Effect of grafting and ripening conditions on some qualitative traits of “Cuore di bue” tomato fruits

BACKGROUND: Grafting technique is increasingly being employed in order to obtain high production in difficult soils and to reduce chemical application. The present experimentalwork addressed the effect of grafting of tomato, cv. ‘‘Profitto’’ (P), on to the rootstocks ‘‘Beaufort’’ (B) and ‘‘Big Power’’ (BP) on fruit quality. Both fruit left to ripen on the plant and fruit stored at low temperature (4 ◦C) were included in the quality assessment. RESULTS: Vitamin C and fructose content decreased in B and BP in fruits stored at 4 ◦C, whereas fruits ripened on the plant showed higher sugar concentrations. The free phenolic acids extracted were identified as caffeic acid, p-coumaric acid, chlorogenic acid and ferulic acid. Higher antioxidant compound content was consistently shown by P. Cold storage conditions caused a higher phenolic acid production due to the increase of ferulic acid. Compared with ripening on the plant, percentage differences ranged between 14.3% (caffeic acid) and 12.5% (p-coumaric and chlorogenic acids). Total phenol content was also affected by maturation, showing higher values in fruits ripened on the plant than under cold storage conditions. CONCLUSIONS: It was possible to observe a significant relationship between tomato fruit quality and grafting and relevant differences in fruit ripening conditions.