The content of selected minerals and vitamin C for potatoes (Solanum tuberosum L.) from the high Tiber Valley area, southeast Tuscany

Potatoes (Solanum tuberosum L.) from the high Tiber valley area (TVA; Tuscany, Italy), have been sampled and analyzed for selected mineral content (Na, Mg, K, Ca, and Mn, Fe, Cu and Zn) and vitamin C, the year 2012; some samples from 2011 and 2013 crops were also collected and analyzed. The varieties were Daytona (DAY), Kennebec (MEN), Sifra (SIF) and Volare (VOL). Control samples consisted of mixed commercial varieties from the local market, namely C1, C2 and C3. The low content of sodium, especially for KEN (46 +/- 3 mg/kg FD (freeze dry), year 2012) and SIF (47 +/- 3) (VOL (55 +/- 3) and DAY (61 +/- 3) have a little higher values) is worth of note and in agreement with the scarce concentration of Na in the soil (291 +/- 12 mg/kg DM). Magnesium was abundant in KEN (1434 +/- 75 mg/kg FD, year 2012) and VOL (1334 +/- 70). The content of K for DAY and KEN (13,147 +/- 900 and 13,185 +/- 900 mg/kg FD) was higher than for VOL and SIF; whereas Ca was in the range 340 +/- 16-490 +/- 28 mg/kg FD. The contents of Cu and Zn were higher in KEN (8.1 +/- 0.3 and 25 +/- 1 mg/kg FD) when compared to the other varieties and controls. The content of vitamin C is high for KEN and SIF and decreased significantly upon cooking (50% for KEN).