Na2co3

For quantification of nitrate, sulfanilamide (AppliChem GmbH, Darmstadt, Germany), ammonium chloride and hydrochloric (Th. Geyer, Renningen, Germany), sodium nitrite and ammonia solution 25% (Merck, Darmstadt, Germany), and N-(1-naphthyl)-ethylene diamine dihydrochloride (Carl Roth GmbH, Karlsruhe, Germany) were used. Regarding total phenolic content measurement, Folin–Ciocalteu reagent and gallic acid were provided by Merck (Darmstadt, Germany). Na₂CO₃ and methanol were purchased from AppliChem GmbH (Darmstadt, Germany) and Carl Roth GmbH (Karlsruhe, Germany), respectively. Ethanol needed for betalain analysis was purchased from Th. Geyer (Renningen, Germany).

Ascorbic acid, Folin–Ciocalteu’s reagent, FeCl₃, FeSO₄, HCl, NaNO₂, NaOH, fructose, glucose, and sucrose were provided from Merck (Darmstadt, Germany). 2,4,6-Tris(2-pyridyl)-1,3,5-triazine (TPTZ) and 2,20-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS), were purchased from Sigma (Darmstadt, Germany). AlCl₃ (Fluka, Seelze, Germany). In addition, 2,2-diphenyl-1-picrylhydrazyl (DPPH) (CalBiochem, Darmstadt, Germany), Gallic acid (Scharlau, Barcelona, Spain), Na₂CO₃ (AppliChem, Darmstadt, Germany), potassium persulfate (Bernd Kraft, Duisburg, Germany), and Trolox (Cayman, Ann Arbor, MI, USA) were used. Methanol and ethanol were purchased from Chemsolute (Hamburg, Germany) and were HPLC grade.

Ascorbic acid, Folin–Ciocalteu’s reagent, FeCl₃, FeSO₄, NaOH, HCl, and NaNO₂, were purchased from Merck (Darmstadt, Germany). 2,4,6-Tris(2-pyridyl)-1,3,5-triazine (TPTZ) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS), were provided from Sigma (Darmstadt, Germany). Gallic acid (Scharlau, Barcelona, Spain), 2,2-diphenyl-1-picrylhydrazyl (DPPH) (CalBiochem, Darmstadt, Germany), AlCl₃ (Fluka, Seelze, Germany), Na₂CO₃ (AppliChem, Darmstadt, Germany), potassium persulfate (Bernd Kraft, Duisburg, Germany), Trolox (Cayman, Ann Arbor, MI, USA), were used. Caffeic acid, myricetin, p-coumaric acid, and quercetin (HPLC grade) were purchased from Sigma (Darmstadt, Germany). Ferrulic acid, Gallic acid, kaempherol, and rutin (HPLC grade) were supplied from Carl Roth GmbH (Karlsruhe, Germany). Methanol and ethanol from Chemsolute (Hamburg, Germany), acetic acid (AppliChem, Darmstadt, Germany), and acetonitrile (J.T.Baker, Hamburg, Germany) purchased were HPLC grade.