Banca de QUALIFICAÇÃO: ALLINY SAMARA LOPES DE LIMA

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : ALLINY SAMARA LOPES DE LIMA
DATE: 20/12/2024
TIME: 14:00
LOCAL: online meet.google.com/fgz-rbiy-dtt
TITLE:

Process Optimization and Development of New Formulations for Kombucha Fermented Beverages

KEY WORDS:

Kombucha. Drying. Spray dryer. Freeze-drying. Functional beverages.

PAGES: 60
BIG AREA: Engenharias
AREA: Engenharia Química
SUBÁREA: Tecnologia Química
SPECIALTY: Alimentos
SUMMARY:

This study investigated the impact of different drying methods (spray dryer and freeze-drying) and adjuvants (maltodextrin and gum Arabic) on the physicochemical properties of kombucha powders, also evaluating the potential application of these powders as starter culture in subsequent fermentations. The physicochemical characteristics of the powders, including moisture, water activity, hygroscopicity, solubility and morphology, were evaluated, as well as the cell viability after reactivation by counting viable cells (acetic acid bacteria, yeasts and total count) and metabolic activity by production of acetic acid and ethanol. The phytochemical profile of the beverages was also evaluated by quantifying total phenolic compounds and evaluating antioxidant activity. The powders presented moisture and water activity values within the parameters of microbiological safety and stability. They demonstrated high reconstitution capacity, with solubility greater than 90% and low hygroscopicity values, lower than 10 g H₂O/100 g. The powders obtained by spray drying exhibited a well-defined spherical shape, while those obtained by freeze drying presented irregular microstructures. In general, all powders demonstrated a predominantly amorphous structure, with no significant influence of the drying method. The metabolic evaluation of the strains revealed that, in the samples encapsulated with maltodextrin, the drying method significantly influenced (p < 0.05) the metabolic activity, with a higher count of acetic acid bacteria and acetic acid production observed in the lyophilized samples at the end of fermentation. For the samples encapsulated with gum Arabic, the freeze-dried samples presented a higher count of viable cells, although no significant difference was identified in the production of acetic acid between the drying methods at the end of fermentation. Ethanol production was below 0.5% (v/v) in all samples, meeting the desired standards and indicating the possibility of standardizing ethanol concentration through drying. Total phenolic compound contents ranged from 271 to 391 mg GAE/L, with higher values in fermented beverages made with freeze-dried powders, although, in general, there were no significant differences. The drying method significantly influenced antioxidant activity, with higher values observed in kombuchas made with freeze-dried powders. The drying processes allowed the production of powders with stable physicochemical characteristics and good reconstitution. The freeze-dried and maltodextrin-encapsulated samples showed higher acetic acid production, indicating greater potential for use as starter culture. Drying processes present numerous advantages for the food industry. The application of these techniques to Kombucha contributes to evaluate how drying processes, including a more economical method (spray drying), and adjuvants affect the viability of microbial cells and the production of metabolites during fermentation. This study may contribute to the conservation of kombucha strains and has the potential for standardizing the beverage.

COMMITTEE MEMBERS:
Presidente - 1517220 - MARCIA REGINA DA SILVA PEDRINI
Externa à Instituição - EDILENE SOUZA DA SILVA - INSA
Externo à Instituição - FÁBIO GONÇALVES MACÊDO DE MEDEIROS