Odinei Hess Gonçalves

Adsorption of natural dyes on clay fixed on polymers

The main purpose of this work was to produce a pellet to minimize undesirable effects in fixed beds, such as colmatation, through clay fixation on the surface of polymeric particles. Preliminary experiments were carried out by heating the clay, namely Tonsil Terrana 580FF, in order to observe variations on its capacity to adsorb anthocyanins derived from red cabbage. Clays was fixed on five samples of high density polyethylene (HDPE) at 180°C -210°C for two hours. The morphological analyses of the resulting particles were accomplished through Scanning Electron Microscopy (SEM). The experiments demonstrated an increase on clays adsorptive capacity of 15.65% at 120°C for 30 hours and 16.80% at 170°C for two hours. The SEM analysis showed that the clay particles adhered on the external surface of the pellets .These results show that it is possible to obtain polymeric pellets using HDPE coated with clay.

Active Food Packaging From Botanical, Animal, Bacterial, and Synthetic Sources

Abstract The use of bioactive substances, especially those that present antimicrobial and antioxidant activities, has attracted considerable attention toward the development of a novel generation of materials with functional properties. In particular, one of the greatest challenges of the food-packaging area is the development of sustainable and biodegradable materials containing active substances capable of being gradually released to the food surface or matrix during its shelf life, ensuring sensorial, nutritional, and microbiological characteristics maintenance, without compromising the mechanical, thermal, and barrier properties quality of food packaging materials. In this context, this chapter presents an overview of the existing strategies to develop viable products by combining biodegradable polymeric matrices of natural or synthetic origin with natural additives able to confer specific functionalities (e.g., natural extracts, essential oils, enzymes, vitamins, and bacteriocins) or improve their mechanical properties (nanoreinforcements from organic or inorganic sources).