Banca de QUALIFICAÇÃO: FRANCISCA PEREIRA DE MORAES

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
DISCENTE : FRANCISCA PEREIRA DE MORAES
DATA : 14/11/2018
HORA: 09:00
LOCAL: SALA NUPEG
TÍTULO:

Chemometric analysis and physico-chemical, bioactive and biological in vitro evaluation of fresh and freeze-dried acerola (Malpighia emarginata). 

PALAVRAS-CHAVES:

acerola, residue, freeze dried, macrophages, anti-inflammatory

PÁGINAS: 120
GRANDE ÁREA: Engenharias
ÁREA: Engenharia Química
SUBÁREA: Tecnologia Química
ESPECIALIDADE: Alimentos
RESUMO:

Brazil is an important producer of tropical fruits. Among these, acerola (Malpighia emarginata) is recognized for its high content of ascorbic acid (AA), total phenolic compounds (TPC), carotenoids, anthocyanins and relevant antioxidant potential. Considering the bioactive and commercial value of this fruit, the present work aimed to evaluate acerola in different approaches, which are presented in the four  chapters of this thesis. The first chapter deals with the topics covered throughout the thesis. The second chapter shows the evaluation of the whole acerola fruit in regard to its concentration of bioactive compounds (AA, TPC) and antioxidant activity (DPPH), by the near infrared (NIR) technique and application of chemometric analysis. In the third chapter, the freeze-dried technique was applied to acerola pulp and acerola pomace in order to compare the final products to the fresh fruit, as well as to monitor the stability of the powders along the storage. In the fourth chapter, commercially purchased freeze-died acerola was evaluated and compared to selected freeze-dried fruits (camu-camu, apple and pineapple) in regard to in vitro biological analyzes. Selected phytochemical compounds were analyzed (AA, TPC, anthocyanins, phenolic acids and antioxidant activity, by two methods of detection: reducing iron potential - FRAP and capturing the radicals of 2,2 - diphenyl - 1 - picrylhydrazyl - DPPH). In addition, the effects of these compounds on reducing the production of reactive oxygen species (ROS) and nitric oxide (NO) in RAW 264.7 macrophages were investigated. Initially, the toxicity of the samples (reduction method of 3- (4,5-dimethylthiazol-2yl) -2,5-diphenyl tetrazolium bromide - MTT) for RAW 264.7 cells was assessed. The anti-inflammatory power of acerola extracts against enzymes and mediators with proinflammatory activity (inducible nitric oxide synthase - iNOS, cyclooxygenase – COX-2, interleukins - IL1β and IL-6, tumor necrosis factor - TNFα) was evaluated in addition to an in vitro assay to investigate the cell migration properties of freeze-dried extracts in adult human dermal fibroblast cells (HDFα). The results show that the NIRS model is a fast and reliable analytical strategy to evaluate the ascorbic acid, phenolic and antioxidant power in whole acerola. It has also been demonstrated that freeze-dried acerola powders retain high ascorbic acid concentrations and that the preservation of ascorbic acid and anthocyanins is more effective under refrigerated storage. The results of the in vitro biological tests showed that acerola extracts, camu-camu, apple and pineapple are able to reduce the production of reactive oxygen species (ROS). Only freeze-dried acerola and camu-camu extracts reduced the production of reactive nitrogen species (NO). Extracts of these fruits also suppressed the expression of IL1β and IL6, and freeze-dried acerola is the only one capable of reducing the expression of COX-2 enzyme. The acerola was also able to enhance cell migration, based on the in vitro results obtained in HDFa cells, which show the skin cells' ability to regenerate after injury. The high ascorbic acid content in acerola seems to play an important role in the observed in vitro biological effects. Overall, it is concluded that acerola presents bioactive and in vitro biological potential, which can be justify its exploitation as functional ingredient in food and pharmaceutical formulations.

MEMBROS DA BANCA:
Externo à Instituição - DEBORA ARAUJO ESPOSITO - NCSU
Externo ao Programa - 3211846 - KARLA SUZANNE FLORENTINO DA SILVA CHAVES DAMASCENO
Interno - 029.669.684-60 - KATIA CRISTINA BORGES - UFRN
Interno - 349802 - MARIA DE FATIMA DANTAS DE MEDEIROS
Presidente - 1246737 - ROBERTA TARGINO HOSKIN