Banca de QUALIFICAÇÃO: SILVIA VALERIA DE MEDEIROS

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
DISCENTE : SILVIA VALERIA DE MEDEIROS
DATA : 30/09/2019
HORA: 09:00
LOCAL: Sala de aula A do Departamento de Nutrição - DNUT/UFRN
TÍTULO:

EFFECT OF CHITOSAN AND BENTONITE FILMS IN POST-HARVEST CONSERVATION OF BANANA (Musa spp.)

PALAVRAS-CHAVES:

Polysaccharides; edible coatings; postharvest quality; fruits; clay.

PÁGINAS: 84
GRANDE ÁREA: Ciências da Saúde
ÁREA: Nutrição
RESUMO:

After harvest, biochemical and physiological processes in the fruits are still activated, leading to physicochemical modifications that lead to ripening and senescence and, consequently, to waste, which occurs due to losses in fruit quality. Banana culture in Brazil plays an important economic role and banana is the most consumed fruit among Brazilians and in the world. However, about 40% of the total produced in the country is lost after harvest, due to the rapid ripening and early deterioration of the fruits, making it difficult to commercialize and export. In this context, the study of coatings and edible films based on natural biodegradable polymers is characterized as a proposal to prolong the shelf life of fruits and replace the use of conventional non-renewable and non-biodegradable plastics in food packaging. Chitosan, a polymer obtained from deacetylation of chitin, has been shown to be a good filmogenic agent, but with limitations in mechanical and barrier properties that can be improved by the addition of nano-reinforcements such as bentonite clay fillers, a clay mineral montmorillonite widely available in nature. Thus, this work aimed to evaluate the postharvest conservation of banana (Musa spp.) coated with biopolymer films based on chitosan and glycerol and clay-biopolymeric films consisting of chitosan, glycerol and bentonite. The morphology, chemical composition and microstructure of the surface of the films were analyzed; the arrangement of bentonite in the polymeric chitosan matrix; thermal decomposition water and vapor permeability of the different film formulations produced. The films will still be analyzed for mechanical strength and elasticity and for antibacterial and antioxidant activities. The evaluation of postharvest conservation was carried out partly from quality physicochemical parameters and by microbiological and physical analysis of fruits in different storage periods. The results discussed for the qualification of the study are partial and concern only the characterization analyzes of the films already made. Regarding the morphology and elemental analysis of the films, there was greater surface uniformity in the biopolymer films and surface roughness of the clay-biopolymer films. The qualitative and quantitative elemental analyzes confirmed the presence of bentonite in the clay-biopolymeric films by detecting elements, such as silicon and aluminum, present in the phyllosilicate structure. As for microstructural analysis, a predominantly amorphous material was found, with a broad peak characteristic of the semi-crystalline phase of the biopolymer, with no noticeable changes with the insertion of bentonite. Infrared spectra showed characteristic bonding and grouping vibrational bands in chitosan, in biopolymer films, in addition to those bonding and grouping characteristics in bentonite structure in clay-biopolymer films. Thermogravimetric analyzes and permeability tests, respectively, showed that the addition of clay resulted in higher residue formation after thermal decomposition of the material and enhanced the barrier property against water vapor permeability of chitosan films. The clay-biopolymer film with higher chitosan concentration presented higher thickness, lower water vapor permeability and lower mass loss related to thermal decomposition of the polymer, when compared to the other films.

MEMBROS DA BANCA:
Presidente - 3211846 - KARLA SUZANNE FLORENTINO DA SILVA CHAVES DAMASCENO
Externo à Instituição - ROBERTO RODRIGUES CUNHA LIMA
Externa ao Programa - 2275877 - THAIS SOUZA PASSOS
Externo ao Programa - 1149328 - VALTER JOSE FERNANDES JUNIOR