Banca de DEFESA: MARIAH ALMEIDA LIMA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : MARIAH ALMEIDA LIMA
DATE: 14/01/2025
TIME: 14:00
LOCAL: Internet
TITLE:

Development and Application of Sodium Alginate-Based Nanoemulsion with Pink Pepper Essential Oil as an Active Coating for Minas Frescal Cheese. 

KEY WORDS:

Nanoemulsions, Pink pepper essential oil, Active coating, Microfluidization, Minas Frescal cheese.

PAGES: 121
BIG AREA: Ciências Agrárias
AREA: Ciência e Tecnologia de Alimentos
SUBÁREA: Tecnologia de Alimentos
SPECIALTY: Tecnologia de Produtos de Origem Animal
SUMMARY:

The aim of this thesis was to develop nanoemulsions based on sodium alginate and pink peppercorn essential oil (PPEO) using the microfluidization technique. Eight formulations were evaluated for the effect of using sunflower oil and soy lecithin as stabilizers, considering their physicochemical, physical and antimicrobial properties against the pathogenic microorganisms Salmonella sp., Escherichia coli, Listeria monocytogenes and Staphylococcus aureus. In addition, the application of these nanoemulsions as an active coating on Minas Frescal cheeses was investigated, analyzing their effects on physicochemical properties, texture, color and antimicrobial efficacy against Listeria monocytogenes and Staphylococcus aureus inoculation for 28 days (4 °C). The results showed that the nanoemulsions had a drop size of less than 200 nm, Newtonian fluid rheological behavior and kinetic stability over 20 days. The dispersed phase of the nanoemulsions (PPEO) was mixed with sunflower oil in order to preserve the essential oil from process conditions (high pressure and temperature). In fact, the addition of sunflower oil to the formulation resulted in 80% retention of PPEO in the nanoemulsions. In vitro antimicrobial tests revealed that the nanoemulsions were effective against Staphylococcus aureus and Listeria monocytogenes, with minimum inhibitory concentrations (MIC) of 200 µg/mL and minimum bactericidal concentrations (MBC) of 800 µg/mL and 400 µg/mL, respectively, highlighting PPEO's potential as a natural biopreservation agent. The nanoemulsions with the best antimicrobial properties against Staphylococcus aureus and Listeria monocytogenes were used as active coatings on Minas Frescal cheese. The active coatings with nanoemulsions contributed to maintaining the humidity and preserving the color of the Minas Frescal cheeses. However, the interaction of the active coating with the cheese matrix favored increased syneresis, negatively affecting draining. With regard to texture parameters, the active coating reduced the hardness and adhesiveness of the cheeses, while increasing cohesiveness, chewiness and gumminess. Despite the physicochemical benefits, the antimicrobial efficacy of the in situ active coating was limited, with no significant impact on reducing the inoculated Listeria monocytogenes and Staphylococcus aureus populations, possibly due to the interactions of the active compounds with the cheese matrix and the high levels of syneresis. It is concluded that nanoemulsions based on sodium alginate and PPEO have significant potential as a sustainable alternative to synthetic preservatives. However, the in situ performance showed the need for adjustments to the formulation and new application strategies, as well as studies in other food matrices, in order to increase their efficiency and viability for the food industry.

COMMITTEE MEMBERS:
Presidente - ***.072.978-** - AMAURI ROSENTHAL - EMBRAPA
Interno - ***.379.796-** - NATHÁLIA RAMOS DE MELO - UFF
Interno - ***.726.462-** - OTNIEL FREITAS SILVA - EMBRAPA
Externa à Instituição - ANA CARLA KAWAZOE SATO - UNICAMP
Externa à Instituição - ANA ELIZABETH CAVALCANTE FAI - UERJ