Banca de DEFESA: DAISY NAZARETH FERREIRA DAMASCENO

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : DAISY NAZARETH FERREIRA DAMASCENO
DATE: 17/12/2025
TIME: 14:30
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: 95
BIG AREA: Engenharias
AREA: Engenharia Química
SUBÁREA: Processos Industriais de Engenharia Química
SPECIALTY: Processos Bioquímicos
SUMMARY:

Brazil is one of the leading countries in the fishing industry, which generates a large volume of waste since only about 30% of fish is converted into fillets. The remaining 70% consists of the head, carcass, viscera, skin, and scales—materials rich in collagen, the most abundant structural protein in the extracellular matrix. This collagen can be extracted using acidic methods, such as acetic acid, or by employing Deep Eutectic Solvents (DES). Collagen from fish has shown highly satisfactory performance and has therefore become one of the most widely used biopolymers in the production of biodegradable films and packaging. In this context, the objective of this work was to evaluate the extraction of collagen from Tilapia skin (Oreochromis niloticus) using two methods—acid extraction with acetic acid and extraction using green solvents (DESs)—and to apply the collagen obtained under the most efficient conditions to develop a microemulsion system.Five different extraction procedures were performed using acetic acid at concentrations of 0.3 mol L⁻¹ (HAC.01), 0.5 mol L⁻¹ (HAC.02), and 0.7 mol L⁻¹ (HAC.03), and using DESs synthesized from three systems: choline chloride (HBA) and acetic acid (HBD) – DES.01; choline chloride (HBA) and lactic acid (HBD) – DES.02; and choline chloride (HBA) and oxalic acid (HBD) – DES.03. After lyophilization, the collagen masses exhibited a spongy texture with some regions that were more rigid and rough. Yields ranged from 4.22 to 6.61% for acidic extraction and from 0.75 to 6.73% for DES extraction. Crude protein content was highest in collagen extracted with HAC.03 (60.85%) and lowest for DES.01 (12.09%).The presence of collagen was confirmed using different analytical techniques. FTIR-ATR spectra showed characteristic protein bands associated with amide vibrations. DSC analysis demonstrated the typical thermal behavior of collagen, with denaturation temperatures ranging from 28.78 to 32.89 °C. Electrophoresis performed on the sample obtained by acidic extraction allowed the identification of type I collagen, supporting the structural characterization observed by FTIR, with visible bands between 120 kDa and 150 kDa corresponding to the α2 and α1 chains of type I collagen, and more diffuse bands above 200 kDa corresponding to β (dimeric) forms.The application of collagen in microemulsion systems showed relevant characteristics, especially electrical conductivity values ranging from 156.4 to 158.9 µS·cm⁻¹ at 25 °C. Zeta potential ranged from 12.49 mV for HAC.02, which showed a particle size of 28.80 nm, to 16.49 mV with a particle size of 63.93 nm, indicating potential for use as a carrier for pharmaceuticals and cosmetic actives, particularly given the good stability observed. Thus, tilapia skin proved to be a sustainable and promising source of collagen, extracted through acids and DESs, aligning with circular-economy principles.

COMMITTEE MEMBERS:
Presidente - 3214434 - NATHALIA SARAIVA RIOS
Interno - 1346198 - EVERALDO SILVINO DOS SANTOS
Externo ao Programa - 3652554 - FRANCISCO CANINDE DE SOUSA JUNIOR - UFRNExterna ao Programa - 1415919 - KATHERINE CARRILHO DE OLIVEIRA DEUS - UFRNExterno à Instituição - WILLYAN ARAÚJO DA COSTA