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       DRAFT  TANZANIA STANDARD  
 
                  Edible Flaxseed (Linseed) oil – Specification  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
                   TANZANIA BUREAU OF STANDARDS  
 
    ©TBS 2022  – All rights reserved  
                                                                                                              
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 Edible Flaxseed (Linseed) oil – Specificatio n  
 
0 Foreword  
 
Edible  Flaxseed (Linseed) oil  comes from  flaxseed ( Linum usitatissimum ). Flaxseed oil contains both 
omega -3 and omega -6 fatty acids, which are essential to human health . It is one of traded edible 
vegetable oil in Tanzania . 
 
This Tanzani a Standard  has been prepared to ensure the safety and quality of edible Flaxseed 
(Linseed) oil produced domestically , exported  or imported into the country.  
 
In preparation of this  Tanzania  standard considerable help was derived from : 
 
CODEX STAN 210 -1999 (Revised  2019 ), Codex standard for named vegetable oil s published by the 
Codex Alimentarius Commission . 
 
In reporting the results of a test or analysis made in accordance with this Tanzania Standard, if the 
final value  observed or calculated is to be rou nded off, it shall be done in accordance with TZS 4.  
 
1 Scope  
 
This Tanzania s tandard specifies  the requiremen ts, sampling  and testing methods  for flaxseed 
(Linseed)  oil derived from the seeds of various cultivated species of Linum usitatissimum  intended  for 
human consumption . 
 
2 Normative r eference s 
 
The following referenced documents are indispensable for the application of this document. For dated 
references, only the edition cited applies. For undated references, the latest edition of the referenced 
document (including any amendments) applies ; 
 
Codex s tan 192, General standards for food additives               
TZS 4 ,  Rounding off numerical values  
TZS 54 , Animal and Vegetable fats and oils – Sampling  
TZS 76 ,  Methods for determination of arsenic  
TZS 109, Food processing units – Code of hygiene — General  
TZS 268 , General atomic absorption – Spectro – Photometric method for determination of lead in 
food stuffs  
TZS 538  , Packaging and labeling of foods  
TZS 799 , Foodstuffs – Determination of aflatoxin B 1, and the total content of aflatoxins B 1, B2, G1 and 
G2 in cereals, nuts and derived products – Highperformance liquid chromatographic method  
TZS 1313 , Fortified edible oils and fats — Specification  
TZS 1322,  Oils and fats Sampling and test methods – Purity test  
 
TZS 1324 , Animal and vegetable fats and oils – Determination of peroxide value -Iodometric (visual) 
end point determination  
TZS 1325 ,  Animal and vegetable fats and oils - Determination of saponification value  
TZS 1326 ,  Animal and vegetable fats  and oils – Determination of moisture and volatile matter  
TZS 1327 ,  Animal and vegetable fats and oils – Determination of iodine value                                                                                                                
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 TZS 1328 ,  Essential oils – Determination of relative density at 20  °C – Reference method  
TZS 1329 ,  Animal and veget able fats and oils – Determination of refractive index  
TZS 1331 ,  Animal and vegetable fats and oils – Determination of acid value and acidity  
TZS 1332 ,  Animal and vegetable fats and oils – Determination of unsaponifiable matter -method using 
diethyl eth er extraction  
TZS 1335 ,  Animal and vegetable fats and oils – Determination of copper, iron and nickel content -
graphite furnace atomic absorption  
TZS 1336 ,  Animal and vegetable fats and oils – Determination of insoluble impurities content  
 
3 Term s and d efinitions  
 
For the purpose of this Tanzania Standard the definition s below shall apply;   
 
3.1 edible flaxseed (l inseed) oil  
 
 oil obtained from dry ripened seed of flax plant ( Linum usitatissimum ) suitable for human consumption  
 
3.2 virgin flaxseed (l inseed) oil 
 
flaxseed (linseed) oil obtained, without altering the nature of the oil, by mechanical procedures, for 
example, expelling or pressing, and the application of heat only. It may have been purified by washing 
with water, settling, filtering and cent rifuging only.  
 
3.3 c old pressed  flaxseed (l inseed) oil   
 
flaxseed (linseed) oil  obtained, without altering the oil, by mechanical procedures only, e.g. expelling 
or pressing, without the application of heat. They may have been purified by washing with wa ter, 
settling, filtering and centrifuging only.  
 
3.4 refined /non -virgin  flaxseed (linseed) oil 
 
flaxseed (linseed) oil obtained, by mechanical procedures and/or solvent extraction and subjected to 
refining processes.  
 
4.Requirements  
 
4.1 General requireme nts 
 
Edible flaxseed (linseed)  oil shall ;  
 
a) be free from  foreign and  rancid odour and taste;  
 
b) be clear and free from adulterants,  sediment s, suspended or foreign matter and separated 
water  
 
4.2 Specific requirements  
Edible flaxseed (linseed)  oil shall comply with  specific requirements  given in Table 1 when 
tested in accordance with the methods specified therein ; 
   
                                                                                                               
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 Table  1- Specific   require ments for edible flaxseed (Linseed) oil 
S. No.  Parameter  Requirement  
 Test method   
i.  Relative density  (at 25 oC/water at 25  oC) 0.925  - 0.935  TZS 1328  
  
ii.  Refractive index at  40 o C  
 
Refractive index at 20 ˚C 1.472 -1.475  
 
1.472 -1.487  
 TZS 1329  
 
iii.  Saponification value, mg KOH/g oil  185 -197 TZS 1325  
 
iv.  Iodine value  (g I 2/100g)  170 - 211 TZS 1327  
v.  Unsaponifiable matter, g/kg, max.   20 
 TZS 1332  
vi.  Moisture and matter volatile at 105 o C, % 
m/m, max.  0.2 TZS 1326  
vii.  Insoluble impurities, % m/m, max.  0.05 TZS 1336  
viii.  Soap content, % m/m, max.  0.005  TZS 1322  
ix.  Iron (Fe) mg/kg  Cold pressed and 
virgin oil:          5  
 
Refined  oil:     1.5  
 TZS 1335  
x.  Copper (Cu) mg/kg  Cold pressed and 
virgin oil:         0.4  
 
Refined  oil:     0.1  
 TZS 1335  
xi.  Acid value , mg KOH/g Oil , max.  Refined  oil:    0.6  
 
Cold pressed and 
virgin oil:        4 
 TZS 1331  
xii.  Peroxide value, mEq/kg, max . Refined  oil :10  
 
Cold pressed and 
virgin oil: 15 
 TZS 1324  
 
5  Food additives  
 
Refined  flaxseed (linseed) oil may contain food additives in accordance with Codex Stan 192. In 
addition , food additives shall not be used  in virgin or cold pressed flaxseed (linseed) oil . 
 
6.  Fortification  
 
Edible flaxseed (linseed) oil may be fortified in acco rdance with TZS 1313.  
                                                                                                               
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 7  Hygiene  
 
Edible flaxseed (linseed) oil shall be processed, handled and stored in accordance with TZS 109  . 
 
8  Contaminants  
 
8.1 Aflatoxin  
Aflatoxin level for edible flaxseed (linseed) oil shall not exceed maximum limits as given  in Table 2 
when tested in accordance with  test method specified therein:  
                         Table 2 - Aflatoxin limits for edible flaxseed (linseed) oil  
S/N Aflatoxin  Maximum limit ( µg/kg)  Method of test  
i) Total aflatoxin  10 TZS 799  
 ii) Aflatox in B1  5  
 
8.2 Pesticide residues  
Edible flaxseed (linseed) oil shall comply with relevant maximum pesticide residue limits established 
by the  Codex Alimentarius Commission online data base.  
8.3. Heavy metal  contaminants  
Edible flaxseed (linseed) oil shall comply with the maximum  heavy metal limits as specified in Table 3 . 
Table 3– Maximum Limits for heavy metal contaminants in edible flaxseed (linseed) oil  
 
S/No  Contaminant  Maximum limit  Test Method  
i Lead (Pb) mg/kg  
 0.08 TZS 268  
ii Arsenic (As) mg/ kg  
 0.1 TZS 76  
 
9  Packing, Marking and Labelling  
 
Edible flaxseed (linseed) oil shall be packed, marked and label led in accordance with TZS 538.  
 
9.1  Pack ing 
 
Edible flaxseed (linseed) oil shall be pack ed in containers of food grade materials  and prope rly sealed 
to ensure safety and quality requirements of the product  are main tained throughout the shelf life . 
 
9.2    Marking and label ling 
 
9.2.1 In addition each c ontainer of  edible flaxseed (linseed) oil  shall be legibly and indelibly marked 
with the f ollowing information:  
 
a) Name of the product  shall be " flaxseed (linseed) oil ";  
b) The words virgin or refined shall be declared on the label to indicate the type of oil  
c) Name, physical address of the manufacturer and/or packer;  
d) Batch or lot number;                                                                                                                
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 e) Date of m anufacturer;  
f) Expiry date;  
g) Net weight in Metric unit;  
h) Country of origin;  
i) Storage conditions;  
j) List of ingredients in descending order, including the specific name of additives;  
9.2.2 The containers may  also  be marked with the TBS Standards Mark of Quality.   
 
NOTE – The TBS Standards Mark of Quality shall be used by the manufacturers only under licence from TBS. 
Particulars of conditions under which the licences are granted, may be obtained from TBS.  
 
10 Sampling and Tests  
 
10.1 Sampling  
 
Edible flaxseed (l inseed) oil shall be sampled in accordance with  TZS 54.  
 
10.2 Tests  
 
Edible flaxseed (linseed) oil shall be tested in accordance with the test methods given in this Tanzania 
standard . 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
                          