Estudo fitoquímico, antioxidante e microbiológico de resíduos agroindus triais de cupuaçu (Theobroma grandiflorum Schum.) da Amazônia
Abstract
The taxonomically verified diversity of tropical rainforest plants includes 14,003
species, of which 6,727 are trees including cupuassu (Theobroma grandiflorum
Schum.) Whose added value is in the pulp and almonds that make up the fruit used
in the food and cosmetics industry. However, with the increasing exploitation there is
a significant increase in the volume of organic waste generated due to agro-industrial
processing, which creates an environmental problem, mainly in Pará, the main
Brazilian producer of cupuassu fruits. Studies focusing on these residues are scarce,
so we aim to analyze the agro-industrial residues of T. grandiflorum through the
phytochemical and biological activities aimed at bioactive products. Phytochemical
characterization was obtained by quantifying the total phenolic compounds, total
flavonoids and condensed tannins. In biological tests, the antioxidant activity was
evaluated by the methods of DPPH and ABTS and antimicrobial activity determined
by the method of diffusion in wells to determine the Minimum Inhibitory Concentration
(MIC). Chemical characterization was performed by High Performance Liquid
Chromatography coupled to a photo-diode array detector (HPLC-PDA), High
Performance Liquid Chromatography coupled to a Mass Spectrometer (HPLC-ESI MS / MS) and annotations of chemical compounds through the Molecular Networking
network. The results obtained showed the fruit with an average weight of 1146.2 g,
corresponding to 37.3% of epicarp, 36.4% of mesocarp, 22.6% of endocarp and
3.7% of central fiber. In the phytochemical characterization the seeds and peels
obtained a higher concentration of phenolic compounds without showing statistical
difference, however the seed stood out for presenting higher levels of flavonoids and
condensed tannins, in relation to the other parts of the fruit. In the antioxidant activity,
the peel showed greater capture of the DPPH and ABTS radicals than the other
samples, which led to ethanolic and hydroalcoholic extracts from the bark residues
which in the chemical characterization by HPLC-PDA showed major bands in the
wavelength λ = 270 nm characteristic of condensed tannins. The analyzes by HPLC ESI-MS/MS characterized 16 substances and, presented ions of greater intensity
with m/z 341 characteristic of the compound caffeic acid 3-glucoside and the ion m/z
289 suggestive of catechin mass for hydroalcoholic extracts and ethanolic,
respectively. The analysis by molecular networks noted 23 substances correlated
with both extracts corresponding to the class of phenolic acids and flavonoids. After
characterization, the extracts were tested for antimicrobial activity with a positive
result for hirdroalcoholic extracts in the strains S. aureus, Salmonella sp, and E. coli.
While the ethanolic extract was active only against Salmonella sp. This
unprecedented study identified phenolic compounds from cupuaçu bark with
antioxidant and antimicrobial potential, and the strategy of combining HPLC-ESI MS/MS and Molecular Networking techniques enabled a quick and optimized
interpretation of the data generated from the de-replication of bark extracts T.
grandiflorum.