Identification of functional compounds in baru (Dipteryx alata Vog.) nuts: Nutritional value, volatile and phenolic composition, antioxidant activity and antiproliferative effect

This work aimed to contribute to the nutritional and functional characterization of roasted baru nuts, a seed widely consumed and produced in Brazil. Baru nut was characterized in terms of its nutritional value and volatile composition (SPME-GC-MS analysis). The ultrasound assisted extraction was used to extract free and bound phenolic compounds that were identified by LC-DAD-ESI-MS/MS method. Bioactivity assays were carried out to evaluate the antioxidant activity (ORAC and HOSC assay) and anticancer effect (inhibition of HT29 cell growth and targeting of cancer stemness) of baru nut extracts and phenolic compounds. Results showed that baru is a good source of protein and monounsaturated fatty acids, specifically oleic acid (47.20 g/100 g). The predominant volatile compounds are hexanal (71.18%) and 2,5-dimethyl-pyrazine (9.43%). The main phenolic compounds identified were gallic acid and its derivatives, such as gallic acid esters and gallotannins. Among all, gallic acid and methyl gallate seemed to be the main compounds responsible for the high antioxidant activity. The antiproliferative effect evaluated of baru extracts in HT29 cell line showed ability to impair cell growth in both monolayer and spheroid cultures and to reduce ALDH+ population. These results supply new information about the functional compounds presents in baru nut, which are important sources of natural antioxidants and antiproliferative compounds.