Effect of Innovative Sediment-Based Growing Media on Fruit Quality of Wild Strawberry (Fragaria vesca L.)

Abstract

The aim of this research was to assess the quality attributes of the fruits of wild strawberry (Fragaria vesca) “Regina delle Valli” plants cultivated in pots in remediated-sediment-based growing media (GM). For this purpose, phytoremediated and landfarmed dredged sediment from Leghorn Harbor (Italy) was mixed into a peat-based commercial substrate at different volume/volume percentages (0, 50 and 100%), and the plants were grown under greenhouse conditions with two different water regimes (WR1 = 950 cc/day; WR2 = 530 cc/day). The fruit quality parameters were differentially affected by the main factors (GM and WR) and their combinations. The fruits obtained from the substrate richest in treated sediment and with the higher water regime (TS100-WR1) showed the highest content of sugars (4056, 5256 and 5178 mg/100 g FW of sucrose, glucose and fructose, respectively), total soluble solids (16 °Brix) and organic acids (30, 490 and 2300 mg/100 g FW of ascorbic, malic and citric acid, respectively). Neither the polyphenol content nor the DPPH radical scavenging activity were significantly affected by the treatments, although the TS100-WR1 plants showed the highest DPPH value (an inhibition of 0.71%). Among the analyzed organic contaminants, only total heavy hydrocarbons (C10–C40) were found in fruits from TS50 and TS100 at very low values, while heavy metals were not detected. The PCA statistical multivariate analysis performed on the visual, olfactory, chewing and tasting aspects of a sensorial evaluation clearly showed that the substrate’s chemical–physical properties exerted a relevant influence on the fruit samples, while the irrigation regimes did not affect significantly fruit quality parameters. A number of highly correlated soil/fruit parameters were found. The remediated sediment proved to be a valid alternative to peat for wild strawberry production, even at the highest concentration.