4 dimethylaminocinnamaldehyde dmac

Analytical and chromatographic grade solvents were used for this study: acetonitrile, methanol, acetone, acetic acid, hydrochloric, and trifluoroacetic acid from Sigma-Aldrich (Steinheim, Germany), ethanol from Vilniaus degtine (Vilnius, Lithuania). Ultrapure water was obtained by a Milli-Q water purification system from Millipore (Bedford, MA, USA).
Standards used in the phytochemical analysis: procyanidins A1, A2, A4, B1, B2, C1, (+)-catechin, and (−)-epicatechin from Sigma-Aldrich; procyanidin B3 from Extrasynthese (Genay, France).
The following reagents were used: 4-dimethylaminocinnamaldehyde (DMAC), 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) from Sigma-Aldrich, and phosphate-buffered saline (PBS) from Gibco (Carlsbad, CA, USA).
Methylcellulose (viscosity 15 cPs) was purchased from Alfa Aesar (Kandel, Germany). Hydroxyethyl cellulose (average M = ~90 kDa) was purchased from Sigma-Aldrich. Polyethylene glycol 400 (PEG 400) was purchased from Carl Roth (Karlsruhe, Germany).

The apple fiber powder was supplied by Biesterfeld AG (Zagreb, Croatia) and both types of pectin were the product of CP Kelco (Atlanta, GA, USA). The 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS), trolox, 4-(dimethylamino)-cinnamaldehyde (DMAC), chlorogenic, caffeic, p-coumaric, gallic and ellagic acids, rutin, quercetin, phloretin and phlorizin were purchased from Sigma-Aldrich (St. Louis, MO, USA). The α-glucosidase (from Saccharomyces cerevisiae) and acarbose were obtained from Sigma-Aldrich (St. Louis, MO, USA). The 4-nitrophenyl-α-D-glucopyranoside was obtained from Alfa Aesar (Kandel, Germany) and potassium dihydrogen phosphate was from BDH Prolabo (Poole, UK). Potassium persulfate, Folin-Chiocalteu reagent and sodium carbonate were obtained from Kemika (Zagreb, Croatia). Neocuproine, 2,4,6-tri(2-pyridyl)-s-triazine (TPTZ) and copper (II) chloride were purchased from Acros Organics (Geel, Belgium). Methanol (HPLC grade) was from J.T. Baker (Deventer, The Netherlands) and orthophosphoric acid (HPLC grade > 85%) was from Fisher Scientific (Loughborough, UK). Iron (III) chloride hexahydrate, sodium acetate, ethanol, ammonium acetate and starch were bought from Gram-mol (Zagreb, Croatia). Cyanidin 3-glucoside was from Extrasynthese (Genay, France).

Cargill, Inc. (Wayzata, MN, USA) generously provided raw unfermented cocoa beans, sourced from Hispaniola. The beans were stored in burlap sacks at 3.5 °C prior to use. LC-MS grade acetonitrile (ACN), LC-MS grade methanol (MeOH), citric acid, yeast extract, malt extract, calcium-lactate pentahydride, tween 80, sodium hydroxide, magnesium sulfate heptahydride, manganese sulfate monohydride, sucrose, glucose, fructose, calcium carbonate, agar, and water were obtained from Thermo-Fisher Scientific (Waltham, MA, USA). Glacial acetic acid, methanol, and acetone were obtained from VWR (Radnor, PA, USA). The standards of (−)-epicatechin (EC), (±)-catechin (C), and procyanidin B2 (PCB2) were obtained from ChromaDex (Irving, CA). Standards of procyanidin C1 (PCC1), cinnamtannin A2 (CinA2), and DP 5-9 purified from cocoa (purity: DP 3-5: 93–99%, DP6-9: 80–92%) were obtained from Planta Analytica (New Milford, CT, USA). Ammonium formate, Folin-Ciocalteu reagent, 4-dimethylaminocinnamaldehyde (DMAC), and α-glucosidase (from Saccharomyces cerevisiae) were obtained from Sigma-Aldrich (G5003, St. Louis, MO, USA). The solvents were ACS grade or higher.

Folin–Ciocalteu reagent, sodium carbonate, gallic acid, aluminium chloride, quercetin, 4-dimethylaminocinnamaldehyde (DMAC), cyanidin-3-glucoside (C3G), and procyanidin B1 dimer were purchased from Sigma-Aldrich (St. Louis, MO, USA). All other chemicals and solvents were obtained from Fisher Scientific (Pittsburg, PA, USA).

Apple fibers in powder form was obtained from Biesterfeld AG (Zagreb, Croatia). 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS), trolox, 4-(dimethylamino)-cinnamaldehyde (DMAC), chlorogenic, caffeic, p-coumaric, gallic and ellagic acids, rutin, quercetin, phloretin, phlorizin, and myrtenol were purchased from Sigma-Aldrich (St. Louis, MO, USA). Potassium persulfate, Folin-Chiocalteu reagent, and sodium carbonate were obtained from Kemika (Zagreb, Croatia). Neocuproine, 2,4,6-tri(2-pyridyl)-s-triazine (TPTZ), and copper (II) chloride were purchased from Acros Organics (Geel, Belgium). Methanol (HPLC grade) was acquired from J.T. Baker (Deventer, The Netherlands), and orthophosphoric acid (HPLC grade > 85%) was obtained from Fisher Scientific (Loughborough, UK). Iron (III) chloride hexahydrate, sodium acetate, ethanol, ammonium acetate, and starch were bought from Gram-mol (Zagreb, Croatia). Cyanidin 3-glucoside was obtained from Extrasynthese (Genay, France), and 3,5-dinitrosalicylic acid was from Alfa Aesar (Kandel Germany). Sucrose was obtained from Fluka (Buchs, Switzerland). Trehalose was a donation from Hayashibara Company (Nagase group, Okayama, Japan).