Assessment of silicon biofortification and its effect on the content of bioactive compounds in strawberry (Fragaria x ananassa 'Elsanta') fruits

Silicon (Si) is an important element in the human diet, being health beneficial, as it improves the bone formation and decreases the bone fragility. However, this beneficial element is often lacking, leading to nutritional imbalances. Silicon also shows positive effects on plant metabolism, as it increases the resistance of plants against biotic and abiotic stresses. In the last decades, biofortification has shown to be a good solution to cope with Si shortage and to increase its concentration. The aim of this study was therefore to assess the biofortification potential of Si in strawberry fruits (Fragaria x ananassa 'Elsanta') grown for 16 weeks in hydroponic solutions at increasing levels of Si (50 and 100 mg L-1). At the stage of commercial maturity, the effects of Si enrichment on the qualitative parameters of strawberry fruits were evaluated. The results showed that some important (i.e., titratable acidity) quality parameters were affected by the Si treatment while the health beneficial compound content was only partially influenced by the Si treatments, with an increase of flavonols concentration. As expected, the Si concentration of the strawberry fruits increased with increasing Si availability in the nutrient solution reaching levels up to 80 mg g(-1) DW. On the whole, the data presented demonstrates that strawberries are a good target for Si biofortification, which indeed also enhances the nutraceutical qualities of the fruits.