Avaliação de frutos amazônicos do gênero Ambelania: estudos químicos e nutricionais

Abstract

The fruits of the species Ambelania acida and Ambelania duckei, popularly known as sweet cucumber and wild cucumber, respectively, they have nutritional and chemical compositions that are not very well evidenced in previous researches so far. Those are native species from the region, not endemic, though. Both belong to the Apocynaceae family, whose fruits have antioxidant and anti-inflammatory activity. Thus, we performed in samples of peel, pulp and seeds of both fruits of the genus Ambelania: analyses of the centesimal composition, minerals, bioactive compounds, antioxidant activity, fatty acids, volatile organic compounds, and identification of compounds by LC-MS. The amount of protein in the pulp of both fruits (2.4 and 2.7 g/100g b.u. for A. duckei and A. acida) was higher when compared to other fruits of the same family and other tropical fruits. The mineral contents of K, Ca and Mg located in the peels and pulps of both, also stood out among the other minerals analyzed. The peels of both fruits presented higher amounts of bioactive compounds as well as better antioxidant activity than their respective pulps. The analysis of the lipid fractions of the peel, pulp and seeds of A. duckei and A. acida fruits resulted, respectively: in 14 and 11 types of fatty acids, being the main ones: oleic acid (peel, 22.52%; 23.57%), palmitic acid (pulp, 17.34%; 34.00%) and linoleic acid (seeds, 47.99%; 47.00%). The lipid profile and nutritional aspects had a PUFA/SFA ratio (0.4-1.8) in the different parts of the two fruits analyzed; the atherogenic (1.87 and 0.72) and thrombogenic (0.62 and 1.63) indices, of the pulp of both, shown respectively for A. duckei and A. acida, were higher compared to the other parts of the fruits. The ratio of hypocholesterolemic to hypercholesterolemic fatty acids (0.5 - 3.8), calculated for both fruits, are within the desirable range for a nutritious food. Among the VOCs identified in the peels and pulps of both fruits, terpenes were the most abundant. Aromatic notes like floral and mint stood out in the aroma of the fruit parts of A. duckei characteristic of β-ionone and 1,8-cineole, while notes like fruity, citrus and woody were some that stood out in the aroma of the fruit parts of A. acida characteristic of α-cubebene, and β-cubebene. The LC-MS analysis of A. duckei fruit peels, pulp and seeds allowed the identification of 26 substances such as phenolic acid, flavonoids, alkaloids, terpenoids and proanthocyanidins, the latter being the dominant class found in the analyzed fruit peels and pulp. In view of the above, it is believed that the pulps of the two fruits studied can be included in a healthy diet, and the parts of the fruits normally not consumable, such as peels and seeds, have potential for commercial applications because of their good quantities of nutritional and bioactive components.