O coumaric

Trifluoracetic acid, acetonitrile, methanol, and ethanol were provided from Penta (Prague, Czech Republic). α-Amylase and neutral detergent solution package (containing sodium lauryl sulphate, EDTA disodium, sodium borate, sodium phosphate dibasic together with triethylene glycol) were purchased from Ankom Technology (Macedon, NY, USA). Folin-Ciocalteu reagent, AlCl₃·6H₂O were purchased from Penta (Prague, Czech Republic). The substance 2,2’-azinobis(3-ethylbenzo-thiazoline-6-sulfonic acid) diammonium salt (ABTS), radical 2,2-diphenyl-1-picrylhydrazyl (DPPH), and standard 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid (trolox) were provided from Sigma-Aldrich (St. Louis, MI, USA). Phenolic and sugar standards were as follows: Epigallocatechin, catechin, epicatechin, rutin, quercetin, kaempferol, neochlorogenic, chlorogenic, gallic, protocatechuic, p‑hydroxybenzoic, vanillic, caffeic, syringic, p-coumaric, ferulic, sinapic, ellagic, o-coumaric, cinnamic acids and protocatechuic acid ethyl ester; D(+)-maltose, D(+)-glucose, D(−)-fructose, D(+)-rhamnose, D(+)-xylose, D(+)-saccharose, all were purchased from Sigma-Aldrich (St. Louis, MI, USA). All standards and solvents used in this study were of HPLC-grade (purity ≥ 98.5–99.0%). Total dietary fiber and resistant starch assay kits were provided from Megazyme International Ireland Ltd. (Wicklow, Ireland).

Ethanol and sodium carbonate were purchased from Avantor Performance Materials Poland (Gliwice, Poland). Gallic, m-coumaric, o-coumaric, p-coumaric, caffeic, 5-O-caffeoylqunic, ferulic, isoferulic, vanillic, salicylic, 3-hydroxybenzoic, 4-hydroxybenzoic, protocatechuic, syringic, rosmarinic acid, quercitrin, apigenin 7-O-glucoside, eriocitrin, taxifolin, 3-O-methylquercetin, isorhamnetin, isorhamnetin-3-O-glucoside, luteolin, kaempferol, rutin, hyperoside, isoquercetin, sakuranetin, aluminum chloride, and LC–MS grade acetonitrile were purchased from Sigma-Aldrich Chemical Co. (St. Louis, Mo, USA). Folin–Ciocalteu reagent was supplied by Chempur (Piekary Śląskie, Poland). Quercetin was purchased from Fluka (Buchs, Switzerland). Catechin, naringenin 7-O-glucoside, eriodictyol, luteolin-7-O-glucoside, naringenin 7-O-glucoside, luteolin 3,7-diglucoside, nicotiflorin, narcissoside, gentisic, sinapic acid, and myricetin were provided by ChromaDex (Irvine, CA, USA). Astragalin, apigenin, naringenin, kaempferol-3-rutinoside, and tiliroside were supplied by Roth (Karlsruhe, Germany). LC–MS grade water was prepared using a Millipore Direct-Q3 purification system (Bedford, MA, USA).

Standards of flavonoids: Quercetin (3,3’,4’,5,7-pentahydroxyflavone), catechin (3,5,7,3’,4’-pentahydroxyflavan), luteolin (3’,4’,5,7-tetrahydroxyflavone), apigenin (4’,5,7-trihydroxyflavone), naringin (naringenin-7-β-rhamnoglucozid), kaempferol (3,4’,5,7-tetrahydroxyflavone), galangin (3,5,7-trihydroxyflavone), pinocembrin (5,7-dixydroxyflavanone), chrysin (5, 7-dihydroxyflavone), acacetin (apigenin-4’-methylether) and different phenolic acids: p-hydroxybenzoic, caffeic, ferulic, chlorogenic, p-coumaric, t-cinnamic, o-coumaric, vanillic, homovanillic, protocatechuic and syringic were acquired from Sigma Aldrich (Saint Louis, MO, US) and Fluka Chemie GmbH (Buchs, Switzerland). Folin–Ciocâlteu reagent (2N), sodium carbonate, 2,2-diphenyl-1-picrylhydrazyl, aluminum chloride, sodium nitrite, sodium hydroxide, Ferrous sulfate, and Trolox (Sigma Aldrich Co.) were used for total phenolics and antioxidant activity determination. Organic solvents (methanol, acetonitrile, ethyl acetate and acetic acid) were analytical, HPLC or MS grade (Sigma Aldrich Co.). Ultrapure water was obtained with a Millipore equipment (MilliQ Integral 3, Millipore, Burlington, MA, USA).