Banca de QUALIFICAÇÃO: DAISY NAZARETH FERREIRA DAMASCENO

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : DAISY NAZARETH FERREIRA DAMASCENO
DATE: 14/11/2025
TIME: 09:00
LOCAL: Via google meet
TITLE:

Collagen extraction from tilapia (Oreochromis niloticus) skin using acids and deep eutectic solvents (DES) with application in a microemulsion system.

KEY WORDS:

Tilapia skin, collagen, extraction and purification, Deep Eutectic Solvents, microemulsion.

PAGES: 97
BIG AREA: Engenharias
AREA: Engenharia Química
SUBÁREA: Processos Industriais de Engenharia Química
SPECIALTY: Processos Bioquímicos
SUMMARY:

Brazil is one of the leading powers in the fishing industry, an activity that generates a large amount of waste. The average fillet yield is approximately 30%, while the remaining 70% of by-products include the head, carcass, viscera, skin, and scales. Collagen is the most abundant structural protein in the extracellular matrix of various tissues. Collagen extraction can be performed using acids, such as acetic acid, or Deep Eutectic Solvents (DES). The application of fish-derived collagen has shown highly satisfactory results, making it one of the most widely used biopolymers in the production of biodegradable films and packaging. In this context, the present study extracted collagen from the skin of Nile tilapia (Oreochromis niloticus) using acid extraction with acetic acid and green solvent extraction with different DES systems, subsequently applying the best results in a microemulsion system. Five extraction conditions were evaluated: acetic acid at concentrations of 0.3, 0.5, and 0.7 M, and two DES systems synthesized using choline chloride (HBA) combined with acetic acid (HBD) or lactic acid (HBD). After lyophilization, the collagen samples exhibited a spongy texture with some denser and rougher regions. Extraction yields ranged from 4.22% to 6.61% for acid extraction and from 0.75% to 6.73% for DES extraction. Crude protein content was higher in collagen obtained with HAc03 (60.85%) and lower in DES01 (12.09%).The presence of collagen was confirmed through different analytical techniques. FTIR-ATR spectra displayed characteristic protein bands associated with amide vibrations. DSC analysis revealed the typical calorimetric behavior of collagen, with denaturation temperatures ranging from 28.78 to 32.89 °C. SDS-PAGE electrophoresis of the acid-extracted sample confirmed the presence of type I collagen, reinforcing the structural characterization indicated by FTIR. Visible bands were observed between 120 and 150 kDa, corresponding to the α2 and α1 chains of type I collagen, while diffuse bands above 200 kDa corresponded to β (dimeric) forms. Application of the extracted collagens in microemulsion systems showed favorable characteristics, with electrical conductivity ranging from 156.4 to 158.9 μS·cm⁻¹ at 25 °C. The Zeta potential ranged from 12.49 mV for HAC02 (with a particle size of 28.80 nm) to 16.49 mV (with a particle size of 63.93 nm), demonstrating potential for pharmacological applications, particularly due to the observed stability of the systems. Thus, tilapia skin proved to be a sustainable and promising source of collagen obtained through DES extraction and ethanol purification, in alignment with the principles of the circular economy.

COMMITTEE MEMBERS:
Presidente - 3214434 - NATHALIA SARAIVA RIOS
Interno - 1346198 - EVERALDO SILVINO DOS SANTOS
Externo ao Programa - 3652554 - FRANCISCO CANINDE DE SOUSA JUNIOR - UFRNExterno à Instituição - WILLYAN ARAÚJO DA COSTA