Effects of Different Ripening Stages on the Content of the Mineral Elements and Vitamin C of the Fruit Extracts of Solanum Species: S. melanocerasum, S. nigrum, S. villosum, and S. retroflexum

Studies on the mineral and vitamin C contents of different species and ripening stages of Solanum fruits are very limited. The aim of the research was to evaluate the content of the mineral elements and vitamin C of four different Solanum species (S. melanocerasum-SM, S. nigrum-SN, S. villosum-SV and S. retroflexum-SR), and three ripening stages. The mineral composition of Solanum fruits was detected using a CEM MARS 6 (R) (Matthews, NC, USA) digestion system outfitted with a 100 mL Teflon vessel, by microwave-assisted extraction (MAE). In total, eleven mineral elements were detected (K, Ca, Mg, P, Fe, Na, Cu, B, Mn, Al, and Zn). Vitamin C content was assessed by a spectrophotometric method. Depending on the ripening stage/species, content of microelements ranged from 756.48 mg kg(-1) DW in SV fruits at ripening stage III, to 211.12 mg kg(-1) DW in SM fruits at ripening stage III. The dominant microelement was Fe. The total content of macroelements in Solanum fruits ranged from 26,104.95 mg kg(-1) DW in SV fruits at ripening stage II to 67,035.23 mg kg(-1) DW in SR fruits at ripening stage I. The dominant macroelement was K. The data from two experimental years showed that the significantly highest content of vitamin C was in SM fruits and ranged from 48.15 mg 100 g(-1) at ripening stage I to 45.10 mg 100 g(-1) at ripening stage III.