FINAL DRAFT UGANDA 
STANDARD  
  FDUS EAS 774
First Edition
2012-mm-dd
 
 Reference numbe r
FDUS EAS 774: 2012
© UNBS 2012
  
Sweetpotato crisps — Specification 
 FDUS EAS 774: 2012 
i i                 ©  U N B S  2012 - All rights reserved 
 Compliance with this standard does not, of itself confer immunity from legal obligations 
A Uganda Standard does not purport to include all necessary provisions of a contract. Users are 
responsible for its correct application  
© UNBS 2012 
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilised in any 
form or by any means, electronic or mechanical, in cluding photocopying and microfilm, without prior written 
permission from UNBS. 
Requests for permission to reproduce this document should be addressed to 
The Executive Director 
Uganda National Bureau of Standards 
P.O. Box 6329 
Kampala  
Uganda 
Tel: 256 41 505 995 
Fax: 256 41 286 123 
E-mail: unbs@infocom.co.ug  
Web: www.unbs.go.ug  
 FDUS EAS 774: 2012 
© UNBS  2012 - All rights rese rved                iii National foreword 
Uganda National Bureau of Standards (UNBS) is a parastatal under the Ministry  of Tourism, Trade and 
Industry established under Cap 327, of the Laws of U ganda. UNBS is mandated to co-ordinate the elaboration 
of standards and is  
(a) a member of International Organisation for Standardisation (ISO) and  
(b) a contact point for the WHO/FAO Codex A limentarius Commission on Food Standards, and  
(c) the National Enquiry Point on TBT/SPS Agr eements of the World Trade Organisation (WTO). 
The work of preparing Uganda Standards is carried out through Technical Committees. A Technical 
Committee is established to deliberate on standards in a gi ven field or area and consists of representatives of 
consumers, traders, academician s, manufacturers, governme nt and other stakeholders. 
Draft Uganda Standards adopted by the Technical Committ ee are widely circulated to stakeholders and the 
general public for comments. The committee reviews the comments before recommending the draft standards 
for approval and declaration as Uganda Standards by the National Standards Council. 
This Final Draft Uganda Standard, FDUS EAS 774: 2012 , Sweetpotato crisps  — Specification, is identical 
with and has been reproduced from an East African Standard, EAS 774: 2012 , Sweetpotato crisps  — 
Specification,  and is being proposed for adoption as a Uganda Standard.  
This standard was developed by Food and agriculture Standards Technical Committee (UNBS/TC 2).  
Wherever the words, “East African Standard" appea r, they should be replaced by "Uganda Standard." 
 
 
   EAS 774:2012
ICS 67.080.20
 
© EAC 2012               First Edition 2012  
 
EAST AFRICAN STANDARD 
 
Sweetpotato crisps — Specification 
 
     
 
               
EAST AFRICAN COMMUNITY EAS 774:2012 9 
 
© EAC 2012 – All rights reserved               ii 
 Foreword 
 
Development of the East African Standards has been necessitated by the need for harmonizing requirements 
governing quality of products and services in East Africa. It is envisaged that through harmonized 
standardization, trade barriers which are encountered when goods and services are exchanged within the 
Community will be removed.   
In order to meet the above objectives, the EAC Partner  States have enacted an East African Standardization, 
Quality Assurance, Metrology and Test Act, 2006 (EAC SQMT Act, 2006) to make provisions for ensuring 
standardization, quality assurance, metrology and testing of  products produced or originating in a third country 
and traded in the Community in order to facilitate industrial development and trade as well as helping to 
protect the health and safety of societ y and the environment in the Community. 
 
East African Standards are formulated  in accordance with the procedures established by the East African 
Standards Committee. The East African Standards Committe e is established under the provisions of Article 4 
of the EAC SQMT Act, 2006. The Committee is compos ed of representatives of the National Standards 
Bodies in Partner States, together with the repr esentatives from the priv ate sectors and consumer 
organizations. Draft East African Standards are circul ated to stakeholders through the National Standards 
Bodies in the Partner States. The comments received are discussed and incorporated before finalization of 
standards, in accordance with t he procedures of the Community.  
 
Article 15(1) of the EAC SQMT Act, 2006 provides that “Wit hin six months of the declar ation of an East African 
Standard, the Partner States shall adopt, without deviation from the approved text of the standard, the East 
African Standard as a national standard and withdraw any existing national standard with similar scope and 
purpose”.  East African Standards are subject to review, to keep pace with technological advances. Users of the East 
African Standards are therefor e expected to ensure that they always hav e the latest versions of the standards 
they are implementing.   
© East African Community 2012 — All rights reserved * 
East African Community  
P O Box 1096  
Arusha 
 
Tanzania  
Tel: 255 27 2504253/8 
Fax: 255-27-2504481/2504255 E-Mail: eac@eachq.org
 
Web: www.each.int 
                                                      
* © 2012 EAC — All rights of exploitation in any form and by an y means reserved worldwide for EAC Partner States’ NSBs.  
 EAS 774:2012 
© EAC 2012 – All rights reserved                 iii 
 Acknowledgement 
This standard was devel oped with support from the Policy Analysi s and Advocacy Programme (PAAP) of the 
Association for Strengthening Agricult ural Research in Eastern and Cent ral Africa (ASARECA). This was 
possible though a grant by the United States Agency for International Development (USAID). This support 
was used in the process of formulation and mobilization of stakeholders to review the standard in national and 
regional fora. This support is hereby acknowledged. EAST AFRICAN STANDARD EAS 774:2012
 
1               © EAC 2012 – All rights reserved 
 Sweetpotato crisps — Specification 
1 Scope 
This East African Standard specifies the requirements and methods of sampling and test for crisps 
made from storage roots of sweetpotato [ Ipomoea batatas (L.) Lam.] 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. For undated  references, the latest edition of the referenced 
document (including any amendments) applies. 
EAS 35, Edible salt – Specification  
EAS 38,  General standard for the labelling of pre-packaged foods  
EAS 39, Hygiene in the food and drink manufacturing industry – Code of practice  
EAS 82, Milled cereal products – Methods of test  
EAS 103, Schedule for permitted food additives 
EAS 771 , Fresh sweetpotatoes – Specification 
EAS 773, Sweetpotato flour – Specification  
CODEX STAN 193 , Codex General Standard for Contaminants and Toxins in Food and Feed 
ISO 712, Cereals and cereal products — Determination of moisture content — Routine reference 
method  
ISO 3960, Animal and vegetable fats and oils – Determination of peroxide value – Iodometric (visual) 
endpoint determination 
ISO 6579, Microbiology of food and animal feeding stuffs  — Horizontal method for the detection of 
Salmonella spp.  
ISO 7251  Microbiology of food and animal feeding stuffs — Horizontal method for the detection and 
enumeration of presumptive Escherichia coli — Most probable number technique 
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 24333, Cereals and cereal products — Sampling   EAS 774:2012 9 
3 Terms and definitions 
For the purpose of this standard, the fo llowing terms and definitions shall apply. 
3.1  
sweetpotato crisps thin slices of peeled and washed  sweetpotat o storage roots, deep -fried  until crunchy 
3.2 food grade material material that is free from substances that ar e hazardous to human health and may be permitted to 
come in contact with food. 
3.3 
foreign matter 
organic and inorganic materials (such as sand, soil, glass) other than extraneous matter in the crisps  
3.4 
extraneous matter 
organic matter of sweetpotato origin  other than sweetpotato crisps 
4 Essential quality and compositional requirements 
4.1 Raw materials 
The following materials shall be used in the processing of sweetpotato crisps: 
a) Sweetpotato stor age roots conforming to EAS 771; 
b) Sweetpotato flour conforming to EAS 773; and 
c) edible oil or fat conforming to  relevant East African Standards. 
4.2 Optional Ingredients 
The following optional ingredients may be used: 
a) spices and condiments conforming to relevant East African Standards; and 
 
b) edible salt conforming to EAS 35. 
 
4.3 Finished product  
4.3.1 Physical and sensory factors 
Sweetpotato crisps shall: 
a) have a colour that is characte ristic of the variety. Where spices or other additives are used, the 
colour shall be characteristic of that ingredient; 
b) be free from off-flavour, rancidity, bitter taste and any other blemish; c) be free from extraneous and foreign matter;  
d) be uniform in size and have a thickness of 1.0 mm - 2.0 mm; and  
 
© EAC 2012 – All rights reserved               2 
 EAS 774:2012 
e) be crunchy or crispy and free fr om sogginess and excessive oil. 
 
4.3.2 Defects 
Sweetpotato crisps shall not contain more than 10 % by mass of small pieces, slivers and irregular 
pieces.  
Packaged sweetpotato crisps shall hav e not more than 1 % by mass of the crisps with the following 
defects: 
a) surface or internal pigmentation; 
b) blisters; 
c) callous area; and d) black specks and spots. 
4.4 Composition requirements for sweetpotato crisps 
Sweetpotato crisps shall conform to the specified composition in Table 1. 
Table 1 — Compositional requirements for sweetpotato crisps 
S/N Parameter Requirements Method of test 
1 Moisture content, %, by mass, max. 5.0 ISO 712 
2 Fat content on dry weight bas is, %, max.  35.0 Annex A 
3 Free fatty acids on dry weight basis, %, max. 0.5 Annex B 
4 Sodium chloride (NaCl) on dry weight basis, %, max 2.0 Annex C 
5 Acid insoluble ash, %, by mass, max 0.05 EAS 82 
6 Peroxide value, meq oxygen per gram 0.5 ISO 3960 
5 Food additives 
Food additives may be used in the preparation of  sweetpotato crisps in  accordance with EAS 103. 
6 Contaminants 
6.1 Pesticide residues  
Sweetpotato crisps shall conform to maximum residue limits for pesticide residues established by the 
Codex Alimentarius Commission for this commodity. 
6.2 Other contaminants  
Sweetpotato crisps shall comply with the maxi mum levels of the Codex General Standard for 
Contaminants and Toxins in Food and Feed (CODEX STAN 193). 
© EAC 2012 – All rights reserved               3 
 EAS 774:2012 9 
7 Hygiene  
Sweetpotato crisps shall be pre pared and handled in a hygienic manne r in accordance with EAS 39   
and shall conform to microbiological limits specified in Table 2. 
Table 2 — Microbiological limits for sweetpotato crisps 
S/N Micro-organism(s) Requirements Method of test 
1 Escherichia coli, cfu/g, max. <1 ISO 7251 
2 Salmonella , 25g, max. absent ISO 6579 
3 Yeasts and moulds, cfu/g, max. 103 ISO 21527-2 
 
8 Packaging 
 
Sweetpotato crisps shall be packaged in food grade  material which will safeguard the hygienic, 
nutritional and organoleptic qualities of the product. 
9 Weights and measures 
Sweetpotato crisps shall be packaged in accordance with the Weights and Measures requirements of 
the destination country.  
10 Labelling  
10.1  In addition to the requirements of EAS 38, the following specific labe lling requirements shall 
apply and shall be legibly  and indelibly marked: 
a) common name of the product ‘sweetpotato crisps’; 
b) name, and physical address of the manufacturer/ distributor and /or trade name/ brand name; 
c) if spiced they shall be label led ‘Spiced sweetpotato crisps’; 
d) date of manufacture; 
e) list of ingredients; 
f) lot identification;  g) expiry date;  
h) country of origin; 
i) the net weight in metric units; j) storage instructions; 
k) declaration stating “salted” or “unsalted”; 
l) declaration of flavouring agent or spice used; and 
 
© EAC 2012 – All rights reserved               4 
 EAS 774:2012 
m) instructions on disposal of used package. 
 
10.2 When labelling non-retail packag es, information for non-retail pa ckages 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. 
11 Sampling 
Sampling of sweetpotato crisps shall be done in accordance with ISO 24333. 
12 Criteria for conformity  
A lot shall be declared as conforming to this standard if samples inspected or analysed for quality 
requirements conform to the provisions of this standard. 
 
  
 
 
 
 
  
 
  
 
 
 
 
 
© EAC 2012 – All rights reserved               5 
 EAS 774:2012 9 
Annex A 
(normative) 
 
Determination of fat content 
A.1 Principle of the method 
This is achieved by the Soxhlet method with ether or petroleum ether. 
When reporting the results, the method and so lvents used for extraction shall be stated. 
All substances which can be extracted from the materials to be tested by the above-mentioned 
solvents, and which are not volatile when dried for one hour at 105 °C, are reported. 
A.2 Soxhlet method 
The fatty substance is extracted comp letely with dry peroxide, free diethyl ether or with dry petroleum 
ether (boiling point below 60 °C) in a Soxhlet apparatus. 
The material to be tested has previously been dried, possibly with addition of Na 2SO 4. 
A.3 Reagents 
A.3.1 Dry peroxide , free ethyl ether or petroleum ether (B.p. below 60 °C). 
A.3.2 Na 2SO 4 
A.4 Apparatus 
A.4.1 Extraction thimble 
A.4.2 Fat-free cotton pad 
A.4.3 Soxhlet apparatus A.4.4 Metal spiral or glass bulb 
A.4.5 Oven,  103 °C – 105 °C  
A.4.6 Desiccator  
A.5 Procedure 
About 5 g – 10 g of the finely ground substance is placed in the extraction thimble and latter closed 
with a fat-free cotton pad.  If the material is very ri ch in fat, it is recommended to mix it intimately with 
an equal amount of dried sand. 
 
© EAC 2012 – All rights reserved               6 
 EAS 774:2012 
If necessary, the thimble with contents is dried at 100 °C. The extraction is performed in the Soxhlet 
apparatus. 
In order to drain off the solvent from the extracti on thimble as completely as possible at the end of 
each siphonage, a metal spiral of a glass bulb is placed under it. 
The extraction shall be continued for at least 4 h, during which time the thimble will have been 
emptied about 30 times.  The apparatus is then ta ken apart and the petroleum ether distilled off.  The 
last traces of ether and moisture are removed by dryi ng for one hour either in vacuum at 70 °C, or in a 
drying oven at 103 °C – 105 °C. 
By passing an air current through the flask before  and after drying, all traces of petroleum ether 
vapour are removed. 
Allow to cool for 20 min in a desiccator and weigh.  As a control, the drying shall be repeated for 30 
min, followed by blowing through, cooling and weighing. 
The difference between two weighings shall not exc eed 0.05 % of the fat values obtained, otherwise 
the drying has to be repeated. 
 
© EAC 2012 – All rights reserved               7 
 EAS 774:2012 9 
Annex B 
(normative) 
 
Determination of free fatty acids 
B.1 Apparatus 
Soxhlet fat extraction apparatus 
B.2 Reagents 
B.2.1 Petroleum ether, distilling below 65 °C, or ethyl ether. 
B.2.2 Alcohol potassium hydroxide, 0.1 N (use absolute or alcohol denatured with methanol 
B.2.3 Alcohol-ether mixture, equal volumes of 96 % alcohol and ethyl ether 
B.2.4 Phenolphthalein solution, 1 % in alcohol or alcohol denatured with methanol. Add 0.3 mL 
per 100 mL mixture of alcohol-ether and add alcoholic KOH solution to a faint pink. 
B.3 Procedure 
B.3.1 Extract 10.00 g ± 0.01 g of the sample taken in a thimble with petroleum ether for about 4 h in 
a Soxhlet extraction apparatus.  Completely evapor ate the solvent from the extraction flask (weighed 
previously) on a steam bath, cool and weigh the extraction flask with the residue.  Dissolve the 
residue in the extraction flask with the 50 mL of the alcohol-ether phenolphthalein solution. Titrate the 
dissolved extract, with standard potas sium hydroxide solution, to a faint pink colour, which persists for 
10 s.  If emulsion is formed during titration, dispel by adding a second 50 mL portion of the alcohol-ether phenolphthalein solution. 
B.3.2 Make a blank titration on 50 mL of the alcohol-ether phenolphthalein solution and substract 
this value from the titration value of the sample.  If the additional 50 mL portion of the alcohol-ether 
phenolphthalein solution is added, double the blank titration. 
B.4 Calculation 
Calculate the acid value from the following formula: 
Acid value (as oleic acid) =  
MVN56.1 
where, 
V is the volume, in mL, of standard potassium hydroxide solution used; 
N is the normality of standard potas sium hydroxide solution; and  
M is the mass, in g, of the material taken for the test. 
 
© EAC 2012 – All rights reserved               8 
 EAS 774:2012 
Annex C 
(normative) 
 
Determination of the sodium chloride content 
C.1 Scope 
This method determines the content of chlorides. 
C.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. 
C.3 Principle 
Quantitative precipitation of the ha lides extracted from the ash in a nitric acid solution with AgNO 3 in 
excess. 
Back titration of the surplus AgNO 3 with ammonium thiocyanate, us ing ferric alum (ferric ammonium 
sulphate) as the indicator. 
C.4 Reagents 
C.4.1 Distilled or demineralized water 
C.4.2 AgNO 3 solution,  0.1 N (16.9888 g AgNO 3) 
C.4.3 NH 4SCN solution , 0.1 N (7.6113 g NH 4SCN). In practice a slightly higher weight is taken and 
the solution is adjusted by dilution against a 0.1 N AgNO 3 solution. 
C.4.4 Cold saturated NH 4Fe(SO 4)2.12H 2O solution  (approximately 40 %). The ensuing brown 
colouring is eliminated by adding pure nitric acid dropwise. 
C.4.5 HNO 3 (approximately 30 %) 
C.4.6 Diethyl ether of nitrobenzene 
C.5 Apparatus 
C.5.1 Measuring flask, 100 mL  
C.5.2 Burette, 50 mL 
C.5.3 Erlenmeyer flask, 200 mL C.5.4 Pipettes 
© EAC 2012 – All rights reserved               9 
 EAS 774:2012 9 
 
© EAC 2012 – All rights reserved               10 
 C.5.5 Funnel, filtering paper 
C.6 Procedure 
The ash (residue after carbonisation 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 aliq uot part of this solution, which should preferably 
contain 50 mg – 100 mg NaCl, taken off, dist illed water being added to obtain a quantity of 
approximately 100 mL. 
Subsequently 5 mL ferric alum so lution (see C.4.4), 20 mL 0.1 N AgNO 3 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 solution 0.1 N (see C.4.3), until the red colouring remains after stirring. 
C.7 Expression of results 
Report in percentage by weight to one decimal place. 
Chloride content = 
P Vx    1V V V 100   x    x  ) (   5.65 3 2−  
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, AgNO 3 added; 
V3 is the volume, in mL, NH 4SCN necessary for back titration. 
 EAS 774:2012
  
© EAC 2012 — All rights reserved