DRAFT ZANZIBAR NATIONAL STANDARD  
 
 
Food grade monosodium L - glutamate — specification  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
ZANZIBAR BUREAU OF STANDARDS  
 
 
©ZBS 2023 - All rights reserved           First Edition  
 
 
 
 
WGD 6: 2021  
PCD 51 3:2023  
ICS 67. 220.20  PCD 513:2023  
 
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 Foreword  
 
The Zanzibar Bureau of Standards (ZBS) was established under Standard Act No. 1 of 2011.  
 
In the preparation of this Standard, the reference was derived from:  
 
Residue Monograph prepared by the meeting of the Joint FAO/WHO Expert Committee on Food 
Additives (JECFA), 31st Meeting 1987  monosodium L-glutamate Published by FAO/WHO 2021  
 
IS 9501 : 2007  Reaffirmed 2021, monosodium l -glutamate, food grade — specification , published by 
Bureau of Indian Standards  
 
Acknowledgement is hereby made for the assistance derived from these sources.  
 
In reporting the results of a test or analysis made in accordance with Zanzibar National Standard, if the 
final value, observed or calculated is to be rounded off, it  shall be done in accordance with ZNS 94.  
 
Technical Committee Representatives  
 
This Zanzibar National Standard was prepared by Food Technical Standard Committee which consists 
of representatives from the following organizations:  
 
Chief Government Chemist Laboratory Agency (CGCLA)  
Ministry of Health Zanzibar  
Said Salim Bakhresa & Company LTD  
The State University of Zanzibar (SUZA)  
Umoja wa Wazalishaji Wadogo Wadogo Zanzibar (UWAZI)  
Ministry of Agriculture, Irrigation, Natural Resources and Livestock (MANRL)  
Zanzibar Food and Drug Agency (ZFDA)  
Zanzibar Livestock Research Institutes (ZALIRI)  
Zanzibar National Chamber of Commerce (ZNCC)  
Zanzibar Bureau of Standards (ZBS) - Secretariat  
 
 
 
 
 
Zanzibar Bureau of Standards (ZBS)  
PO Box 1136  
Zanzibar  
Tel:  +255 24 2232225  
Fax: +255 24 2232225  
E-mail: info@zbs.go.tz  
Web: www.zbs.go.tz  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 PCD 513:2023  
 
©ZBS 2023 - All rights reserved  
 iii 
 Introduction  
 
 
With the increased production of processed foods, manufacturers have started adding a large number 
of substances, generalIy in small quantities, to improve the appearance, flavour, texture or storage 
properties of the processed foods. As impurities in these substances have been found to be harmful,  it 
is necessary to have a strict quality control of these food additives. This standard would help in checking 
purity which requires to be checked at the stage of manufacture, for it is extremely dif ficult (and in many 
cases impossible) to detect the impu rity once these substances are added to the processed foods.  
 
Chemical names are monosodium L -glutamate monohydrate, sodium glutamate, Monosodium 
glutamate ( MSG ), INS No. 621 . Its empirical formula is C5H8O4NNa.H2O .  
 
Its molecular weight is 187.13 and structural formula is:   
PCD 513:2023  
 
©ZBS 2023 - All rights reserved  
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 Food grade monosodium L - glutamate — specification  
 
1 Scope 
 
This draft Zanzibar national standard specifies requirements, method of sampling and test for food grade 
monosodium L - glutamate.  
 
2 Normative references 
 
The following referenced documents are indispensable for the application of this working draft Zanzibar 
National Standard. For dated references, only the edition cited applies. For undated references, the 
latest edition of the referenced document (including any amendments) applies.  
AOAC 925.55 , Loss on drying (moisture) in salt  
 
AOAC 2013.06 , Arsenic, Cadmium, Mercury, and Lead in Foods  
 
CODEX STAN 193, Codex general standard for contaminants and toxins in food and feed  
 
EAS 39, Hygiene in the food and drink manufacturing industry — Code of practice  
 
ZNS 61 , Packaging and labelling  of food  
 
ZNS 94, Rounding off numerical values  
 
 
3 Terms  and definitio ns 
 
For the purposes of this standard, the following terms and definitions shall apply. 
 
3.1  
food grade  packaging  material 
any material, made of substances that 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 Requir ements 
 
4.1 General  requirements 
 
Monosodium L -glutamate shall be  
 
a) in the form of white, practically odourless crystals or crystalline powder.  
b) have either a slightly sweet or a slightly salty taste.  
c) freely soluble in water, sparingly soluble in ethanol and practically insoluble in ether  
 
4.2 Specific requirements  
 
monosodium L - glutamate shall conform to the chemical requirements in Table 1 when  tested in 
accordance  with the methods prescribed therein. 
 
 
Table 1 — Specific requiremen ts for monosodium L - glutamate  
 
SN Characteristic Requirement Test method 
i.  Purity as C 5H8O4NNa.H2O % by mass, min  99 Annex A  
ii.  Loss on drying, % by mass, at 98oC for 5h, max , 0.5  AOAC 925.55  
iii.  Chloride, % by mass, max  0.2 Annex B  PCD 513:2023  
 
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4.3 Specific Rotation shall be [alpha] 20, D: between+ 24.8 and+ 25.3° [ 10 percent  (w/v) solution 
in 2N hydrochloric acid].  
 
4.4 pH of 1 in 20 solutions of the material shall be between 6.7 and 7.2.  
 
5 Contaminants  
 
5.1 Pesticide residues  
 
monosodium L - glutamate shall conform to those maximum residue limits established by the Codex 
Committee on Pesticide Re sidues for this commodity. 
 
5.2 Metal contaminants  
 
S/N Heavy Metal  Limit  (mg/kg)  Test Method  
i.  Arsenic  (As) 2 
AOAC 2013.06  
ii.  Lead  (Pb) 1 
 
 
6 Hygiene 
 
6.1 Monosodium L - glutamate shall be prepared under hygienic conditions in accordance with EAS 
39. 
 
 
7 Weights and measures  
Monosodium L - glutamate shall be packed in accordance with the weights and measures regulations of 
Zanzibar.  
 
8 Packaging and Labelling  
 
8.1 Packaging  
 
Monosodium L - glutamate shall be packaged in food grade material that secures the integrity and the 
safety of the product.  
 
8.2 Labelling   
 
8.2.1  In addition to the labelling requirements specified in ZNS 61, the containers shall be also  
legibly and indelibly labelled with the following: - 
 
a) name of the product as ‘ monosodium L - glutam ate, Sodium glutamate or glutamic acid 
monosodium salt ; 
b) brand name/trade name if any;  
c) name and address of producer/packer/distributor;  
d) storage condition and transportation;  
e) date of manufacturing;  
f) best before date;  
g) lot identification or batch or code numb er; 
h) country of origin;  PCD 513:2023  
 
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 i) net weight in metric unit; and  
j) instruction for disposal of used packaged material.  
8.2.2  The language on the label shall be ‘Kiswahili’ and/or English. Additional language may be 
used depending on the designated market.  
 
9 Sampling  
 
Sampling of shall be done according  to Annex C . 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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Annex A  
(normative)  
Determination  of Purity  
 
 
Dissolve about 200 mg of sample, previously dried  and accurately weighed, in 6 ml of formic acid and 
add 100ml of glacial acetic acid.  Titrate with 0.1 N perchloric  acid determining the end point 
potentiometrically. Run  a blank determination in the same manner and correct for the blank.  Each ml of 
0.1 N perchloric acid is equivalent  to 9.356 mg of C5H8O4NNaH 2O 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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 Annex B 
(normative)  
Determination of Chloride  
 
Unless otherwise specified, place 0.07 g of the  sample in a Nessler tube, dissolve it in about 30 ml of  
water, and neutralize with dilute nitric acid if  the solution  is alkaline. Add 6 ml of dilute nitric acid TS and 
dilute to  50 ml with water. Transfer 0.4 ml of 0.01 N hydrochloric  acid into another Nessler tube to serve 
as the standard,  add 6 ml of dilute nitric acid TS, and dilute to 50 ml with  water.  
 
If the solution containing the sample is not clear, filter both solutions under the same conditions. Add 1 
ml of silver nitrate TS to each solution, mix thoroughly, and allow to stand for 5 min protected from direct 
sunlight. Compare the turbidity of the t wo solutions by observing th e Nessler tubes from tie sides and 
the tops against a black background. The turbidity of the sample solution does not exceed that of the 
standard.  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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 Annex C 
(normative)  
Method of sampling  
 
 
C.1 General Requirements of Sampling  
 
C.1.1  In drawing, preparing, storing and handling test samples , the precautions and directions as 
given below shall be observed.  
 
C.1.2  The samples shall be taken  in a protected place not exposed to damp a ir, dust or soot.  
 
C.1.3  The sampling instrument  shall be clean and dry.  
 
C.1.4  Precaution, shall be taken to  protect the  sample, the material being sampled . the sampling  
instrument and the containers for samples from adventitious contamination  
 
C.1.5  To draw a representati ve sample , the content  of each container selected for sampling shall be 
mixed as thoroughly as possible by suitable means  
 
C.1.6  The sample shall be placed in dean, dry, air  tight glass containers or other suitable containers 
on which the material has no action.  
 
C.1.7  The sample containers shall be of such a size  that they are almost completely filled by the 
sample.  
 
C.1.8  Each sample container shall be sealed air -tight with a stopper after filling, and marked with f ull 
details of  sampling, date of  sampling, batch and code  number.  
 
C.1.9  The samples shall be stored in such a manner  that the temperature of the material does not 
vary unduly from the normal atmospheric temperature.  
 
C.1.10  The sampling shall be done by a person agreed  to between the purchaser and the supplier 
and in a  presence of the purchaser (or his representative ) and the supplier (or his representative)  
 
C.2 Scale of sampling  
 
C.2.1  Lot 
 
All the containers  of the same material produced  under the same conditions of manufacture shall be  
grouped together to constitute a lot.  
 
The sample shall be tested  from each lot for ascertaining  the conformity of the material to the 
requirements of the specification.  
 
C.2.2  The number of containers to be selected from  the lot shall depend on the size of the lot and 
shall be in accordance with Table C.1. 
 
Table C.1: Number of Containers to be Selected  for Samplin g 
 
Lot Size  No of containers to be selected  
2-15 2 
16-50 3 
51-150 5 
151 and above  9 
Note These containers shall be selected at random from the lot  
 
 
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 C.3 Test samples and referee sample  
 
Draw with an appropriate sampling instrument, small  quantities  of the material from different parts of  
each conta iner s elected according to col 2 of Table  C.1. Mix all the portion, so drawn, thoroughly to form  
a composite sample  weighing not less than 30 g.  Divide the composite sample into three equal parts  to 
form test samp le. Each part thus obtained shall  constitute the test sample weighing not less than 10g 
and shall be sufficient to conduct all the tests, The  test samples shall he transferred  immediately to  
thoroughly clean  and dry containers which shall be  sealed air -tight. These shall be labelled with the  
particulars given in C.1.8 . One sample shall be for the purchaser. the second for the supplier and the  
third sample bearing the seals of the purchaser and  the supplier shall constitute the referee sample to 
be used in case of dispute between the purchaser and  the supplier and shall be kept a place  agreed to  
between the purchaser and the supplier  
 
C.4 Criterion for Conformity  
 
C.4.1  The test for the various characte ristics shall  be performed  on the composite samples and shall  
meet the corresponding requirements specified in th is standard  
 
C.4.2  In case any of the samples selected as per  Table C.1 fail in any of the tests, two more  samples 
shall be selected  from the unopened containers  from the sample  lot for retest,  if these two samples  
satisfy the r equirements of the specification, the lot  shall he deemed to compl y with the requirements  
specified in the standard.  If either of the two samples fail in the retests, the  lot shall be deemed a s not 
conforming to the  requirements specified in th is standard