Banca de QUALIFICAÇÃO: FRANCISCO LEONARDO GOMES DE MENEZES

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
DISCENTE: FRANCISCO LEONARDO GOMES DE MENEZES
DATA: 29/09/2021
HORA: 08:30
LOCAL: Google Meet
TÍTULO:

Artigo 1: TiO2-enhanced chitosan/cassava starch biofilms for sustainable food packaging / Artigo 2: TiO2 incorporated into a blend of biopolymeric matrices improves film properties and affects the postharvest conservation of papaya fruits under UV light

PALAVRAS-CHAVES:

Artigo 1: Keywords: Bionanocomposite; Biopolymers; Titanium Dioxide (TiO2); Cassava Starch, Chitosan. / Artigo 2 : Keywords: Carica papaya L; Coating; Quality; Titanium Dioxide (TiO2); mechanical; barrier; Biopolymer.

PÁGINAS: 54
GRANDE ÁREA: Ciências Agrárias
ÁREA: Agronomia
RESUMO:

Artigo 1:

ABSTRACT
Biopolymeric films with the addition of nanoparticles have been studied as an alternative to replace petroleum-based synthetic packaging, which is difficult to recycle and leads to a major environmental problem. The goal of this study is to develop and characterise biopolymeric films of chitosan and cassava starch with the addition of titanium dioxide (TiO2) nanoparticles for use as food packaging. Chitosan film (2%w), cassava starch film (2%w), and chitosan/cassava starch (1:1) blend were developed in the absence and presence of TiO2 nanoparticles (0.25 and 1% w/w) and characterised in terms of physicochemical properties. The results indicate that the properties of films related to water (permeability, solubility, and water sorption) and mechanical (tension, elongation, and Young's modulus) are strongly influenced by the characteristics of the biopolymers used and can be improved with the introduction of TiO2. The water sorption was reduced with the addition of TiO2, which makes the film more hydrophobic and exhibits a higher tensile strength by more than 15% and elongation by more than 100%. The addition of 1% TiO2 also leads to a reduction in transmittance of 97% in UVA, UVB, and UVC regions, which is a valuable feature for food preservation.

Artigo 2:

ABSTRACT
This work investigated the properties of bio-nanocomposite films containing nanometric TiO2 particles in a biopolymeric matrix of chitosan-cassava starch and its viability on the postharvest conservation of papaya fruits. The effects of both chitosan and nano-TiO2 concentrations on the film properties were studied using a response surface methodology (RSM). To evaluate its viability as an edible coating for Formosa papaya, three treatments were applied: T1: uncoated papaya (control), T2: coated papaya fruits containing chitosan/cassava starch edible coating (1:1), and T3: coated papaya fruits containing chitosan/cassava starch (1:1) associated to 1% TiO2, under both the presence and absence of UV light, at 15±1ºC, 90±1% RH for 24 days. Starch-chitosan blend films showed intermediate hydrophobicity and improved mechanical properties. However, the addition of TiO2 exceeding 1% led to the formation of agglomerates and reduced film transparency. The addition of 1% TiO2 into the polymeric matrix of starch/chitosan (1:1) improved the mechanical properties, solubility, and reduced transmittance by more than 97% within UV regions, thereby presenting suitable transparency. UV light provided superficial damage on the fruit peel, which was evidenced by a higher weight loss; however, the addition of 1% nano TiO2 to the chitosan/starch biopolymer blend reduced weight loss and delayed fruit ripening, which were associated with the maintenance of pulp firmness, soluble solids contents, pH and vitamin C. Coated fruits showed suitable external and internal qualities for commercialization when storage for up to 24 d at 15 ºC and 90 ± 1% RH.

MEMBROS DA BANCA:
Presidente - 1509522 - EDNA MARIA MENDES AROUCHA
Externo à Instituição - HELIANE ROSA DO AMARAL - UFES
Externo ao Programa - 1346487 - RICARDO HENRIQUE DE LIMA LEITE