AFDC 26  (1113) DTZS 
 
DRAFT TANZANIA STANDARD  
 
 
Green beans – specification  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
TANZANIA BUREAU OF STANDARD  
 
 
 
 0 Foreword  
 
Green beans also known as s nap beans, string beans or french bean s. They  are grown 
for its long pods consumed as a vegetable while young and tender and before the seeds 
becomes enlarged and mature. Green bean s are rich in vitamins (vitamin A, C, K, folate, 
thiamine, niacin),  minerals (Ca, Fe, M g, P, K, Zn), fibers and antioxidants . 
This Tanzania Standard was prepared in order to provide guidance to green beans 
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-06 BEANS 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 requirements  quality and safety requirements , methods of 
sampling and test  of green beans of  varieties (cultivars) grown from Phaseolus vulgaris  
L. and Phaseolus coccineus  L. to be  supplied fresh to the consumer.  Beans for shel ling 
or industrial processing are excluded.  
 
 
2. Normative r eferences  
 
The following referenced standards are indispensable for the application of this standard. 
For dated references, only the edition cited applies. For 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 127 -1 - Microbiology of the food chain - Horizontal method for the determination 
of Vibrio spp.  - Part 1: Detection of potentially enteropathogenic  
Vibrioparahaemolyticus, V ibrio cholerae and Vibrio vulnificus  
e) TZS 538, Packaging, marking and labeling of foods  
f) TZS 552, Code of Hygienic Practice for Fresh leafy Vegetables   
 g) TZS 852 -1- Microbiology of the food chain - Horizontal method for the detection and 
enumeration of Listeria  monocytogenes  and of Listeria spp  - Part 1: Detection method  
h) TZS 1002, Fresh fruits and vegetables - Sampling . 
i) TZS 1003, Guide to the pre -packaging of fresh fruits and vegetables  
j) TZS 2424 -1 - Microbiology of the food chain - Horizontal method for determination of 
hepatitis A virus and norovirus using real -time RT -PCR -Part 1: Method for  
quantification  
k) TZS 2425  - Microbiology of food and animal feeding stuffs - Horizontal method for the 
detection of Escherichia coli O157  
l) Codex Stan 193 , Codex General standard for contaminants and toxins in food and 
feed  
m) Codex pesticide residues in food online data base  
 
n) TZS 3004  - Microbiology of the food chain - Detection and enumeration of  
Cryptosporidium and Giardia in fresh leafy green vegetables and  berry fruits  
 
3 Terms and definitions  
For the purposes of this standard, the following terms and definitions apply;  
 
3.1 damage  
any defect or injury which materially affects the appearance or storage quality of the  
vegetable  
 
 
3.2 fresh  
pods are not wilted in appearance and the beans are not soft, limp, or shriveled  
 
3.3 misshaped  
pods are so bent, twisted or otherwise misshapen that appreciable waste is thereby  
caused in their preparation for use  
 
3.4 stringy  
over-matured and have become fibrous  beans  
 
3.5 c lean 
free of any visible foreign matter  
 
3.6  sound;   
produce not affected by rotting or deterioration to make it fit for consumption  
 
 
  
 4 Requirements  
 
4.1 General requirements  
 
In all classes, subject to the special provisions for each class and the tolerances allowed, 
the beans shall be:  
 intact ; 
 sound;  
 clean ;  
 fresh in appearance ; 
 free from parchment (hard endoderm) ;  
 practically free from pests and damage caused by them ; 
 free of abnormal external moisture ; 
 free of any foreign smell and/or taste  
 
4.1.1  The development and condition of the  green  beans shall be such as to enable them  
to:  
• withstand transportation and handling  
• arrive in satisfactory condition at the place of destination.  
 
 
4.2 Classification  
Green beans shall be  classified in three classes, as defined below:  
 
4.2.1 “Extra” c lass 
Green beans in this class shall be of superior quality. They shall be characteristic of the 
variety and/or commercial type.  
 
They shall be:  
• turgid, easily snapped  
• very tender  
• practically straight  
• stringless.  
 
Seeds, if present, shall be small and soft and needle beans shall be seedless.  
They shall be free from defects, with the exception of very slight superficial defects, 
provided they do not affect the general appearance of the produce, the quality, the 
keeping quality and presentation in the package.  
 
 
4.2.2 Class I  
Green beans in this class shall be of good quality. They shall be characteristic of the 
variety and/or commercial type.  
 
They shall be:  
 turgid   
  young and tender  
 practically stringless except in the case of beans for slicing.  
 
Seeds, if present shall be small and soft.  
 
The following slight defects, may be allowed, provided they do not affect the general 
appearance of the produce, the quality, the keeping quality and presentation in the 
package:  
 
 a slight defect in shape  
 slight defects in colouring  
 slight skin defects.  
 
 
4.2.3 Class II  
This class includes green beans that do not qualify for inclusion in the higher classes but 
satisfy the general  requirements specified in clause 4.1 .  
 
They shall be:  
 reasonably tender  
 free from rust spots in the case of needle beans.  
 
Seeds, if present, shall not be too large and shall be reasonably soft.  
 
The following defects may be allowed, provided the green beans retain their essential 
characteristics with regards to the quality, the keeping quality and presentation:  
 defects in s hape  
 defects in colouring  
 skin defects  
 strings  
 slight rust spots except in the case of needle beans.  
 
 
4.3 Provisions concerning sizing  
Size is determined by the maximum width of the pod measur ed at right angles to the 
seam.  
 
To ensure uniformity in size, needle beans in the same package shall not exceed:  
 6 mm when marked “very fine”  
 9 mm when marked “fine”  
 12 mm when marked “medi um” 
 
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 t olerances  
 
4.4.1.1 “Extra” c lass 
A total tolerance of 5%, by number or weight, of  green  beans not satisfying the 
requirements of the class but meeting those of Class I is allowed. Within this tolerance 
not more than 0.5% in total may consist of produce satisfying the requirements of Class 
II quality.  
 
4.4.1.2 Class I  
A total tolerance of 10 %, by number or weigh t, of green beans not satisfying the 
requirements of the class but meeting those of Class II is allo wed. Within this tolerance 
not more than 1 % in total may consist of produce satisfyi ng neither the requirements of 
Class II quality nor the general  requirements, or of produce affected by decay.  
No tolerance is allowed for produce affected by Colletotrichum lindemuthianum  (bean 
spot disease).  
 
Within this tolerance, a maximum of 5 %, by number or weight, may have strings in the 
case of a variety and/or commercial type tha t should be stringless.  
 
In addition, a maximum of 15 %, by number or weight, of  green  beans (excluding needle 
beans) may have the stalk and a small section of the narrow part of the neck missing, 
provided these pods remain closed, dry and not discoloured.  
 
4.4.1.3 Class II  
A total tolerance of 10 %, by number or weight, o f green beans satisfying neither the 
requirements of the class nor the general  requirements is allowed. Within this tolerance 
not more than 2%  in total may consist of produce affected by decay. No tolerance is 
allowed for produce affected by Colletotrichum lindemuthianum  (bean spot disease).  
 
In addition,  a maximum of 30 %, by number or weig ht, of green beans (excluding needle 
beans) may have the stalk and a small section of the na rrow part of the neck missing, 
provided these pods remain closed, dry and not discoloured.  
 
 
4.4.2 Size Tolerances  
For all classes (if sized); a total tolerance of 10%, by number or weight, of green beans 
not satisfying the requirements with regard s to sizing is allowed.  
 
4.5 Provisions concerning presentation  
 
4.5.1 Uniformity  
The contents of each package shall be uniform and contain only green beans of the same 
origin, variety or commercial type, quality and size (if sized).  
 
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 Green beans  shall also comply with the microbial requirements prescribed in Table 1.  
 
Table 1 Microbiological limits  for green beans  
S/N Test Test method  Requirement  
1. 
2. 
3. 
 Listeria monocytogenes  per 25g  
Escherichia coli O157:H7  
Salmonella  per 25g  
 TZS 852 -1 
TZS 2425  
TZS 122 -1 
  Absent  
Absent  
Absent  
 
 
7 Contaminants  
 
7.1 Heavy metal contaminants  
Green beans  shall comply with those maximum metal contaminants established by the 
Codex Stan 193.  
 
7.2 Pesticide residues  
Green beans  shall comply with those maximum residue limits established in the Codex 
pesticide residues in food online dat a base.  
 
 
8 Sampling and tests  
 
8.1 Sampling  
Representative samples of green beans  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 a nd labelling  
 
9.1 Packing  
Green beans  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 ma terials, particularly of paper or 
stamps 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 green beans . 
Packages shall be free of foreign matter and objectionable smell.  
 
9.1.2 The use of any su bstance 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, green beans  shall also be 
packed in accordance with TZS 538 and TZ S 1003 (See clause 2).  
 
 
9.2 Marking and labelling  
 
9.2.1  Each package shall legibly and indelibly bear the following 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 (green beans )  
c) Name of the variety  
d) Country of origin  
e) Class;  
f) Size; 
 for needle beans expressed as “very fine”, “fine”, “medium” ;  
for other beans (if sized) expressed as minimum and maximum width of the 
pods  
g) Net weight  (kg); 
h) Storage condition.  
i) Batch number  
 
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 granted to manufacturers or producers, may be 
obtained from TBS.