Banca de QUALIFICAÇÃO: MARCELO DA SILVA PEDRO

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : MARCELO DA SILVA PEDRO
DATE: 14/06/2024
TIME: 14:30
LOCAL: Remoto (através do Google Meet)
TITLE:

Synthesis of Lignin Nanoparticles from Sugarcane Bagasse for Application in Stabilization of Water/Water Pickering Emulsions and Bioactives Encapsulation

KEY WORDS:

Sugarcane bagasse, water-in-water Pickering emulsions, lignin nanoparticles, encapsulation, quercetin.

PAGES: 114
BIG AREA: Engenharias
AREA: Engenharia Química
SUBÁREA: Processos Industriais de Engenharia Química
SPECIALTY: Processos Bioquímicos
SUMMARY:

The Lignin is the second most abundant biopolymer on the planet and one of the main components of the plant cell wall, along with cellulose and hemicellulose. Lignocellulosic biomass consists of 18% to 35% lignin. For example, sugarcane bagasse contains an average of 23% lignin. This biopolymer is produced in large quantities as a by-product of lignocellulosic biorefineries and the pulp and paper industry. However, only 5% of the 50 to 70 million tons of industrial lignin produced annually are utilized in value-added products. Consequently, numerous studies have explored lignin's applications in various fields, including drug delivery systems, catalysis, and the encapsulation of sensitive nutrients. Notably, the production of lignin nanoparticles has shown promising results in stabilizing Pickering oil/water (O/W) and water/oil (W/O) emulsions, including for encapsulating bioactives. Pickering O/W and W/O emulsions have limitations, especially in probiotic encapsulation, low-calorie food production, and drug formulation with hydrophilic properties. Conversely, Pickering water/water (A/W) emulsions can mimic biological environments, with stability ensured by nanoparticles adsorbing at liquid-liquid interfaces. This study investigated using lignin from sugarcane bagasse, a cheap, non-toxic, and biodegradable polymer, as a source of nanoparticles for stabilizing Pickering O/W emulsions for quercetin encapsulation and Pickering A/W emulsions formed from maltodextrin (MD) and polyethylene glycol (PEG). Nanoparticles were prepared from alkaline lignin and oxidized alkaline lignin. The nanoparticles differed in size, with oxidized alkaline lignin nanoparticles (NPLOs) being smaller (327.8 nm) than alkaline lignin nanoparticles (NPLs) (689.8 nm). NPLs and NPLOs were used for quercetin encapsulation using the Pickering O/W emulsion template. The encapsulation results were promising, showing quercetin tended to become trapped in the oil phase droplets in the presence of lignin nanoparticles, giving the upper phase of the test tube a yellowish color. At pH levels below 3, both types of nanoparticles agglomerated and formed a layer in the upper phase. The stability of Pickering A/W emulsions formed from MD and PEG was evaluated with NPLs and NPLOs at different concentrations (0%, 0.1%, 0.3%, 0.5%, and 1%, w/w). Systems with NPLOs exhibited better emulsification rates and smaller droplet sizes than those with NPLs. The most promising stabilization results for the MD/PEG 6000 system were obtained at a concentration of 1% w/w of NPLOs, achieving an emulsification index of up to 63% even after two weeks. These results suggest lignin's great potential as a source of nanoparticles for bioactive encapsulation and position this biopolymer as a potential candidate for advanced studies of Pickering W/W emulsions.

COMMITTEE MEMBERS:
Interno - 3304882 - CARLOS EDUARDO DE ARAÚJO PADILHA
Interno - 1346198 - EVERALDO SILVINO DOS SANTOS
Interno - 1547970 - JACKSON ARAUJO DE OLIVEIRA
Interna - 3214434 - NATHALIA SARAIVA RIOS
Externo à Instituição - ANDERSON ALLES DE JESUS - UFMA