Phloridzin, a natural dihydrochalcone, exhibits a wide range of beneficial effects and even broader applications, spanning from the pharmaceutical to the food industry. It is found in high concentrations in apple fruit. When apples are processed into juice, approximately 30% of their weight remains as a byproduct known as pomace, making pomace an intriguing candidate as a source of phloridzin. 

In this study, 13 apple cultivars were evaluated for their phloridzin content across different apple parts: flesh, peel, and seeds, as well as in apple juice and the byproduct pomace. The physical characteristics of the apples, including weight, size, starch content, and firmness, were measured to ensure their suitability for comparison. Methanol extracts were analyzed using the Folin–Ciocalteu assay for total phenolic content, HPLC for phloridzin quantification, and the FRAP assay for antioxidant activity.Among the solid parts, seeds exhibited the highest phloridzin content, with an average of 7.2 g/kg of apple dry weight, followed by the peel and flesh. Regarding total phenolic content, the flesh and seeds were comparable, with averages of 8.8 g and 7.8 g of gallic acid equivalent per kg of apple dry weight, respectively. For juices and pomace, phloridzin concentrations were similar across all samples, ranging from 0.32 to 0.57 g/kg of apple dry weight. In terms of total phenolic content, untreated juice contained an average of 42 g/kg of apple dry weight. 

Antioxidant activity was highest in the peel for the solid parts, with an average of 11.4 g of ascorbic acid equivalent per kg of apple dry weight, followed by the flesh and seeds. Among the juices, the treated juice exhibited the highest antioxidant activity, with an average of 29.7 g/kg of apple dry weight. Given the substantial amount of pomace produced during apple processing, it presents a promising and sustainable source for phloridzin extraction, particularly when using environmentally friendly extraction methods. The data sheet represents the concentrations of each sample resulting from the three primary tests (HPLC, Folin–Ciocalteu assay, and FRAP). Additionally, each apple cultivar's physical characteristics (weight, size, starch, firmness). This project IT-ETN-956257 is funded by Horizon 2020