Banca de DEFESA: JÉSSICA ANARELLIS BARBOSA DOS SANTOS

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : JÉSSICA ANARELLIS BARBOSA DOS SANTOS
DATE: 24/08/2023
TIME: 14:00
LOCAL: Departamento de Nutrição da UFRN
TITLE:

EXTRACTION AND ENCAPSULATION OF ANTHOCYANINS AND OTHER POLYPHENOLS FROM JAMBOLAN (Syzygium cumini (L.) Skeels)

KEY WORDS:

Natural Pigments. Antioxidants. Ultrasound Assisted Extraction. Nanoprecipitation. Whey Protein

PAGES: 100
BIG AREA: Ciências da Saúde
AREA: Nutrição
SUMMARY:

Jambolan (Syzygium cumini L. Skeels) has been studied as a potential source of antioxidants and food colorant due to its phenolic composition, which includes flavonoids such as anthocyanins. The objective of this work was to obtain and encapsulate an extract rich in anthocyanins and other polyphenols from jambolan. Three extraction techniques in 70% (v/v) acidified ethanol were compared: water bath (BM); exhaustive centrifugation (CE); and ultrasonic bath (UAE). The efficiency of these methods was evaluated by the content of Total Phenolics (FT), Total Monomeric Anthocyanins (AMT) and antioxidant activity (ABTS and DPPH tests). For encapsulation, two formulations were developed, containing 2.2 g extract (20 mg AMT; 97 mg FT), 0.5 g pectin; and 1.5 g whey protein concentrate (EWPC) or whey protein isolate (EWPI). Nanoprecipitation was performed in organic solvent with different antisolvent phase compositions (absolute acetone – EWPC100 and EWPI100, 70% v/v – EWPC70 and EWPI70, or 50% v/v – EWPC50 and EWPI50). The encapsulates were characterized in terms of encapsulation efficiency (EE%), in order to select the best formulations, which were characterized by dynamic light scattering (DLS), Zeta potential, Fourier transform infrared spectroscopy (FTIR) and X ray diffraction (DRX). The FT content did not differ between methods (BM: 17.01 ± 0.55; EC: 16.86 ± 0.63; UAE: 17.75 ± 0.44 mg/g), but the AMT content differed significantly between BM and the other methods (BM: 4.88 ± 0.13 mg/g; EC: 5.79 ± 0.33 mg/g; UAE: 6.16 ± 0.26 mg/g), with UAE extracted the same amount of AMT in 1/3 of the EC time. In the antioxidant activity, EC was lower than BM and UAE by ABTS (BM: 100.84 ± 1.83; EC: 74.38 ± 1.34; UAE: 100.78 ± 4.80) and DPPH (BM: 555, 73 ± 118.80; EC: 352.06 ± 46.03; UAE: 544.05 ± 96.57), results expressed in mmol Trolox equivalent/ g of dried fruit, suggesting a profile of different compounds in the extracts. The IC50 in the ABTS test (BM: 0.18; EC: 0.20; UAE: 0.21 mg/mL) were similar to other plant matrices, corroborating to the antioxidant potential of jambolan. Sequentially, UAE was used in the encapsulation step because it presents a good extraction yield of the compounds of interest and saves time. There was no significant difference between the EE% of FT (73.81± 6.72% to 84.65 ± 1.26%) among the encapsulated materials, however EWPC100, EWPC50, EWPI100 and EWPI50 showed higher EE% of AMT (56 .89 ± 1.29%; 48.65 ± 1.74%; 35.24 ± 1.24%; 36.33 ± 2.76, respectively). Zeta potential analysis at pH 4.7 showed values between -8.3 to -10.3 mV, and particle sizes ranged from 302 nm (EWPI50) to 1263.8 nm (EWPC100). FTIR showed that all encapsulated presented spectra similar to those of the proteins used, in addition to displacements and formation of new bands (1072 to 1022 cm-1 in EWPC100, EWPC50 and EWPI50 and in 1072 and 1026 cm-1 in EWPI100), which indicates interaction between the materials. The diffractograms showed that all encapsulated presented amorphous structure. These results show the potential of nanoprecipitation and the combination of encapsulating agents in the production of nanoparticles containing jambolan polyphenols, which can protect and optimize the application of these compounds.

COMMITTEE MEMBERS:
Externa à Instituição - JALUZA LUANA CARVALHO DE QUEIROZ - UnP
Presidente - 1971809 - JULIANA KELLY DA SILVA MAIA
Interna - 1610982 - PRISCILLA MOURA ROLIM
Interna - 2275877 - THAIS SOUZA PASSOS