Chemical characterization, antioxidant and antimicrobial activities of açaí seed (Euterpe oleracea Mart.) extracts containing A- and B-type procyanidins

• Published in: Food science & technology Vol. 132; p. 109830
• Main Authors: Martins, Gabriel R., do Amaral, Felipe Rafael L., Brum, Felipe L., Mohana-Borges, Ronaldo, de Moura, Sayonara S.T., Ferreira, Fabienne A., Sangenito, Leandro S., Santos, André L.S., Figueiredo, Natália G., Silva, Ayla Sant’Ana da
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.10.2020
• Subjects: Antimicrobial analysis; Antioxidant assays; Açaí seeds; Mass spectrometry imaging; Polyphenols; Polyphenols; Antioxidant assays; Antimicrobial analysis; Mass spectrometry imaging; Açaí seeds
• ISSN: 0023-6438; 1096-1127
• DOI: 10.1016/j.lwt.2020.109830

Açaí seed extracts are reported for containing polyphenols with pharmacological properties against inflammation, hypertension, and metabolic syndrome. However, presently, those seeds accumulate as waste, causing environmental problems. Therefore, we aimed to characterize the polyphenol profile of açaí seed extracts to investigate its composition and biological effects. Multiple techniques were used for the identification of the extract's metabolites, such as HPLC, mass spectrometry, and mass spectrometry imaging (MALDI-IMS). The extract was majorly composed of B-type and A-type oligomeric procyanidins with a mean degree of polymerization of 11.4 (>3000 Da), formed by catechin and epicatechin as starter and extension subunits, respectively. MALDI-IMS confirmed, for the first time, the presence of A-type procyanidins in the seed's tegument. The extract was not cytotoxic to THP1 (macrophage cell line) and LLC-MK2 (epithelial cell) and, moreover, it efficiently protected macrophages from oxidative stress, which correlated to its high antioxidant capacity, confirmed by DPPH, TEAC and ORAC methods. Additionally, the extract presented antimicrobial activity against gram-positive bacterial strains and Candida albicans. These data indicate the potential use of seed extracts for cosmetic and pharmaceutical formulations. [Display omitted] •The extract is composed of B- and A-types oligomeric procyanidins (>3000 Da).•MALDI-IMS was used to identify procyanidins in situ for the first time.•Procyanidins were active against gram-positive bacteria and C. albicans.•The extract was not cytotoxic for mammalian cells.•Açaí seed extract has a high antioxidant activity that prevents oxidative stress.