AFDC 21 (389) CD 3 
ICS 67.0 80.20 
 
                 
 
DRAFT TANZANIA STANDARD  
 
 
 
Pre-cooked semi -dried  sweet potato chips (matobo lwa)- 
Specification  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  
  
               iii 
 AFDC 21 (389) CD3  
ICS 67.0 80.20 
 
1 
  
0. Foreword  
0.1 Pre-cooked semi -dried  sweet potato chips is a product obtained from sweet potato cured to obtain 
the desired sugar con tent, heated, sliced to a desired thickness  and semi -dried . The demand for the 
product is increasing thus the need to ensure  the safety and quality of the  products produced and / or 
marketed in Tanzania.  
0.2 In reporting the result of a test or analysis ma de in accordance with this standard, if the final value 
observed or calculated, is to be rounded off, it shall be done in accord ance with TZS 4 (See clause 2).  
1 Scope  
This Tanzania standard  prescribes  the requirements , methods of sampling and test ing for pre-cooked 
semi -dried  sweet potato  chips  (Matobol wa) intended for human consumption.  
2 Normative references   
The following referenced documents are indispensable for the application of this document. For dated 
references, only the edition cited applies. Fo r undated references, the latest edition of the referenced 
document (including any amendments) applies.  
TZS 4, Rounding off numerical values  
TZS 109, Food Processing units - Code of h ygiene  
TZS 122 -1:2018/ISO 6579 -1: 2017 - Microbiology of the food chain — Horizontal method for the 
detection, enumeration and serotyping of Salmonella - Part 1: Detection of Salmonella spp.  
CODEX STAN 193, Codex general standard for contaminants and toxins in food and feed  
TZS 538:2015 (EAS 38:2014) - Labelling of pre -packaged f oods — General requirements  
TZS 731: 2018/ ISO 7251: 2006 - Microbiology of food and animal feeding stuffs -  Horizontal method 
for the detection and enumeration of presumptive Escherichia coli - Most probable number technique  
TZS 960:2007/ISO 3593:1981, Starch - Determination of ash   
TZS 961:2007/ISO 1666:1996, Starch - Determination of moistu re content - Oven -drying method  
1276: 2012 /EAS 771, Fresh sweet potatoes – Specification  
TZS 2044:2017/ISO 5985:2002 Animal feeding stuffs – Determination of ash insolub le in hydrochloric  
 ISO 24333, Cereals and cereal products — Sampling    
TZS 2426 -1: 2020/ ISO 21527 -1: 2008 - Microbiology of food and animal feeding stuffs - Horizontal 
method for the enumeration of yeasts and moulds - Part 1: Colony count technique in pr oducts with 
water activity greater than 0.95  
TZS 2565:2019 Bio fortified Sweet Potato –Specification   
 
              2 
  ISO 5498, Agricultural food products — Determination of Crude Fibre Content — Modified Scharrer 
Method  
3 Terms and definitions  
For the purpose of this sta ndard, the following terms and definitions shall apply.  
3.1  
pre-cooked  semi -dried  sweet  potato chips  (Matobo lwa) 
piece s of sweet potato es obtained by slicing or chipping peeled pre-cooked sweet potato es followed 
by drying with  or without additional proces sing 
3.2 
food grade material  
material that will not transfer non -food chemicals into the food and contains no chemicals which would 
be hazardous to human health  
 
3.3 
foreign matter  
organic and inorganic materials (such as sand, soil, glass)  other than extr aneous matter in the semi -
dried  chips  
 
3.4 
extraneous matter  
organic matter of sweet potato  origin other than semi -dried  sweet  potato chips   
 
4 Requirements  
4.1 General requirements  
4.1.1 The raw material sh all be f resh sweet potato es that comply with the requirements of TZS 1276  
and TZS 2565.  
4.1.2 Pre-cooked  semi -dried  sweet  potato  chips shall be safe and suitable for human consumption 
and shall conform to the following requirements:  
-aroma - shall b e characteristic of the product;  
-texture shall be gummy  and soft;  
-shall have sweet taste ; 
-the colour of the chips shall be characteristic of the variety;  and  
-shall be free from extraneous and foreign matter . 
 
4.2 Specific requirements  
Pre-cooked semi -dried  sweet potato chips shall conform to the compositio nal requirements in Table 1          
              3 
           Table 1 — Compositional requirements for  pre-cooked semi -dried  sweet potato  chips  
S/NO Parameter  Requirement , by mass, %, 
max Method of test  
1 Moist ure content,  30 TZS 961  
2 Total  ash on dry m atter basis.  3 TZS 960  
3 Acid insoluble ash,  on dry matter 
basis,  0.15 TZS 2044  
4 Crude fibr e on dry matter basis  2 ISO 5498  
5 Contaminants  
5.1 Other contaminants  
Pre-cooked semi -dried sweet potato chips shall conform to those maximum levels of the Codex 
General St andard for Contaminants and Toxins in Food and Feed (CODEX STAN 193).  
5.2 Pesticide residues  
Pre-cooked semi -dried  sweet potato  chips shall conform  to those  maximum residue limits for 
pesticides established by the Codex Alimentarius Commission for this pr oduct.  
6 Hygiene  
6.1 The product covered by the provisions of this standard shall be processed, packaged, stored 
and transported under hygi enic conditions conforming to TZS 109 . 
6.2 Pre-cooked -semi -dried  sweet potato  chips shall conform to the requirements  for microbiological 
limits in Table 2. 
Table 2 — Microbio logical limits for pre-cooked -semi -dried  sweet potato  chips  
S/NO Micro organisms  Requirement  Method of test  
1 Escherichia coli  cfu/g,  Absent  TZS 73 1 
2 Salmonella , per 25 g,  Absent  TZS 122  
3 Yeasts and moulds, cfu/g, max.  104 TZS 2426 -1 
 
7 Sampling and test  
7.1 Sampling  
Sampling of Pre-cooked semi -dried  sweet potato  chips shall be done according to ISO 24333 . 
7.2 Test  
Testing of Pre-cooked semi -dried  sweet potato  chips shall be done according  to test methods 
prescribed in Table 1 and 2 of this standard .  
 
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 8 Weights and measures  
Pre-cooked -semi -dried  sweet potato  chips shall be packag ed in accordance with the weight s and 
measures requirements in the destination country . 
9 Pack ing, marking and lab elling  
9.1 Pack ing 
Pre-cooked semi -dried  sweet potato  chips shall be pack ed in suitable food grade materials  
9.2 Marking and labelling  
In addition to the requirements of TZS 538 ; the following labelling  requirements shall apply and shall 
be legibly and in delibly marked . 
a) name of the product to be sho wn on the label shall be “ Pre-cooked semi -dried  sweet potato  chips  
‘matobolwa ”;  
b) name and location address of the manufacturer or packer shall be declared;  
c) country of origin of the product ;  
d) batch number  
e) net weight  
f) best before date;  
g) date of manufacture ; 
h) the words "Human food ”; 
i) storage conditions  such “ store in cool dry place"; away from contaminants ; and 
j) declaration stating “salted” or “unsalted” .  
9.3 When labelling non -retail packages, information for non -retail packag es shall either be given on 
the packages or in accompanying documents, except that the name of the product, lot identification 
and the name and address of the manufacturer or packer shall appear on the package . 
9.4 The container may also be marked  with TBS Quality Mark.  
 
NOTE: The TBS Standards Mark of Quality may be used by the  manufacturers only under licens e 
from TBS. Particulars of conditions under which the license are gr anted may be obtained from TBS