Banca de DEFESA: ALICE DA CONCEIÇÃO ALVES DE LIMA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : ALICE DA CONCEIÇÃO ALVES DE LIMA
DATE: 27/10/2022
TIME: 09:00
LOCAL: Programa de Pós-Graduação em Ciência de Materiais
TITLE:

DEVELOPMENT OF BACTERIAL CELLULOSE / POLY (VINYL ALCOHOL) AND BACTERIAL CELLULOSE / CARBOXYMETHYLCELLULOSE BLENDS ENRICHED WITH ANTIOXIDANT

KEY WORDS:

Bacterial cellulose; Carboxymethylcellulose; Poly (vinyl alcohol); Antioxidant complex; Active packaging.

PAGES: 89
BIG AREA: Outra
AREA: Multidisciplinar
SUMMARY:

Active packaging from biodegradable polymers emerges as ecological alternatives to prolong the shelf life of food and ensure food safety. These packages are formulated from blends of biodegradable polymers and incorporated with active compounds, offering new biological properties, such as antioxidant or antimicrobial properties. In this scenario, we have bacterial cellulose (BC), poly (vinyl alcohol) (PVA) and carboxymethylcellulose (CMC) which are biodegradable polymers and can be used for this purpose. Therefore, in this work, blends of BC/PVA and BC/CMC incorporated with an antioxidant complex (EXT) were developed and evaluated in different concentrations from the in situ method, aiming at future applications as antioxidant active packaging. Analyzes of Water Retention Capacity (WRC), Infrared Spectroscopy (FTIR), Thermogravimetry (TGA), Scanning Electron Microscopy (SEM), X-Ray Diffractometry (XRD), antioxidant activity by the DPPH and ABTS methods, and water vapor permeability (WVP). The incorporation of EXT, by the in situ technique, was successful in the BC/PVA and BC/CMC blends, with confirmation from the FTIR and XRD analyses. Both blends also showed highly porous morphology, characteristic of bacterial cellulose, and reduced water holding capacity after the incorporation of EXT. The BC/PVA blends incorporated with EXT showed lower thermal stability. In addition, the BC/PVA blends incorporated with the highest concentration of EXT demonstrated greater crystallite size and antioxidant activity, in addition to lower crystallinity and permeability to water vapor. On the other hand, the BC/CMC blends showed greater thermal stability and, as the concentration of EXT incorporated in the blend increased, an increase in crystallite size, percentage of crystallinity and antioxidant activity was observed, in addition to a decrease in vapor permeability of water. Finally, both blends produced showed potential for future application in the active packaging sector with antioxidant properties, but the BC/CMC blend stood out with better thermal stability properties, antioxidant activity and water vapor protection capacity, contributing to increasing the shelf life of packaged products and can be applied to products that are more sensitive to moisture when compared to the BC/PVA blend.

COMMITTEE MEMBERS:
Presidente - 2572606 - GLORIA MARIA VINHAS
Externo ao Programa - 3285750 - PEDRO FERREIRA DE SOUZA FILHO - nullInterna - 1283002 - YEDA MEDEIROS BASTOS DE ALMEIDA