AOAC OMB Final Action Recommendation (December 2019)-2016.14

2016.14 (October 2019) – FOS-03 MANUSCRIPT

FOR ERP USE ONLY DO NOT DISTRIBUTE

(r) Fructanase, mixture of highly purified recombinant exo- and endo-inulinases and 1 recombinant endo-levanase .—100 µL of enzyme mixture working solution D(k) should 2 be able to hydrolyse 70 µg of fructans under the conditions described in the method 3 (40 min at 40 °C) (Fructan Assay Kit, K-FRUC, Megazyme International Ireland Ltd, or 4 equivalent). 5 D. Preparation of Reagents 6 (a) Sodium hydroxide (2 M) .—Dissolve 40 g NaOH pellets in 250 mL of water in a 500-mL 7 volumetric flask. After cooling down to room temperature, make up to the mark with water 8 and mix well. Stable for 6 months at room temperature. 9 (b) Sodium maleate buffer (100 mM, pH 6.5) .—Into a beaker (>500-mL) weigh 5.8 g maleic 10 acid and dissolve with 450 mL of water (using magnetic stirrer). Adjust the pH to 6.5 with 11 2 M NaOH solution D(a) . Transfer the solution to a 500-mL volumetric flask and make up 12 to the mark with water. Stable for 3 months at 4 °C. 13 (c) Sodium acetate buffer (100 mM, pH 4.5) .—Into a beaker (>500-mL) containing 450 mL of 14 water, pipette 2.9 mL glacial acetic acid. Adjust to pH 4.5 with 2 M NaOH solution D(a) . 15 Transfer the solution to a 500-mL volumetric flask and make up to the mark with water. 16 Stable for 3 months at 4 °C. 17 (d) N,N’-diacetylchitobiose internal standard solution (600 µg/mL) .—Into a 25-mL 18 volumetric flask weigh 15 mg N,N’-diacetylchitobiose and make up to the mark with water. 19 Stable for 1 year at -20 °C. 20 (e) Glucose stock solution (5 mg/mL) .—Into a 25-mL volumetric flask accurately weigh 21 125 mg glucose and make up to the mark with water. Stable for 1 year at -20 °C. 22 (f) Fructose stock solution (10 mg/mL) .—Into a 25-mL volumetric flask accurately weigh 23 250 mg fructose and make up to the mark with water. Stable for 1 year at -20 °C. 24

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