactivities. In this study, the relationship between the crystalline structure, thermostability, morphological properties and in vitro digestibility of high amylose maize starch (HAMS) and preformed V-amylose (V6a, V6h, V7a, V7h, V8a, V8h) inclusion complexes with ARs-17 were investigated by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC), and scanning electron microscope (SEM). XRD and FTIR results revealed that both HAMS and V-amylose could form V6-type crystalline inclusion complexes with ARs-17, and the hydrophobic alkyl chain of ARs-17 located in the amylose helix cavity, while the hydrophilic phenolic hydroxyl group of ARs-17 located outside the helix. DSC analysis demonstrated that the complexation of V-amylose and ARs-17 was beneficial to the formation of stable type VIIb complexes with higher peak temperature over 140 °C, while the endothermal peak of HAMS-ARs-17 inclusion complex was only around 115 °C. SEM images detected that V-amylose and their complexes were spherical shape with the close-packed structure and aggregated together. By parameterizing digestion kinetics through logarithm-of-slope analysis (LOS) plot fitting, V6a-ARs-17 and V6h-ARs-17 inclusion complexes exhibited the lowest digestibility. This study suggests the great potential to apply V-amylose as functional ingredient for improving both processing and digestion stability of alkylresorcinols and thereby enhancing its bioaccessibility.

Interaction of Squid (Dosidicus giga) Mantle Protein with a Mixtures of Potato and Corn Starch in an Extruded Snack, as Characterized by FTIR and DSC

The majority of snacks expanded by extrusion (SEE) are made with vegetable sources, to improve their nutritional content; it has been proposed to incorporate squid (Dosidicus gigas), due to its high protein content, low price and high availability. However, the interaction of proteins of animal origin with starch during extrusion causes negative effects on the sensory properties of SEE, so it is necessary to know the type of protein–carbohydrate interactions and their effect on these properties. The objective of this research was to study the interaction of proteins and carbohydrates of SEE elaborated with squid mantle, potato and corn. The nutritional composition and protein digestibility were evaluated, Fourier transform infrared (FTIR) and Differential Scanning Calorimetry (DSC) were used to study the formation of protein–starch complexes and the possible regions responsible for their interactions. The SEE had a high protein content (40–85%) and biological value (>93%). The melting temperature (Tm) was found between 145 and 225 ◦C; the Tm values in extruded samples are directly proportional to the squid content. The extrusion process reduced the amine groups I and II responsible for the protein–protein interaction and increased the O-glucosidic bonds, so these bonds could be responsible for the protein–carbohydrate interactions.

Effect of High Pressure Homogenization on the Structure and Antioxidant Properties of EGCG-OSA Corn Starch Complex

Aiming to investigate the effect of high pressure homogenization on EGCG-OSA corn starch complex, EGCG-OSA corn starch complex was prepared by heating, high pressure homogenization and high pressure homogenization followed by heating respectively. Also, Fourier infrared (FT-IR), X-ray diffraction (XRD), scanning electron microscope (SEM) was utilized to characterize its structure and morphology. Rheometer and particle size analyzer was applied to analyze its rheology; and the DPPH and ABTS free radical scavenging rate was measured to compare the oxidation resistance. The research results indicated that the three kinds of complexes had high oxidation resistance, and the decline within the number of days was insignificant. Among these complexes, the one generated by sequential homogenization and heating obtained the highest oxidation resistance, and the DPPH clearance rate after 30 days still reached 89.63%, besides, the ABTS free radical scavenging rate reached 98.66%. According to the infrared and X-ray results, there was no evidence that the composite had any new chemical bonds or functional groups; the rheological results illustrated that the viscosity of the composite after high-pressure homogenization decreased more and its particle size was reduced. In summary, the complex prepared by high pressure homogenization followed by heating has higher oxidation resistance and better storage stability, which provides theoretical and experimental basis for the application of EGCG in the processing and production of starch food.

Resistant structure of extruded starch: Effects of fatty acids with different chain lengths and degree of unsaturation

This study investigated the formation mechanism of enzyme-resistant structures in extruded starch, specifically, fatty acid–starch complexes (FASCs). The effects of fatty acids (FAs) with different carbon-chain lengths (C12–C18) and degrees of unsaturation (C18:0–C18:2) on complex formation were evaluated, with fluorescence microscopy verifying complex formation. The complexed-lipid content and degree of relative crystallinity increased with the carbon-chain length and degree of FA unsaturation. FAs with fewer carbons were more likely to generate stable complexes (e.g., form II, melted at 100–120 °C), while FAs with more carbons tended to produce relatively unstable complexes (e.g., form I, melted at 80–100 °C). After reheating and cooling, a new amylose–lipid complex and an amylose-amylopectin network was formed in the unsaturated FASC samples, which restricted the penetration of enzymes into starch granules. A starch-linoleic acid complex exhibited the highest resistant starch content (15.7%) and lowest predicted glycaemic index (88.4).

Life cycle assessment of an alternative enzymatic-biological treatment for effluents from industrial processing of potatoes

Enzymatic processes offer an option for the treatment of rich-starch effluents from the industrial processing of potatoes, which has been usually provided by means coagulation-flocculation units followed by settling, filtering or mechanical separation stages. Pre-treatment of these effluents with amylase enzymes increases the biodegradable-soluble COD fraction (bsCOD) by hydrolysis of starch and other complex molecules therein present. For this reason, it has been thought the coupling of an enzymatic pre-treatment with a combined biological process (anaerobic + aerobic) as an alternative treatment for these starchy liquid streams. This “enzymatic-biological” concept would allow valuable biogas for its own operational needs and to reduce relevant environmental impacts regarding to the typical physicochemical processes, such as elevated consumption of energy and chemicals, as well the production of hardly biodegradable sludge. The apparent environmental advantages claimed by the enzymatic-biological treatment concept (alternative scenario) have been elucidated through a comparative life cycle assessment (LCA) against a solely physicochemical-based treatment (baseline scenario). Inventory data for the enzymatic pre-treatment were obtained and fitted from lab-scale tests, whilst average operational data were assumed for the anaerobic and aerobic units, as well for the baseline scenario. Environmental benefits have been unfolded by evaluating three mid-point environmental categories prioritized in this study, namely, global power warming, eutrophication potential and non-renewable energy consumption. The LCA results suggest the possible replacement of the physicochemical-based approach to treat starchy streams by applying the alternative enzymatic-biological process proposed in this study.

New glyoxalated pre-gelatinized starch as release retardant for extended release pellets containing zaltoprofen: statistical optimization, in-vitro and in-vivo evaluation

The aim of the present investigation is to develop zaltoprofen-loaded extended-release (ER) pellets formulation by an extrusion-spheronization technique using glyoxalated pre-gelatinized starch (GPS) complex as a novel matrix-forming polymer. The prime objective was to prepare an efficient and robust ER drug delivery system of zaltoprofen. Pellets were characterized by physicochemical, morphological, and solid-state characterization. The formulation was also analyzed for in-vitro drug release and in-vivo pharmacokinetic parameters. The FTIR analysis confirmed the GPS complex formation through the formation of the hemiacetal group while the ketone groups of glyoxal are abolished. Optimized formulation G5 containing 5:8 ratio of GPS complex and MCC showed 99.03 ± 2.12 percent cumulative drug releases in 14 h. The in-vivo study showed decreased C max and increased t 1/2 compared to bulk zaltoprofen, and hence would be a viable alternative for ER-type formulations. In the author’s opinion, the GPS-based ER pellet formulation would be an excellent delivery system for zaltoprofen.

On-site smart biomimetic mineralization of starch-templated CaP prenucleation clusters triggered by α-amylase

With the attention of biomineralization, calcium phosphate precursor phases regulated by different organic templates are synthesized and used as mineral sources for biomimetic mineralization. However, most of the organic templates have limited ability to stabilize calcium and phosphorus ions, or the selected templates have poor biocompatibility and irremovability, which make them difficult to co-exist in long-term stability and crystal transformation, and to achieve convenient and harmless clinical application. Herein, we propose a calcium phosphate prenucleation clusters (CaP-PNCs)/starch complex, which includes uniform-sized, separate, and homogeneously distributed amorphous calcium phosphate nanoclusters of about 1 nm. By means of freeze-drying and redissolution, the CaP-PNCs/starch complex can be converted between liquid and spongy solid without changing their morphology and amorphous phase, and the freeze-dried CaP-PNCs/starch complex can be stored at room temperature for at least 5 months. Imitating the mechanism of protein-protease controlled biomineralization in organisms, the CaP-PNCs/starch complex is mixed with α-amylase during application. Starch templates are removed by enzymolysis and CaP-PNCs can be released, thus triggering on-site biomimetic mineralization with enamel-like structures to repair tooth tissue defects (including enamel and dentin). CaP-PNCs/starch complex provides a smart mineral source supply for biomimetic mineralization and a new pathway for the design of biomimetic materials.

Changes in Phenolics during Cooking Extrusion: A Review.

In this paper, significant attention is paid to the retention of phenolics in extrudates and their health effects. Due to the large number of recent articles devoted to total phenolic content (TPC) of input mixtures and extrudates, the technological changes are only presented for basic raw materials and the originating extrudates, and only the composites identified has having the highest amounts of TPC are referred to. The paper is also devoted to the changes in individual phenolics during extrusion (phenolic acids, flavonoids, flavonols, proanthocyanidins, flavanones, flavones, isoflavons, and 3-deoxyanthocyanidins). These changes are related to the choice or raw materials, the configuration of the extruder, and the setting the technological parameters. The results found in this study, presented in the form of tables, also indicate whether a single-screw or twin-screw extruder was used for the experiments. To design an extrusion process, other physico-chemical changes in the input material must also be taken into account, such as gelatinization of starch; denaturation of protein and formation of starch, lipids, and protein complexes; formation of soluble dietary fiber; destruction of antinutritional factors and contaminating microorganisms; and lipid oxidation reduction. The chemical changes also include starch depolymerization, the Maillard reaction, and decomposition of vitamins.

Effects of degree of milling on the starch digestibility of cooked rice during (in vitro) small intestine digestion

Effects of degree of milling on starch digestibility of cooked rice during (in vitro) small intestine digestion were investigated. By fitting starch digestograms to the logarithm of slope plot and combination of parallel and sequential digestion kinetics model, two starch fractions with distinct digestion rate constants were identified. Results from scanning electronic microscope and confocal laser scanning microscope showed that the rapidly digestible starch fraction (RDF) was mainly composed of gelatinized starch, while the slowly digestible starch fraction (SDF) was consisted of relatively intact starch granules, protein matrix encapsulated starch and starch-protein binary complex. The cooked rice with milling treatment had more loosely packed and larger network cells compared to that for brown rice. Consequentially, the RDF content was decreased, while that for SDF was increased by the milling treatment. These results could help the rice processing industry to develop healthy rice products with desirable starch digestibility.

Enhancing gelling properties of high internal phase emulsion-filled chicken gels: Effect of droplet fractions and salts

Effects of high internal phase emulsion (HIPE) stabilized by egg yolk-modified starch complex on the gelling properties of chicken gels with or without sodium chloride (NaCl)/sodium tripolyphosphate (TP) were studied. The addition of 30 % HIPE increased the hardness from 376 g to 590 g. The NaCl addition further improved textural and viscoelastic properties compared with the gels without NaCl. 30 % HIPE-filled gels with salts (NaCl and TP) has the highest hardness (3562 g) and the lowest cooking loss (3.41 %). Fourier transform infrared spectra (FTIR) revealed that salts, especially TP, could promote the transition of α-helices to β-sheets structure. Moreover, the chicken gels with TP had higher acyl chain disorder. In summary, the co-addition of HIPE and salt (NaCl/TP) has a positive effect on the formation of chicken gel, thereby providing potential applications in comminuted meat products.

The effect of cassava and wheat starches complexation with selected fatty acids on their functional properties

The aim of the study was to evaluate the impact of selected fatty acids: palmitic, stearic or oleic on functional properties of cassava and wheat starches. Effectiveness of complexation procedure was evaluated by determination of complexing index, lipids content and fatty acid composition. Native starches and their complexes with fatty acids were analyzed for water binding capacity and solubility in water, in vitro digestibility, pasting characteristic and rheological properties. On the basis of the obtained results it was found that values of complexing index values for both starches complexed with oleic acid were remarkably higher than those determined in palmitic or stearic counterparts. Starches complexation with fatty acids resulted in a significant increase in the percentage share of used fatty acid in total fatty acid composition. Presence of oleic acid in cassava starch significantly limited its water binding capacity and solubility in water. Complexation with all fatty acids used in the study resulted in an increase in final viscosity and rheological stability of cassava starch pastes. Wheat starch complexes with fatty acids were characterised by higher pasting temperatures as compared to non-complexed counterpart, with the greatest effect observed for starch–oleic acid complex. In most cases complexation of starches with fatty acids contribute to an increase in contents of resistant starch fraction. Analysis of rheological model parameters revealed that procedure of oleic acid complexation increased by twice the values of consistency coefficient, and significantly decreased flow index of both wheat and cassava starches.

Probing the Role of the Solvation Shell for the Iodine–Starch Complex Using Millifluidic Devices

Probing the Role of the Solvation Shell for the Iodine–Starch Complex Using Millifluidic Devices

Interaction of Squid (Dosidicus giga) Mantle Protein with a Mixtures of Potato and Corn Starch in an Extruded Snack, as Characterized by FTIR and DSC.

The majority of snacks expanded by extrusion (SEE) are made with vegetable sources, to improve their nutritional content; it has been proposed to incorporate squid (Dosidicus gigas), due to its high protein content, low price and high availability. However, the interaction of proteins of animal origin with starch during extrusion causes negative effects on the sensory properties of SEE, so it is necessary to know the type of protein–carbohydrate interactions and their effect on these properties. The objective of this research was to study the interaction of proteins and carbohydrates of SEE elaborated with squid mantle, potato and corn. The nutritional composition and protein digestibility were evaluated, Fourier transform infrared (FTIR) and Differential Scanning Calorimetry (DSC) were used to study the formation of protein–starch complexes and the possible regions responsible for their interactions. The SEE had a high protein content (40–85%) and biological value (>93%). The melting temperature (Tm) was found between 145 and 225 °C; the Tm values in extruded samples are directly proportional to the squid content. The extrusion process reduced the amine groups I and II responsible for the protein–protein interaction and increased the O-glucosidic bonds, so these bonds could be responsible for the protein–carbohydrate interactions.

Preparation and characterization of native starch-ibuprofen molecular inclusion complexes

Starch is a biodegradable and biocompatible polymer recognized as a versatile starting material for developing innovative drug delivery systems. In this way, the present research work investigates the ability of bamboo and corn starches to carrier ibuprofen via the formation of molecular inclusion complexes by the Acidification of an Alkaline Solution and the Heating-Sealing methods. The water ratio and the reaction time used in each procedure influence the yield and efficiency of complexation; thus, the yield varies between 16.3% and 89.6% for the bamboo starch and between 30.3% and 74.5% for the corn starch. The complexing efficiencies reach values up to 10.30% ± 0.02% when bamboo starch was used and up to 22.35% ± 0.04% for corn starch. The thermal characteristics and the pH-dependent drug release pattern exhibited by the obtained complexes keep a closer relationship with their semicrystalline structures. On this basis, starch complexes arise as promising alternatives to deliver active molecules at the intestinal level and offer attractive possibilities for generating added value to native starch sources like bamboo.

Simple and Equipment-Free Paper-Based Device for Determination of Mercury in Contaminated Soil.

This work presents a simple and innovative protocol employing a microfluidic paper-based analytical device (µPAD) for equipment-free determination of mercury. In this method, mercury (II) forms an ionic-association complex of tetraiodomercurate (II) ion (HgI42−(aq)) using a known excess amount of iodide. The residual iodide flows by capillary action into a second region of the paper where it is converted to iodine by pre-deposited iodate to liberate I2(g) under acidic condition. Iodine vapor diffuses across the spacer region of the µPAD to form a purple colored of tri-iodide starch complex in a detection zone located in a separate layer of the µPAD. The digital image of the complex is analyzed using ImageJ software. The method has a linear calibration range of 50–350 mg L−1 Hg with the detection limit of 20 mg L−1. The method was successfully applied to the determination of mercury in contaminated soil and water samples which the results agreed well with the ICP-MS method. Three soil samples were highly contaminated with mercury above the acceptable WHO limits (0.05 mg kg−1). To the best of our knowledge, this is the first colorimetric µPAD method that is applicable for soil samples including mercury contaminated soils from gold mining areas.

Utilization of high internal phase emulsion stabilized by egg yolk-modified starch complex for the delivery of lutein

The purpose of this study was to evaluate the physicochemical stability and potential gastrointestinal fate of the lutein-enriched high internal phase emulsions (LE-HIPE) stabilized by egg yolk-modified starch complex. Results showed that the physical stability and lutein retention of the LF-HIPE stabilized by egg yolk-hydroxypropyl distarch phosphate (EY-HPDSP) or egg yolk-octenyl succinic anhydride starch (EY-OSA) complex were both significantly improved at 4 °C. However, the LE-HIPE stabilized by EY-HPDSP complex showed better physical stability, lower lipid oxidation and higher lutein retention during storage at 37 °C than that stabilized by EY-OSA complex, which was related with the results of smaller droplets, more restricted water and oil protons for the former. In vitro digestion results showed that high level of HPDSP in LE-HIPE was beneficial to the improvement of the bioaccessibility of lutein. These results could be useful in the development of nutrient delivery system based on egg yolk-modified starch complex stabilized HIPE.