Reference number  
DRS 171:2018  
© RSB 2018  
 
 
 RWANDA 
STANDARD  DRS 
171 
 
Second edition  
2018 -mm-dd 
 
Roasted macadamia — Specification  
  DRS 171:2018  
©RSB 2018  - 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 2018  
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  
P.O Box 7099 Kigali -Rwanda  
KK 15 Rd, 49  
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Toll Free: 3250  
E-mail: info@rsb.gov.rw  
Website: www.rs b.gov.rw   
ePortal: www.portal.rsb.gov.rw   DRS 171:2018  
iii                ©RSB 2018  - All rights reserved  
 Contents  Page 
Foreword  ................................ ................................ ................................ ................................ ............................  iv 
1 Scope  ................................ ................................ ................................ ................................ ......................  1 
2 Normative references  ................................ ................................ ................................ ............................  1 
3 Terms and definitions  ................................ ................................ ................................ ...........................  2 
4 Requirements  ................................ ................................ ................................ ................................ .........  3 
4.1 General requirements  ................................ ................................ ................................ ...........................  3 
4.2 Specific requirements  ................................ ................................ ................................ ...........................  3 
4.3 Grading  ................................ ................................ ................................ ................................ ...................  4 
5 Food additives  ................................ ................................ ................................ ................................ ....... 4 
6 Contaminants  ................................ ................................ ................................ ................................ .........  4 
6.1 Pesticide residues  ................................ ................................ ................................ ................................ . 4 
6.2 Heavy metals  ................................ ................................ ................................ ................................ ..........  4 
7 Hygiene  ................................ ................................ ................................ ................................ ...................  5 
8 Mycotoxin limits  ................................ ................................ ................................ ................................ .... 5 
9 Packaging  ................................ ................................ ................................ ................................ ...............  5 
10 Weights and measures  ................................ ................................ ................................ .........................  5 
11 Labelling  ................................ ................................ ................................ ................................ .................  5 
12 Sampling  ................................ ................................ ................................ ................................ ................  6 
Annex  A (normative)  Determination of moisture content for Roasted macadamia  ................................ ... 7 
A.1 Procedure  ................................ ................................ ................................ ................................ ...............  7 
Annex  B (normative)  Determination of oil content  ................................ ................................ ........................  8 
B.1 Reagents  ................................ ................................ ................................ ................................ ................  8 
B.2 Procedure  ................................ ................................ ................................ ................................ ...............  8 
B.3 Calculation and expression of results  ................................ ................................ ................................  8 
Annex  C (normative)  Determination of free fatty acid  ................................ ................................ ...................  9 
C.1 Apparatus  ................................ ................................ ................................ ................................ ...............  9 
C.2 Reagents  ................................ ................................ ................................ ................................ ................  9 
C.3 Procedure  ................................ ................................ ................................ ................................ ...............  9 
Annex  D (normative)  Determination of salt  ................................ ................................ ................................ .. 10 
D.1 Reagents  ................................ ................................ ................................ ................................ ..............  10 
D.2 Procedure  ................................ ................................ ................................ ................................ .............  10 
 DRS 171:2018  
©RSB 2018  - 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 o f 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 171 was prepared by Technical Co mmittee RSB/TC 038, Processed fruits and vegetables.  
This second  edition cancels and replaces the first edition (RS  171:2012 ), which has been technically revised.  
Committee membership  
The following organizations were represented on the Technical Committee on Processed fruits and 
vegetables ( RSB/TC 038) in the preparation of this standard.  
Enterprise Urwibutso  
FRESHCO  
National Agricultural Export Development Board (NAEB)  
NORELGA Macadami a 
PEBEC Ltd  
Rwanda Nuts Company  
SORWATOM  
Rwanda  Standards Board  (RSB) – Secretariat  
 DRS 171:2018  
1                ©RSB 2018  - All rights reserved  
 Roasted macadamia — Specification  
1 Scope   
This Draft Rwanda Standard specifies the requirements, sampling and test methods for roasted macadamia of 
varieties (cultivars) grown from Macadamia integrifolia , Macadamia ternifolia , Macadamia tetraphylla , and their 
hybrids 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.  
AOAC 999.10,  Lead, Cadmium, Copper, Iron, and Zinc in foods, Atomic Absorption Spectrophotometry after 
microwave digestion  
RS CAC/RCP  1, Code of practice  — General Principle for food Hygiene  
RS CODEX STAN 192, Codex general standard for food additives  
RS EAS 38 , Labelling of pre -packaged foods — General  requirements  
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 -positi ve 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 2171, Cereals, pulses and by -products — Determination of ash yield by incineration  
RS ISO 3960, Animal and vegetable fats and oils — Determination of peroxide value — Iodometric (visual) 
endpoint determination  
RS ISO 4833 -1, Microbiology of the food chain — Horizontal method for the enumeration of microorganisms 
— Part 1: Colony count at 30 degrees C by the pour plate technique  
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 .  
©RSB 2018  - All rights reserved                  2 
 3 Terms and definitions   
For the purposes of this standard, the follow ing terms and definitions apply . 
3.1 
roasted macadamia  
kernels which have been subjected to heat by dry or wet roasting and to which salt , sugar, honey or other 
permitted food additives  may have been added  
3.2 
whole kernel  
kernel that is not split or separated into halves. The kernel contour is not more than m aterially affected by a 
missing portion or portions. Not more than ¼ of the kernel is chipped off or missing  
3.3 
half kernel/split  
approximately half of a whole kernel, with not more than 1/8 of its mass chipped off or missing  
3.4 
piece  
unit of a kernel wh ich is less than half a kernel  
3.5 
clean kernel  
kernel which is practically free from dirt or other foreign material, or the general appearance of the lot is not  
more than appreciably affected by dirt or other foreign or extraneous substance  
3.6 
foreign ma tter 
organic and inorganic material other than roasted macadamia  
3.7 
defective kernels  
defective kernels shall mean any or all of the following:  
a) kernels with adhering of foreign matter;  DRS 171:2018  
3                ©RSB 2018  - All rights reserved  
 b) insect damaged kernels;  
c) excessively soft kernels;  
d) rancid kernels;  
e) immature kernels;  
f) weather -damaged kernels.  
3.8 
off flavour  
odour or flavour which is not characteristic of macadamia kernels and which appreciably affect the eating 
quality  of the kernel  
4 Requirements  
4.1 General requirements  
Roasted macadamia sh all: 
a) be of the characteristic colour ;  
b) be free from objectionable odour;  
c) be free from dust ; 
d) be free from decayed or mould damaged kernels ; and 
e) be free from  live insects, insect fragments and mites.  
4.2 Specific  requirements  
Roasted Macadamia shall comply with the specific requirements stipulated in Table 1  when tested in 
accordance with test methods specified therein . 
Table 1 — Specific requirements for roasted macadamia  
S/N Characteristic  Limits  Test method  
i.  Moisture content, % , m/m, max.  1.5 Annex A  
ii.  Oil content on dry weight basis, % , m/m, min.  85 Annex B  
iii.  Free fatty acid, calculated as Oleic acid %, m/m, 
max.  0.5 Annex C   
©RSB 2018  - All rights reserved                  4 
 iv.  Total ash (roasted and salted), % m/m, max.  4 RS ISO 2171  
v.  Peroxide value, meq/kg , max.   3 RS ISO 3960  
4.3 Grading  
Roasted Macadamia shall be graded in compliance with the stipulations in Table 2  when tested in accordance 
with test methods specified therein . 
Table 2 — Grades for roasted macadamia  
S/N 
 Grade  
 Description  Whole kernel 
percentage  Size range  (m/m)  
i.  Premium  Whole kernels  100a 25 to 15  
ii.  Popular  Wholes and halves  50 min. 17 to 10  
iii.  Cocktail  Wholes and halves  11 to 49  17 to 10  
iv.  Medium  Halves and pieces  10 Max.  12 to 4  
v.  Chips  Pieces and bits  None  5 to 0.5  
a. Tolerance — Up to 5 % by mass of the next lower grade.  
5 Food additives  
Food additives which may be used in R oasted Macadamia  shall comply with  RS CODEX STAN 192.  
6 Contaminants  
6.1 Pesticide residues  
Roasted macadamia shall comply with  those maximum residue lim its for pesticide residues established by 
Codex Alimentarius Commission for this commodity.  
6.2 Heavy metals  
Roasted macadamia shall not contain heavy metals in amounts which can represent a hazard to human 
health and shall comply with the limits in Table 3. when tested in accordance with test methods specified 
therein . 
Table 3 —Heavy metals contaminant limits  
S/N  Heavy metal  Maximum limit  
mg/kg  Test method  
 Lead (Pb),  0.10 AOAC 999.10  
 Cadmium (Cd),   0.02 DRS 171:2018  
5                ©RSB 2018  - All rights reserved  
 7 Hygiene  
7.1 Roasted macadamia shall be handled in hygienic manner in accordance with RS CAC/RCP 1.  
7.2 Roasted macadamia shall comply with the microbiological limits given in Table 4 when tested in 
accordance with test methods specified therein.  
Table 4 — Microbiological limits for Roasted macadamia  
S/N Microorganism  Maximum limit  Test method   
i.  Total plate count, CFU /g 103 RS ISO 4833 -1 
ii.  Escherichia coli,  CFU/g  <1 RS ISO 16649 -2 
iii.  Salmonella spp  in 25g absent  RS ISO 6579 -1 
iv.  Yeasts and Moulds CFU in g  10 RS ISO 21527 -2 
8 Mycotoxin limits  
Total aflatoxin levels in  roasted macadamia kernels for human consumption shall not exceed 10 µg/kg and 
aflatoxin B1 shall not exceed 5 µg/kg when tested in accordance with  RS ISO 16050.  
9 Packaging  
9.1 Roasted m acadamia shall be packaged in food grade materials t hat will safeguard the hygienic, 
nutritional, technological and organoleptic qualities of the pro duct. They shall be packaged in s uch a way to 
protect the product  from mechanical, heat and frost damage.  
9.2 The packaging materials shall conform to the envi ronmental legislation of the destination country . 
10 Weights and measures  
Roasted Macadamia shall be packaged in accordance with the national weights and measurement 
regulations. and environmental requirements in the destination country.be in accordance with.  
11 Labelling  
In addition to the requirements of RS EAS 38, the following information shall be legibly and indelibly marked:  
f) name of the product shall be “Roasted macadamia ” 
g) name and location address of the exporter and/or packer;  
h) country of origin;  
i) net weight;   
©RSB 2018  - All rights reserved                  6 
 j) lot identification (batch number);  
k) declaration of preservatives, if used;  
l) date of manufacture;  
m) expiry date;  
n) grading; and  
o) storage conditions.  
11.2 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 produce, lot identification and the 
name and address of the manufacturer or packer shall appear on the package.  
12 Sampling  
Sampling shall be done in accordance to RS ISO 24333.  DRS 171:2018  
7                ©RSB 2018  - All rights reserved  
 Annex  A 
(normative)  
 
Determination of moisture content  for Roasted macadamia  
A.1 Procedure  
A.1.1  Weigh accurately about 10 g of the material in a suitable moisture dish previously dried in an electric 
oven and weighed. Place the dish in a vacuum oven at 95 0C to 100 0C under press ure 100 mm/Hg. Cool the 
dish in a desiccator and weigh with the lid on. Repeat the process of heating, cooling and weighing at halfhour 
intervals until the loss in weight between two successive weighings is less than 1 mg. Record the lowest 
weight obtained . 
A.1.2  Calculation and expression of results, moisture % by mass  
3 12 1 100×) (
m mm m

 
where:  
1m
 is the mass in g of the dish and sample before drying;  
2m
 is the mass in g of the dish and sample after drying; and  
3m
 is the mass in g of the dish only.  
 
 
 
   
©RSB 2018  - All rights reserved                  8 
 Annex  B 
(normative)  
 
Determination of oil content  
B.1 Reagents  
B.1.1  Petroleum ether of boiling range of 40 0C to 60 0C. 
B.1.2  Hezane of food grade.  
B.2 Procedure  
B.2.1  Weigh accurately about 2.5 g of the sample, dried as described under A .1.1, and extract with 
petroleum ether or hexane, food grade, in a Soxhlet or other suitable extractor. The extraction period may vary 
from 4  h at a condensation rate of 5.6 drops per second. Dry the extract on a steam bat h for 30 min ., cool in a 
desiccator and weigh. Continue at 30 min . intervals this alternative drying and weighing until the difference 
between two successive weighings is less than 1 mg.  
B.2.2  Note the lowest mass.  
B.3 Calculation and expression of results  
Crude fat (on moisture -free basis), % by mass  
32 1 ) (100mm m
 
where,  
1m
 is the mass in g of the extraction flask with dried extract;  
2m
 is the mass in g of extraction flask; and  
3m
 is the mass in g of the dried sample for the test.  
 
 
 DRS 171:2018  
9                ©RSB 2018  - All rights reserved  
 Annex  C 
(normative)  
 
Determination of free fatty acid  
C.1 Apparatus  
Soxhlet fat extraction apparatus.  
C.2 Reagents  
C.2.1  Petroleum, ether, distilling below 65 0C, or ethyl ether . 
C.2.2  Alcohol potassium hydroxide, 0.1N (use absolute or alcohol denatured with MeOH).  
C.2.3 Alcohol -ether mixture, equal volumes of 96 % alcohol and ethyl ether.  
C.2.4  Phenolphthalein  solution, one % in alcohol ether and add alcoholic KOH solution to a faint pink.  
C.3 Procedure  
C.3.1  Extract 10.00 g ± 0.01 g of the sample taken in a thimble with petroleum ether for about 16 h in a  
Soxhlet extraction apparatus. Completely evaporate the solv ent from extraction flask (weighed previously) on  
a steam bath, cool and weigh the Soxhlet flask with the residue and from the difference of the mass of fat  
obtained from the material. Dissolve the residue in the extraction flask with 50 ml of the alcohol -ether  
phenolphthalein solution. Titrate the dissolved extract, with standard potassium hydroxide solution to a faint  
pink colour which persists for 10  s. If emulsion is formed during titration, dispel by adding second 50 ml portion  
of the alcohol -ether phe nolphthalein solution.  
C.3.2  Make a blank titration on 50 ml of the alcohol -ether phenolphthalein solution and subtract this value from 
the titration value of the sample. If the additional 50 ml portion of the alcohol -ether phenolphthalein  solution is 
adde d, double the blank titration  
 
 
 
 
 
  
©RSB 2018  - All rights reserved                  10 
 Annex  D 
(normative)  
 
Determination of salt 
D.1 Reagents  
D.1.1  Acetone.  
D.1.2  10 % calcium acetate solution.  
D.1.3  HNO3.  
D.1.4   0,1 N AgNO3.  
D.1.5  Fe Alum indicator.  
D.1.6  0.1 N NH4SCN.  
D.2 Procedure  
D.2.1  Weight 2 g of thoroughly mixed sample into a platinum or silica dish.  
D.2.2  Disperse sample with 10 ml of acetone.  
D.2.3  Remove acetone at room temperature, with air current.  
D.2.4  Add, and thoroughly mix, 10 ml of 10 % calcium acetate.  
D.2.5  Carefully dry on a steam bath.  
D.2.6  Ash in a muffle oven at 550 0C (10220F) (complete ashing is not necessary).  
D.2.7  Place ash in a beaker and dissolve ash in 25 ml HNO3 (1 + 3).  
D.2.8  Add at least 2 - 4 ml of 0.1 N AgNO3 that is just enough to precipitate all chloride present.  
D.2.9  Add at  least 5 ml of 0.1 N AgNO3 in excess, to 8.  
D.2.10  Heat to boil, cool, then add 5 ml Fe  Alum indicator.  DRS 171:2018  
11                ©RSB 2018  - All rights reserved  
 D.2.11  Titrate excess Ag with 0.1 N NH4SCN (which has been standardized to equalize normalities ) to a  
permanent light brown end point.  
D.2.12 Subtract t he amount of NH4 SCN used (D.2.11) from the total AgNO3 used in D.2.8 and D.2.9. The  
resulting difference is the ml of 0.1 N AgNO3 used in the calculation of salt (D.2.13).  
D.2.13  Calculate as % NaCl = 
) ()100)( 05845.0(3 1.0 (
ple gramsofsamNAgNO mLof
 DRS 171:2018  
ICS 67.080  
 
 
©RSB 2018  - All right s reserved