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...
......
GB/T 5009.7-2008
ICS 67.040
C 53
GB
NATIONAL STANDARD
OF THE PEOPLE’S REPUBLIC OF CHINA
Replacing GB/T 5009.7-2003
Determination of reducing sugar in foods
ISSUED ON. NOVEMBER 21, 2008
IMPLEMENTED ON. MARCH 1, 2009
Issued by.
General Administration of Quality Supervision, Inspection
and Quarantine of the People’s Republic of China;
Standardization Administration of the People’s Republic of
China
Table of Contents
Foreword ... 3
1 Scope ... 4
2 Principle... 4
3 Reagents ... 4
4 Instruments ... 6
5 Analytical procedure ... 6
6 Result calculation ... 8
7 Principle... 9
8 Reagents ... 9
9 Instruments ... 10
10 Analytical procedure ... 11
11 Precision ... 23
Foreword
This Standard replaces GB/T 5009.7-2003 of Determination of reducing sugar in foods.
Compared with GB/T 5009.7-2003, main changes of this Standard are as follow.
— The detection limits are included;
— The categories of food samples are redefined;
— The anti-titration formula of the first method "Direct Titration" is included;
— The calculated significant digits are defined.
The Standard was proposed by and shall be administered by Ministry of Health of the
People’s Republic of China.
Drafting organizations of this Standard. National Institute for Nutrition and Food Safety of
Chinese Center for Disease Control and Prevention, and Beijing Center for Diseases
Prevention and Control.
The main drafters of this Standard are. Yang Dajin, Chang Di, Zhao Xin, Wu Guohua, and
Xue Ying.
The previous versions of the standard replaced by this standard are as follows.
— GB/T 5009.7-1985 and GB/T 5009.7-2003.
Determination of reducing sugar in foods
1 Scope
This Standard specifies the determination method of reducing sugar content in food.
This standard applies to the determination of reducing sugar content in food.
When 5.0g of sample is taken, the detection limit of direct titration is 0.25g/100g, and the
detection limit of permanganate titration is 0.5g/100g.
The First method - Direct titration
2 Principle
After the sample’s protein is removed, under the condition of heating, TAKE the
methylene blue as the indicator. TITRATE the marked alkaline copper tartrate solution
(marked by reducing sugar standard solution). Calculate the reducing sugar content
according to the consumed volume of the sample solution.
3 Reagents
Unless otherwise specified, reagents applied in this method are all analytical reagents.
3.1 Hydrochloric acid (HCl).
3.2 Copper sulfate (CuSO 4•5H2O).
3.3 Methylene blue (C16H18C1N3S·3H2O). Indicator.
3.4 Sodium potassium tartrate [C4H4O5KNa·4H2O].
3.5 Sodium hydroxide (NaOH).
3.6 Zinc acetate [Zn(CH3COO)2•2H2O].
3.7 Glacial acetic acid (C2H4O2).
3.8 Potassium ferrocyanide [K4Fe(CN)6•3H2O].
3.9 Dextrose (C6H12O6).
3.10 Fructose (C6H12O6).
water to dissolve it. Put it into a triangular flask with plug. Then add 5mL of hydrochloric
acid (1+1). Heat it for 15min in water at 68°C-70°C. And then place it till the temperature
turning to the indoor temperature. After that, transfer the solution into a 1000mL volumetric
flask and dilute to 1000mL. Per milliliter of this standard solution equal to 1.0mg of
inverted sugar.
4 Instruments
4.1 Acid burette. 25mL;
4.2 Adjustable electric furnace. equipped with asbestos board.
5 Analytical procedure
5.1 Sample processing
5.1.1 General food. Take about 2.5g-5g of smashed solid sample or 5g-25g blended
fluid sample, with the measurement accurate to 0.001g. Put it into a 250mL volumetric
flask, add 50mL of water. Slowly inject 5mL of zinc acetate solution and 5mL of Potassium
ferrocyanide solution. Then raise the solution level with water to the scale. Blend the
solution. Place it for 30min. Filter it with dry filter paper. Dispose the primary filtrate. Take
out the subsequent filtrate for standby.
5.1.2 Stimulant. Take about 100g of blended sample, accurate to 0.01g. Put it into an
evaporating dish. Neutralize it with sodium hydroxide (40g/L) solution to neutral state.
Evaporate it to 1/4 of its initial volume by bathing it in the water. Transfer it to a 250mL
volumetric flask. Manipulate the following procedure according to the regulations of 5.1.1
from "slowly inject 5mL of zinc acetate solution".
5.1.3 Foods containing large quantity of starch. Take about 10g-20g of smashed or
blended sample, with the measurement accurate to 0.001g. Put it into a 250mL volumetric
flask. Add 200mL of water. Heat it for 1h in a 45°C water bath, shaking it frequently. After
cooled, add water to the scale. Blend it. Place it and precipitate it. Absorb 200mL of
supernate and put it into another 250mL volumetric flask. Manipulate the following
too high, it shall dilute appropriately before starting the formal determination. Ensure that
the volume of the consumed sample solution each time is similar to that of the consumed
reducing sugar standard solution used for the determination of the alkaline copper tartrate
solution, which is about 10mL. The result is calculated according to formula (1). When the
concentration is too low, add 10mL of sample solution rather than 10mL of water. Add
reducing sugar standard solution to the end. Record the difference between the
consumed volume AND the volume of the reducing sugar standard solution consumed for
determination, with such difference is equivalent to the reducing sugar content in 10mL
sample solution. Calculate the result according to formula (2).
5.4 Determination of the sample solution
Absorb 5.0mL of alkaline copper tartrate A solution and 5.0mL of alkaline copper tartrate B
solution. Put them into one 150mL conical flask. Add 10mL of water and two glass balls.
Then use burette to drop sample solution which is 1mL less than the forecasted volume to
the conical flask. Ensure it get boiling within 2min. Keep the boiling and drop solution at a
speed of 1 drop/2s to the moment of the disappearance of the blue color. Record the total
consumed volume. Operate 3 such solutions simultaneously and in parallel. Obtain the
average consumed volume.
6 Result calculation
The reducing sugar content in the sample (calculating a certain kind of reducing sugar)
shall be determined according to formula (1).
Where.
X — The reducing sugar content in the sample (calculating a certain kind of reducing
sugar), g/100g;
m1 — The alkaline copper tartrate solution (A solution and B solution each half) which is
equal to the mass of a certain kind of reducing sugar, mg;
8.1 Copper sulfate (CuSO4 • 5H2O).
8.2 Sodium hydroxide (NaOH).
8.3 Sodium potassium tartrate (C4H4O6KNa • 4H2O).
8.4 Ferric sulfate [Fe2(SO4)3].
8.5 Hydrochloric acid (HC1).
8.6 Alkaline copper tartrate A solution. Take 34.639g of copper sulfate (CuSO4·5H2O).
Add some water to dissolve it. Then add 0.5mL of sulfuric acid. Dilute it with water to
500mL. And filtrate it with refined asbestos.
8.7 Alkaline copper tartrate B solution. Take 173g of potassium sodium tartrate, 50g of
sodium hydroxide. Add a moderate amount of water to dissolve it. And dilute it to 500mL.
Filtrate it with refined asbestos. And store the solution in a glass bottle with rubber plug.
8.8 Sodium hydroxide solution (40g/L). Take 4g of sodium hydroxide. Add water to
dissolve and dilute it to 100mL.
8.9 Ferric sulfate solution (50g/L). Take 50g of ferric sulfate. Add 200mL of water to
dissolve it. Slowly add 100mL sulfuric acid into it. And dilute it to 1000mL after cooling.
8.10 Hydrochloric acid (3mol/L). Take 30mL of hydrochloric acid and dilute it with water to
120mL.
8.11 Permanganate standard solution [c(1/5KMnO4)=0.1000mol/L].
8.12 Refined asbestos . Before using the asbestos, soak it into the hydrochloric acid
(3mol/L) for 2d-3d. Wash it with water. Add sodium hydroxide solution (400g/L) to soak it
for 2d-3d. Discard the solution. Then use hot alkaline copper tartrate B solution to soak it
for several hours. Wash it with water. Then put it into hydrochloric acid (3mol/L) for several
hours. Keep washing it with water till it is not acidic. Add water and shake it. Make it form
tiny soft fiber of pulpiness. Put it into water and store it in a glass bottle. That is to be used
to fill Gooch crucible.
9 Instruments
9.1 25mL Gooch crucible or G4 vertical melting crucible.
alkaline copper tartrate A solution and 25mL of B solution. Cover a watch glass over the
beaker. Heat it. Ensure it to boil within 4min. Keep boiling for another 2min accurately.
While it is hot, leach it with Gooch crucible or G4 vertical melting crucible which are laid
with asbestos. Wash the beaker and sedimentation with 60ºC water till the water is not
alkaline. Put the Gooch crucible and vertical melting crucible bac...
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| 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 | | Standard ID | GB/T 5009.7-2008 (GB/T5009.7-2008) | | Description (Translated English) | Determination of reducing sugar in foods | | Sector / Industry | National Standard (Recommended) | | Classification of Chinese Standard | C53 | | Classification of International Standard | 67.040 | | Word Count Estimation | 13,126 | | Date of Issue | 2008-11-21 | | Date of Implementation | 2009-03-01 | | Older Standard (superseded by this standard) | GB/T 5009.7-2003 | | Drafting Organization | China Disease Prevention and Control Center of Nutrition and Food Safety | | Administrative Organization | Ministry of Health | | Regulation (derived from) | National Standard Approval Announcement 2008 No.22 (Total No.135) | | Proposing organization | People's Republic of China Ministry of Health | | Issuing agency(ies) | Ministry of Health of People's Republic of China; Standardization Administration of China | | Summary | This standard specifies the method for determination of reducing sugar content of foods. This standard applies to the determination of reducing sugar content of foods. When the sample weight is 5. 0g, the direct titration method detection limit is 0. 25g/100g, potassium permanganate titration method detection limit of 0. 5g/100g. | | Standard ID | GB/T 5009.7-2003 (GB/T5009.7-2003) | | Description (Translated English) | Determination of reducing sugar in foods | | Sector / Industry | National Standard (Recommended) | | Classification of Chinese Standard | C53 | | Classification of International Standard | 67.04 | | Word Count Estimation | 10,148 | | Date of Issue | 2003/8/11 | | Date of Implementation | 2004/1/1 | | Older Standard (superseded by this standard) | GB/T 5009.7-1985 | | Regulation (derived from) | Announcement of Newly Approved National Standards No. 22 of 2008 (No. 135 overall) | | Proposing organization | Ministry of Health of the People Republic of China | | Issuing agency(ies) | The People Republic of China Ministry of Health, China National Standardization Management Committee |
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