Nutritional and functional profiling of traditional Italian 'San Marzano' tomatoes

The preservation of local landraces represents a crucial point in biodiversity maintenance and it necessarily starts from a qualitative and morphological characterization. The ‘San Marzano’ tomato (Solanum lycopersicum L.) is an elongated fruit cultivar particularly suitable for processing and represents one of the most significant horticultural products for the Italian food industry. Five ‘San Marzano’ landraces (‘SM Bellizzi 1’, ‘SM Bellizzi 2’, ‘SM Bellizzi 3’, ‘SM Montoro Inferiore’ and ‘SM Sarno’) characterized by different fruit shapes (pointed, round and hollow) were compared in terms of yield, nutritional and functional quality. The fruit dry matter percentage as well as the juice EC ranged from 4.94 to 7.10% and from 3.04 to 3.80 dS m^‑1, respectively, with the lowest values observed in ‘SM Montoro Inferiore’. The highest total soluble solids content was recorded in both ‘SM Montoro Inferiore’ and ‘SM Sarbo’, followed by ‘SM Bellizzi 1’ and ‘SM Bellizzi 3’, whereas the lowest values were observed in both ‘SM Bellizzi 2’ and ‘SM Bellizzi 3’. Among the three macronutrients analyzed K was the most abundant macro-mineral, followed by phosphorus and finally nitrate. ‘SM Bellizzi 1’ was richer in P and K compared to the rest of the landraces tested. The highest levels of hydrophilic and lipophilic antioxidant activities were recorded in ‘SM Sarno’ and ‘SM Bellizzi 3', respectively. Our findings will contribute toward the documentation of nutritional and functional quality profiles of an important collection of niche products such as the SM tomato.