AOAC OMB Final Action Recommendation (December 2019)-2016.14

2016.14 (October 2019) – FOS-03 METHOD

FOR ERP USE ONLY DO NOT DISTRIBUTE

- Only the 2/3 of the NaOH solution in the original bottle should be used for preparing eluents.

80

Remaining solution can be used for other applications, including preparation of the solution

81

for post-column addition.

82

(k) Sodium hydroxide .—Pellets for analysis.

83

(l) Sodium chloride .—For analysis, ACS,ISO,Reag. Ph Eur.

84

(m) Sodium azide.— [Optional].

85

(n) D-(-)Fructose .—≥99.0 %.

86

(o) D-(+)-Glucose. —≥99.5 %.

87

(p) N,N’-diacetylchitobiose .—>90 %.

88

(q) Mixture of highly purified sucrase, β -amylase, pullulanase and maltase .—200 µL of enzyme 89 mixture working solution D(j) should be able to completely hydrolyse 2 mg of sucrose under the 90 conditions described in the method (90 min at 40 °C) without hydrolysing any fructans (Fructan 91

92

Assay Kit, K-FRUC, Megazyme International Ireland Ltd, or equivalent).

(r) Fructanase, mixture of highly purified recombinant exo- and endo-inulinases and recombinant 93 endo-levanase .—100 µL of enzyme mixture working solution D(k) should be able to hydrolyse 94 70 µg of fructans under the conditions described in the method (40 min at 40 °C) (Fructan Assay 95

96

Kit, K-FRUC, Megazyme International Ireland Ltd, or equivalent).

D.

Preparation of Reagents

97

(a) Sodium hydroxide (2 M) .—Dissolve 40 g NaOH pellets in 250 mL of water in a 500-mL volumetric

98

99

flask. After cooling down to room temperature, make up to the mark with water and mix well.

100

Stable for 6 months at room temperature.

(b) Sodium maleate buffer (100 mM, pH 6.5) .—Into a beaker (>500-mL) weigh 5.8 g maleic acid and

101

102

dissolve with 450 mL of water (using magnetic stirrer). Adjust the pH to 6.5 with 2 M NaOH

5