Chemical characterization and functional properties in vitro and in vivo of macauba (Acrocomia aculeata)
Authors:   , Santʼana Cíntia Tomaz 
Published: May 2023

Macauba (Acrocomia aculeata) is a Brazilian palm tree, and its fruit is formed by shell, pulp, endocarp and kernel. This fruit has several bioactive compounds such as carotenoids, tocopherol, oleic acid, proteins, fibers and phenolic compounds. However, macauba is still little used in human food, being mostly used in the biodiesel industry and animal feed. In this way, as macauba has great potential for use in human food, conferring health benefits due to its good composition, this thesis aimed to investigate: (I) complete composition of all parts of macauba and its co- products, and the potential action of macauba oils in the reduction of reactive oxygen species (ROS) in cells (lung adenocarcinoma, colorectal adenocarcinoma, hepatocarcinoma, lung fibloblast); (II) effect of macauba pulp oil on obesity and oxidative stress in mice fed a high-fat diet; (III) effect of macauba pulp oil on the intestinal microbiota of mice fed a high-fat diet; (IV) effect of macauba pulp oil on lipid metabolism and longevity in Caenorhabditis elegans. The methods used were: (I) analysis of moisture, ash, lipids, proteins, dietary fiber, total phenolics, phytic acid, tannins, minerals, carotenoids, tocopherol, fatty acid, and analysis of cell viability and formation of reactive oxygen species in cell lines; (II) C57BL/6 mice were fed for 8 weeks with a control diet, a high-fat diet, a high-fat diet with macauba pulp oil, and biochemical (cholesterol and fractions, superoxide dismutase, catalase, malondialdehyde, total antioxidant capacity, nitric oxide), histological and gene expression analyzes were performed in adipose tissue and liver (genes of the inflammation, adipogenesis, synthesis and oxidation of fatty acids pathway); (III) C57BL/6 mice were fed for 8 weeks with a control diet, a high-fat diet, a high-fat diet with macauba pulp oil, and short-chain fatty acid analysis, fecal pH, colon histology (crypt width and depth, goblet cells number, thickness of the circular and longitudinal muscle layer) and microbiota sequencing were performed using the 16S rRNA method; (IV) Caenorhabditis elegans was used as an experimental model and kept in the presence of macauba pulp oil for 4 days and was performed analysis of lipid, glycerol, gene expression, fatty acids, and lifespan was performed. Among the results obtained, it was found that shell showed high amount of dietary fiber, minerals, and bioactive compounds, whereas its pulp and kernel oils were rich in oleic acid and lauric acid, respectively. Both pulp and kernel oil extraction coproducts (pulp and kernel press-cakes) showed high contents of dietary fiber, proteins, and bioactive compounds, and macauba pulp and kernel oils were able to reduce the ROS in cell lines. Consumption of macauba pulp oil increased antioxidant capacity and prevented oxidative stress, inflammation and adipogenesis in mice fed a high-fat diet. Macauba pulp oil changed the profile of gut microbiota, promoted short-chain fatty acid production, enhanced intestinal barrier integrity, and increased goblet cells in mice fed a high-fat diet. In addition, macauba pulp oil reduced the fat accumulation and increased lifespan in C. elegans in low temperature, and these results were associated by fat mobilization and unsaturated fatty acid biosynthesis. Our results demonstrate that macauba and its co-products has great potential to be included in human food because it is a source of bioactive compounds and the macauba pulp oil has positive effects on metabolic changes, demonstrating great potential to contribute to public health. Keywords: Macauba. Bioactive compounds. Co-products. Gut microbiota. Caenorhabditis elegans.