Synchronization between photosynthetic responses to seasonality during fruit development and fatty acid profile of mesocarp oil in macauba (Acrocomia aculeata)

Macauba palm (Acrocomia aculeata (Jacq.) Lodd. ex Mart. Arecaceae) is a novel oil crop with wide industrial applicability. However, little is known about the photosynthetic responses to seasonality during fruit development in macauba palm and its effects on the fatty acid profile of mesocarp oil and its physicochemical and spectroscopic characteristics. The fatty acid profile changed in six fruit developmental stages (ranging from 180 days after anthesis to full ripening and dispersion). This occurred during the transition from dry to rainy season concomitant with adjustments in photosynthetic responses. The increase in mesocarp oil yield in the fruit was synchronized with the higher photosynthetic capacity at the beginning of the rainy season, being characterized by a raise in oleic acid. The dynamics of soluble solids, acidity, pH, total sugars and starch were proportional to the spectroscopic changes and allowed to determine the ideal harvest point: 360 days after anthesis, with fruits still in the bunch. The macauba palm fruits in this stage showed suitable physical and chemical characteristics for industrial use, as well as higher oil yield. The monitoring of chemical changes with Fournier transformed infrared spectroscopy techniques would aid fast and precise detection of the fruit development and its ideal harvest point. •Macauba is an emerging tropical crop with potential use in biodiesel production.•Seasonal photosynthetic adjustments are synchronized with fruit development.•Environmental factors during fruit development affect the mesocarp oil concentration.•Final ripening stage can be monitored by physicochemical or spectroscopic techniques.•Fruits for oil production can be collected in the bunch, 360 days after anthesis.