GB 5009.7-2016 (GB5009.7-2016) & related versions
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GB 5009.7-2016
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
National food safety standard -
Determination of reducing sugar in foods
ISSUED ON. AUGUST 31, 2016
IMPLEMENTED ON. MARCH 01, 2017
Issued by. National Health and Family Planning Commission of the
People’s Republic of China
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Table of Contents
Foreword ... 4
1 Scope ... 5
2 Principle ... 5
3 Reagents and materials ... 5
4 Instruments and equipment ... 7
5 Analysis procedure ... 7
6 Expression of analysis results ... 9
7 Precision ... 10
8 Others ... 10
9 Principle ... 11
10 Reagents and materials ... 11
11 Instruments and equipment ... 12
12 Analysis procedure ... 12
13 Expression of analysis results ... 13
14 Precision ... 14
15 Others ... 15
16 Principle ... 15
17 Reagents ... 15
18 Instruments and equipment ... 16
19 Analysis procedure ... 16
20 Expression of analysis results ... 17
21 Precision ... 18
22 Principle ... 18
23 Reagents and materials ... 18
24 Instruments and equipment ... 20
25 Analysis procedure ... 21
26 Expression of analysis results ... 22
27 Precision ... 22
28 Others ... 22
Annex A ... 23
Foreword
This Standard replaces GB/T 5009.7-2008 “Determination of reducing sugar in foods”,
GB/T 5513-2008 “Inspection of grain and oils - Determination of reduced sugar and
non-reduced sugar in grain” and NY/T 1751-2009 “Determination of reducing sugar in
sugar beet root”.
Compared with GB/T 5009.7-2008, the main modifications of this Standard are as
follows.
- MODIFY the standard name to “National food safety standard - Determination of
reducing sugar in foods”;
- MERGE the portion about the redacting sugar in GB/T 5009.7-2008 and GB/T
5513-2008.
National food safety standard -
Determination of reducing sugar in foods
1 Scope
This Standard specifies the determination of reducing sugar content in foods.
Method I and method II of this Standard apply to the determination of reducing sugar
content in foods.
Method III of this Standard applies to the determination of reducing sugar content in
wheat flour.
Method IV of this Standard applies to the determination of reducing sugar content in
sugar beet root.
Method I Direct titration
2 Principle
After the protein in the sample is removed, use methylene blue as indicator, titrate the
calibrated alkaline copper tartrate solution (calibrated with the reducing sugar standard
solution) under heating conditions, and calculate the content of reduced sugar
according to the volume of the sample solution consumed.
3 Reagents and materials
Unless otherwise stated, the reagents used in this method are analytical reagents and
the water is the tertiary water specified in GB/T 6682.
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 Potassium tartrate (C4H4O6KNa · 4H2O).
3.1.5 Sodium hydroxide (NaOH).
5.1.2 Alcoholic beverages. WEIGH 100 g (accurate to 0.01 g) of mixed sample; PLACE
in an evaporative dish; NEUTRALIZE with sodium hydroxide solution to neutral;
EVAPORATE in the water bath to 1/4 of the original volume; TRANSFER to a 250-mL
volumetric flask; slowly ADD 5 mL of zinc acetate solution and 5 mL of potassium
ferrocyanide solution; ADD water to the scale; MIX well. STAND for 30 min; FILTER
with dry filter paper; DISCARD the original filtrate; TAKE the follow-up filtrate for further
use.
5.1.3 Carbonated beverages. WEIGH 100 g (accurate to 0.01 g) of mixed sample;
PLACE in an evaporative dish; REMOVE carbon dioxide in the water bath; TRANSFER
to a 250-mL volumetric flask; WASH the evaporative dish with water; ADD the washing
liquid into the volumetric flask; ADD water to the scale; MIX well; for further use.
5.1.4 Other foods. WEIGH 2.5 g ~ 5.0 g (accurate to 0.001 g) of crushed solid sample
or 25 g ~ 50 g (accurate to 0.001 g) of mixed liquid sample; PLACE in a 250-mL
volumetric flask; ADD 50 mL of water; slowly ADD 5 mL of zinc acetate solution and 5
mL of potassium ferrocyanide solution; ADD water to the scale; MIX well. STAND for
30 min; FILTER with dry filter paper; DISCARD the original filtrate; TAKE the follow-up
filtrate for further use.
5.2 Calibration of alkaline copper tartrate solution
PIPETTE 5.0 mL of alkaline copper tartrate solution A and 5.0 mL of alkaline copper
tartrate solution B; PLACE in a 150-mL Erlenmeyer flask; ADD 10 mL of water; ADD 2
~ 4 glass beads. ADD dropwise about 9 mL of glucose (3.4.1) [or other reducing sugar
standard solution (3.4.2, or 3.4.3, or 3.4.4)] from the burette; HEAT to boil in 2 min;
CONTINUE to add dropwise glucose [or other reducing sugar standard solution (3.4.2,
or 3.4.3, or 3.4.4)] at a rate of 1 drop every 2 seconds until the blue of the solution
fades, that is the end point; RECORD the total volume of glucose (or other reducing
sugar standard solution) consumed. TEST 3 samples in parallel; TAKE the average
value. CALCULATE the mass (mg) of glucose (or other reducing sugar) equivalent to
per 10 mL (each 5 mL of alkaline copper tartrate solution A and B) of alkaline copper
tartrate solution.
NOTE. It may also calibrate 4 mL ~ 20 mL alkaline copper tartrate solution (solution A, B are of
half-and-half) according to the above method to adapt to the concentration change of reducing
sugar in the sample.
5.3 Prediction of sample solution
PIPETTE 5.0 mL of alkaline copper tartrate solution A and 5.0 mL of alkaline copper
tartrate solution B; PLACE in a 150-mL Erlenmeyer flask; ADD 10 mL of water; ADD 2
~ 4 glass beads. HEAT to boil in 2 min; KEEP boiling and ADD dropwise the sample
solution from the burette at a speed of from fast to slow, and keep boiling state, until
the solution color becomes lighter. TITRATE at a rate of 1 drop/2 s until the blue of the
(mL);
250 - the constant volume, in milliliters (mL);
1000 - the conversion coefficient.
When the concentration is too low, the content of reducing sugar in the sample
(calculated as a certain type of reducing sugar) is calculated as equation (2).
where.
X - the content of reducing sugar in the sample (calculated as a certain type of
reducing sugar), in grams per gram (g/100 g);
m2 - the mass of a certain type of reducing sugar equivalent to the difference
between the volume of reducing sugar standard solution and the volume of the
reducing sugar standard solution consumed after adding the sample, in milligrams
(mg);
m - the mass of the sample, in grams (g);
F - the coefficient, 1 for 5.1.1, 5.1.3, 5.1.4 and 0.80 for 5.1.2;
10 - the volume of the sample solution, in milliliters (mL);
250 - the constant volume, in milliliters (mL);
1000 - the conversion coefficient.
When the content of reducing sugar ≥ 10 g/100 g, the calculation result retains three
significant digits; when the content of reducing sugar < 10 g/100 g, the calculation
result retains two significant digits.
7 Precision
The absolute difference between the two independent determination results obtained
u...
......
| Standard ID | GB 5009.7-2016 (GB5009.7-2016) | | Description (Translated English) | Determination of reducing sugar in foods | | Sector / Industry | National Standard | | Classification of Chinese Standard | C53 | | Word Count Estimation | 21,250 | | Date of Issue | 2016-08-31 | | Date of Implementation | 2017-03-01 | | Older Standard (superseded by this standard) | NY/T 1751-2009; GB/T 5513-2008; GB/T 5009.7-2008 | | Regulation (derived from) | Announcement of the State Administration of Public Health and Family Planning 2016 No.11 |
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