The effect of UV-B irradiation on structural and functional properties of corn and potato starches and their components

Combined effect of heating temperature and content of pectin on the textural properties, rheology, and 3D printability of potato starch gel

Three-dimensional (3D) printing is one of the emerging techniques which fabricates customized foods with desired sensory characteristics. Rheological properties of 3D printing materials are vitally important in printability which govern the flowability and structural stability. Due to its unique gel-forming characteristics, potato starch has been extensively used in myriad food applications, such as 3D printing. However, little attention has been paid to the combined effect of heating temperature and pectin addition on the properties of potato starch gels. Thus, this study investigated the impact of different pectin contents (1, 1.5, and 2 %) on printability and the rheological and textural properties of potato starch gels heated at different temperatures (70, 80, and 90 °C). The gel heating temperature governs pectin-driven modifications in potato starch gels. Pectin addition increased the 3D printability, viscosity, storage modulus, hardness, gumminess, and springiness of starch gel at higher temperatures (80 °C and 90 °C). In contrast, at lower temperatures (70 °C), pectin addition decreased printability, viscosity, storage modulus, hardness, gumminess, and springiness. Therefore, the gel heating temperature influences the impact of pectin on printability, rheology, and textural properties. Accordingly, the combined effects of pectin and heating temperature should be considered in pectin-based 3D food-printing ink formulations.

Native Potato Starch and Tara Gum as Polymeric Matrices to Obtain Iron-Loaded Microcapsules from Ovine and Bovine Erythrocytes

Iron deficiency leads to ferropenic anemia in humans. This study aimed to encapsulate iron-rich ovine and bovine erythrocytes using tara gum and native potato starch as matrices. Solutions containing 20% erythrocytes and different proportions of encapsulants (5, 10, and 20%) were used, followed by spray drying at 120 and 140 °C. Iron content in erythrocytes ranged between 2.24 and 2.52 mg of Fe/g; microcapsules ranged from 1.54 to 2.02 mg of Fe/g. Yields varied from 50.55 to 63.40%, and temperature and encapsulant proportion affected moisture and water activity. Various red hues, sizes, and shapes were observed in the microcapsules. SEM-EDS analysis revealed the surface presence of iron in microcapsules with openings on their exterior, along with a negative zeta potential. Thermal and infrared analyses confirmed core encapsulation within the matrices. Iron release varied between 92.30 and 93.13% at 120 min. Finally, the most effective treatments were those with higher encapsulant percentages and dried at elevated temperatures, which could enable their utilization in functional food fortification to combat anemia in developing countries.

Food-Grade Physically Unclonable Functions

Counterfeit products in the pharmaceutical and food industries have posed an overwhelmingly increasing threat to the health of individuals and societies. An effective approach to prevent counterfeiting is the attachment of security labels directly on drugs and food products. This approach requires the development of security labels composed of safely digestible materials. In this study, we present the fabrication of security labels entirely based on the use of food-grade materials. The key idea proposed in this study is the exploitation of food-grade corn starch (CS) as an encoding material based on the microscopic dimensions, particulate structure, and adsorbent characteristics. The strong adsorption of a food colorant, erythrosine B (ErB), onto CS results in fluorescent CS@ErB microparticles. Randomly positioned CS@ErB particles can be obtained simply by spin-coating from aqueous solutions of tuned concentrations followed by transfer to an edible gelatin film. The optical and fluorescence microscopy images of randomly positioned particles are then used to construct keys for a physically unclonable function (PUF)-based security label. The performance of PUFs evaluated by uniformity, uniqueness, and randomness analysis demonstrates the strong promise of this platform. The biocompatibility of the fabricated PUFs is confirmed with assays using murine fibroblast cells. The extremely low-cost and sustainable security primitives fabricated from off-the-shelf food materials offer new routes in the fight against counterfeiting.

A Comparative Investigation of the Surface Properties of Corn-Starch-Microfibrillated Cellulose Composite Films

Starch-based materials seem to be an excellent alternative for conventional plastics used in various applications. Microfibralted cellulose can be used to improve the surface properties of starch-based materials. This study aims to analyze the surface properties of starch-microfibrillated cellulose materials. The surface properties of films were evaluated by ATR-FTIR, surface roughness, water wettability, and surface free energy. The surface homogeneity between corn starch and microfibrillated cellulose (MFC) fibers was confirmed by scanning electron microscopy (SEM) and atomic force microscopy (AFM). Microscopic analyses of the film surfaces confirm good compatibility of starch and MFC. The addition of MFC increased the surface roughness and polarity of developed starch/MFC materials. The surface roughness parameter has increased from 1.44 ± 0.59 to 2.32 ± 1.13 for pure starch-based materials and starch/MFC material with the highest MFC content. The WCA contact angle has decreased from 70.3 ± 2.4 to 39.1 ± 1.0°, while the surface free energy is 46.2 ± 3.4 to 66.2 ± 1.5 mJ·m^-2, respectively. The findings of this study present that surface structure starch/MFC films exhibit homogeneity, which would be helpful in the application of MFC/starch materials for biodegradable packaging purposes.

The microstructure and thermal properties of pulsed electric field pretreated oxidized starch

The structure and thermal properties of pulsed electric field (PEF) assisted sodium hypochlorite oxidized starch were investigated. The carboxyl content of the oxidized starch was increased by 25 % when compared with the traditional oxidation method. Dents and cracks were evident on the surface of the PEF-pretreated starch. Compared with native starch, the peak gelatinization temperature (T_p) of PEF-assisted oxidized starch (POS) was reduced by 10.3 °C, while that of the oxidized starch without PEF treatment (NOS) was only reduced by 7.4 °C. In addition, PEF treatment further reduces the viscosity and improve the thermal stability of the starch slurry. Therefore, PEF treatment combined with hypochlorite oxidation is an effective method to prepare oxidized starch. PEF showed great potential in expanding starch modification, to promote a wider application of oxidized starch in the paper, the textile and the food industry.