Assessment of the differences in the phenolic composition of five strawberry cultivars (Fragaria x ananassa Duch.) grown in two different soilless systems

The phenolics from different strawberry cultivars (Aromas, Camarosa, Diamante, Medina, and Ventana) cultivated in two different soilless systems (with and without recycling nutrient solution) were quantified to assess differences in their profiles as a function of both the variety and the cultivation system. Considering groups of phenols, it was found that either anthocyanins (including pelargonidin-3-glucoside, cyanidin-3-glucoside, pelargonidin-3-rutinoside, pelargonidin-3-acetylglucoside, and two unidentified pelargonidin derivatives) or phenolic acids (including caffeic, ferulic, p-coumaric, p-hydroxybenzoic, and ellagic acid) were quantitatively more important than those of flavonols (quercetin and kaempferol); the ranges of values were 78.81-198.88, 49.77-128.37, and 12.85-43.04 microg/g, respectively. Considering individual compounds and after applying relevant pattern recognition techniques, it was concluded that the contents of cyanidin-3-glucoside, pelargonidin-3-rutinoside, p-coumaric acid, and pelargonidin-3-glucoside were the most appropriate variables to discriminate among varieties, whereas those of p-hydroxybenzoic acid and pelargonidin-derivative 1 were the most appropriate to discriminate between cultivation systems. The first factor of PCA was mainly linked to anthocyanins and quercetin, whereas the second principal component (PC) was related to kaempferol and p-coumaric acid.