Bioactive compounds, antioxidant activity and minerals of Caju (Anacardium humile St. Hill) during the ripening

The present study aimed to determine the content of minerals, bioactive compounds and the antioxidant activity of ‘Cajui’ (Anacardium humille St. Hill) during the ripening. The fruits were collected in three maturity stages. The content of the minerals, total phenolics, proanthocyanidin and carotenoids contents as well as the antioxidant activity, ABTS (2,2-azinobis-3-ethylben-zothiazoline-6-sulphonic acid), DPPH (2,2-diphenyl-1-picrylhydrazyl) and FRAP (ferric reducing antioxidant power) were determined, with results expressed on Trolox equivalent antioxidant capacity (TEAC). The Student’s t-test was employed to analyse the data, based on a significance level of p < 0.05. The total phenolic contents were determined as 1424.33 ± 28.62, 991.16 ± 21.52 and 867.08 ± 28.56 mg GAE.100 g-1 for the immature, semi-mature and mature stages, respectively. Regarding the carotenoid content, 18.05 ± 1.01 was obtained for the immature stage, 8.62 ± 0.96 was obtained for the semi-mature stage, and 8.32 ± 0.97 mg-β-carotene.100 g-1 was obtained for the mature stage. Regarding the antioxidant activity; it was particularly relevant for the fruits in the immature stage in the three methods used: DPPH (30399.63 ± 27.06 µM TEAC.100g-1), ABTS (40860.62 ± 9.32 µM TEAC 100 g-1) and FRAP (6118.22 ± 83.04 µM TEAC.100 g-1). The ‘cajui’ exhibited high antioxidant activity and content of bioactive compounds, especially for the immature stage. Among the minerals, ‘cajui’ showed high levels of K (potassium), P (phosphorus), and Mg (magnesium). Thus, the cajui presents itself as a good source of antioxidant compounds which can be exploited by the food industry as an ingredient for the development of a food with functional properties and the pharmaceutical industry, as phytochemical.   Key words: Minerals, phenolic compounds; maturation stages; antioxidant activity.