DRAFT UGANDA STANDARD  
       DUS 1926  
First Edition  
2018 -mm-dd 
  
 
 Reference number  
DUS  1926: 2018 
© UNBS 2018   
  
Aspartame  (food grade)  — Specification  
 
  
 DUS  1926 : 2018  
ii © UNBS 2018  – All rights reserved  
 Compliance with this standard does not, of itself confer immunity from legal obligations  
A Uganda Standard does not purport to include all necessary provisions of a contract. Users are 
responsible for its correct application  
© UNBS 2018  
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permission from UNBS.  
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The Executive Director  
Uganda National Bureau of Standards  
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Kampala  
Uganda  
Tel: +256 41 7 333 250/1/2  
Fax: +256 414 286 123  
E-mail: info@unbs.go.ug  
Web: www.unbs.go.ug  DUS 1926: 2018  
© UNBS 2018  – All rights reserved  iii 
 Contents  Page 
Foreword  ................................ ................................ ................................ ................................ ...................  iv 
Introduction  ................................ ................................ ................................ ................................ ................  v 
1 Scope  ................................ ................................ ................................ ................................ .............  1 
2 Normative references  ................................ ................................ ................................ ...................  1 
3 Terms and definitions  ................................ ................................ ................................ ..................  1 
4 Requirements  ................................ ................................ ................................ ................................  1 
4.1 General requirements  ................................ ................................ ................................ ..................  1 
4.2 Specific requirements  ................................ ................................ ................................ ..................  1 
5 Contaminants  ................................ ................................ ................................ ................................  2 
6 Packaging  ................................ ................................ ................................ ................................ ...... 2 
7 Weights and Meas ures ................................ ................................ ................................ .................  2 
8 Labelling  ................................ ................................ ................................ ................................ ........  2 
9 Sampling  ................................ ................................ ................................ ................................ ....... 3 
Annex  A  (normative)   Assay: Test for purity  ................................ ................................ ........................  4 
Annex  B  (normative)   Determination of sulphated ash  ................................ ................................ ....... 5 
Annex  C (normative)  Determination of pH  ................................ ................................ .............................  6 
Annex  D (normative)  Test for 5 -Benzyl–3,6–dioxo–2–piperazineacetic acid  ................................ ..... 7 
Annex  E (normative)  Test for amine group  ................................ ................................ ............................  9 
Annex  F (normative)  Test for ester group  ................................ ................................ ............................  10 
Bibliography  ................................ ................................ ................................ ................................ .............  11 
 DUS  1926 : 2018  
iv © UNBS 2018  – All rights reserved  
 Foreword  
Uganda National Bureau of Standards (UNBS) is a parastatal under the Ministry of Trade , Industry and 
Cooperatives established under Cap 327 , of the Laws of Uganda , as amended .  UNBS is mandated to co -
ordinate the elaboration of standards and is  
(a) a member of International Organisation for Standardisation (ISO) and  
(b) a contact point for the WHO/FAO Codex Alimentarius Commission on Food Standards, and  
(c) the National Enquiry Point o n TBT  Agreement  of the World Trade Organisation (WTO).  
The work of preparing Uganda Standards is carried out through Technical Committees. A Technical Committee 
is established to deliberate on standards in a given field or area and consists of key stakehol ders including 
government, academia, consumer groups, private sector and other interested parties.  
Draft Uganda Standards adopted by the Technical Committee are widely circulated to stakeholders and the 
general public for comments. The committee reviews t he comments before recommending the draft standards 
for approval and declaration as Uganda Standards by the National Standards Council.  
The committee responsible for this document is UNBS/TC 2 [ Food and Agriculture standards ], Subcommittee 
SC 6, [ Food Addi tives and contaminants ]. DUS 1926: 2018  
© UNBS 2018  – All rights reserved  v 
 Introduction  
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 diabetics.  
Aspartame is made of  two naturally occurring amino acids, phenyl alanine 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 intestine s. It is fully broken down to aspartic acid and phenylalani ne, 
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 a bsorbed  and most of it used to produce energy.  
The use of aspartame as a sugar replacer remains a controversial topic with some scientific studies validating 
its safety while others suggest it could have effects on the consumer.  
In the Codex Alimentarius Commission International Numbering System, aspartame is assigned as INS 951 
and the  FAO/WHO Joint Experts Committee on Food Additives (JECFA) established the Acceptable Daily Intake 
(ADI) for aspartame at 0 – 40 mg/kg body weight . 
This standard has been developed to ensure that that the usage of aspartame in food products conforms to 
acceptable limits . 
 
 
 
 
 
 
 
 
 
  
 DRAFT UGANDA STANDARD  DUS  1926: 2018  
 
© UNBS 2018  – All rights  reserved  1 
 Aspartame  (food grade) — Specification  
1 Scope  
This Draft Uganda S tandard 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 refere nces, only the edition cited applies. For undated 
references, the latest edition of the referenced document (including any amendments) applies.  
AOAC 999 .11, Determination of Lead, Cadmium, Copper, Iron, and Zinc in Foods, Atomic Absorption 
Spectrophotometr y after Dry Ashing  
US 277, General standard for the labelling of food additives when sold as such  
US CAC/GL 50 , General guidelines on sampling  
FDUS ISO 760, Determination of water — Karl Fischer Method (General method)  
3 Terms and definitions  
For the purpo ses of this document, the following terms and definitions apply.   
ISO and IEC maintain terminological databases for use in standardization at the following address:  
— ISO Online browsing platform: available at http://www.iso.org/obp   
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  
Food grade aspartame  shall be : 
 a white , odourless,  crystal line powder with a strong sweet aroma ; and 
 slightly soluble in water and ethanol/methanol;  
A saturated aqueous solution of the product shall be acidic . 
4.2 Specific requirements  
Food grade aspartame  shall com ply with the specific  requirements given in Table 1  when tested in accordance 
with the test methods  specified therein . 
  DUS  1926: 2018  
2 © UNBS 2018  – All rights reserved  
 Table 1 — Specific r equirements for food grade aspartame  
S/N Characteristic  Requirement  Test method  
i) Purity as C14H18N2O5, % m/m  (dry basis)  98.0 – 102.0   Annex A 
ii) Moisture %m/m, max.  4.3 FDUS 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, 
(diketopiperazine), %m/m, max.  1.5  Annex D 
vi) Test for amine  group  To pass test  Annex E  
Vii) Test for ester group  To pass test  Annex F  
 
5 Contaminants  
Food grade aspartame  shall comply with the Maximum Levels of  contaminants  given in Table 2 when tested in 
accordance with the test methods specified therein.   
Table 2  — Maximum Limits for conta minants in food grade aspartame   
S/N Contaminant  Maximum level  Test method  
i) Heavy metals (as Pb), mg/kg, m ax.  1 AOAC 9 99.11 
ii) Arsenic (as As), mg/kg, max.  3 AOAC 952.13  
 
6 Packaging  
The product shall be securely packaged in containers made of food grade material s conforming to US 1659. 
The packages shall preserve the quality of the product, prevent entry of light and preclude contamination  from 
the external environment.  
7 Weights and Measures  
The weight of the product when package d shall comply with the  Weights and Measures Regulations . 
8 Labelling  
In addition to the requirements of US 277 , 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 manufacturer/distributor;  
iii) Net weight in metric units;  
iv) Batch/lot number;  
v) Directions for storage;  
vi) Date of manufacture; and the  
vii) Expiry date.  DUS  1926: 2018  
© UNBS 2018  – All rights reserved  3 
 9 Sampling  
Representative samples of the product shall be drawn in accordance with US CAC/GL 50.  DUS  1926: 2018  
4 © UNBS 2018  – All rights reserved  
 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 C 14H18N2O5. 
Caution: Protect the solution from absor ption  of carbon dioxide and moisture by covering the titration vessel with aluminium 
foil while dissolving the sample  and during the titration.  
 
 
 
 
 
 
 
 
 
 
 
  DUS  1926: 2018  
© UNBS 2018  – All rights reserved  5 
 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 th e entire sample. Heat gently, until the sample is 
dry and thoroughly charred, then 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 i n the same manner 
until the remainder of the sample and any excess sulphuric acid 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 = 
0X101
MM  
where  
M1 is the mass, in grams, of residue after igniting, and  
M is the mass, in grams, of the sample tested.  
 
 
 DUS  1926: 2018  
6 © UNBS 2018  – All rights reserved  
 Annex  C 
(normative)  
 
Determination of pH   
C.1 Procedure  
Dissolve 1  g of sample in  125 ml of distilled water and measure the mea sure the pH of the solution using a 
calibrated pH meter.  DUS  1926: 2018  
© UNBS 2018  – All rights reserved  7 
 Annex  D 
(normative)  
 
Test fo r 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  colum ns 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 readjus tment and equilibration to  the operating condition. To preclude build -up of  
silicon  oxide, clean the detector with acetone frequently.  
D.1.1.1 Operating conditions : The operating param eters may vary depending on the particular instrument 
used, but a suitable chromatogram  may be obtained using the following conditions:  
a) Column tem perature   200 °C  
b) Inlet temperature    200 °C  
c) Detector tem perature   275 °C 
d) Carrier gas – Nitrogen, flowing at a rate of 75 ml per minute  
e) Hydrogen and air flow to burner – optimised  to give maximum sensitivity  
f) Recorder – 1 mV  full scale  
D.2 Reagents  
D.2.1 Silation reagent : Just before use, dilute 3 parts, by volu me, of N, O -bis-(trimethylsilyl) acetamide with 2 
parts of dimethylformamide.    
D.2.2 S tandard preparation: Transfer about 25 mg of 5 -Benzyl -3, 6-dioxo -2-piperazineacetic acid Refere nce 
Standard , accurately  weighed, into a 50 -ml volumetric flask, dissolve in methanol, dilu te 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  second solution into a 2 -dram vial, with Teflon -lined cap, and evaporate to  
dryness on a ste am 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 min utes. Remove the  vial from the oven, shake for 15 sec onds , and cool to room 
temperature.  
D.2.3  Sample preparation: Trans fer 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 sec onds , 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 produced by the 5 -benzyl -3, 6-dioxo -2-piperazineacetic acid, and record it as 
P. Under the s tated conditions, the elution time is about  7-9 min. Similarly, inject a 3 µl portion of  the s ample 
prepa ration, 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. 
 DUS  1926: 2018  
8 © UNBS 2018  – All rights reserved  
 D.4 Calculation  
The percentage of 5 -Benzyl –3, 6–dioxo –2–piperazineacetic acid in the sample can be computed as  
PmpM
 x  x 500 x  x 3
   
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.  DUS  1926: 2018  
© UNBS 2018  – All rights reserved  9 
 Annex  E 
(normativ e) 
 
Test for amine  group  
E.1 Procedure  
Dissolve 2 g of ninhydrin in 75 ml of dimethylsulfoxide, 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.   
 
 DUS  1926: 2018  
10 © UNBS 2018  – All rights reserved  
 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 5 N potassium hydroxide in methanol. Heat the mixture 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.  
 
 
 DUS  1926: 2018  
© UNBS 2018  – All rights reserved  11 
 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 a spartame  
 DUS  1926 : 2018  
© UNBS 2018  – All rights  reserved  13 
 Certification marking  
Products that conform to Uganda  standards may be marked with Uganda National Bureau of Standards (UNBS) 
Certification Mark shown in the figure below.  
The use of the UNBS Certification Mark is governed by the Standards Act, and the Regulations made 
thereunder. This mark can be used only  by those licensed under the certification mark scheme operated by the 
Uganda National Bureau of Standards and in conjunction with the relevant Uganda Standard. The presence of 
this mark on a product or in relation to a product is an assurance that the goo ds comply with the requirements 
of that standard under a system of supervision, control and testing in accordance with the certification mark 
scheme of the Uganda National Bureau of Standards. UNBS marked products are continually checked by UNBS 
for confor mity to that standard.  
Further particulars of the terms and conditions of licensing may be obtained from the Director, Uganda National 
Bureau of Standards.  
 
 
DUS  1926: 2018    
 
ICS 67.220.20  
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