ICS  
 
Reference number  
DRS  482: 2021  
© RSB 2021  
  
 RWANDA 
STANDARD  DRS  
482  
 
Second edition  
2021-mm-dd 
(Reaffirmed yyyy-mm-dd) 
Dried cassava  roots  (imivunde/ibibaru)  — 
Specification  
  
   
DRS 482 : 2021  
©RSB 2021  - All rights reserved                  ii 
 In order to match with technological development and to keep continuous progress in industries, 
standards are subject to periodic review. Users shall ascertain that they are in possession of the latest 
edition  
 
 
 
 
 
 
 
 
© RSB 2021  
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized 
in any form or by any means, electronic or mechanical, including photocopying and microfilm, without 
prior written permission from R SB. 
Requests for permission to reprodu ce this document should be addressed to : 
Rwanda Standards  Board  
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E-mail: info@rsb.gov.rw  
Website: www.rs b.gov.rw  
ePortal: www.portal.rsb.gov.rw   DRS 482 : 2021  
iii                ©RSB 2021  - All rights reserved  
 Contents  Page 
Foreword  ................................ ................................ ................................ ................................ ...................  iv 
1 Scope  ................................ ................................ ................................ ................................ .............  1 
2 Normative references  ................................ ................................ ................................ ...................  1 
3 Terms and definitions  ................................ ................................ ................................ ..................  2 
4 Requirement  ................................ ................................ ................................ ................................ .. 3 
4.1 Raw materials  ................................ ................................ ................................ ...............................  3 
4.2 General requirements  ................................ ................................ ................................ ..................  3 
4.3 Specific requirements  ................................ ................................ ................................ ..................  3 
5 Contam inants  ................................ ................................ ................................ ................................  4 
5.1 Mycotoxin  ................................ ................................ ................................ ................................ ...... 4 
5.2 Pesticide residues  ................................ ................................ ................................ ........................  4 
6 Hygiene  ................................ ................................ ................................ ................................ ..........  4 
7 Packaging  ................................ ................................ ................................ ................................ ...... 5 
8 Labelling  ................................ ................................ ................................ ................................ ........  5 
9 Sampling  ................................ ................................ ................................ ................................ ....... 5 
 DRS 482 : 2021  
©RSB 2021  - All rights reserved                  iv 
 Foreword   
Rwanda Standard s are prepared  by Technical Committees and approved by R wanda Standards Board (RSB) 
Board  of Directors in  accordance with the procedures of RSB, in compliance with Annex 3 of the WTO/TBT 
agreement on the preparation, adoption and application of standards.  
The main task of technical committees is to prepare national standards.  Final Draft Rwanda S tandards adop ted 
by Technical committ ees are ratified  by me mbers of RSB Board of Director s for publication and gazettment as 
Rwanda Standards.  
DRS 482 was prepared by Technical Committee RSB/TC 030, Root and tubers . 
Committee membership  
The following organizations were  represented on the Technical Committee on Root and Tubers (RSB/TC 030) 
in the preparation of this standard.  
University of Rwanda  
Rwanda Food and Drug Authority  
TREBUCO Ltd  
INNOPRO Ltd   
Kinazi Cassava Plant  
World Food Program  
Rwanda Agriculture Board  
Rwanda  Standards Board  (RSB) – Secretariat  
 DRS 482 : 2021  
i Error! Reference source not found.  
 Dried cassava  roots  — Specification  
1 Scope   
This Draft Standard specifies the requirement, methods of sampling and testing for dried cassava  roots, which 
may be fermented or not,  intended for human consumption , produced from cassava roots  (Manihot esculenta  
crantz ) 
2 Normative references   
The followin g documents are referred to in the text in such a way that some or all of their content constitutes 
requirements 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.  
 ISO 5983 -1, animal feeding stuffs — determination of nitrogen content and calculation of crude protein content 
— part 1: kjeldahl method  
AOAC 2001.04, Determination of Fumonisins B -1 and B -2 in Corn and Corn Flakes by Liquid Chromatography 
with Immunoaffinity  
RS CAC/RCP 1, General principles for food hygiene — Code of practice  
RS CODEX STAN 192, General standard for food additives  
RS EAS 38, Labelling of pre - packaged foods — General requirements  
RS EAS 744, Cassava and cassava products —Determination of total cyanogens — Enzymatic assay method  
RS ISO 16050,  Foodstuffs — Determination of aflatoxin B1, and the total content of aflatoxins B1, B2, G1 and 
G2 in cereals, nuts and derived products — High-performance  liquid chromatographic method  
RS ISO 16649 -2, Microbiology of food and animal feeding stuffs — Horizontal method for the enumeration of 
beta-glucuronidase -positive Escherichia coli — Part 2: Colony -count technique at 44 degrees C using 5 -bromo -
4-chloro -3-indolyl beta -D-glucuronide  
RS ISO 21527 -2, Microbiology of food and animal feeding stuffs — Horizontal method for the enumeration of 
yeasts and moulds — Part 2: Colony count technique in products with water activity less than or equal to 0.95  
RS ISO 24333,  Cereals and cereal products — Sampling   
 RS ISO 5498, Agricultural food products — Determination crude fibre Content -General method  
RS ISO 5985, Animal feeding stuffs — Determination of ash insoluble in hydrochloric acid  
RS ISO 6540, Maize — Determination o f moisture content (on milled grains and on whole grains)  
RS ISO 6579 -1, Microbiology of the food chain — Horizontal method for the detection, enumeration and 
serotyping of Salmonella — Part 1: Detection of Salmonella spp  
RS ISO 6888 -1, Microbiology of foo d and animal feeding stuffs — Horizontal method for the enumeration of 
coagulase -positive staphylococci (Staphylococcus aureus and other species) — Part 1: Technique using Baird -
Parker agar medium  
ISO 5983 -1, Animal feeding stuffs — determination of nitrogen content and calculation of c rude protein content 
— part 1: Kjeldahl method  
ISO 1666, Starch — Determination of moisture content — Oven -drying method  
AOAC915.05  B- Hyrocyanic acid;Titrimetric  Method : 18th edition,2005 . Actually, this is the method usually 
used in RSB laboratory/ICH . 
3 Terms and definitions   
For the purposes of this standard, the following terms and definitions shall apply.  
3.1 
dried cassava  root 
product obtained by drying peeled cassava roots  which have undergone  fermentation  (submerged or solid state 
fermentation ) or not  
3.2 
solid state  (dry) fermentation  
fermentation of peeled  cassava root without soaking, by piling and covering them for appropriate number of 
days to breakdown the potentially toxic cyanogenic glucosides present in fresh bitter cassava  so that t he 
subsequent drying can reduce  the HCN content to acceptable level .  
3.3 
Submerged  (wet)  fermentation  
fermentation of peeled or unpeeled cassava root by soaking them in water fo r appropriate number of days to 
breakdown the potentially toxic cyanogenic glucosides present in fresh bitter cassava so that the subsequent 
drying can reduce the HCN content to acceptable level   
3                ©RSB 2021  - All rights reserved  
 3.4 
bitter cassava  
 
cassava having high levels of hydrogen cyanide (more than 50 mg/kg of cyanides expressed as hydrogen 
cyanide on fresh weight basis) and not suitable for direct human consumption  
4 Requirement  
4.1 Raw materials  
4.1.1  Fresh  sweet or bitter  cassava roots , comply RS EAS 738  and RS  EAS 778, respectively;   
4.1.2  Fresh cassava roots shall not be woody or s pongy  
4.1.3  For submerged fermentation, the water used shall be of good quality and potable  complying with RS 
EAS 12    
4.2 General requirements  
4.2.1  dried cassava  roots  shall be  
a) Free from organic and inorganic extraneous matter  
b) Free from filth and live insects  
c) Free from moulds   
d) Have characteristic colour of the type of the fermentation and variety  
4.2.2  dried cassava  roots may be reduced into longitudinal or transversal pieces  
4.3 Specific requirements  
Dried cassava  roots  shall comply with specific requirements in table 1 when tested by test method specified 
therein.   
 Table 1 — Specific requirement for dried cassava  roots   
S/N  Parameter  Requirements  Test method  
i.  Moisture content, %, m/m, max   12 ISO 1666  
ii.  Starch content , %, min  75 ISO 6493  
iii.  Total ash, %, m/m, max   3 ISO 2171  
iv.  Acid insoluble ash, %, m/m, 
max   0.1 RS ISO 5985  
v.  Crude fiber,  %, m/m, max   2 ISO 5498  
vi.  Hydrogen  cyanide mg/kg  10 RS EAS 744  
AOAC915.05  
 
5 Contaminants  
5.1 Mycotoxin  
dried cassava  roots  shall comply with mycotoxin limits specified in Table 3 when tested in accordance with test 
methods specified therein.  
Table 2—Mycotoxin limits for dried cassava  roots  
S/N Mycotoxin  Maximum limit μg/kg  Test method  
i.  Total aflatoxins  10 RS ISO 16050  
ii.  Aflatoxins B1  5 
5.2 Pesticide residues  
dried cassava  roots  shall comply with the maximum residue limits established by the Codex Alimentarius 
Commission.  
6 Hygiene  
6.1 Dried cassava  roots  shall be produced, prepared and handled in accordance with RS CAC/RCP 1.  
6.2 dried cassava  roots  shall not exceed microbiological limits given in Table 2 when tested in accordance 
with the test methods specified therein.  
 
  
5                ©RSB 2021  - All rights reserved  
 Table 2 — Microbiological limits for dried cassava  roots  
S/N Microorganism  Maximum limit  Test method  
i.  Escherichia coli,  cfu/g  Absent  RS ISO 16649 -2 
ii.  Salmonella spp  in 25 g  Absent  RS ISO 6579 -1 
iii.  Staphylococcus aureus , cfu/ g  Absent  RS ISO 6888 -1 
iv.  Yeasts and moulds, cfu/g , max  1000  RS ISO 21527 -2 
7 Packaging  
dried cassava  roots  shall be packaged in suitable food grade packaging materials that shall not affect the quality 
of the product”. The packages shall be well closed to avoid contamination during transport . 
8 Labelling  
In addition to the requirements in RS EAS 38, each package shall be legibly and indelibly marked with the 
following:  
a) Name of the product as “as dried cassava  roots ”; 
b) Name, location and physical address of the producer;   
c) net content;  
d) batch number;  
e) Country of origin;  
f) Date  of production;  
g) Expiry date;  
h) storage conditions.  
9 Sampling  
Sampling shall be done in accordance RS ISO 24333.