Reference number  
DRS 302: 2016  
© RBS yyyy 
© RSB 2016  
 
 RWANDA 
STANDARD  DRS  
302 
 
First edition  
2016 -mm-dd 
Processed mushrooms  — Specification  
  DRS 302: 2016  
©RSB 2016 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 2016  
All rights reserved. Unless otherwise spec ified, 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 reproduce this document shou ld be addressed to  
Rwanda Standards  Board  
P.O Box 7099 Kigali -Rwanda  
Tel. +250 252 586103/ 582945  
E-mail: info@rsb.gov.rw   
Website: www.rsb.gov.rw   DRS 302: 2016  
iii                 ©RSB 2016  All rights reserved  
 
 Contents  Page 
Foreword  ................................ ................................ ................................ ................................ ............................  iv 
1 Scope  ................................ ................................ ................................ ................................ ......................  1 
2 Normative references  ................................ ................................ ................................ ............................  1 
3 Terms and definitions  ................................ ................................ ................................ ...........................  2 
4 General requirements  ................................ ................................ ................................ ...........................  5 
5 Specific requirements  ................................ ................................ ................................ ...........................  6 
5.1 Dried mushrooms  ................................ ................................ ................................ ................................ .. 6 
5.2 Mushroom grits and mushroom powder  ................................ ................................ ............................  7 
5.3 Pickled and fermented mushrooms  ................................ ................................ ................................ .... 7 
5.4 Quick frozen mushrooms and mushrooms in olive oil and other vegetable oil  .............................  7 
5.5 Salted and sterilized mushrooms  ................................ ................................ ................................ ........  8 
5.6 Mushroom extract, Mushroom concentrated and dried mushroom concentrate ...........................  8 
6 Contaminants  ................................ ................................ ................................ ................................ .........  9 
7 Hygiene  ................................ ................................ ................................ ................................ ...................  9 
8 Packaging  ................................ ................................ ................................ ................................ .............  10 
9 Marking and labeling  ................................ ................................ ................................ ...........................  10 
 DRS 302: 2016  
©RSB 2016 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 
adopted by Technical committ ees are ratified by me mbers of RSB Board of Director s for publication and 
gazettment as Rwanda Standards.  
DRS 302 was prepared by Technical Committee RSB/TC 017, Prepared and Pre -packaged Foods . 
Committee membership  
The following organizations were represented on the Technical Committee on Prepared and pre -packaged 
Foods (RSB/TC 017) in the preparation of this sta ndard.  
Ministry of Agriculture  
Alimentation KIME  
National Agricultural Export Development Board (NAEB)  
UR-Collede of Agriculture and Veterinary Medicine (UR -CAVM  
Rwanda Agriculture Board (RAB)  
Shekina Entreprise  
Sosoma Industries  
ADMA  International  
Blasse rie et Limonaderies du Rwanda ( BRALIRWA ) 
Inyange Industries  
Sulfo Rwanda  
Entreprise  Urwibutso  
MUSHUBI Tea Factory  
INES  
AZAM  
Blessed Dairy  
SPERANZA Group Ltd  
Rwanda  Standards Board  (RSB) – Secretariat  
  DRS 302: 2016  
1                 ©RSB 2016  All rights reserved  
 
 Processed mushrooms  — Specification  
1 Scope  
This Draft Rwanda S tandard prescribes requirements and methods of sampl ing and tests for processed 
mushrooms of edible species . 
2 Normative references  
The following referenced documents are indispensable for the application of this document. For dated 
references, only the edition cited applies. For undated references, the lates t edition of the referenced 
document (including any amendments) applies.  
AOAC 967.24 Filth in mushrooms  
AOAC 967.19 water in dried vegetables  
ISO 763:2003 , Fruit and vegetable products -- Determination of ash insoluble in hydrochloric acid  
ISO 1026  Fruit and vegetable products -- Determination of dry matter content by drying under reduced 
pressure and of water content by azeotropic distillation  
ISO 17239  Fruits, vegetables and derived products -- Determination of arsenic content -- Method using 
hydride generation atomic absorption spectrometry  
ISO 9526  Fruits, vegetables and derived products -- Determination of iron content by flame atomic absorption 
spectrometry  
ISO 6633  Fruits, vegetables and derived products -- Determination of lead content -- Flameless atomic 
absorption spectrometric me thod 
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  
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  
ISO 21527 -1 Microbiology of food and animal feeding s tuffs -- Horizontal method for the enumeration of 
yeasts and moulds -- Part 1: Colony count technique in products with water activity greater than 0,95  
ISO 6 888-2 Microbiology of food and animal feeding stuffs -- Horizontal method for the enumeration of 
coagulase -positive staphylococci (Staphylococcus aureus and other species) -- Part 2: Technique using rabbit 
plasma fibrinogen agar medium   
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 ISO 16649 -1 Microbiology of food and animal feeding stuffs -- Horizontal method for the enumeration of beta -
glucuronidase -positive Escherichia coli -- Part 1: Colony -count techn ique at 44 degrees C using membranes 
and 5 -bromo -4-chloro -3-indolyl beta -D-glucuronide  
ISO/TS 6579 -2 Microbiology of food and animal feed -- Horizontal metho d for the detection, enumeration and 
serotyping of Salmonella -- Part 2: Enumeration by a miniaturized most probable number technique  
3 Terms and definitions  
For the purposes of this standard, the following terms and definitions apply.  
3.1. 
edible mushrooms  
fruit bodies of the fungi plant group suitable for use as human food.  
3.2  
processed mushrooms  
dried  edible mushrooms (including freeze -dried mushrooms, mushroom grits, mushroom powder), pickled 
mushroom, salted mushroom, fermented mushrooms, mushrooms in vegetable oils, quick frozen mushrooms, 
sterilized mushrooms, mushroom extracts, mushroom concentrat e and dried mushroom concentrate.  
3.3  
dried mushrooms - 
mushrooms obtained by drying or freeze drying of edible mushrooms of one species, whether whole or sliced.  
3.4  
mushroom grits 
coarsely ground dried edible mushrooms of one species.  
3.5 
mushroom pow der 
dried edible mushroom of one species ground finely  
3.6 
pickled mushroom  
fresh  or preserved edible mushroom of one or more species appropriately prepared after cleaning, washing 
and blanching, soaked in vinegar and with or without the addition of salt, spices, sugars, vegetable oils, acetic, 
lactic, citric or ascorbic acid, and then  pasteurilized in hermetically sealed container.  DRS 302: 2016  
3                 ©RSB 2016  All rights reserved  
 
 3.7 
salted mushroom  
fresh edible mushrooms of one species, either whole or sliced, preserved in brine after cleaning, washing and 
blanching .  
3.8 
fermented mushrooms  
fresh edible mushrooms of one species pr eserved by salt and by lactic acid fermentation . 
3.9  
quick frozen mushroo m 
fresh edible mushrooms of one species which, after cleaning, washing and blanching are subjected to a 
freezing process  
3.10 
mushroom extract  
products concentrated from fresh edible  mushroom juice or from dried mushroom water of edible mushroom 
of one or more species with the addition of salt and which is concentrated to 7% salt less extract.  
3.11 
mushroom concentrate  
product  concentrated from fresh edible mushroom juice or from dried mushroom water of edible mushroom of 
one or more species with the addition of salt which is concentrated to 24% of salt less extract.  
3.12 
dried mushroom concentrated  
dried product obtained from mushroom extract or mushroom concentrate.   
3.13 
sterilized mushroom  
edible mushroom, fresh, salted or frozen, of one or more species, whole or sliced, packed in air tight 
containers in water and salt, and heat treated to a degree guaranteeing the resista nce of the product to 
spoilage.   
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 3.14  
mushroom in olive oil and other vegetable oils  
edible  mushrooms either fresh or previously salted, of one species, whole or sliced, packed in airtight 
containers in olive oil or other vegetable oil and heat treated to a degree guaranteeing the resistance of the 
product to spoilage.  
3.15 
whole dried mushroom  
product obtained from whole cleaned and dried edible mushrooms. Their stalks may be shortened.  
3.16  
whole caps without stems  
product obtained from whole caps with their stems having been removed.  
3.17  
cut dried mushrooms  
mushrooms obtained from whole edible mushrooms sliced and dried; the thickness of the individual slices 
being 1 -4 mm.  
3.18 
damaged mushroom  
mushroom with more than quarter of the cap missing.  
3.19 
crushed mushroom  
parts of mushroom passing through sieve having 5 x 5 mm mesh for dried  mushroom.  
3.20  
carbonized mushrooms  
whole or dried mushrooms with traces of carbonization on their surface.  
3.21 
insect damaged mushrooms  
mushroom that have holes cause d by maggots and other insects.  DRS 302: 2016  
5                 ©RSB 2016  All rights reserved  
 
 3.22 
seriously maggot damaged mushrooms  
mushrooms  having four or more holes caused by maggots.  
3.23 
fallen off stalks  
stalks separated from the caps.  
3.24 
organic impurities of vegetable origin  
admixture of other edible mushrooms , parts of plants such a s leaves and other tree stalks.  
3.25 
Filth  
Organic impurities of animal origin  
3.26 
inorganic  impurities  
stones, glass, pieces of soil and other mineral matter  
3.27  
spoiled mushrooms  
mushrooms which are brownish or rotten as a result of attack by  micro -organisms and /or mould.  
4 General requirements  
4.1 Processed mushrooms may include a wide range of pr oducts specified under clause 3 ; and their form 
being described as provided under their definition in clause 3.  
4.2 All products falling under the scope of this standard shall belong to the edible  species  
4.3` All mushrooms raw material  shall, in all cases , be free from poisonous mushrooms and other toxic 
ingredients; and shall not be a mi xture of more than one species.  
4.4 All mushrooms that are to be harvested, marketed or preserved or to be used in the p reparation of 
mushroom products shall be carefully examined by qualified person  to determine whether there are any 
inedible mushrooms amongst them .  
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 4.5 Raw materials: Only fresh edible mushrooms which have been treated or processed before 
deterioration set s in shall be used in the preparation of processed mushrooms. Both the raw material and 
preserved mushroom shall be healthy clean, undamaged, free as practicable of maggots damage and shall 
process the flavour and taste  characteristic to the species.  
4.6 Mushroom products may contain , but not limited to , salt (sodium chloride), vinegar, spices and herbs, 
sugars, refined edible vegetable oil, butter, milk, milk powder, cream water and w ine. 
4.7 Styles –Processed mushrooms may be presented in various styles,  e.g whole with stalks, whole caps 
(buttons) without stalks, slices, pieces and stalks, grits, powder or concentrate.  
4.7.1  Other styles - Any other presentation of the product shall be permitted provided that the product is 
sufficiently distinctive from ot her forms of presentations described in this standard and meet the requirements 
of this standard.  
4.8 Composition –Except in the case processed mushrooms consisting entirely of caps or where the 
addition o f stalks is stated on the label, the number of stal ks shall not exceed the number of caps.  
5 Specific  requirements  
5.1 Dried mushrooms  
5.1.1  Dried mushrooms shall have colour  odour, texture  and flavour characteris tic to the species  
5.1.2  They shall be clean and comply with the requirement speci fied in table 1  
Table  1 — Physical and chemical requirements for dried mushrooms  
Type of dried mushroom  Dried (other 
than freeze 
dried)  Freeze dried  Dried Shiitake (other 
than freeze dried)  Test 
Method  
Moisture % m/m, max  12 6 13 ISO 1026  
Acid insoluble ash,% m/m, max  2 2 2 ISO 763  
Organic impur ities of vegetable 
origin,% m/m, max 0.02 0.02 1 Note  
Filth (impurities of animal origin) , ,% 
m/m, max 1 1 1 AOAC 
967.24  
Crushed mushroom  ,% m/m, max 6 6 6 Note  
Damaged mushroom  ,% m/m, max 20 20 20 Note  
Inorganic impurities  ,% m/m, max 2 2 2 Note  
Insect  damaged mushroom % m/m, 
max 1 1 1 Note  
NOTE impurities, crushed mushroom, damaged mushroom and insect damaged mushrooms shall be determined 
by normal count under normal vision of a naked eye or by magnifying lense of X10, if necessary.  DRS 302: 2016  
7                 ©RSB 2016  All rights reserved  
 
 5.2 Mushroom grits and mushroom powder  
5.2.1  Particle size: Not less than 90% shall pass through a 600 μm sieve for fine flour and not less than 
90% shall pass through a 1200 μm sieve for Mushroom grit . Testing for particle size shall be done in 
accordance with  EAS 82.  
5.2.2  The chemical requirement s for mushroom grits and mushroom powder shall be as given in Table 2.  
Table  2 — Chemical requirements for mushroom grits and mushroom powder  
Parameter  Requirements  Test method  
Moisture % m/m, max.  12 ISO 1026  
Acid insoluble ash,% m/m, max  2 ISO 763  
5.3 Pickled and fermented mushrooms  
The chemical and physical requirements for pickled and fermented mushrooms shall be as given in Table 3  
Table  3 — Chemical and physical requirements for pickled and fermented mushrooms  
Parameter  Pickled 
mushroom  Fermented 
mushrooms  Test method  
Salt (sodium chloride) % m/m  ≤ 2.5  3-6  
Sugar % m/m, max  2.5 -  
Vinegar, expressed as acetic acid %, m/m , max  2 -  
Acid insoluble ash % m/m, max  0.1 0.2 ISO 763  
Organic impurities of vegetable origin % m/m,  max 0.02 0.1 Note  
Filth, %, max  1 1 AOAC 967.24  
Damaged mushroom, %, max  20 20 Note  
Inorganic impurities, %, max  2 2 Note  
Insect  damaged mushroom % m/m, max  1 4 Note  
NOTE  impurities , crushed mushroom, damaged mushroom  and insect  damaged mushrooms shall be determined by 
normal count under normal vision of a naked eye or by magnifying lenses of X10, if necessary.  
 
5.3.2  The permitted ingredients in the case of pickled mushrooms are salt as sodium chloride, sugars and 
vinegar . 
5.3.3  The permitted ingredients in the case of fermented mushroom are salt as sodium chloride and lactic 
acid occurring naturally into the product as a result of fermentation  and it shall  not to exceed 1 % m/m.  
5.4 Quick frozen mushrooms and mushrooms in oliv e oil and other vegetable oil  
5.4.1  The chemical and physical requirements for mushrooms in olive oil and other vegetable oils  shall be 
as given in Table 4.   
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 Table  4 — Chemical and physical requirements for quick frozen mushrooms and mushrooms in olive 
oil and other vegetable oil  
Parameter  Quick frozen  mushroom in 
olive oil and 
other vegetable 
oils Test method  
Salt (sodium chloride) % m/m , max  - 1  
Acid insoluble ash % m/m, max  0.2 0.1 ISO 763  
Organic impurities of vegetable origin % m/m,  0.02 0.02 Note  
Filth, %, max  1 1 AOAC 967.24  
Damaged mushroom, %, max  20 20 Note  
Inorganic impurities, %, max  2 2 Note  
Insect  damaged mushroom % m/m, max  2 2 Note  
NOTE  impurities , crushed mushroom, damaged mushroom  and insect  damaged mushrooms shall be determined by 
normal count under normal vision of a naked eye or by magnifying lense  of X10, if necessary.  
 
5.5 Salted and sterilized mushrooms  
5.5.1  The chemical and physical requirements for salted and sterilized mushrooms shall be as given in 
Table 5.  
Table  5 — Chemical and Physical requirements for salted and sterilized mushrooms  
Parameter  Salted 
mushrooms  Sterilized 
mushrooms  Test method  
Salt (sodium chloride) % m/m  15-18 ≤ 2  
Acid insoluble ash % m/m, max  0.3 0.2 ISO 763  
Organic impurities of vegetable origin % m/m,  max 0.03 0.02 Note  
Maggot damaged mushroom % m/m, max  1 1 Note  
Filth, %, max  1 1 AOAC 967.24  
Damaged mushroom, %, max  20 20 Note  
NOTE  impurities , crushed mushroom, damaged mushroom  and maggot damaged mushrooms shall be determined by 
normal count under normal vision of a naked eye or by magnifying lense of X10, if necessary.  
5.5.2  The only permitted ingredient for both salted and sterilized mushrooms is salt as sodium chloride . 
5.6 Mushroom extract, Mushroom concentrated and dried  mushroom concentrate  
5.6.1  The chemical and physical requirement s for mushroom extract, mushroom concentrate and dried 
mushroom concentrated shall be as given in Table 6.  DRS 302: 2016  
9                 ©RSB 2016  All rights reserved  
 
 Table  5 — Chemical and Physical re quirements for mushroom extract, mushroom concentrate and 
dried mushroom concentrate  
Parameter  Mushroom 
extract and 
mushroom 
concentrate  Dried mushroom 
concentrate  Test method  
Salt (sodium chloride) % m/m , max  20 5  
Acid insoluble ash % m/m, max  Nil  Nil  ISO 763  
Organic impurities of vegetable origin % m/m,  Nil  Nil  Note  
Filth  1 1 AOAC 967.24  
Moisture content % m/m, max  - 9 ISO 1026  
NOTE: Organic impurities shall be determined by normal count under normal vision of a naked eye or by magnifying 
lens of X10, if necessary.  
5.6.2  The only permitted ingredient in mushroom extract, mushroom concentrate and dried mushroom 
concentrate is salt as sodium ch loride.  
6 Contaminants  
6.1 Processed mushrooms shall comply with those maximum limits for pesticide residues as specified by 
codex alimentalius   
6.2 Processed mushroom shall comply with maximum limits for heavy metals  given in table 6  
Table  6 — Maximum limits for heavy metals  
Metal  Limits  Test method  
Arsenic, mg/kg, max  0.2 ISO 17239  
Lead mg/kg, max  0.2 ISO 6633  
Iron mg/kg, max  9 ISO 9526  
6.3 Processed mushroom shall not exceed the limit on aflatoxin as specified in table 7  
Table  7 — Maximum limits for aflatoxin  
Aflatoxin  Limits  Test method  
B1, µg/kg 5 ISO 16050  
Total aflatoxin µg/kg 10 ISO 16050  
7 Hygiene  
7.1 Processed mushroom shall handled in accordance with the provisions provided in RS CAC/RCP 1  
7.2 The product shall be free from parasites which may represent a hazard to health and shall also not 
contain any substance originating from microorganisms in amou nts which may represent a hazard to health.   
©RSB 2016 All rights reserved                  10 
 
 7.3 Processed mushrooms shall comply with microbiological requirements as set in table 7  
Table  7 — Microbiological limits  
Metal  Limits  Test method  
Total plate count, cfu/g max  103 RS ISO 4833  
E. Coli,  absent  ISO 16649 -1 
Staphylococcus aureus, cfu/25g , max  102 ISO 6888 -2 
Salmonella, cfu/25g , max  absent  ISO/TS 6579 -2 
Mould, max, cfu/g  103 ISO 21527 -1 or 
ISO 21527 -2 
8 Packaging  
Processed mushroom sha ll be packed in such a way as to protect it properly against any damage or expose it 
such that it can easily be attacked by pests or other kind of infestation or moisture ingress. The packaging 
material should  preferably allow the consumer to view the product. The packages shall be free from any 
foreign matter, objectionable smell and shall be of food grade.  
9 Marking and label ling  
In addition to the requirements in RS EAS 38, processed mushrooms shall be legibly and indelibly marked on 
the label  with the f ollowing information  
a) name of the product as “ as defined in clause 3 ”  
b) Species  of the processed mushroom  
The common and scientific name of the species of fungus used, but the terms "fungus" and "fungi" may be 
replaced by terms which have customarily been used to describe the genus or species concerned in the 
country in which the product is intended to be sold , e.g. "mushroom" or "mushrooms" for the genus Agaricus:  
In the case of processed mushrooms consisting of more than one species, such fact as “mixed” shall form part 
of the designation  
c) Style of presentation  
d) List of ingredients in descending order of propo rtion except for those product exclusively made from 
mushroom  
e) name and physical and postal address of producer/packer or distributor ; 
f) Country of origin ; 
g) Net weight /or Drained weight where applicable  
h) Manufacturing date  ; DRS 302: 2016  
11                 ©RSB 2016  All rights reserved  
 
 i) storage instruction;  
j) Expiry  date  
©RSB 2016 All rights reserved                  12 
 
 Annex  A 
(normative)  
 
List of edible mushroom species  
A.1 Agaricus bisporus  
A.2 Auricularia polytrich a or Auricularia auricula -judae   
A.3 Flammulina velutipes  
A.4 Hypsizygus tessulatus   
A.5 Lentinus edodes . 
A.6 Pleurotus cornucopiae  
A.7 Pleurotus eryngii   
A.8 Pleurotus ostreatus   
A.9 Rhizopus oligosporus  -. 
A.10  Sparassis crispa . 
A.11  Tremella fuciformis  (. 
A.12  Tuber aestivum   
A.13  Tuber magnatum   
A.14  Tuber melanosporum   
A.15  T.melanosporum x T.ma gnatum  
A.16  Terfezia  sp.  
A.17  Ustilago maydis . 
A.18  Volvariella volvacea . DRS 302: 2016  
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 A.19  Fusarium venenatum   DRS 302: 2016  
ICS 67 080 01  
 
 
©RSB 2016  All right s reserved