Physical and chemical characteristics of the ripe pepino (Solanum muricatum) fruit grown in Turkey

Abstract

The pepino (Solanum muricatum Aiton, Solanaceae) is a little-known crop from the tropical and subtropical regions esteemed for its edible fruits, which are aromatic, juicy, scented, mild sweet, and may have great variation in size, shape and colour depending on the cultivar. Organic acids, sugar fractions, total phenolics and some quality characteristics (titratable acidity, pH, soluble solids, colour, etc.) of pepino fruits (cultivar Miski) obtained from Akyazi, Sakarya, Turkey, were determined. High-performance liquid chromatographic methods were used to identify and quantify non-volatile organic acids and sugars. Pepino fruits (cv. Miski) were egg-shaped, watery, of 210-370 g/fruit weight, 6-12.5 cm in diameter, 7-14.5 cm long, hollow in the middle with several small seeds attached, and with 82-89% edible part. The juice yield (%) of pepino varied from 60.0 to 68.0. Ripe pepino fruits had the titratable acidity (%) ranging from 0.090 to 0.124, Brix (total soluble solids, SSC) from 4.91 to 5.40, and pH values from 4.72 to 5.22. beta-carotene (mu g/g DW) content was ranging from 57 to 68 in ripe pepino fruit. Three organic acids (citric, malic and ascorbic acids) and three sugars (sucrose, glucose and fructose) were detected by HPLC. The major organic acid was citric acid (0.053-0.065 g/100 g). Ascorbic acid was the second most abundant organic acid in the pepino fruit and malic acid was the third one. With regard to sugars, fructose was present in the largest amount for pepino fruits cv. Miski (1.49-1.55 g/100 g), accounting for about 39.28% of total sugar.