Neohesperidin

The flavanone composition was measured according to Huang et al. [29 (link)] with some modifications. Briefly, juice was diluted 2.33 times with methanol and flavonoid standards (eriocitrin, neoeriocitrin, narirutin, naringin, neohesperidin from Sigma-Aldrich (St. Louis, MO, USA)) were dissolved in methanol and sufficiently mixed. After filtration through a PTFE membrane with φ = 13 mm and pore size of 0.45 mm, 10 μL of samples (or standard solutions) were injected into the HPLC system (Waters e2695, Waters, Milford, MA, USA) coupled with a UV/vis detector (Waters 2489, Waters, Milford, MA, USA). The XDB-C18 column (250 × 4.6 mm, Agilent, Santa Clara, CA, USA) was kept at 25 °C with a flow rate of 0.7 mL/min. Solution A (0.1% formic acid) and solution B (methanol) were used as the mobile phase with the gradient elution as follows: 0–20 min, 63–50% A; 20–25 min, 50–20% A; 25–30 min, 20–0% A; 30–35 min, 0% A; 35–40 min, 0–63% A; 40–42 min, 63% A. The detection was performed at 283 nm. The flavonoids were identified and quantified according to the standard curves (Figure S1).

Chemicals of both analytical grade and chromatographic grade were purchased from Carlo Erba, Milan, Italy. 2,2-Diphenyl-1-picrylhydrazyl (DPPH) and pure standards of naringin, neoeriocitrin and neohesperidin, were from Sigma-Aldrich Chemical Co. (St. Louis, MO, USA). TPTZ (2,4,6-tripyridyl-s-triazine for FRAP reagent (Ferric Reducing Ability of Plasma) was from Fluka Chemicals Switzerland. Brutieridin and melitidin as pure standards were obtained as described by Di Donna et al. [16 (link)].

Sodium hydroxide, L‐ascorbic acid, butylated hydroxytoluene (BHT), lycopene, β‐carotene, narirutin, naringin, neohesperidin, didymin, poncirin, limonin, 6′, 7′‐dihydroxybergamottin (DHB), catechin, Folin‐Ciocalteu reagent, sodium carbonate, and 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) were procured from Sigma Aldrich Co. (St. Louis, MO, USA). Analytical grade solvents were obtained from Fisher Scientific Research (Pittsburgh, PA, USA).