Expanding cassava production and commercialization

June 12 15.00 – 15.40

Chair: Prof. Lennart Salomonsson

Cassava commercialization – adding value through product development -

The SLU Global Food Security Research Symposium

Results of a Swedish Government Initiative June 12-13

By Leon Brimer , Emmanuel Ohene Afoakwa , Drinah Banda Nyrienda & Linley Chiwona-Karltun

Right now there is much emphasis on Africa’s growth • food is in this respect a factor of great importance , because:

• Growing populations means growing demands in general • Growing wealth means growing wishes for a higher food diversity • Growing towns means growing needs for food with a long shelf life • Changed life styles means growing markets for “convenience food”

• Food products developed need to fulfill these demands at the same time this means: • possibilities of adding value to the products

• whether sold locally • nationally • or exported

Plant crops – which and why those? • Out of the estimated more than 300.000 green plant species

• Mankind basically depends on very few staple crops

• In a modern African context maize and cassava are among the most important ; especially with regard to energy (starch crops)

• Both were brought to the continent from the Americas

• Cassava is estimated to be the major calorie providing crop for at least 500 million people However: • The starch containing root after harvest is highly perishable • Out of the major staple crops worldwide cassava is , however, the only one

domesticated as landraces/cultivars containing acutely poisonous concentrations of naturally occurring plant toxins (so-called cyanogens)

HO OH R2 R2

R3 - C - C - CN = HO - C - CN C = O + HCN R2 R1 R3 R3

+ R1 - OH

O R2

R3 - C - C - CN R1 - O - C - CN

R2 R1 R3

Cyanohydrin Cyanohydrin

Hydroxynitrilelyase or

OH-

Hydrogen-cyanide

H3O+

2,3-Epoxynitrile

H2OHydrolases

Cyanogenic glycoside/lipid

CN- +H2O

OH-H+

Cyanide

Reactions to form cyanide: Cyanogens = cyanogenic compounds

In the case of Cassava

Both due to perishability and to the potential toxicity! • cassava roots in general must be processed soon after

harvest

The reactions to the new varieties – 1.

• In West Africa (notably Nigeria and Ghana) an established industrial production of stable fermented food products - such as Gari.

Standards for cassava

• 1993 JECFA – max. 10 mg HCN/kg flour • 2003 Codex – max. 50 mg HCN/kg fresh (sweet) root • 2010 Codex – fresh bitter roots (over 50 mg HCN/kg)

must be labled to be processed to detoxify • 2010 EAC – bitter roots contain more than 50 mg

HCN/kg f.w. However,sweet roots when analysed must contain up to 200 mg HCN/kg

• 2000 – Indonesia ”food” must not contain more than 40 mg HCN/kg f.w.

However • Imported fresh roots for sale in retail shops as sweet cassava

in Europe have been shown to often have a higher content: (Kolind-Hansen and Brimer, 2010)

• As has frozen peeled large pieces imported to Australia (Burns et al., 2012).

• And cassava chips imported to Australia

Kolind-Hansen, L. & Brimer, L. (2010). The retail market for fresh cassava root tubers in the European Union (EU); the case of Copenhagen, Denmark. A chemical food safety issue? J. Sci. Food Agric. 90, 252-256.

Burns, A. E., Bradbury, J. H., Cavagnaro, T. R. & Gleadow, R. M. (2012). Total cyanide content of cassava food products in Australia. J. Food Comp. Anal. 25, 79-82.

So – quality assurance must be in place for food safety – AND to ensure export!

The reactions to the new varieties – 2.

A few small and medium-scale traders and processors have emerged to experiment with cassava-processing ventures

Towards effective production, product diversification, quality assurance

1 – Basic survey to disclose the following a – what is grown? b – what is generally known about the grown landraces/cultivars? c – which cultivars are used for which products? d – how are the products produced (description of processing)? e – what are the general characteristics of each product? f – what is known (can be shown through analysis) about product food safety? g - what is the situation concerning commercial production and marketing?

Nyirenda, D.B., Chiwona-Karltun, L., Chitundu, M., Haggblade, S. and Brimer, L. (2011). Chemical food safety of cassava products in regions adopting cassava production and processing – experience from Southern Africa. Food and Chemical Toxicology 49, 607-612

Haggblade, S., Andersson Djurfeldt, A., Banda Nyrendah, D., Bergman-Lodin, J., Brimer, L., Chitundu, M., Chiwona-Karltun, L., Cuambe, C., Dolislager, M., Donovan, C., Droppelmann, K., Jirström, M., Mudema, J., Kambwea, E., Kambewa, P., Nielson, H., Nyembe, M., Salegua, V.A., Tomo, A. and Weber, M. (2012). Cassava Commercialization in Southeastern Africa. Journal of Agribusiness in Developing and Emerging Economies. 2(1), 4-40.

On the basis of the information gathered a new more detailed survey of cassava cultivars was performed

First study period of CATISA and its results

The purpose of a second survey was: • To investigate the dynamics (changes) in landraces/cultivars used

• To disclose the reasoning for keeping cultivars or to skip them, respectively

• To disclose changes in products and product processing if any

• To thereby get a solid background for further product and processing development

INFORMATION OBTAINED ON THE CASSAVA VARIETIES

1. Information on the source and description of the cassava varieties

CASSAVA VARIETIES

PART A: INFORMATION ON THE SOURCE PART B: INFORMATION ON THE DESCRIPTION Source Local/Hybrid Institution which

introduced the variety

Characteristics of the leaves and stalks/stems

Characteristics of the tubers outer covers

Resistance to disease and drought tolerance

Kampolombo

MST Varieties –Kasama Roots and Tubers Res Center

Hybrid and sweet variety

FODIS Large brown leaves

Large light brown tubers

Become less disease resistant after growing for a longer period (4Years). Less drought tolerant

Bangweulu Same as above

Hybrid and bitter variety

FODIS Purplish leaves Brown tubers Less disease resistant and less drought tolerant

Chila

Same as above

Hybrid and a slightly bitter variety

FODIS Green leaves Light brown tubers

Disease tolerant but attacked by ants, a bit drought tolerant

Mweru Same as above

Hybrid and sweet variety

FODIS Brown stem Medium brownish tubers

Disease tolerant and not drought tolerant

Mweulu Tanzania Local and sweet variety

Chinsali District Green thin leaves, reddish stalks

Brown outer cover but reddish tubers

Disease resistant and drought tolerant

Tanganyika Tanzania Local and sweet variety

Chinsali District Light green leaves, whitish stalks

Whitish tubers Disease resistant and drought tolerant

Nalumino

MST Varieties –Kasama Roots and

Hybrid FODIS Light brownish leaves, brown stalks

Large brown tubers

Disease resistant and attacked by ants during drought.

1. Information on the preference and use of the cassava varieties

CASSAVA VARIETY

PART C: INFORMATION ON THE PREFERENCE AND USE PREFERENCE USE

Liking of the variety

Reason(s) for liking the variety How the variety is used

Kampolombo

Yes

The leaves are nice for relish), the tubers can be cooked fresh because they are sweet and milled dried tuber make a nice cassava mealie meal for Nshima.

The fresh tuber can be eaten raw, cooked or roasted. The fresh leaves can be pound and cooked as relish. The dried tubers can be stored up to six months and milled into cassava mealie-meal and flour.

Bangweulu

Yes The tubers are bigger and more starchy but bitter

The dried tubers can be milled into cassava mealie-meal and flour. The tubers cannot be eaten raw but can be roasted after soaking.

Chila Yes

High yield but is bitter

The dried tubers can be milled into mealie-meal and flour. The tubers cannot be eaten raw but can be cooked or roasted after soaking. The fresh leaves can be pound and cooked as relish.

Mweru

Yes

Tubers are starchy and high yielding and sweet

The fresh tuber can be eaten raw, cooked or roasted. The fresh leaves can be pound and cooked as relish. The dried tubers can be milled into mealie-meal and flour.

Mweulu- local

Yes

Gives high yields and it’s not bitter

The fresh tuber can be eaten raw, cooked or roasted. The fresh leaves can be pound and cooked as relish. The dried tubers can be milled into mealie-meal and flour.

Tanganyika Yes Tubers can be cooked fresh, are sweet

Can be eaten raw, cooked or roasted. Milled into mealie meal and flour.

Nalumino

Yes

The tubers grow bigger (After 2 years) and give a high yield and are

The fresh tuber can be eaten raw, cooked or roasted. The fresh leaves can be pound and cooked as relish. The dried tubers can be

CASSAVA VARIETY PART C: INFORMATION ON THE PROCESSING METHODS AND STORAGE

PROCESSING METHODS STORAGE

Method(s) Used Reason(s) for using this/these method(s)

Storage of flour and dried cassava products

Shelf life of flour and dried cassava products

Kampolombo Chipping, Grating or Soaking

Soaking method; people just like it.

Dried cassava products are stored in sacks, store for longer. The flour is stored in plastic packages – store for shorter period.

Dried products can stay for a longer time without being attacked by weevils while flour can be stored for 6-10 months.

Bangweulu

Soaking. To increase the yield, Bangweulu after soaking, can be mixed with pounded chips of any sweet variety prior to drying.

To remove cyanides and give fermented flavour

Chila Soaking method; for mealie meal. Chipping; for flour.

Mweru Chipping, Grating or Soaking

Soaking for fermented taste

Mweulu

Chipping, Soaking Nshima prepared chipped mealie meal is thick just like maize. Nshima form soaked cassava is slippery and hold the stomach for a longer time.

Tanganyika Chipping. However, the chips can soaked for a day( If they taste bitter) prior to drying

Nshima prepared from this cassava mealie-meal tastes like maize meal.

Nalumino Chipping, Soaking For fermented taste

Manyokola

•Information on the processing methods and storage of the varieties

To choose cultivars for optimal product development

physiochemical properties must be known

So the following investiations has been undertaken: • Proximate analysis (crude protein etc)

• Minerals

• Total cyanogens (toxins)

• Viscoelastic

Of different cultivars

And since cassava roots

and their products do not show any significant levels

of the mycotoxins aflatoxins

– in contrast to maize -

Figure 1. Chemical structure of sterigmatocystin (A) and aflatoxin B1 (B).

Now we are ready and so are farmers for further product development

industrialisation of production

Thank you!

Leon Brimer - M.Sc., Ph.D. and D.Sc. (pharm) – Associate Professor of Chemical Food Safety, University of Copenhagen, Faculty of Health and Medical Sciences, Department of Veterinary Disease Biology Appointed Panel member (by the EFSA’s Management Board) of :

•the “EU Scientific Panel on Food contact materials, flavourings, enzymes and processing aids ” (CEF), under the European Food Safety Authority (EFSA), Parma, Italy. ♦Under CEF member of the two workgroups (WG’s):

♦ (1) Flavourings WG and ♦(2) Processing Aids WG

Additional: member of the “Work Group on alkaloids in food” under the Panel of Contaminants in the Food Chain (CONTAM) under (EFSA).