Chemical characterization, antioxidant properties, and volatile constituents of naranjilla (Solanum quitoense Lam.) cultivated in Costa Rica

Naranjilla (Solanum quitoense Lam.) is a native fruit of the Andes, cultivated and consumed mainly in Ecuador, Colombia, and Central America. Because of its pleasant aroma and attractive color, it has high potential as an ingredient of products such as juices, nectars, and jams. The main characteristics of mature naranjilla fruits cultivated in Costa Rica were assessed, including sugar content, total titratable acidity, total soluble solids, oxygen radical absorbance capacity (H-ORAC), and total polyphenolic and ascorbic acid content. Carotenoid and volatile compound identification was also done. The samples showed sucrose, glucose, and fructose content of 1.6 +/- 0.3, 0.68 +/- 0.05, and 0.7 +/- 0.1 g/100 g, respectively. Total titratable acidity was 2.63 +/- 0.07 g citric acid equivalent / 100 g and total soluble solids amounted to 9.1 +/- 0.5 degrees Brix. H-ORAC value was 17 +/- 1 micromol Trolox equivalent /g, total polyphenolic content was 48 +/- 3 mg gallic acid equivalent /100 g and ascorbic acid content was 12.5 +/- 0.0 mg/100 g. Carotenoid content of the whole fruit and pulp was 33.3 +/- 0.6 and 7.2 +/- 0.3 microg/g, respectively. The predominant carotenoid among the compounds identified in the whole fruit was beta-carotene. Ten volatile compounds were identified in naranjillapulp, the predominant being methyl butanoate. The chemical composition of naranjilla cultivated in Costa Rica does not seem to differ from that previously reported in studies at different locations.