Search

Abstract: Detection of traces from pharmaceutical drugs such as antibiotics in drinking water and foodstuff is essential for guaranteeing human health in some environments, and this has to be done with low cost technologies to be widely deployed in public services and industry. In this paper, we describe an ultralow cost (

In current study, starch/TiO 2 bionanocomposites were produced by photochemical reactions as a biodegradable food packaging material. Physical, mechanical, thermal and water-vapor permeability properties were investigated. Then, the photo-degradation properties of nanocomposite films were studied. This is the first report of the photo-producible and photo-degradable bionanocomposite as a food packaging material. Film-forming solutions were exposed to ultraviolet A (UV-A) for different times. Our results showed that UV-A irradiation increased the hydrophobicity of starch films. With increasing UV-A exposure time, tensile strength and Young’s modulus of the specimens were decreased. On the other hand, elongation at break of the films was increased with increasing UV-A irradiation. The glass transition temperature and melting point of the films were increased by increasing UV-A exposure time. Nevertheless, the results showed that photo-degradation properties of photo-produced starch/TiO 2 nanocomposite were significantly higher than virgin starch and virgin starch/TiO 2 films. According to obtain results and bibliography a schema was developed to describe the mechanism of photo-production and photo-degradation of starch/TiO 2 by UV-A ray. It can be concluded, the modification of starch based biopolymer by UV-A and nano-TiO 2 , is an easy and accessible process to improve the packaging properties and photo-degradability of biopolymer based films. [ABSTRACT FROM AUTHOR]

In the paper, a comprehensive study of rheological properties of 3% (w/v) Japanese kuzu starch pastes was conducted. To describe the experimental data obtained from oscillatory and creep tests, the new rheological model-which was a modification of the fractional Kelvin-Voigt model-was proposed. The model provided an accurate description of the dynamic data in a range of nearly seven logarithmic decades of oscillation frequency v, with an average error equal to 4.7%. It allowed for a precise determination of 17 rheological parameters of the biopolymer in a function of temperature and time of pasting. These parameters have provided a lot of additional information about structure and viscoelastic properties of the test medium in comparison to the classical analysis of dynamic curves G0 and G00 and shear creep compliance J(t). The study indicated that kuzu starch pastes were viscoelastic polydisperse solids. Rising temperature and time of pasting caused an increase in elastic properties and average molecular weight of the biopolymer. The analysis also showed that the specific pasting conditions, 80°C, 15 min; 95°C, 75 min; and 80°C, 30 min, are particularly important from the point of view of structure and rheological properties of products in food, pharmaceutical, and cosmetics industry, respectively. [ABSTRACT FROM AUTHOR]

The use of native starch as a thermoplastic polymer is limited by its fragility and high moisture absorption. Native potato starch was derivatized using different agents in order to reduce its hydrophobicity. A reduction in starch mechanical properties was also found as a side effect of derivatization treatments. The addition of nanocellulose allows to considerably improve mechanical properties of biopolymers as well as to maintain their inherent biodegradation capability. Cellulose nanofibers were added to native and modified starch in order to improve the mechanical properties. The mechanical properties of starch/cellulose nanocomposite films were evaluated, finding that they considerably improved with the addition of cellulosic nanofibers. This contribution demonstrates a new approach in order to produce bioplastics with combined effect: improved moisture and heat resistance (due to the chemical treatment) and high mechanical properties (after the addition of nanocellulose). [ABSTRACT FROM AUTHOR]