GCC STANDARDIZATION ORGANIZATION ( GSO )  
 
 
 
 
 
 
 
  
 
 
 
 
GSO5/  DS / 1201   : 2009  
 
 
 
 
 
 
 
 
Gluten free foods  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
ICS :  67.040   
 
 
المقدمة 
 
    هيئت الخقييس لذول هجلس الخعبوى لذول الخليج العشبيت هيئت إقليويت حضن في عضىيخهب الأجهزة  
للىطٌيت للوىاصفبث والوقبييس في دول الخليج العشبيت، وهي ههبم الهيئت إعذاد الوىاصفبث القيبسيت 
بىاسطت لجبى فٌيت هخخصصت. 
 
    وقذ قبهج هيئت الخقييس لذول هجلس الخعبوى لذول الخلي ج العشبيت ضوي بشًبهج عول اللجٌت الفٌيت    
سقن 5 ( اللجٌت الفٌيت لوىاصفبث قطبع الوٌخجبث الغزائيت والزساعيت ) بخحذيث "الأغزيت الخبليت هي 
الجلىحيي "  هي قبل دولت قطش وقذ حن إعذاد الوششوع بعذ اسخعشاض الوىاصفبث القيبسيت والعشبيت 
والأجٌبيت والذوليت والوؤلفبث الوشجعيت راث الصلت.  
 
وقذ اعخوذث هزٍ الوىاصفت كوىاصفت  قيبسيت خليجيت بلغخهب الأصليت دوى إدخبل أيت حعذيلاث فٌيت عليهب  
ورلك في اجخوبع هجلس إداسة الهيئت سقن (   )  ، الزي عقذ         بخبسيخ   /    /      هـ ، الوىافق   /    /    
م. 
 
 
 
FOREWORD  
 
    The Gulf Stan dardization Organization for GCC (GSO) is a regional 
organization which consists of the National Standards Bodies of  GCC 
member States. One of GSO main functions is to issue Gulf Standards / 
Technical regulation through specialized technical committees ( TCs ).  
 
GSO through the technical program of committee TC NO.5 "Gulf technical 
committee for standards of food and agriculture products " has updated                
"  Gluten free foods " the draft standard has been prepared by the state of 
Qatar. The draf t standard has been prepared based on relevant ADMO, 
International and national foreign standards and references.  
 
This standard has been approved as Gulf standard without any technical 
modifications by GSO Board of Direction in its meeting  No…/…. ……held 
on   /  /   /  H,  /  /  GGSO  STANDARD  GSO 1021/2000  
 
1 Gluten free foods  
 
1      Scope :  
The standard is concerned with the foods for special dietary uses that have been 
formulated,  processed or prepared to meet the special dietary needs of people 
intolerant to gluten. Foods for ge neral consumption which by their nature are 
suitable for use by people with gluten intolerance.  
 
2         Complementary references :  
2.1 GSO 9 “ Labelling of Prepackaged Foods  ”. 
2.2 GSO 21 “ Hygienic Regulations for Food Plants and Their Personnel  ”. 
2.3 GSO 150 " Expiration periods of food products ".  
2.4      GSO 382 „Maximum Limits for Pesticide Residues in Agricultural Food   
          Products – Part 1”.  
2.5 GSO 383 “ Maximum Limits for Pesticide Residues in Agricultural Food  
          Products – Part 2 ”. 
2.6 GSO 654 “ General Requirements for Foods for Special Dietary Uses  ”. 
2.7 GSO 841 “  Maximum Limits of Mycotoxins permitted in Foods  and    
          animal seeds – Aflatoxins ".  
Draft GSO  Standard to be approved by the organization on:  
2.8 “ Methods of Determination of Mycotoxins in foods  ”. 
2.9 “ Method for Determination of Pesticide Residues in Agricultural Food  
            Products  ”. 
2.10 “ Microbiological Criteria for Foodstuffs Part 2  ”. 
 
3       Definitions : - 
3.1 Gluten  
For the purpose  of this standard, "gluten" is defined as a protein fraction from 
wheat, rye,  barley, oats   or their crossbred varieties and derivatives thereof, to 
which some persons are  intolerant and that is insoluble in water and 0.5M NaCl.  
 
 
 
 GSO  STANDARD  GSO 1021/2000  
 
2 3.2     Prolamins  
Prola mins are defined as the fraction from gluten that can be extracted by 40 - 
70% of ethanol.  The prolamin from wheat is gliadin, from rye is secalin, from 
barley hordein and from oats   avenin.  It is however an established custom to 
speak of gluten sensitivit y. The prolamin content of  gluten is generally taken as 
50%.  
 
3.3 Gluten -free foods  
            
Gluten -free foods are dietary foods  :  
 
3.3.1  consisting of or made only from one or more ingredients which do not 
contain wheat (i.e., all  Triticum species, s uch as durum wheat, spelt, and 
kamut), rye, barley, oats   or their crossbred  varieties, and the gluten level does 
not exceed 20 mg/kg in total, based on the food as sold or  distributed to the 
consumer, and/or  
 
3.3.2  consisting of one or more ingredients f rom wheat (i.e., all Triticum 
species, such as  durum wheat, spelt, and kamut), rye, barley, oats1 or their 
crossbred varieties, which have  been specially processed to remove gluten, and 
the gluten level does not exceed 20 mg/kg  in total, based on the food as sold or 
distributed to the consumer.  
 
3.4  Foods specially processed to reduce gluten content to a level above 20 up to  
100 mg/kg  These foods consist of one or more ingredients from wheat (i.e., all 
Triticum species, such as  durum wheat, spelt, and kamu t), rye, barley, oats1 or 
their crossbred varieties, which have been  specially processed to reduce the 
gluten content to a level above 20 up to 100 mg/kg in total,  based on the food as 
sold or distributed to the consumer.  Decisions on the marketing of prod ucts 
described in this section may be determined at the  national level.  
 
 
4 Requirements : -  
The following requirements shall be met in gluten - free foods:  
 
4.1 The general requirements mentioned in GSO  standard item ( 2.6 ) shall be  
          met. 
4.2 All ingredients used in the production shall conform to relevant GSO   
         standards.  GSO  STANDARD  GSO 1021/2000  
 
3 4.3 The product shall be manufactured and packed according to the hygienic 
requirements given the GSO  standard mentioned in item  ( 2.2 ). 
4.4 The products  shall be prepared with special care under Good    
           Manufacturing Practice (GMP) to avoid contamination with  gluten.  
 
4.5 Products covered by this standard substituting important basic foods,  
          should supply  approximately the same amount of vitami ns and minerals  
          as the original foods they replace.  
 
 
4.6 The gluten content shall not exceed 20 mg/kg in the food as sold or  
          distributed to the consumer  as limits given in GSO standard mentioned in 
item ( 3.3 ) . 
 
4.7     The gluten c ontent shall not exceed 100 mg/kg in the food as sold or  
          distributed to the consumer  as limits given in GSO standard mentioned in 
item ( 3.4 ) . 
4.8    The mycotoxins limits shall not exceed those limits given in GSO  standard 
mentioned in item ( 2.7 ). 
4.9 The pesticides residues shall not exceed those limits given in GSO  
standards mentioned in items  ( 2.4 ) and ( 2.5 ). 
4.10 The microbiological limits shall be according to those given in GSO  
standard mentioned in item ( 2.10 ). 
 
5 Samplings : -  
 Samples shall be drawn in accordance with relevant GSO  standard for the 
product to be tested.  
 
6 Methods of testing and examinations : - 
6.1 Method of testing  
6.1.1  Determination of mycotoxins shall be carried out according to GSO  
standard mentioned in it em ( 2.8 ) . 
6.1.2  Determination of pesticide residues shall be carried out according to GSO  
standard mentioned in item ( 2.9 ). 
6.1.3  Determination of gluten  
6.1.3.1 Principle  
 The determination of gluten is based on an immunology and chemical  
          methods:  GSO  STANDARD  GSO 1021/2000  
 
4 6.1.3.2   The extraction of proteins  
6.1.3.2.1  Pretreatment of solid foodstuffs and ingredients  
6.1.3.2.1.1  Products with a fat -content higher than 10%.: Five grams of the 
product are homogenized with a blender in 50 ml hexane. The suspensions 
centrifuged for 30 min at 1500 x g; the supernatant discarded and the extraction 
step is repeated until the sample is fat -free. The pellet is dried at 60oC, weighed, 
milled and an aliquot is used for analysis.  
6.1.3.2.1.2  In products with a fat -content lower t han 10% an extraction is 
generally not necessary.  
Five grams of the product are dried at 60oC milled and an aliquot is used for 
analysis.  
 
6.1.3.2.2  Extraction  
6.1.3.2.2.1  Solid food stuffs and ingredients   
An aliquot of the dried sample is homogenized wit h 60% aqueous ethanol in a 
volume 10 time its weight; homogenized for 2 minutes and after 15 minutes. 
Centrifuged for 10 min at 1500 x 9. The supernatant is taken off and stead if 
necessary at 4oC before determination. When precipitate is formed this is sp un 
down and discarded.  
6.1.3.2.2.2  Liquid foodstuffs and ingredients  
An aliquot of a liquid product is diluted with ethanol; the added volume of 
ethanol being calculate to yield 60% ethanol in the resulting mixture. The 
mixture is homogenized and further t reated like solid food extracts.  
 
6.1.3.3  Determination of gliadin  
6.1.3.3.1  Plate preparation  
Microtiter plates are coated overnight with an antibody against glidain in an 
appropriate dilution (e.g. 1 in 600) in a sodium carbonate buffer. The plate is 
washed three items with phosphate -buffered saline with 0.05% Tween (PBS -T) 
and once more with deionized water containing 0.03% Na -azide. Plates can be 
stored at 4oC in a sealed plastic bag.  
6.1.3.3.2  Standard  
It is necessary to use a gliadin standard in order  to minimize inter assay 
variation. Apart from the a „golden standard” should be used to make 
comparison of the results from different laboratories with different ELISA -GSO  STANDARD  GSO 1021/2000  
 
5 techniques and with different antisera possible. The “golden standard” should 
be prepar ed by one laboratory under strictly standardized conditions.  
 
6.1.3.3.3  Determination  
After appropriate dilution of the extract the samples and the necessary standard 
dilutions to obtain a standard curve are brought into the wells of the plate. After 
incub ation for 2 hours, the plates are washed three times with cold PBS -T .To 
the wells the monoclonal or polyclonal antibody against gliadin conjugated with 
an enzyme is added and after incubation for 2 hours the plates are emptied and 
washed three times with PBS-T. Then a substrate for the enzyme is added. After 
an appropriate time the reaction is stopped. The absorptions measured directly 
in the micrometer plates.  
The gliadin concentrations is determined from the standard curve obtained. The 
result is multipl ied by 2 to obtain the gluten content and expressed in ppm of 
the original product.  
 
6.1.3.4  Remarks  
6.1.3.4.1  The method determines the amount of prolamin in a product. It is 
however important to stress that the total daily intake of prolamin for coeliac 
patients should not exceed 10 mg per day.  
6.1.3.4.2  The method is sensitive for native prolamins. The sensitivity for 
heated products is depending on the temperature and time of heating lower. It 
may be reduced to 10% of the original sensitivity. The reduc tion in sensitivity is 
related to the amount of w -gliadin in the sample and the sensitivity of the 
antibody  for the different subfractions in the gliadin.  
6.1.3.4.3  Depending on the specificity of the antibody, the method 
determines also the prolamins fro m rye, barley and oats as gliadin equivalents. 
The response in the assay however can be different from that for gliadin and 
must in that case be determined separately with an appropriate standard.  
6.1.3.4.4  If the method gives a positive result and there i s some doubt about 
the specificity, a blot after electrophoretic separation of the sample can be 
performed.  
6.1.3.4.5  Products from partial hydrolysis of prolamins can, depending on 
the degree of hydrolysis, not always been determined by the method describ ed. 
6.1.3.4.6  Polyphenols such as those from tea, hops or cocoa decrease the  
yield of the extraction of prolamins by binding to the latter. Addition of casein 
as a competing protein as well as urea is necessary in that case.  GSO  STANDARD  GSO 1021/2000  
 
6 6.1.3.4.7  The detection limit of the method should be at least 10 ppm in the 
product on a dry matter basis.  
 
6.2 Tests  : - 
Exams  shall be carried out in the  representative samples drawn according to 
item (5) to determine its compliance with limits of this standard.  
 
7 Packaging , tran sportation and storage : -  
7.1 Packaging  : -  
 The product shall be packed in hygienic clean suitable container so as to 
avoid any changes in its properties during storage.  
7.2 Transportation  : -  
 Transportation shall be carried out in such away so as to  protected 
containers from mechanical damage and contamination.  
7.3 Storage  : - 
 The product shall be stored in a well ventilated place away from the 
source of direct heat, moisture and contamination.  
  
8  Labelling : -  
Without prejudice to what is given in GSO  standards mentioned in 2.1 and 2.5 
the following information shall be declared on the label of the containers:  
8.1 The term “gluten - free” shall be given in the immediate proximity of the 
name of the product.  
8.2     The labe lling of products described in item (  3.4  )should be determined 
at the national level. However these products must not be called gluten -
free. The labelling terms for such products should indicate the true nature 
of the food, and shall be printed in the im mediate proximity of the name 
of the product.  
8.3     A food which, by its nature, is suitable for use as part of a gluten -free 
diet, shall not be  designated “special dietary”, “special dietetic”  or any 
other equivalent term. However, such a  food may bear a statement on the 
label that “this food is by its nature gluten -free” provided that  it complies 
with the essential composition provis ions for gluten -free as set out in item 
( 4.3 )  and provided that such a statement does not mislead the consumer. 
More det ailed rules in order to  ensure that the consumer is not misled 
may be determined at the national level.  GSO  STANDARD  GSO 1021/2000  
 
7  
Main references  
118
 2008
Codex standard  
 
No. 118 - 2008  
 
Foods for spe cial dietary use  
persons intolerant to gluten