This standard specifies the determination method for the content of reducing sugar in foods.
Method I and Method II in this standard are applicable to the determination of reducing sugar content in foods.
Method III in this standard is applicable to the determination of reducing sugar content in wheat flour.
Method IV in this standard is applicable to the determination of reducing sugar content in sugar beet root.
Method I: Direct Titrimetric Method
2 Principle
After removing the protein in the specimen, titrate the calibrated alkaline cupric tartrate solution (which has been calibrated with reducing sugar standard solution) under heating conditions with methylene blue as the indicator, and then calculate the reducing sugar content according to the consumed volume of sample solution.
3 Reagents and Materials
Unless otherwise specified, analytically-pure reagents and Grade-III water (defined in GB/T 6682) are adopted for the purpose of this method.
3.1 Reagents
3.1.1 Hydrochloric acid (HCl).
3.1.2 Copper sulfate (CuSO4•5H2O).
3.1.3 Methylene blue (C16H18ClN3S•3H2O).
3.1.4 Sodium potassium tartrate (C4H4O6KNa•4H2O).
3.1.5 Sodium hydroxide (NaOH).
3.1.6 Zinc acetate [Zn(CH3COO)2•2H2O].
Contents Foreword I 1 Scope 2 Principle 3 Reagents and Materials 4 Instruments and Apparatus 5 Analysis Steps 6 Expression of Analysis Result 7 Precision 8 Other 9 Principle 10 Reagents and Materials 11 Instruments and Apparatus 12 Analysis Steps 13 Expression of Analysis Result 14 Precision 15 Other 16 Principle 17 Reagents 18 Instruments and Apparatus 19 Analysis Steps 20 Expression of Analysis Results 21 Precision 22 Principle 23 Reagents and Materials 24 Instruments and Apparatus 25 Analysis Steps 26 Expression of Analysis Results 27 Precision 28 Other Appendix A
