ICS 67.230  
 
Reference number
DRS 149: 2022
© RSB 2023
  
 RWANDA 
STANDARD  DRS 
149 
 
Third edition  
yyy-mm-dd  
 
Cooked packaged beans— Specification 
   
DRS 149: 2023 
©RSB 2023- 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 2023 
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 RSB. 
Requests for permission to reproduce this document should be addressed to: 
Rwanda Standards Board 
P.O Box 7099 Kigali-Rwanda 
KK 15 Rd, 49 
Tel. +250 788303492 
Toll Free: 3250 
E-mail: info@rsb.gov.rw  
Website: www.rsb.gov.rw  
ePortal: www.portal.rsb.gov.rw  DRS 149: 2023 
iii                ©RSB 2023- All rights reserved 
 Contents Page 
Foreword ............................................................................................................................................................ iv 
1 Scope ................................................................................................................................................................ 1 
2 Normative references ...................................................................................................................................... 1 
3 Terms and definitions ..................................................................................................................................... 2 
4 Requirements ................................................................................................................................................... 3 
4.1 Ingredients .................................................................................................................................................... 3 
4.1.1 Essential ingredients ............................................................................................................................ 3 
4.1.2 Optional ingredients .............................................................................................................................. 3 
4.2 General requirements .................................................................................................................................. 3 
4.3 Specific requirements .................................................................................................................................. 4 
4.4 Microbiological limits ................................................................................................................................... 4 
5 Food additives ................................................................................................................................................. 4 
6 Contaminants ................................................................................................................................................... 5 
6.1 Pesticide residues ........................................................................................................................................ 5 
6.2 Heavy metals ................................................................................................................................................. 5 
7 Hygiene ............................................................................................................................................................. 5 
8 Packaging ......................................................................................................................................................... 5 
9 Labelling ........................................................................................................................................................... 5 
10 Sampling ........................................................................................................................................................ 6 
Annex A  (normative)  Determination of drained weight ................................................................................ 7 
A.1 Definition ...................................................................................................................................................... 7 
A.2 Apparatus ..................................................................................................................................................... 7 
A.3 Procedure ..................................................................................................................................................... 7 
A.4 Calculation .................................................................................................................................................... 7 
Annex B  (normative)  Determination of Sodium chloride content ............................................................... 8 
B.1 Scope ............................................................................................................................................................ 8 
B.2 Definition ...................................................................................................................................................... 8 
B.3 Principle ........................................................................................................................................................ 8 
B.4 Reagents ....................................................................................................................................................... 8 
B.5 Apparatus ..................................................................................................................................................... 8 
B.6 Procedure ..................................................................................................................................................... 9 
B.7 Expression of results .................................................................................................................................. 9 
Annex C  (normative)  Determination of soluble solids (Brix) ..................................................................... 10 
C.1 Definition .................................................................................................................................................... 10 
C.2 Scope .......................................................................................................................................................... 10 
C.3 Apparatus ................................................................................................................................................... 10 
C.4 Procedure ................................................................................................................................................... 10 
C.5 Reference .................................................................................................................................................... 11 
 DRS 149: 2023 
©RSB 2023- All rights reserved                  iv 
 Foreword 
Rwanda Standards are prepared by Technical Committees and approved by Rwanda 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 Standards 
adopted by Technical committees are ratified by members of RSB Board of Directors for publication and 
gazettment as Rwanda Standards. 
RS 149 was prepared by Technical Committee RSB/TC 003, Cereals, pulses, legumes and cereal products  
In the preparation of this standard, reference was made to the following standard (s): 
1) CODEX STAN 16:1981, Recommended international Standard for Canned Green Beans and Canned 
Wax Beans 
2) IS 9790: 1981, Specification for canned fresh beans 
3) MS 998: 1986, Canned Beans — Specification 
4) MS 997: 2009, Canned baked beans in tomato sauce — specification 
The assistance derived from the above source is hereby acknowledged with thanks. 
This thirdedition cancels and replaces the secondedition (RS 149: 2018 ), which has been technically revised.  
Committee membership  
The following organizations were represented on the Technical Committee on Cereals, pulses, legumes and 
cereal products (RSB/TC 003) in the preparation of this standard. 
Enterprise URWIBUTSO/SINA GERARD 
MANOSALIWA Food Industries Ltd  
MINIMEX Ltd  
National Agricultural Export Development Board (NAEB) 
National Industrial Research and Development Agency (NIRDA) 
Nyarutarama Business Incubation Center DRS 149: 2023 
v                ©RSB 2023- All rights reserved 
 One Acre Fund-Tubura 
Rwanda Food and Drugs Authority 
Zamura Feeds Ltd 
Rwanda Standards Board (RSB) – Secretariat 
 DRS 149: 2023 
1                ©RSB 2023- All rights reserved 
 Cooked packaged beans — Specification 
1 Scope 
This Draft Rwanda Standard specifies the requirements, sampling and test methods for cooked packaged 
beans (Phaseolus vulgaris L.) intended for human consumption. 
2 Normative references 
The following 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 11289, Heat-processed foods in hermetically sealed containers — Determination of pH 
RS 288, Mixed beans — Specification 
RS 350Iron bio-fortified beans — Specification  
RS 362, Fish flour — Specification 
RS CAC/RCP 1 , General principles of food hygiene 
RS CODEX STAN 192, Codex general standard for food additives 
RS CODEX STAN 193, Codex general Standard for Contaminants and Toxins in Food and Feed 
RS EAS 12 , Potable water — Specification 
RS EAS 35, Fortified edible salt — Specification 
RS EAS 38, Labelling of pre- packaged foods — General requirements 
RS EAS 46, Dry beans — Specification 
RS ISO 16050, Foodstuffs — Determination of aflatoxin B1, and the total content of aflatoxins B1, B2, G1 and 
G2in 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   
©RSB 2023- All rights reserved                  2 
 RS ISO 24333, Cereals and cereal products — Sampling  
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 
3 Terms and definitions 
For the purposes of this standard, the following terms and definitions apply. 
3.1 
dry beans 
dry threshed field and garden beans of the species of Phaseolus vulgaris  L. 
3.2 
mixed dry beans  
dry beans that consist of a mixture of same size groups, different colour and shape groups irrespective of varieties. 
3.3  
iron bio-fortified dry beans  
dry beans produced from varieties that have higher level of iron  
3.4 
Cooked packaged beans  
beans which have been subjected to boiling or steaming and packed in food grade packaging materials  
3.5 
drained weight 
weight of the contents of the container after draining  
3.6 
food gradepackaging material 
packaging material, made of substances which are safe and suitable for their intended use and which will not 
impart any toxic substance or undesirable odour or flavour to the product. DRS 149: 2023 
3                ©RSB 2023- All rights reserved 
 4 Requirements 
4.1 Ingredients 
4.1.1 Essential ingredients 
The following essential ingredients  shall be used in the preparation of cooked packaged beansand shall 
comply with relevant standards: 
a) dry beans, mixed dry beans and iron bio-fortified beans, conforming to RS EAS 46, RS 288 and RS 350,  
respectively; and 
b) potable water conforming to RS EAS 12. 
4.1.2 Optional ingredients 
The following optional ingredients including but not limited to the following may be used in cooked packaged 
beans and shall comply with relevant standards: 
a) sweetening ingredients such as sucrose, invert sugar, dextrose, glucose syrup; 
b) tomato paste/puree RS EAS 66-3; 
c) herbs and spices; 
d) cheese; 
e) edible oil complying with RS EAS 321; 
f) fish flour complying with  RS 362; 
g)  vegetables; and 
h) edible salt complying to RS EAS 35. 
4.2 General requirements 
Cooked packaged beans shall: 
a) be practically free from extraneous matter; 
b) be free from off flavours and odours; 
c) be practically free from any insects;  
©RSB 2023- All rights reserved                  4 
 d) be safe and suitable for human consumption;and 
e) be well cooked, slightly soft or slightly firm; and their skins shall be tender. 
4.3 Specific requirements 
4.4.1 Cooked packaged beans shall comply with the requirements specified in Table 1 when tested in 
accordance with test methods specified therein. 
Table 1 — Specific requirements for cooked packaged beans 
S/N Parameter Requirements Test method 
i.  Drained weight, % of net weight, min. 80 Annex A 
ii.  Salt content (as sodium chloride), %, w/w, max. 1.2 Annex B 
iii.  Total soluble solids in sauce, Brix % max. 6 Annex C 
iv.  pH 5 - 6  ISO 11289 
4.4.2 For cooked iron bio-fortified beans, the levels of iron shall not exceed the limits in Table 2 when tested 
in accordance with test methods specified therein. 
Table 2 — Iron content in cooked iron bio-fortified beans 
S/N Parameter Iron levels,(mg/kg) Test method 
i.  Class 1 (C1)  ≥ 90 AOAC 999.10 
ii.  Class 2 (C2) ≥ 80 to ˂ 90 
iii.  Class 3 (C3) ≥ 60 to ˂ 80 
4.4 Microbiological limits 
Cooked packaged beans shall comply with the microbiological limits specified in Table 3 when tested in 
accordance with test methods specified therein. 
Table 3 — Microbiological limits for cooked packaged beans 
S/N Micro-organism Maximum limits Test method 
i. Total viable count, CFU/g  103 RS ISO 4833-1 
ii. E. coli, CFU/g Absent RS ISO 16649-2 
iii. Salmonella ssp ,in 25 g Absent RS ISO 6579-1 
iv. Yeasts and moulds, CFU/g 102 RS ISO 21527-2 
v. Clostridium botulinum , CFU/g Absent RS ISO 7937 
5 Food additives 
Food additives which may be used in the preparation of cooked packaged beans shall comply with RS 
CODEX STAN 192. DRS 149: 2023 
5                ©RSB 2023- All rights reserved 
 6 Contaminants 
6.1 Pesticide residues 
Cooked packaged beans shall conform to maximum residue limits for pesticide residues established by the 
Codex Alimentarius Commission for this commodity. 
6.2 Heavy metals 
Cooked packaged beans shall comply with the maximum heavy metal limits indicated in Table 4 when tested 
in accordance with test method specified therein. 
Table 4 — Maximum limits for heavy metal inCooked packaged beans 
S/N Heavy metal Maximum limits(mg/kg) Test method 
i.  Cadmium  0.1  AOAC 999.11  
ii.  Lead  0.1  
iii.  Tina  250  
a For canned cooked beans  
7 Hygiene 
Cooked packaged beans shall be prepared and handled  in accordance with RS CAC/RCP 1. 
8 Packaging 
Cooked packaged beans shall be packaged in food grade packaging material that ensures the integrity and 
safety of the product 
9 Labelling 
9.1 In addition to the requirements of RS EAS 38, the following requirements shall apply and shall be 
legibly and indelibly marked: 
a) name of the product as “Cooked packaged beans”or “Cooked packaged mixed beans”or “Cooked 
packaged iron-biofortified beans”; 
b) declaration of iron content, if iron bio fortified beans have been used; 
c) nameand  address of the manufacturer/packer/distributor/ importer/exporter/vendor of the food shall be 
declared. 
d) date of manufacture; 
e) batch number;  
©RSB 2023- All rights reserved                  6 
 f) list of ingredients in descending order; 
g) expiry date; 
h) country of origin; 
i) the net content shall be declared in the metric system; 
j) instructions for use; 
k) storage instructions;  
l) the statement ‘Human Food’ shall appear on the package;and 
m) instructions on disposal of used package. 
9.2 When labelling non-retail packages, information for non-retail packages 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 packages. 
10 Sampling 
Sampling of Cooked packaged beans shall be done in accordance with RS ISO 24333. DRS 149: 2023 
7                ©RSB 2023- All rights reserved Annex A 
(normative)  
 
Determination of drained weight 
A.1 Definition 
Drained weight expresses percentage of solid content as determined by the procedure described below. 
A.2 Apparatus 
A sieve 20 cm (check) in diameter. The meshes of such sieves are made by so weaving wire as to form 
square openings of 2.8 mm by 2.8 mm. 
A.3 Procedure 
Carefully weigh the clean and dry sieve. Weigh the container plus the contents. Empty the contents of the 
container into the sieve taking care to distribute the maize evenly. Without shifting the product, incline the 
sieve at an angle of approximately 17 % to 20° to facilitate drainage. Drain the product for two minutes and 
then weigh the sieve plus the product. Weigh the dry empty container. 
A.4 Calculation 
Drained weight, as per cent of net weight = 
 
Where, 
M=is the weight, in grams, of the sieve; 
M1=is the weight, in grams, of the sieve with the product; 
M2=is the weight, in grams, of the empty container; and 
M3=is the weight, in grams, of the container with the contents 
 
  
 
©RSB 2023- All rights reserved                  8 
 Annex B 
(normative) 
 
Determination of Sodium chloride content 
B.1 Scope 
This method determines the content of chlorides. 
B.2 Definition 
The chloride content corresponds to the sum of all anions (halides) calculated as sodium chloride precipitable 
with silver ions in a nitric acid solution. 
B.3 Principle 
Quantitative precipitation of the halides extracted from the ash in a nitric acid solution with AgNO3 in excess. 
Back titration of the surplus AgNO3 with ammonium thiocyanate, using ferric alum (ferric ammonium sulphate) 
as the indicator. 
B.4 Reagents 
B.4.1 Distilled or demineralized water 
B.4.2 AgNO3 solution, 0.1 N (16.9888 g AgNO3) 
B.4.3 NH4SCN solution, 0.1 N (7.6113 g NH4SCN). In practice a slightly higher weight is taken and the 
solution is adjusted by dilution against a 0.1 N AgNO3 solution 
B.4.4 Cold saturated NH4Fe (SO4) 2.12H2O solution (approximately 40 %). The ensuing brown colouring is 
eliminated by adding pure nitric acid drop wise 
B.4.5 HNO3 (approximately 30 %) 
B.4.6 Diethyl ether of nitrobenzene 
B.5 Apparatus 
B.5.1 Measuring flask, 100 ml 
B.5.2 Burette, 50 ml 
B.5.3 Erlenmeyer flask, 200 ml DRS 149: 2023 
9                ©RSB 2023- All rights reserved B.5.4 Pipettes 
B.5.5 Funnel, filtering paper 
B.6 Procedure 
The ash (residue after carbonization and incineration of the potato crisp at a maximum temperature of 550 °C 
in a muffle furnace) obtained from 1 g – 2 g dry matter is extracted by means of 80 ml – 90 ml hot distilled 
water acidified with a few drops of nitric acid. The washings are filtered off into a 100-ml measuring flask; after 
cooling distilled water is added until the mark is reached (stock solution). In proportion to the expected 
chloride content aliquot part of this solution, which should preferably contain 50 mg – 100 mg NaCl, taken off, 
distilled water being added to obtain a quantity of approximately 100 ml Subsequently 5 ml ferric alum solution 
(see C.4.4), 20 ml 0.1 N AgNO3 solution (see C.4.2) and 5 ml – 10 ml ether or 1 ml nitrobenzene are added; 
titration is carried out by means of an ammonium thiocyanate solution0.1 N (see C.4.3), until the red coloring 
remains after stirring. 
B.7 Expression of results 
Report in percentage by weight to one decimal place. 
Chloride content = 
 
where, 
P = is the test portion, in mg, incinerated; 
V = is the ml of the stock solution derived from the ash; 
V1 = is the volume, in ml, stock solution used from titration; 
V2 = is the volume, in ml, AgNO3 added; and 
V3 = is the volume, in ml, NH4SCN necessary for back titration. 
 
 
 
 
©RSB 2023- All rights reserved                  10 
 Annex C 
(normative) 
 
Determination of soluble solids (Brix) 
C.1 Definition 
Determination of Total Soluble Solids (Brix). 
C.2 Scope 
All range of products with aqueous solution. 
C.3 Apparatus 
C.3.1 Sieve No. 8 (model: BS410) 2.36 m minimum diameter 
C.3.2 Analytical balance, capable of weighing to the nearest 0.001 g. 
C.3.3 Tin opener 
C.3.4 Stainless steel tray 
C.3.5 Spoon 
C.4 Procedure 
C.4.1 Adjust the temperature of the sample to room temperature 
C.4.2 Open the cover (day light plate) at the refracting prism of the refractometer 
C.4.3 Stir the samples thoroughly and wet the surface of the prism 
C.4.4 Cover the prism with the day light plate 
C.4.5 Look through the eyepiece at the opposite end of the refracting prism directly under the light source 
C.4.6 Focus the eyepiece by turning the adjustment knob until a clear reading and a boundary line is seen 
C.4.7 Record the reading 
C.4.8 Flush the prism surface with distilled water DRS 149: 2023 
11                ©RSB 2023- All rights reserved 
 C.4.9 Dry the surface with soft tissue. 
C.5 Reference 
At ago Hand Refractometer N Types Series Instruction Manual  
©RSB 2023- All rights reserved                  12 
 Bibliography 
[1] RS 149: 2018, Cooked packaged beans— Specification (Second edition)  
 DRS 149: 2023 
 
Price based on 11pages  
©RSB 2023- All rights reserved