Banca de DEFESA: JÉSSICA CAROLINE ARAUJO SILVA SANDES

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : JÉSSICA CAROLINE ARAUJO SILVA SANDES
DATE: 10/12/2024
TIME: 14:00
LOCAL: on line
TITLE:

Microbial prediction in unpasteurized and frozen fruit pulp and beverage under abusive storage conditions.

KEY WORDS:

Predictive microbiology; Food safety; Tropical fruits

PAGES: 107
BIG AREA: Ciências Agrárias
AREA: Ciência e Tecnologia de Alimentos
SUBÁREA: Tecnologia de Alimentos
SPECIALTY: Tecnologia de Produtos de Origem Vegetal
SUMMARY:

Fruits are of great importance in human nutrition due to their constituents. They contain water,
sugars, fiber, mineral salts and antioxidant components, such as phenolic compounds and
vitamins. Fruit pulps and beverages can be exposed to adverse conditions, which affect their
safety and quality. This happens due to the high perishability of vegetal products against the
action of heat, enzymes, oxygen, light, and also microorganisms. Potentially pathogenic
microorganisms, as Escherichia coli, Salmonella spp. and Listeria monocytogenes cause
foodborne illnesses, can be transmitted by beverages and fruit pulps, degrading the quality and
safety of the product. In the present study, fruit beverages and pulps preserved only by freezing
were evaluated for microbial prediction of such food pathogens, using açaí pulp (Euterpe
oleracea) and coconut water (Cocos nucifera L.) as models. Predictive analyzes were also
applied to verify the of spoilage microorganisms profiles (mesophilic aerobic bacteria, molds
and yeasts). The beverage and fruit pulp were analyzed, after storage at -20 °C, under
refrigeration temperatures (5 °C) and abusive temperatures (10, 15 and 30 °C), in order to study
the effect of abusive storage conditions in microbial behavior. The quality of the açaí pulp was
evaluated after the temperature abuses in comparison with the pulp that did not undergo abusive
temperatures of thawing-refreezing. The microbiological, physicochemical and phytochemical
studies were carried out on coconut water and açaí pulp for nine months at -20 °C. In coconut
water, the pathogens showed inhibition behavior at 5 °C, but grew at 10 and 15 °C. The spoilage
microorganisms showed growth curves in coconut water at the three temperatures evaluated. In
the açaí pulp, subjected to thawing-refreezing cycles, all the microorganisms evaluated showed
inhibition behavior, except in one sample with mesophilic aerobic bacteria. E. coli was the
microorganism that showed the greatest inhibition in açaí pulp at safe levels (> 5.00 log CFU.g-
1). Regarding the quality of the açaí pulp, the abusive conditions led to changes in the
concentration of the phytochemical compounds and the anthocyanins decreased (p < 0.01) by
approximately 82% of the initial concentration. The microbiological study revealed that all
microorganisms studied showed inhibition behavior at -20 °C in nine months. Under these
conditions, the açaí pulp reached safe levels of inhibition of the pathogens E. coli, Salmonella
spp. and L. monocytogenes, but the same was not seen in the coconut water. After nine months,
the concentrations of the anthocyanins cyanidin-3-O-glucoside and cyanidin-3-O-rutenoside
decreased (p < 0.01) by around 70% in the frozen açaí pulp.

COMMITTEE MEMBERS:
Presidente - ***.646.967-** - LOURDES MARIA CORRÊA CABRAL - EMBRAPA
Interno - ***.072.978-** - AMAURI ROSENTHAL - EMBRAPA
Externa à Instituição - VALERIA SALDANHA BEZERRA - EMBRAPA
Externa à Instituição - KAREN SIGNORI PEREIRA - UFRJ
Externa à Instituição - RENATA TORREZAN - EMBRAPA