AFDC 26 (111 4) DTZS  
 
 
DRAFT TANZANIA STANDARD  
 
 
Leeks  - specification  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
TANZANIA BUREAU OF STANDARD  
 
 0 foreword  
 
Leek is a leafy vegetable which the edible part is whitish green stem with a bundle of leaf 
sheaths  and slightly developed bulb. It can be consumed cooked or raw, with or without 
leaves.  Leek is rich in vitamins (A, C and K) and magnesium.  
 
   
This Tanzania Standard was prepared in order to provide guidance to leeks  producers 
and traders as well as regulators, and to ensure safety and quality of the produce . 
In the preparation of this Tanzania Standard considerable assistance was derived from: 
UNECE standard FFV -21 LEEKS  2017 .  
 
In reporting the results of a test or analysis made in accordance with this standard, if the 
final value observed or calculated is to be rounded off, it shall be done in accordance with 
TZS 4 (see clause 2).  
 
1. Scope  
 
This standard specifies  quality and safety requirements, methods of sampling and tests 
of leeks varieties (cultivars) gr own from Allium ampeloprasum L. of the family Alliaceae  
to be  supplied fresh to the consumer.  Leeks for industrial processing are excluded.  
 
 
2. Normative references  
 
The following referenced standards are indispensable for the application of this standard. 
For dated references, only the edition cited applies  whereas f or undated references, the 
latest edition of the referenced standards (including any amendments) applies.  
 
a) TZS 4, Rounding off of numerical values  
b) TZS 109, Code of hygiene for food processing unit  
c) TZS 122 -1- Microbiology of the food chain — Horizontal method for the detection, 
enumeration and serotyping of Salmonella - Part 1: Detection of Salmonella spp.  
d) TZS 538, Packaging, marking and labeling of foods.  
e) TZS 552, Code of hygienic practice for  fresh leafy vegetables  
f) TZS 729, Microbiology of food and animal feeding stuffs — Horizontal method for the 
enumeration of coliforms — Colony -count technique   
 g) TZS 730 -2, Microbiology of food and animal feeding stuffs – Horizontal method for the 
enumeration of -b-glucuronidase -positive Escherichia coli – Part 2 – Colony -count 
technique at 44 0C using 5 -bromo -4-chloro -3-indolyl -b-D-glucuronide  
h) TZS 1002, Fresh fruits and vege tables - Sampling.  
i) TZS 1003, Guide to the pre -packaging of fresh fruits and vegetables  
j) Codex Stan 193, Codex General standard for contaminants and toxins in food and 
feed 
k) Codex pesticide residues in food online data base  
 
3 Terms and definitions  
 
3.1 sound  
produce neither affected by rotting nor deterioration such as to make it unfit for 
consumption  
 
3.2 clean  
practically free of any visible foreign matter; however, the roots may have remnants of 
soil adhering to them and traces of soiling within the sheath ed part are allowed  
 
3.3 pests  
any organism that directly or indirectly affects the quality and safety of the produce  
 
 
4 Requirements  
 
4.1 General requirements  
 
a. In all classes, subject to the special provisions for each class and the tolerances 
allowed, the leeks shall be: 
 intact (this requirement does not apply, however, to roots and ends of 
leaves which  may be cut)  
 sound;  
 clean,  
 fresh in appearance, with wilted or withered leaves removed  
 practically free from pests  and damage caused by them  
 not running to seed  
 free of abnormal external moisture  
 free of any foreign smell and/or taste  
b. When the leaves are cut, they shall be neatly cut  
 
c. The development and condition of the leeks shall be such as to enable them:   
  to withstand transportation and handling  
 to arrive in satisfactory condition at the place of destination  
 
4.2 Classification  
Leeks shall be  classified in two classes, as defined below:  
 
 
4.2.1  Class I  
Leeks in this class shall be of good quality. They shall be characteristic of the variety  
and/or commercial type.  
 
The white to greenish white  part of the leeks shall represent at least one -third of the total  
length of the sheathed part. 
 
The following slight defects, may be allowed, provided the y do not affect the general  
appearance of the produce, the quality, the keeping quality and presentation in the 
package:  
• slight superficial and dry damage on not more than two leaves  
• slight b ruising on the leaves  
• slight damage caused by thrips on the leaves  
 
4.2.2  Class II  
This class includes leeks that do not qualify for inclusion in Class I but satisfy the general  
requirements specified in clause 4.1 . 
 
The following defects may be allowed, provided the leeks retain their essential 
characteristics  as regards the quality, the keeping quality and presentation:  
 slight superficial and dry damage  
 slight bruising  
 damage caused by thrips  
 slight traces of rust on  the leaves  
 slight brownish discoloration due to low temperatures  
 a tender flowering stem, provided that it is enclosed within the sheathed part.  
 
4.3 Provisions concerning sizing  
Size is determined by the diameter measured at right angles to the longitudinal axis in the  
middle of the sheathed part.  
 
To ensure uniformity in size, the diameter of the largest lee k in the same bundle or 
package must not be more than twice the diameter of the smallest leek.  
 
Uniformity in size is compulsory for Class I. 
 
 
 
  
 4.4 Provisions concerning tolerances  
At all marketing stages, tolerances in respect of quality and size shall be allowed in each 
lot for produce not satisfying the requirements of the class indicated.  
 
4.4.1 Quality tolerances  
 
4.4.1.1  Class I  
A total tolerance of 10% , by number or weig ht, of leeks not satisfying the requirements of 
the class but meeting those of Class II is allowed. Within this tolerance no t more than 1 % 
in total may consist of produce satisfy ing neither the requirements of Class  II quality nor 
the general  requirements, or of produce affected by decay.  
 
4.4.1. 2 Class II  
A total tolerance of 10%, by number or weight, of leeks satisfying neither the requirements 
of the class nor the general  requirements  are allowed. Within this tolerance not more than 
2% in total may consist of produce affected by decay.  
 
4.4.2 Size tolerances  
For all classes (if sized) ; a total tolerance of 10 %, by number or weight, of leeks not 
satisfying the requirements as regards sizing  is allowed.  
 
4.5 Provisions concerning presentation  
 
4.5.1 Uniformity  
The contents of each package, or each bundle in the same package shall be uniform and  
contain only leeks of the same origin, variety or commercial type, quality and size (if  
sized), and  appreciably the same degree of development and colouring.  
 
The visible part of the contents of the package shall be representative of the entire 
contents.  
 
 
5 
 
6 Hygiene  
 
6.1 It is recommended that the produce covered by the provisions of this Standard be 
prepared and handled in accordance with TZS 109 (see clause 2) and TZS 552.  
 
 
6.2 Leeks  shall be free from any pathogenic micro organisms, parasites or toxins that 
may present hazards to human health. Leeks  shall comply with the microbial 
requirements prescribed in Table 1.  
 
 
  
 Table 1 Microbiological limits for leeks  
 
Test  
 Test method   
Requirement  
Total coliforms cfu/g TZS 729   Max 103 
Presumptive Escherichia coli,  cfu/g   TZS 730 -2 Absent  
Salmonella,  in 25 g  TZS 122 -1 
 Absen t 
 
 
7 Contaminants  
 
7.1 Heavy metal contaminants  
Leeks  shall comply with those maximum metal contaminants established by the Codex 
Stan 193.  
 
7.2 Pesticide residues  
Leeks  shall comply with those maximum residue limits established in the Codex pesticide 
residues in food online data base.  
 
 
8 Sampling and tests  
 
8.1 Sampling  
Representative samples of leeks  shall be drawn as prescribed in TZS 1002 (see clause 
2). 
 
8.2  Tests  
Tests shall be done in accordance with the methods prescribed  in this standard.  
 
 
9. Packing, marking and labelling  
 
9.1 Packing  
Leeks  shall be packed in such a way as to protect the produce properly. The materials 
used shall be of food grade, clean and of a quality such as to avoid causing any external 
or internal damage to the produce. The use of materials, particularly of paper or stam ps 
bearing trade specifications, is allowed, provided the printing or labelling has been done 
with nontoxic ink or glue.  
 
9.1.1  The containers shall meet the quality, hygiene, ventilation and resistance 
characteristics that shall ensure suitable handling, shipping and preserving leeks . 
Packages shall be free of foreign matter and objectionable smell.  
 
9.1.2 The use of any substance tending to modify the natural characteristics of the 
produce, especially form, texture and taste shall be prohibited.  
   
 9.1.3  In addition to the provisions covered by this standard, leeks  shall also be packed in 
accordance with TZS 538 and TZS 1003 (See clause 2).  
 
 
9.2 Marking and labelling  
 
9.2.1  Each package shall legibly and indelibly bear the followin g information  in Swahili or 
and English  on the same side:  
a) Name and address of exporter/importer, packer and/or dispatcher/distributor;  
b) Name of the produce (leeks );  
c) Country of origin ; 
d) Class ; 
e) Batch number;  
f) Net weight (in kg);  
g) Storage condition.  
 
9.2.2 Certification mark – Each container may also be marked with TBS certification mark.  
NOTE:  The use of TBS certification mark is governed by provisions of the 
Standards Act, 2009.  Details of the conditions under which a license for the use of 
TBS certification mark may be gran ted to manufacturers or producers, may be 
obtained from TBS.