AOAC 2019 First Action Methods

(h) Centrifuge. (i) Centrifuge tubes. –50 mL HDPE plastic with screw caps. D. Reagents

(a) Solvents and chemicals. –ACS grade glacial acetic acid; ACS grade acetone; ACS grade ethanol; ACS grade methanol; ACS grade concentrated hydrochloric acid; ProA2 standard; and cranberry-PAC (c-PAC) standard. (b) Deionized water. – Resistivity of ≥1 mega -ohm/cm. (c) Acetic acid solution. –2% (v/v), prepared by adding 20 mL of acetic acid to a 1 L volumetric flask and dilute to volume with deionized water. (d) Dilution solution. –75% (v/v) reagent alcohol: prepared by adding 750 mL of reagent alcohol to a 1 L volumetric flask and diluting to volume with deionized water. (e) Reaction buffer .–12.5% (v/v) concentrated hydrochloric acid, 75% reagent alcohol: prepared by adding 125 mL of concentrate hydrochloric acid and 125 mL of deionized water in a 1 L volumetric flask and diluting to volume with reagent alcohol. (f) DMAC solution .–0.1% (w/v): prepared by weighing 25 mg DMAC in a 25 mL volumetric flask and dissolving to volume with reaction buffer. (g) ProA2 standard solutions. – (1) Stock solution. –500 µg/mL: accurately weigh 5 mg ProA2 into a 10 mL volumetric flask and dilute to volume with methanol. Final calculated concentration of the stock solution may require adjustment based on manufacturer’s claim of purity. ( 2 ) Working standard solutions. –Dilute stock standard to 4, 10, 20, 30, 40, and 50 µg/mL with dilution solution using volumetric flask. (h) Cranberry PAC (c-PAC) standard solutions. – (1) Stock solution.-- 0.9013 mg/mL: accurately weigh 9 mg c-PAC standard into a 10 mL volumetric flask and dilute to volume with methanol. ( 2 ) Dilute stock standard to 13.5, 27.0, 54.0, 81.0, 108, and 135 µg/mL with dilution solution using volumetric flask. (a) Cranberry extract powder. –Weigh 100 mg sample into 50 mL centrifuge tube and add 5 mL acetic acid solution. Vortex tube and sonicate for 10 minutes. Add 15 mL acetone, vortex, and sonicate for 30 minutes. Centrifuge tube at 1800g for 10 minutes at 20 ° C. Dilute extracted solutions as necessary with dilution solution. (b) Cranberry fiber powder. –Weigh 500 mg sample into 50 mL centrifuge tube and add 5 mL acetic acid solution. Vortex tube and bath sonicate for 10 minutes. Add 15 mL acetone, vortex, and sonicate for 30 E. Sample Extraction