AFDC 12 (1030) DTZS  
(REV TZS 1190)  
  1 
  
                                                                       AFDC 12 (1030) DTZS   
(REV TZS 1190)  
 
 
TANZANIA STANDARD  
 
Dried Rosella  – Specification  
 
 
 
 
 
 
 
  
  
 
 
 
 
 
  
 
   
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
TANZANIA BUREAU OF STANDARDS  
     
 
AFDC 12 (1030) DTZS  
(REV TZS 1190)  
  2 
 Dried Rosella – Specification  
0 Foreword  
Rosella  (Hibiscus sabdariffa ) is an annual herbaceous shrub of the Malvaceae  family, whose leaves are 
normally used as a vegetable and the red pods that occur enclosed in their calyces are used in the food 
industry in making salads, soup , sauces, jam , beverages and other products.  
In light of the need to safeguard the consumer and in order to ensure the safety and quality of dried 
rosella  this Tanzania Standard was thus developed.  
This standard is the revision of TZS 1190 :2010  which was revised to include requirements for dried 
rosella in powdered form  
In reporting the results of a test or analysis made in accordance with this Tanzania Standard, if the final 
value observed or calculated is to be rounded off, it shall be done in accordance  with TZS 4 Rounding off 
numerical values (see clause 2).  
 
1. Scope  
This Tanzania Standard prescribes requirements , methods of sampling and tests for dried rosella , 
Hibiscus subdariffa , of Malvaceae  family  in whole or ground form  intended for human consump tion or 
industry use . 
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.  
Codex Stan 192, General standard for food additives   
TZS 4 , Rounding off numerical values   
TZS 1502, Fruits and Vegetables – Determination of Arsenic content  
TZS 109  - Food processing units – Code of hygiene   
TZS 118/ISO 4833 -1, Microbiology of food and animal feeding stuffs – Horizontal method for the 
enumeration of microorganisms – Colony -count technique at 30O C 
TZS 119 / ISO 4831 , Microbiology of food and animal feeding stuffs – Horizontal method for detection a nd 
enumeration of coliforms – Most probable number technique  
TZS 125(Part 1) , Microbiology of food and animal feeding stuffs – Horizontal method for the enumeration 
of coagulase -positive staphylococci (Staphylococcus aureus and other species) – Part 1: Colony Count 
Technique using  
TZS 131/ISO 7954 , Microbiology of food and animal feeding stuff – General guidance for enumeration of 
yeasts and moulds – Colony count technique at 25oC 
TZS 163, Processed fruits and vegetable products – Method of sampling and te st 
TZS 268 , Method for determination of lead in food stuffs  
TZS 538 , Packaging , marking and labeling of foods  AFDC 12 (1030) DTZS  
(REV TZS 1190)  
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 TZS 1316/ISO 928,  Spices and condiments - Determination of total ash  
TZS 1317/ISO 930,  Spices and condiments - Determination of acid insoluble ash  
TZS 1318 /ISO 939,  Spices and condiments - Determination of moisture content Entrainment method  
TZS 1315 /ISO 927 , Spice and Condiments - Determination of Extraneous matter and foreign matter 
content  
 
TZS 122 / ISO6579 -1, Microbiology of food and feeding stu ffs – Horizontal method for the detection of 
salmonella spp  
 
3. Terms and definitions  
For the purposes of this Tanzania s tandard, the following terms and definitions  shall apply;  
3.1 dried rosella  
the dried (flowers) calyces of herbaceous shrub of Hibiscus  sabdariffa  either whole or grounded . 
3.2 spoiled rosella  
rosella that is bruised or showing visible decomposition caused by mo ulds or any other indication of 
disease  or darkened in colour.  
3.3 extraneous matter   
dirty, pieces of skin, twigs, glass, feat hers, bits of wood, soil or any other foreign matter among or on the 
rosella.  
4. Requirements  
4.1 General   
4.1.1 Description  
Dried rosella is a sun or solar dried or artificially dried calyces (flowers) of Hibscus sabdariffa , obtained 
from a sufficiently mature red pod  presented in a whole or grounded form . Drying shall be done such that 
it prevents direct sun baking or does not make the product  prone to insect infestation and mould  growth . 
Hot air drying may be used. During drying the product shall be pro tected against high humidity, insects, 
birds, rodents and dust.  
4.1.2 Colour  
Dried rosella shall possess the characteristic purple red colour by visual examination.  
 4.1.3 Aroma  
Dried rosella shall have a floral, berry – like aroma; free from objectiona ble off odour .  
4.1.4 Flavour  
 Dried rosella, prepared with soaking and mashing in clean water shall have a well -balanced tart and 
astringent flavour. Shall be free from off flavours and other undesirable spice or cheese like flavour. When 
prepared in solu tion the solution shall visually be clear, deep red with some back ground of purple. Blue 
hue of the solution is undesirable.  AFDC 12 (1030) DTZS  
(REV TZS 1190)  
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4.1.5 Texture  
Dried rosella shall be lump free; and free flowing  
4.1.6 Extraneous  matters  
Dried rosella shall be free  from extr aneous matters when tested in accordance with Annex A.  
4.1.7 Fineness of ground dried rosell a 
Ground dried rosell a shall be free from coarse particles and shall be of such fineness that the whole of it 
passes through a sieve of 1.00 mm aperture size when t ested in accordance with the methods prescribed 
under TZS 1315.  
 
4.2 Specific  requirements  
4.2.1 Dried rosella shall also meet the physical and chemical requirement given in Table 1.  
Table 1—Requirements  for dried rosell a 
Parameter  Limit  Method of test  
Moisture, % m/m (on dry  matter basis) , 
max.  10 TZS 1318  
Acid insoluble ash; % m/m , max.  1.5 TZS 1317  
Total ash , % (m/m) max . 8  TZS 1316  
Extraneous matters . Absent  Annex A  
Particle size (for ground dried rosella)  
mm  
Less than 1   
TZS 1315  
 
 
5. Food a dditives  
Use of food additives shall be in accordance with Codex Stan 192  
 6.  Hygiene  
Dried rosell a shall be prepared  in accordance with TZS 109. The product on testing shall comply with the 
microbiological limits given in T able 2.  
 
 
 
 AFDC 12 (1030) DTZS  
(REV TZS 1190)  
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Table 2—Microbio logical  limits for dried rosell a 
Microbiological parameter,  Limit  Method of test  
Total plate count, cfu/g,  max. 103 TZS 118  
Yeast s and moulds, cfu/g, max.      103 TZS 131  
Coliforms, MPN, max.   Absent  TZS 119  
Staphylococcus aureus , cfu/ 25g , 
max.  10 TZS 125 -1 
Salmonella, cfu/ 25g  Absent  TZS 122  
 
7. Contaminants .  
7.1   Heavy metal contaminants  
Dried Rosella  shall not contain metal contaminants in excess of quantities specified in Table 3. 
 
Table 3:  Limits for metal contaminants  
 
7.2 Pesticide residues  
The maximum allowable pesticide residue limits in dried rosell a shall be as prescribed in Codex 
Alimentarius Commission . 
8. Methods of sampling and test   
 8.1 Sampling  
Dried rosella shall be sampled in accordance with TZS 163   
8.2 Test  
Dried rosella shall be  tested for compliance with the requirements of this standard as described in this 
standard.    Heavy metals  Maximu m limit  
mg/kg  Test method  
Arsenic (As )  0.2 TZS 1502  
Lead (Pb)  0.2 TZS 268 AFDC 12 (1030) DTZS  
(REV TZS 1190)  
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 9.  Packing, marking and labeling    
9.1 Packing  
Dried r osella shall be packed in such a way that the produc t is protected from undue spoilage. The 
packaging materials  shall be of food-grade , clean and of a quality such as to avoid causing any damage 
to the produc t and  prevent or minimize moisture loss and oxi dation .  
 
9.2 Marking and Labelling  
In addition to TZS 538 the following particulars shall legibly and indelibly be marked or labeled on each 
container.  
i) Name of the produc t – “Dried rosell a calyces”  or “ground rosel la” 
ii) Brand or trade name, if any  
iii) Name and address of the producer/ packer/exporter or dispatcher  
iv) Country  of origin   
v) Storage conditions  
vi) Net weight  in gm or kg  
vii) Batch number in code or in clear.  
viii) Date of packing and best before date 
ix) Instruction for use  
9.3 Each c ontainer may also be marked with the TBS standards mark of quality.  
 
NOTE  – The use of the TBS certification mark is governed by the provision of the  
Standards Act, 2009.  Details of conditions under which a license for the use of TBS certification 
mark m ay be granted to the manufacturer may be obtained from TBS.  
 
 
 
 
 
 
 
 
 
 AFDC 12 (1030) DTZS  
(REV TZS 1190)  
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Annex A  
Determination of filth  
A.1 Principle  
Visual inspection and examination of the residue after physical separation of filth from the  
material being investigated.  
A-2 Examination of heavy filth such as glass and sand  
A-2.1 Procedure  
Weigh 10 g sample into 250 ml beaker. Add 150 ml petroleum ether and boil gently for 15 minutes on 
steam bath in hood. Occasionally  add petroleum ether to keep volume constant. Decant petroleum ether 
on to smoot h 7 cm paper in Buchner . Add 150 ml CHCl 3 to beaker and let stand for 30 minutes with 
occasional stirring. Decant sample and CHCl 3 on to funnel, leaving the heavy residue of glass, sand, soil, 
if any in the beaker. If appreciable quantity of sample tissues  remains on the bottom of beaker, add 
successive portion of CHCl 3 mixed with CCl 4 to give increasingly higher specific gravity until practically all 
sample tissue is floated off. Transfer residue from the beaker to an ashless paper and examine 
microscopica lly to establish presence of any sand, glass or soil. If there is an appreciable amount of 
residue, place paper in weighed crucible, ignite, and weigh to determine quantitatively the amount of 
glass sand and soil.  
A.2.2 Expression of result  
Express the res ults in terms of presence or absence of filth under investigation.  
A-3 Examination of light filth such as rodent hair  
A-3.1 Procedure  
Thoroughly dry the material in buchner and transfer, including fine material that must be  scraped from 
paper, to the trap flask. Add approximately 150 ml of water, heat to boiling point, and simmer 15 minutes, 
with stirring; wash down inside of flask with H 20; and cool to less than 20 ºC. Add 25 ml heptane, mix 
thoroughly, and let it stand for 5 minutes, then fill the flask w ith water and let it stand for 30 minutes. Stir 
every 5 minutes, trap off; and filter. Add approximately 15 ml heptane and mix thoroughly; trap off and 
filter second time after 15 minutes. If the second extraction yields appreciable amount of filth, decant  most 
of the liquid from the flask, add 15 ml heptane and make third extraction. Finally examine the paper 
microscopically for any presence of feathers or rodent hair.  
A-3.2 Expression of results  
Express the results in terms of presence or absence of filth  under investigation.  
 
 
 
 AFDC 12 (1030) DTZS  
(REV TZS 1190)  
  8