Banca de DEFESA: ELAINE CRISTINA DA SILVA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : ELAINE CRISTINA DA SILVA
DATE: 29/06/2022
TIME: 14:00
LOCAL: google meet
TITLE:

Production, characterization and biotechnological application of exopolysaccharides from probiotic lactic acid bacteria using cheese whey as a culture medium.

KEY WORDS:

Carbohydrates; biopolymers; bioconversion

PAGES: 61
BIG AREA: Ciências Agrárias
AREA: Ciência e Tecnologia de Alimentos
SUBÁREA: Ciência de Alimentos
SUMMARY:

Exopolysaccharides (EPS) synthesized by lactic acid bacteria (LAB) have aroused much interest due to their various functional characteristics in several industries. The aim of this work was to produce, characterize and biotechnologically apply exopolysaccharides produced by lactic acid bacteria through cheese whey fermentation. More than sixty LAB, including probiotic strains Lactobacillus, Enterococcus, Streptococcus and Lactococcus were cultivated in cheese whey and evaluated for high EPS production. To optimize the production of EPS by the selected BAL, a statistical experimental design was used in which pH, temperature and fermentation time were evaluated. Prior characterization of the polymer was performed through tests such as: total sugars, uronic acid, protein, and identification of functional groups by FTIR. Finally, to evaluate the ability to scavenging free radicals, the EPS was tested in concentrations from 0.2 to 2 mg/ml, for antioxidant activity, using radicals such as DPPH, ABTS, hydroxyl and superoxide. The results obtained revealed that the BAL selected for EPS production was Enterococcus spp. (133v) with 6.58 mg/ml. The maximum production of EPS133v, after experimental design, was 21.74 mg/ml under the condition of fermentation at 42 °C of temperature and 14 hours of cultivation in cheese whey. The data for EPS characterization indicate that the polymer presents 1.86% of uronic acid and 5.28% of proteins. FTIR results showed typical functional groups of carbohydrates. In vitro antioxidant activity assays showed that DPPH, ABTS and superoxide radicals had their capacity reduced at all EPS concentrations with maximum of 27.72%, 72.20% and 43.23%, respectively. The hydroxyl scavenging capacity by EPS was obtained from the maximum concentration of 2 mg/ml with 1.29%. In summary, this work shows that cheese whey proved to be a good alternative for fermentation of Enterococcus spp. resulting in the production of EPS with potential to be a natural antioxidant or functional additive in the food industry.

BANKING MEMBERS:
Presidente - 2526149 - MARIA TACIANA CAVALCANTI VIEIRA SOARES
Interna - 1508562 - KEILA APARECIDA MOREIRA
Interna - 2066204 - RAQUEL PEDROSA BEZERRA
Interna - 1803550 - TATIANA SOUZA PORTO
Externo à Instituição - PAULO ANTONIO GALINDO SOARES - UFPE