AFDC 05(6093 ) P3 
 
 
                  
DRAFT TANZANIA STANDARD  
 
 
 
 
 
 
Aspartame (food grade) — Specification  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
                                    TANZANIA BUREAU OF STANDARDS                                                                                                                       
AFDC 05( 6093)P 3 
 Aspartame (food grade) — Specification  
 
0.  Foreword  
 
Aspartame (3 -Amino -N-(α-carbomethoxy -phenethyl) -succinamic acid, N -L-α-aspartyl -L-phenylalanine -1-
methyl ester, C14H18N2O5) is a low calorie artificial sweetener, sugar substitute and flavour enhancer. It is 
100 – 200 times sweeter than sucrose. It is one  of the most popular artificial sweeteners and it is widely used 
in the preparation of beverages, desserts, sweets, dairy products, chewing gums, energy -reduced and weight 
control products, as a table -top sweetener and in the preparation of food for diabet ics. 
 
Aspartame is made of two naturally occurring amino acids, phenylalanine and aspartic acid. The 
phenylalanine in aspartame is slightly modified by adding a methyl group giving the product its sweet taste. 
Just like proteins, aspartame is digested once  it reaches the intestines. It is fully broken down to aspartic acid 
and phenylalanine, which are absorbed into the body. In addition, the methyl group from the modified 
phenylalanine is released in the gut to form methanol. The methanol is absorbed and mo st of it used to 
produce energy.   
 
 
In preparation of this draft Tanzania standard assistance was drawn from India standard;  
IS13657 Food grade Aspartame – Specification published by Bureau of India Standards (BIS)  
 
This standard has been developed to ensure  that the usage of aspartame in food products conforms to 
acceptable limits.  
 
In reporting the result of a test or analysis made in accordance with the Tanzania standard, if the final value 
observed or calculated is to be rounded off, it shall be do ne in accordance with TZS 4: (see clause 2)  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
                                                                                                                        
AFDC 05( 6093)P 3 
  
 
1 Scope  
 
This draft Tanzania Standard specifies requirements, sampling and test methods for food grade aspartame.  
 
2 Normative references   
 
The following referenced documents are referred to in the text in such a way that some or all their content 
constitutes requirements of this document. For dated references, only the edition cited applies. For undated 
references, the latest edition of the referenced document (inclu ding any amendments) applies.  
 
AOAC 999.11, Determination of Lead, Cadmium, Copper, Iron, and Zinc in Foods, Atomic Absorption  
Spectrophotometry after Dry Ashing  
 
TZS 539, Methods of test for the assessment of odors and taint from packaging  material s used for food stuffs  
 
TZS 538, Labelling  of pre \-packaged foods — General requirements  
 
TZS 116, General standard for the labelling of food additives when sold as such  
 
TZS 109, Food processing units – Code of hygiene  
 
CAC/GL 50, General guidelines on sampling  
 
ISO 760, Determination of water  — Karl Fischer Method (General method)  
 
TZS 4, Rounding off numerical values  
  
3 Terms and definitions  
 
For the purposes of this document, the following terms and definitions apply.  
 
3.1 a spartame is an odorless   low calorie artificial sweetener, sugar substitute and flavor  enhancer  
 
 
3.2 a rtificial sweetener  is artificial substance that has a similar taste to sugar other than sugar u sed to 
sweeten food or drink.  
 
3.3 food grade material   
material, made of substances which are safe and suitable for their intended use and which will not impart any 
toxic substance or undesirable odour or flavour to the product  
 
4 Requirements  
 
4.1 General requirements  
 
4.1.1 Aspartame shall be, free from off odors, foreign matter and adulterants.  
 
4.1.2 Food grade aspartame shall be:  
 
a) a white, odorless , crystalline powder with a strong sweet aroma; and  
 
b) slightly soluble in water and ethanol/methanol;  
 
4.1.3 A saturated aqueous solution of the Food grade aspartame  shall be acidic.  
 
 
 
 
 
 
 
 
                                                                                                                        
AFDC 05( 6093)P 3 
  
 
 
 
 
4.2 Specific requirements  
 
Food grade aspartame shall comply with the specific requirements given in Table 1 when tested in 
accordance with the test methods specified therein.  
Table 1 — Specific requirements for fo od grade aspartame   
S/N Characteristic  Requirement  Test method  
    
i) Purity as C14H18N2O5, % m/m (dry basis)  
98.0 – 102.0  Annex A    
    
ii) Moistu re %m/m, max.  4.3 ISO 760  
    
iii) Sulphated ash, % m/m (dry basis), max.  0.2 Annex B  
    
iv) pH (0.8% solution)  4.5 – 6.0 Annex C  
    
v) 5-Benzyl –3,6–dioxo –2–piperazineacetic 
acid,  
1.5 Annex D  
(diketopiperazine), %m/m, max.     
    
vi) Test f or amine group  To pass test  Annex E  
    
Vii) Test for ester group  To pass test  Annex F  
     
 
 
 
5. Food additives  
Only the food additives permitted by CODEX STAN 192 in the manufacture of food grade aspartame may be 
used without exceeding the limits.  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
                                                                                                                        
AFDC 05( 6093)P 3 
  
6. Hygiene  
 
6.1 Food grade aspartame shall be prepared and packaged in premises built and maintained under hygienic 
condition in accordance with TZS 109.  
  
6.2   Food grade aspartame shall be free from pathogenic organisms.  
 
6.3 Contaminants  
Food grade aspartame shall comply with the Maximum Levels of contaminants given in Table 2 when test ed 
in accordance with the test methods specified therein.  
 
Table 2 — Maximum Limits for contaminants in food grade aspartame   
S/N Contaminant  Maximum level  Test method  
i) Lead ( Pb), mg/kg, max.  1 AOAC 999.11  
    
ii) Arsenic ( As), mg/kg, max.  3 AOAC 952.13  
    
 
7. Sampling  
 
Representative samples of the product shall be drawn in accordance with CAC/GL 50.   
 
 
8. Packaging, marking and labelling.  
 
8.1 The product shall be securely packaged in containers made of food grade materials conforming to TZS 
539. The packages shall preserve the quality of the product, prevent entry of light and preclude contamination 
from the external environment.  
 
8.2 Marking and labelling  
 
8.2.1  In addition to the requirements of TZS 538  and TZS 116, the product label shall be legibly and indelibly 
labelled with the following:  
 
(i) Name of the product as Aspartame with the words ‘Food Grade’;  
(ii) Name and physical address of the manuf acturer/distributor;  
(iii) Net weight in metric units;  
(iv) Batch/lot number;  
(v) Directions for storage;  
(vi) Date of manufacture; and the  
(vii) Expiry date.  
(viii) Instruction for use (refer codex stan for food additives when sold as such)  
(ix) Statutory warnings (For industrial use)  
 
 
8.2.2  The language on the label shall be “Kiswahili” or Kiswahili and English. A second language may be used 
depending on the designated market.  
8.2.3         The packages of the buns may also be marked with the TBS certification mark.  
NOTE - The TBS Standards M ark of Quality may be used by the manufacturers only under license  from TBS. 
Particulars of conditions under which the licences are granted, may be obtained from TBS   
 
 
 
 
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Annex A  
(normative)  
 
Assay: Test for purity  
A.1 Reagents  
 
A.1.1 Dimethylformamide  
A.1.2 Thymol Blue  
A.1.3 Lithium Methoxide/Sodium Methoxide  
A.2 Procedure  
Accurately weigh 150 mg of the sample, previously dried at 105 °C for 4 hours. Dissolve in 35 ml of 
dimethylformamide, add 5 drops of thymol blue, and titrate with a micro burette to a dark blue end -point with 
0.1N lithium methoxide or sodium methoxide. Perform a blank determination and make any necessary 
correction. Each ml of 0.1N lithium methoxide/sodium methoxide is equivalent to 29.43 mg of C14H 18N2O5.  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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AFDC 05( 6093)P 3 
 Annex B  
(normative)  
Determination of sulphated ash  
 
B.1 Reagents  
 
B.1.1 Dilute Sulphric acid – 10 percent (m/v).  
B.2 Procedure  
Transfer about 2 g of the sample, accurately weighed, to a tared 50 -ml to 100 -ml platinum dish or other 
suitable container and add sufficient dilute sulphuric acid to moisten the entire sample. Heat gently, until the 
sample is dry and thoroughly charred, t hen continue heating until all the sample has been volatilized or nearly 
all of the carbon has been oxidized. Cool, moisten the residue with 0.1 ml of sulphuric acid, and heat in the 
same manner until the remainder of the sample and any excess sulphuric ac id have been volatilized. Finally 
ignite in a muffle furnace at 800 °C ± 25 °C for 15 minutes. Cool in a desiccator and weigh.  
 
B.3 Calculation
Sulphated ash, percent by mass= 
M1 X100  
    M 
 
 
where   
 
 
M1 is the mass, in grams, of residue after igniting, and  
 
- M- is the mass, in grams, of the sample tested.  
 
 
 
 
 
 
 
 
 
 
 
 
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AFDC 05( 6093)P 3 
 Annex C  
(normative)  
 
Determination of pH  
 
C.1 Procedure  
Dissolve 1 g of sample in 125 ml of distilled water and measure the measure the pH of the solution using a 
calibrated pH meter.  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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AFDC 05( 6093)P 3 
  
Annex D  
(normative)  
Test for 5 -Benzyl–3,6–dioxo–2–piperazineacetic acid  
 
D.1 Apparatus  
D.1.1 Gas Chromatograph of a suitable type, equipped with a hydrogen flame ionization detector and 
designed  for handling glass columns with on -column injection (Micro -Tek 220 or equivalent), containing a 1.83 
m x 4 mm ( inside diameter) glass column packed with 3 percent OV -1 on 80/100 -mesh supelcoport. Condition 
the column overnight at 250 °C before readjustment and equilibration to the operating condition. To preclude 
build -up of silicon oxide, clean the detector with a cetone frequently.  
D.1.1.1 Operating conditions: The operating parameters may vary depending on the particular instrument  
used, but a suitable chromatogram may be obtained using the following conditions:  
 
a) Column temperature  200 °C  
b) Inlet t emperature  200 °C  
c) Detector temperature  275 °C  
 
- Carrier gas – Nitrogen, flowing at a rate of 75 ml per minute  
 
- Hydrogen and air flow to burner – optimised to give maximum sensitivity  
 
- Recorder – 1 mV full scale  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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D.2 Reagents  
D.2.1 Silation reagent: Just before use, dilute 3 parts, by volume, of N, O -bis-(trimethylsilyl) acetamide with 2  
parts of dimethylformamide.  
D.2.2 Standard preparation: Transfer about 25 mg of 5 -Benzyl -3, 6-dioxo -2-piperazineacetic acid Reference  
Standard, accurately weighed, into a 50 -ml volumetric flask, dissolve in methanol, dilute to volume with 
methanol, and mix. Pipet 10 ml of this solution into a second 100 -ml volumetric flask, dilute to volume with 
methanol, and mix. Pipet 3 ml of the seco nd solution into a 2 -dram vial, with Teflon -lined cap, and evaporate 
to dryness on a steam bath. Add 1 ml of the Silylation reagent to the residue, cap the vial tightly, shake and 
heat in an oven at 80 °C for 30 minutes. Remove the vial from the oven, shak e for 15 seconds, and cool to 
room temperature.  
D.2.3 Sample preparation: Transfer about 10 mg of the sample, accurately weighed, into a 2 -dram vial, with  
Teflon -lined cap, add 1 ml of the Silylation reagent, cap tightly, shake, and heat in an oven at 80 ° C for 30 
minutes. Remove the vial from the oven, shake for 15 seconds, and cool to room temperature.  
 
D.3 Procedure  
 
Inject a 3 µl portion of the standard preparation into the gas chromatograph and obtain the chromatogram. 
Measure the height of the peak pr oduced by the 5 -benzyl -3, 6-dioxo -2-piperazineacetic acid, and record it as 
P. Under the stated conditions, the elution time is about 7 -9 min. Similarly, inject a 3 µl portion of the sample  
preparation, obtain the chromatogram and measure the height of the  peak produced by any 5 -benzyl -3,6-
dioxo -2-piperazineacetic acid contained in the sample, and record it as p. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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AFDC 05( 6093)P 3 
 
D.4 Calculation  
The percentage of 5 -Benzyl –3, 6–dioxo –2–piperazineacetic  acid in the sample can be computed as  
3 x M x p   
500 x m x P 
where,  
 
M -is the mass, in milligrams, of the reference standard taken  
 
m is the mass in milligrams, of aspartame analysed  
 
p is the height of peak produced by 5 -benzyl -3, 6-dioxo -2-piperazineacetic acid contained in 
sample; and  
 
P height of peak produced by 5 -benzyl -3, 6-dioxo -2-piperazineacetic acid contained in standard.  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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AFDC 05( 6093)P 3 
  
Annex E  
(normative)  
 
Test for amine group  
 
E.1 Procedure  
 
Dissolve 2 g of ninhydrin in 75 ml of dimethyl sulfoxide, add 62 mg of hydrindantin, dilute to 100 ml with 4M 
lithium acetate buffer solution (pH 9), and filter. Transfer about 10 mg of the sample to a test tube, add 2 ml of 
the reagent solution , and heat. A dark purple colour is formed.  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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Annex F  
(normative)  
 
Test for ester group  
F.1 Reagents  
F.1.1 Methanol  
F.1.2 Methanol saturated with hydroxylamine hydrochloride  
F.1.3 5N potassium hydroxide  
F.1.4 Hydrochloric acid  
F.1.5 Ferric chloride  
F.2 Procedure  
Dissolve about 20 mg of sample in 1 ml of methanol, add 0.5 ml of methanol saturated with hydroxylamine 
hydrochloride, mix, and then add 0.3 ml of 5N potassium hydroxide in methanol. Heat the mixt ure to boiling, 
then cool, adjust the pH to between 1 and 1.5 with hydrochloric acid, and add 0.1 ml of ferric chloride. A 
burgundy/maroon colour is produced.  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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Bibliography  
 
[1] IS 13657: 1993 (Reaffirmed in 2003) , Aspartame, food grade — Specification  
 
[2] JECFA monograph, Aspartame  
 
[3] Food chemicals codex (5th Edition)  
 
[4] EFSA Journal (2013) – Scientific opinion on aspartame   
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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DRAFT TANZANIAN STANDARD