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Aqueous suspensions (30% w/w) of spelt, amaranth and wheat starches were illuminated with linearly polarised visible light for 5, 15, 25 and 50 h. For native and illuminated samples, the weight-average molecular weight, the radii of gyration of the starch polysaccharide chains, and the distribution of the amylopectin structural units of the illuminated starches were determined. The susceptibility to α-amylolysis together with the iodine-binding properties and crystalline structure were studied for each of the starch samples. Illumination with linearly polarised visible light indicated changes in the crystalline structure of the polysaccharide chains and led to an increased enzymatic hydrolysis rate constant for the first stage of hydrolysis and final hydrolysis extent. Changes in the molecular structure of the starch indicate that illumination of the starches induced depolymerisation-repolymerisation reactions of starch polysaccharide chains. That rearrangements of the molecular starch structure depend on the illumination time and the botanical source of the starch., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Environmentally friendly method of the preparation of dialdehyde starch (DAS) based composites containing nanosilver (DAS/Ag) and nanogold (DAS/Au) as reducing and protecting agents was developed. UV-vis spectroscopy, transmission electron microscopy (TEM) and X-ray diffraction (XRD) confirmed formation of about 10nm ball shaped Ag and Au nanoparticles situated within the polysaccharide template. Thermal properties of the composites were characterized involving differential scanning calorimetry (DSC), whereas molecular weights of polysaccharide chains of the matrix were estimated with the size exclusion chromatography coupled with multiangle laser light scattering and refractometric detectors (HPSEC-MALLS-RI). Formation of nanosilver and nanogold containing composites led to induction of the polymerization and/or crosslinking reactions of DAS molecules, resulting in a significant rise of molecular weight of polysaccharide chains constituting DAS/Ag and DAS/Au composite templates., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

Rapid industrial growth is associated with an increase in the production of environmentally harmful waste. A potential solution to significantly reduce pollution is to replace current synthetic materials with readily biodegradable plastics. Moreover, to meet the demands of technological advancements, it is essential to develop materials with unprecedented properties to enhance their functionality. Polysaccharide composites demonstrate significant potential in this regard. Polysaccharides possess exceptional film-forming abilities and are safe for human use, biodegradable, widely available, and easily modifiable. Unfortunately, polysaccharide-based films fall short of meeting all expectations. To address this issue, the current study focused on incorporating carbon quantum dots (CQDs), which are approximately 10 nm in size, into the structure of a starch/chitosan biocomposite at varying concentrations. This modification has improved the mechanical properties of the resulting nanocomposites. The inclusion of nanoparticles led to a slight reduction in solubility and an increase in the swelling degree. The optical characteristics of the obtained films were influenced by the presence of CQDs, and the fluorescence intensity of the nanocomposites changed due to the specific heavy metal ions and amino acids used. Consequently, these nanocomposites show great potential for detecting these compounds. Cellular viability assessments and comet assays confirm that the resulting nanocomposites do not exhibit any cytotoxic properties based on this specific analytic method. The tested nanocomposites with the addition of carbon quantum dots (NC/CD II and NC/CD III) were characterised by greater genotoxicity compared to the negative control. The positive control, the starch/chitosan composite alone, was also characterised by a greater induction of chromatin damage in mouse cells compared to a pure mouse blood sample. [ABSTRACT FROM AUTHOR]

Nanocomposites are an emerging technology for ensuring food safety and quality. Their unique properties, attributed to nanoparticle presence, facilitate the development of sophisticated sensors and biosensors for detecting harmful substances, microbial growth, and environmental changes in food products. Smart and/or active food packaging development also benefits from the use of nanocomposites. This packaging, or portions of it, provide active protection for its contents and serve as sensors to promptly, simply, and safely identify any detrimental changes in stored food, without elaborate techniques or analyses. Films made from potato starch and chitosan were produced and quantum dots of zinc sulfide (ZnS) and cadmium sulfide (CdS)were synthesized in them for this study. The presence and dimensions of the QDs (quantum dots) were examined with scanning electron microscopy (SEM) and ultraviolet-visible (UV-VIS) spectroscopy. The study aimed to establish the toxicity profile of a starch–chitosan bionanocomposite integrated with ZnS and CdS quantum dots. Cytotoxic and genotoxic features were assessed through cytogenetic instability assessments, consisting of the alkaline comet assay, erythrocyte micronucleus assay, and peripheral blood cell viability analysis of a laboratory mouse model. [ABSTRACT FROM AUTHOR]

The dynamic development of the food industry and the growing interest of consumers in innovative solutions that increase the comfort and quality of life push the industry towards seeking pioneering solutions in the field of food packaging. Intelligent and active packaging, which affects the quality and durability of food products and allows one to determine their freshness, is still a modern concept. The aim of our study was to obtain two types of films based on chitosan and starch with micellar nanostructures containing extracts from turmeric rhizomes and hibiscus flowers. The presence of spherical nanostructures was confirmed using a scanning electron microscope. The structural and optical properties of the obtained composites were characterised by Fourier-transform infrared (FTIR), UltraViolet-Visible (UV-VIS), and photoluminescence (PL) spectroscopy. Scanning electron microscopy (SEM) analysis confirmed the presence of spherical micellar structures with a size of about 800 nm in the obtained biocomposites. The presence of nano-/microstructures containing extracts affected the mechanical properties of the composites: it weakened the strength of the films and improved their elongation at break (EAB). Films with nano-/microparticles were characterised by a higher water content compared to the control sample and lower solubility, and they showed stronger hydrophilic properties. Preliminary storage tests showed that the obtained biocomposites are sensitive to changes occurring during the storage of products such as cheese or fish. In addition, it was found that the film with the addition of turmeric extract inhibited the growth of microorganisms during storage. The results suggest that the obtained bionanocomposites can be used as active and/or intelligent materials. [ABSTRACT FROM AUTHOR]

Nanometal-containing biocomposites find wide use in many industries and fields of science. The physicochemical properties of these materials depend on the character of the polymer, the size and shape of the metallic nanoparticles, and the interactions between the biopolymer and the nanoparticles. The aim of the work was to synthesise and study the effect of plasma-treated water on the properties of the obtained metallic nanoparticles as well as the physicochemical and functional properties of nanocomposites based on potato starch. The metallic nanoparticles were synthesised within a starch paste made in distilled water and in distilled water exposed to low-temperature, low-pressure plasma. The materials produced were characterised in terms of their physicochemical properties. Studies have shown that gold and silver nanoparticles were successfully obtained in a matrix of potato starch in distilled water and plasma water. SEM (Scanning Electron Microscopy) images and UV-Vis spectra confirmed the presence of nanosilver and nanosilver in the obtained composites. On the basis of microscopic images, the size of nanoparticles was estimated in the range from 5 to 20 nm for nanoAg and from 15 to 40 nm for nanoAu. The analysis of FTIR-ATR spectra showed that the type of water used and the synthesis of gold and silver nanoparticles did not lead to changes in the chemical structure of potato starch. DLS analysis showed that the nanoAg obtained in the plasma water-based starch matrix were smaller than the Ag particles obtained using distilled water. Colour analysis showed that the nanocomposites without nanometals were colourless, while those containing nanoAg were yellow, while those with nanoAu were dark purple. This work shows the possibility of using plasma water in the synthesis of nanometals using potato starch, which is a very promising polysaccharide in terms of many potential applications. [ABSTRACT FROM AUTHOR]

This study describes functional properties of bionanocomposites consisting of starch/chitosan/graphene oxide (GO) obtained using the green synthesis method, such as water-barrier and optical properties, as well as the rate of degradation by enzymatic and acid hydrolysis. The toxicity of the composites and their effects on the development of pathogenic microflora during storage of meat food products was also investigated. Although the results showed that the barrier properties of the composites were weak, they were similar to those of biological systems. The studies carried out confirmed the good optical properties of the composites containing chitosan, which makes it possible to use them as active elements of packaging. The susceptibility of starch and chitosan films to enzymatic and acid hydrolyses indicates their relatively high biodegradability. The lack of toxicity and the high barrier against many microorganisms offer great potential for applications in the food industry. [ABSTRACT FROM AUTHOR]

Inorganic nanocomposites can find application in various branches of industry, including food technology. Quantum dots have already been reported as promising nanosensors for the detection of heavy metal ions in soil, water and food. This study presents novel starch-based nanocomposites containing ZnS quantum dots capped with L-cysteine. The nanocomposites were prepared in form of gels and foils of potato starch with embedded spherical quantum dots sized 10-20 nm. They were characterized using photoluminescence, IR and UV spectra and TEM/SEM photographs. Pb2+ and Cu2+ ions decreased emission intensity of the photoluminescent spectral bands. The described quantum dots have been obtained using a simple, safe and low-cost method. Their properties make them alternative sensors for Pb2+ and Cu2+ ions that could be applied in biotechnology and food technology. [ABSTRACT FROM AUTHOR]

The aim of the present study was to reinforce starch-based films with psyllium mucilage in order to obtain natural, edible, and biodegradable films with improved mechanical and functional properties. The rheological properties of film-forming solutions can be controlled by the concentration levels of added mucilage. The addition of mucilage reduced the decomposition of the system, which made these films more thermally stable. Those starch-mucilage films were sufficiently transparent and exhibited a low aqueous solubility and as shown in SEM images of such films spherical particles appeared in the structure, probably microcapsules. The addition of mucilage did see an improvement in the mechanical properties of those films, especially at a higher concentration of starch (4% rather than 3%). [ABSTRACT FROM AUTHOR]

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Nanocomposite materials are increasingly commonly used to ensure food safety and quality. Thanks to their unique properties, stemming from the presence of nanoparticles, they are used to develop advanced sensors and biosensors, e.g., for various harmful substances, heavy metals, microorganism growth, and environmental changes in food products. The aim of this study is to produce novel films based on natural resources—potato starch and chitosan—incorporating generated quantum dots of zinc sulfide and cadmium sulfide. The biocomposites were subjected to the following assays: FTIR spectroscopy, UV-VIS spectroscopy, photoluminescence spectroscopy, and SEM/TEM spectroscopy. Their mechanical properties were also analyzed, a colorimetric analysis was performed, and the water content, solubility, and water absorption capacity were determined. A storage test was also performed, using poultry meat covered with the produced films, to assess the microbiological quality. The results confirmed the presence of the quantum dots in the starch–chitosan matrix. The unique optical properties of the films were also demonstrated. It was shown that the composites with nanoparticles limited the growth of selected microorganisms in poultry meat. The food storage time was found to have an impact on the fluorescent properties of the composites. The results point to the possibility of using the produced films as active and smart packaging. [ABSTRACT FROM AUTHOR]

The application of natural polymer matrices as medical device components or food packaging materials has gained a considerable popularity in recent years, this has occurred in response to the increasing plastic pollution hazard. Currently, constant progress is being made in designing two-component or three-component systems that combine natural materials which help to achieve a quality comparable to the purely synthetic counterparts. This study describes a green synthesis preparation of new bionanocomposites consisting of starch/chitosan/graphene oxide (GO), that possess improved biological activities; namely, good tolerability by human cells with concomitant antimicrobial activity. The structural and morphological properties of bionanocomposites were analyzed using the following techniques: dynamic light scattering, scanning and transmission electron microscopy, wettability and free surface energy determination, and Fourier transform infrared spectroscopy. The study confirmed the homogenous distribution of GO layers within the starch/chitosan matrix and their large particle size. The interactions among the components were stronger in thin films. Additionally, differential scanning calorimetry analysis, UV–vis spectroscopy, surface colour measurements, transparency, water content, solubility, and swelling degree of composites were also performed. The mechanical parameters, such as tensile strength and elongation at break (EAB) were measured in order to characterise the functional properties of obtained nanocomposites. The GO additive altered the thermal features of the composites and decreased their brightness. The EAB of composite was improved by the introduction of GO. Importantly, cell-based analyses revealed no toxic effect of the composites on HaCat keratinocytes and HepG2 hepatoma cells, although a pronounced bacteriostatic effect against various strains of pathogenic bacteria was observed. In conclusion, the starch/chitosan/GO nanocomposites reveal numerous useful physicochemical and biological features, which make them a promising alternative for purely synthetic materials. [ABSTRACT FROM AUTHOR]

The aims of this study were to evaluate the effect of chemical modification of waxy maize starch on its sorption, pasting properties, and in vitro digestibility, and to investigate the relationships among tested properties. The research materials were octenyl succinate, acetylated, oxidized, and acetylated‐oxidized starches. Starch acetylation and octenyl succinylation decreased amount of moisture content adsorbed above 0.4 water activity. For all tested starches, the bound adsorption predominates over free adsorption. Esterification with octenyl succinic or acetic anhydrides increased pastes hot paste and final viscosities. The rapidly digestible starch content decreased after performed modifications of waxy maize starch. Correlation analysis showed that peak viscosity and breakdown parameter of starch pastes were largely dependent on the properties of sorbed water. Ratio of free to bound water (F/B) at different water activities correlated with the setback values and contents of slowly digestible and resistant starch fractions. Practical applications: Generally, both sorption and functional properties of starch are modified in order to functionalize the polymer to meet specific requirements in the areas of food production and preservation. The research was aimed not only to investigate the sorption and functional properties of chemically modified starches, but also to find a relationships between the obtained results. Knowledge of these relationships can be used to formulate composition of food product, optimize processing parameters and select proper storage conditions to prevent product failure. On the basis of obtained results it was revealed that octenyl succinate and acetylated‐oxidized waxy maize starches exhibited lower amount of moisture content adsorbed at aw < 0.4. Therefore, these starches may be useful for processing and storing of low‐moisture starchy foods. Moreover starches with lower water absorbability form more stable gels. Obtained findings may be an useful tool for estimating the functional properties and the critical moisture contents during starchy food storage, that can assist to improve shelf‐life of stored products. [ABSTRACT FROM AUTHOR]

This paper presents studies on the structure, rheological, textural and thermal properties of potato starch + inulin gels at widely differentiated overall concentration and proportions of both gel components. The increase of polysaccharides concentration changed viscoelastic properties and firmness of gels, compared to control samples. Noticeable differences were observed at 6% concentration of starch and 25% of inulin. DSC suggested that gelatinization of potato starch with inulin produced the binary gel of the common network, that could resulted from the competition of both components for water (caused by high affinity of these polysaccharides to water molecules), which was a key factor influencing starch gelatinization and affected properties of the obtained gels. [ABSTRACT FROM AUTHOR]

Potatoes, especially colored, are perceived as a valuable source of bioactive compounds, and they are also an important raw material for starch production. There is virtually no information about starch from colored potatoes grown in Central Europe. Therefore, starches from light and colored potato varieties are isolated, and their particle size distributions, molecular masses, phosphorus content, gelatinization properties, water binding capacity, and solubility are analyzed. It is found that the mean and minimum granule size is similar for all investigated varieties, but colored varieties have larger granules. Moreover, starches isolated from colored potatoes are characterized by a higher phosphorus content than those isolated from light ones. It is shown that the solubility and water‐binding capacity of starch from colored potatoes is greater than that of light flesh, especially at higher temperatures. Starches from light flesh potatoes are characterized by significantly higher gelatinization enthalpy values than those from colored potatoes. [ABSTRACT FROM AUTHOR]

The aim of the research was to compare several physico-chemical parameters and rheological properties of potato starch from light and colour (red and purple) flesh potatoes, including content of amylose and non-carbohydrate compounds, granule diameter and particle size distribution, FTIR–ATR spectra of starches, as well as pasting ability, and rheological properties. There were no differences in protein and fat content, however coloured flesh potatoes starches contained higher amount of ash in comparison with light flesh varieties. The pasting properties of starches differed from each other and the viscosity of the pastes was influenced by amylose content. Starch pastes obtained from coloured flesh potatoes exhibited higher maximum viscosity than those with light flesh. All analyzed gels were characterized by the non-Newtonian, pseudoplastic, shear-thinning fluids with antithixotropic properties. [Display omitted] • Selected properties of potato starch from light and colour (red and purple) flesh potatoes were compared. • The variety and the year of cultivation of potatoes did not have an impact on protein and fat content in starches. • Starch pastes obtained from coloured flesh potatoes exhibited higher maximum viscosity than those with light flesh. • Starch gels were characterized by the non-Newtonian, pseudoplastic, shear-thinning fluids with antithixotropic properties. [ABSTRACT FROM AUTHOR]