Previous PageTable Of ContentsNext Page

Organization: Institute of Agricultural Research Organization, Holetta Agricultural Research Center (IARO) (http://www.)
Author: Alemayehu Refera
Edited by AGSI/FAO: Danilo Mejia (Technical), Beverly Lewis (Language & Style), Beverly Lewis (HTML transfer)

CHAPTER XVI TEF: Post-harvest Operations


1.1 Economic and Social Impact of Tef

1.2 World Trade

1.3 Primary Products

1.4 Secondary and derived product

1.6 Consumer preference


1. Introduction

Preface

A large amount of time and effort is required to produce a crop until it is harvested. The importance of post production operations is as important as pre-production operations. The utilization of certain crops in different ways as one component and storage and handling of the product as a second component should be given due consideration especially in developing and underdeveloped countries. In a few developing and underdeveloped countries, certain crops are especially produced and consumed, which are not known or totally neglected by the developed countries. Excellent examples are Tef, Eragrostis tef (Zucc.) Trotter and Niger (locally known as Noog), Guizotia abyssinica (L. f.) Cass, which is produced in Ethiopia and India consisting about 50 percent of Ethiopian and 3 percent of Indian oilseed production. These crops amongst others have a stable system of pre-and post harvest operations and utilization. However, no or little emphasis is given to these crops by developed countries. Both the production and research for the improvements of these crops are borne by underdeveloped nations. It is essential that the pre- and post production systems and problems encountered be brought to the attention of developed countries. In this way, system problems attached to post production systems can be solved.

By reducing losses due to post harvest handling problems, it can be possible to feed more people in the world. Apparently, it is possible to reduce loss of the produce during harvesting, threshing, cleaning, transporting, storage and preparation as human consumption and as animal feed.

1. Introduction

Tee, Eragrostis tef (Zucc.) Trotter is a staple food crop of Ethiopia. It has existed in Ethiopia since recorded history of the country and some authorities believed that the pre-Semitic inhabitants might have domesticated it in BC. Tef originated and has diversified in Ethiopia. Ethiopian farmers grew it for centuries because of its various merits. Otherwise it would not have existed after the introduction of other cereals such as maize, wheat, barley and others. Tef accounts for about two-third of the daily protein intake in the diet of the population (Ethiopian Nutrition Survey, 1959). Its grain is mainly used for making different kinds of Enjera (pancake-like flat bread), porridge and feed. It is also used in making a local alcoholic drink called Arak'e or katikalla and a native beer called T'ella or Fersso. The straw is used mainly for reinforcing mud for plastering wooden walls of buildings and for livestock feed. It is also used as mulch. Tef has a high economic value as its grain can be kept for many years in practically any kind of storage facilities without being seriously damaged by common storage insect pests (Tadesse, 1969). The area under cultivation is over one million hectares of land each year. During the 1994/95 cropping season, tef occupied 32 percent of the cultivated land under cereals, while maize occupied 19 percent, sorghum 16 percent, barley 15 percent, wheat 13 percent, millet 4 percent and oats 1 percent [Central Statistical Authority (CSA), 1995]. This is similar to previous production years and clearly shows the importance of tef in Ethiopia. During the Belg season, which is the autumn season in Ethiopian (from February to the end of May) tef, is grown in very limited areas and occupies less land. According to the Central Statistical Office, 1996, the share of tef against cereals was 6.40 percent and the total production share is 4.33 percent, indicating that tef is predominately a main season crop. Tef is also an export crop. The crop was exported to the Middle East, North America and to many European countries, mainly for Ethiopians or of Ethiopian origin that have immigrated to these countries. Outside Ethiopia, there is a growing interest in using tef. For example, small-scale commercial production of tef has begun in a few areas of the wheat belts of the USA, Canada and Australia. Tef has been introduced to South Africa and is cultivated as a forage crop and in recent years, it has been cultivated as a cereal crop in Northern Kenya (Seyfu, 1997).

Origin and Centre of Diversity

Vavilov (1951) identified Ethiopia as the centre and origin of tef. Hence, Ethiopia is the appropriate and most important centre for the collection of tef germplasm. Tef belongs to the genus Eragrostis. This genus contains about 300 species. Within the genus Eragrostis, 43 percent of the species seem to have originated in Africa, 18 percent in South America, 12 percent in Asia, 10 percent in Australia, 9 percent in Central America, 6 percent in North America, and 2 percent in Europe (Costanza, 1974). Of the 54 Eragrostis species listed in Ethiopia, 14 (or 26 percent) are endemic (Cufodontis, 1974).

Tef is endemic to Ethiopia and its major diversity is found only in that country. As with several other crops, the exact date and location for the domestication of tef is unknown. However, there is no doubt that it is a very ancient crop in Ethiopia, where domestication took place before the birth of Christ (Seyfu, 1997). According to Ponti (1978) tef was introduced to Ethiopia well before the Semitic invasion of 1000 to 4000 BC. It was probably cultivated in Ethiopia even before the ancient introduction of emmer and barley.

Names of the species and taxonomy

Tef, Eragrostis tef (Zucc.) Trotter belongs to the family Poaceae, subfamily Eragrostoideae, Tribe Eragrostae and genus Eragrostis. The genus contains about 300 species (Costanza 1974). Accepted synonyms of Eragrostis tef (Zucc.) Trotter, are E. pilosa (L.), P. Beauv sub-sp. abyssinica (Jacq.) Aschers et Garebn., E. abyssinica (Jacq.) Link, Cynodon abyssincus (Jacq.) Rasp, Poa cerealis Salisb, P. abyssinica Jacquin, P. tef Zuccagni,

The common vernacular name of the crop in Ethiopia is Tef. It is also known by the vernacular name Tafi in Oromigna another main language of the Ethiopian people and Taf in Tigrigna, which is also another language of the Ethiopian people.

Brief Description of the Crop

Tef is a C4*, self-pollinated, chasmogamous annual cereal. It has a fibrous roots system with mostly erect stems, although some cultivars are bending or elbowing types. The sheaths of tef are smooth, glabrous, open and distinctly shorter than the internodes. Its ligule is very short and ciliated while its lamina is slender, narrow and nearly linear with elongated acute tips. It has a panicle type of inflorescence showing different forms, from very loose, loose, semi loose, semi-compact to compact. The semi-compact to compact types appearing like a spike. Its spikelets have 2-12 florets. Each floret has lemma, palea, three stamens, an ovary and mostly two, in exceptional cases three, feathery stigmas (Figure 1).

 Figure 1:Tef plant white and red (brown).

*C4 plants are plants whose primary product is a 4-carbon molecule. Oxaloacetate is the first stable product in Hatch and Slack cycle. C3 plants whose first stable primary is a 3-carbon molecule, which is Phosphoglyceric acid in Calvin cycle. C4 plants are CO 2 and water efficient while C3 plants are light efficient. C4 plants are basically adapted to warmer regions and the C3 plants are mostly adapted to the temperate regions (Pandey and Sinha, 1972).

The caryopsis is 0.9-1.7mm in length, and 0.7-1.0mm in diameter, which is very small and its colour varies from white to dark brown (Figure 2) (Tadesse, 1975). Tef is an allotetraploid plant with a chromosome number of 2n=40 (Assefa, 1976). The basic chromosome number of the genus Eragrostis is X=10. When two accessions of tef were observed, measurements of the largest chromosome were 1.6-2.9m m and of the smallest were 0.8-1.1m m. The range within each measurement was attributed to differences in condensation (Tavassoli, 1986). According to Melake Hail and Guad (1966), the extent of out-crossing in tef is very low, 0.2-1.0 percent.

 Figure 2: White, mixed and red (brown) seeds.

Most of the Ethiopian farmers use traditional landraces of tef and these are distributed all over the country. (Seyfu, 1997). Tef has been introduced to different parts of the world through diverse institutions and individuals. The Royal Botanic Gardens, Kew, London, United Kingdom, obtained tef seeds from Ethiopia in 1866 and 1886 and distributed it to some countries in the then British colonies, i.e. India, Australia, the United States of America, South Africa and British Guyana. According to Tadesse, (1975), Burt Davy in 1916 introduced tef to California (USA), Malawi, Zaire, India, Sri Lanka, Australia, New Zealand and Argentina. Skyes in 1911 introduced it to Zimbabwe, Mozambique, Kenya, Uganda, and Tanzania. In 1940 Horuitz introduced tef to Palestine. It has been reported that tef made excellent hay in all these places.

Tef plants cannot compete with weeds especially during the young growing stage. It is best to start with a weed-free, clean field that has been ploughed frequently during the appropriate season, in order to kill the weeds. The work should also start with clean tef seeds that are free of weed seeds (Seyfu, 1997).

Genetic resources

Existing genetic variation

Studies made at the Institute of Bio-diversity and Research, Ethiopia, Seyfu, (1993) characterized 2 255 pure line varieties of tef germplasm for 15 morphological and agronomic traits. All the traits studied showed a wide magnitude of variation and had statistically significant differences. This elucidates the existence of a great wealth of genetic diversity in tef, which could be utilized in the improvement programme of the crop (Table 1). Out of the 15 traits studied, maximum genetic diversity was observed in the flag leaf area, grain yield per plant and straw yield per plant.

Properties

The composition of tef is similar to that of millet, although it generally contains a higher amount of essential amino acids, including lysine, the most limiting amino acid (Jansen et al. 1962). The amino acid composition of tef is excellent, its lysine content is higher than that of all cereals except rice and oats, it has good mineral content and its straw is nutritious (Table 2, 3, and 4). The fractional composition of the protein in tef indicated that glutelins and albumins were the major protein storage components and their order of fractional importance was glutelins 44.55 percent, albumins 36.6 percent, prolamin 11.8 percent and globulins 6.7 percent. In tef seed the distribution of protein, percentage of ash and mineral elements is higher in the pericarp than in the endosperm (Mulugeta, 1978). According to Assefa (1979), the protein concentrations in the grain varied significantly between cultivars, ranging from 8.8 to 15 percent.

According to Besrat et. al (1980), the iron content of 35 samples of acid washed white and red tef (also known as brown tef) grain, was 3.6 to 7.8 mg/100 g DM. The relatively high values reported for tef as consumed were caused by contamination, probably with soil. Tadesse (1969), Molineaux and Biru (1965) reported that non-tef consumers have a lower level of hemoglobin, and hookworm anaemia develops in non-tef eaters if they are infested with hookworm. On the other hand, since tef eaters have higher levels of hemoglobin in their blood, they do not suffer from hookworm anaemia even when infested.

Table 1. Descriptive statistical values for phenological traits, components of height, shoot biomass, harvest index, flag leaf area and culm thickness for 2 255 pure line accessions of tef (Seyfu, 1993)

Character

Min

Max

Mean

SD

SE

CV (%)

Days to germination

4

12

5

0.70

0.01

13

Days to heading

26

54

37

3.80

0.08

10

Days to maturity

62

123

93

7.36

0.16

8

Days heading to maturity

29

76

56

6.23

0.13

11

Culm length (cm)

11

82

38

7.57

0.16

20

Peduncle length (cm)

7

42

19

4.54

0.09

23

Panicle length (cm)

14

65

41

6.99

0.15

17

Plant height (cm)

31

155

98

12.97

0.27

13

Grain yield/panicle (g)

0.3

3.0

0.9

0.34

0.01

38

Grain yield/plant (g)

4

22

8

4.01

0.08

48

Straw yield/plant (g)

20

90

41

15.83

0.33

39

Total shoot biomass per plant (g)

26

105

49

18.58

0.39

38

Harvest index (%)

7.0

38.0

17

5.51

0.12

33

Flag leaf area (cm2) *

2.0

26.0

12

6.22

0.62

52

Culm of first internod (mm)**

1.2

5.0

3

1.12

0.17

37

Culm of second internod (mm)**

1.2

5.0

3

1.10

0.16

38

* Data taken from 100 germplasm accessions.
** Data taken from 45 germplasm accessions.

In addition, according to the same study, malaria is frequently found in groups with lower hemoglobin levels. Moreover, consuming tef is reported to prevent anaemia related to pregnancy. Tef contains more calcium, copper, zinc, aluminium and barium than winter wheat, barley and sorghum (Melak Hail, 1966).

Other grains such as wheat, corn, sorghum, or a mixture of these, can be used for making Enjera. However, tef alone is preferred. Compared to other cereals, Enjera made out of tef grain has a better odour, flavour, texture and long-keeping quality. Enjera made from tef is traditionally consumed with Wot, a sauce made of meat or ground pulses like lentil, faba bean, field pea, broad bean and chickpea. Generally there are two kinds of Wot: kayy wot is red Wot highly seasoned with ground dry pepper and other spices. This also gives it the red colour. The second type is called Alecha .

Taddesse (1969) and Beyene (1965) suggested that fenugreek (Trigonella foenumgraecum) seeds, which is reach in protein, is a good supplement if used with tef. In some regions of Ethiopia, e.g. Welo, women usually prepare Enjera by adding some fenugreek flour to tef to improve its baking quality. Because of this, the Enjera becomes softer and has a shiny appearance. Thus women are encouraged to continue this traditional practice and should be made aware that this will not only improve the baking quality of the Enjera but also supplement its protein content, especially lysine. The grains give higher returns both in flour upon milling (i.e. 99 percent compared to 60-80 percent from that of wheat) and in Enjera upon baking. The flour is also used for the preparation of tef porridge and not raised bread called Kitta. Sometimes, the grain is also brewed into a native beer called Tella, Fersso and a more alcoholic traditional liquor, locally known as Arak'e, or Katikalla. Alternate tef dishes such as tef breakfast cereal, tef waffles, tef banana bread and the like, are appearing in the Western world particularly in the United States of America. Tef is found to be a very nutritious cereal grain. Tef seed is especially high in iron and calcium but lacks glutelin, which makes it unfit for making raised bread (Seyfu, 1997).

1.1 Economic and Social Impact of Tef

Tef is the major staple cereal of Ethiopia. According to data collected over a six-year period (1992/93-1997/98) from the Central Statistics Authority, tef is annually cultivated on about 1.8 million hectares of land (Table 2), thereby covering about 29.4 of the total average of cereals. Its area has been expanding over time and shows a respective increase of 2.8 percent, 33.3 percent, 13.9 percent and 3.5 percent, from 1993/94 up to 1996/97 when compared to each preceding year. The highest acreage was recorded in 1996/97 (2.2 million hectares), which was a favourable year with a record harvest in the country. A slight decline in area under all cereal crops decreased by 15 percent in 1997/98 owing to shortage of rainfall in some agro-ecologies both in the Belg and main season. With an average of 1.6 million tons of grain per year, tef constitutes about 23 percent (second to maize, which is about 29 percent) of the gross yearly grain production of cereals (EARO, 1999).

Table 2. Area under cultivation, yield and production of tef from 1992/93 to 1997/98.

Year

Area

(000 ha)

Yield

(Q/ha)*

Production

(000Q)

1992/93

1993/94

1994/95

1995/96

1996/97

1997/98

1 385.7

1 425.1

1 899.0

2 162.9

2 238.7

1 807.1

9.8

8.8

9.8

8.3

9.1

7.4

13 559.7

12 546.2

18 582.0

17 926.3

20 371.7

13 287.8

Average

1 819.7

8.9

16 045.6

*1 Q = 100kg
(Source: Central Statistical Authority, 1997 and 1999).
On the whole the area devoted to tef cultivation is on the increase owing to the versatile merits of tef to the Ethiopia farmers. Firstly, both the grain and straw fetch a relatively high price in the market compared to other cereal crops. Secondly, tef is a crop, which adapts itself excellently to changing environments in the country, and, therefore, is considered a low risk for farmers. In some environments where farmers face a complete crop failure due to moisture stress, tef is their choice in order to obtain a harvest (EARO, 1999).


Price and contribution to the GDP

Based on DZARC price data (unpublished) for grain and straw collected from different district markets of East and North Shewa from 1992/93-1997/98, the prices of both the grain and the straw have increased steadily. The prices were collected from markets where farmers sell their produce directly to consumers. The grain price is an average of harvesting and planting time data of white, mixed locally called Sergagna and red (brown) seeds. At the harvesting time, average prices of the three classes of tef rose from 200 Birr per quintal in 1992/93 to 212 Birr per quintal in 1997/98. Likewise, the straw price increased from 19 Birr to 38 Birr per quintal. Based on an average of four years the Debre Zeit Agricultural Research Centre (DZARC) price data the grain of tef contributed 3.3 billion Birr and the straw 1.7 billion Birr to the Gross Domestic Product (GDP) of the country. The total contribution is estimated to reach five billion Birr (Table 3).

 Figure 3: Tef produce transported to the market by donkey.

In many parts of Ethiopia such as Showa and Gojam, tef is used as a principal cash crop while in other parts it is used as a secondary cash crop. Tef is marketed throughout the year. Poor farmers who cannot wait for a better price sell their tef just after the harvesting season. This enables them to buy clothing for the family, to pay taxes and to pay other debts. The grain is taken to the market in sacks, bags, or an Akomada (goatskin bag) on donkeys (Figure 3), mules or horses. Sometimes the farmer will carry the seed on his head or shoulders, or his wife may carry it on her back. Traders and farmers with a lot of produce use modern transport methods that start from the farm gate to the trains. Ships and aeroplanes are used for export of the product.

At the market place, tef is sold at a special location called the tef-tara, which means a place where only tef is sold. Often in the market places, more standardized measuring units are used, called Tassa. These are usually about a kilogram or Kubbayya for about half a kilogram. In many parts of the country they have begun selling tef seed by weight, i.e. by using modern weighing systems.

1.2 World Trade

Official figures on the export status of tef have appeared during the past two years (Table 4). Almost equal amounts (1.8 thousand quintals) of tef grain were exported in 1997/98 and 1998/99, but the value obtained differs remarkably. About nine million Birr was obtained in 1997/98 (493.37 Birr/Q) whilst 14.6 million Birr was obtained 1998/99 (791.83 Birr/Q). The trend indicates that there is a good export market for this crop in the Middle East, North America and Europe and others mainly for Ethiopians who immigrated to the above mentioned regions (Customs Authority, 1999).

Table 3. Value (Birr)* of tef grain and straw at the national level from 1992/93 to 1997/98.

Year

Grain

Production

(000 Q)

Straw Production 1

(000 Q)

Value from

Grain (Million Birr)2

Value from

Straw (million Birr)

Total Value from Grain & Straw based in DZARC price (Million Birr)3

1992/93

1995/96

1996/97

1997/98

13 559.7

17 926.3

20 371.7

13 287.8

42 012.8

55 542.1

63 118.9

41 170.4

2 711.94

3 746.60

3 952.11

2 817.01

798.24

2 017.85

2 261.55

1 569.83

3 510.18

5 764.45

6 213.66

4 386.84

Average

16 286.4

50 461.1

3 306.92

1 661.87

4 968.78

  1. Tef straw was estimated based on an average of 24.4 percent harvest index (Seyfu, 1997).
    1. DZARC (Debre Zeit Agricultural Centre) price data (unpublished) for grain and straw were collected from different district markets of east Shewa and North Shewa where farmers sell their produce directly to consumers. The figures for the grains are an average of white, mixed (Sergagena) and brown seeds and the average of harvesting time and planting time prices were taken.
    2. The current exchange rate for the month of January 2000 is 1USD = 8.141 Ethiopian Birr.

    The major requirement for export of white and brown tef is its cleanliness. The seeds must be the same colour and free of inert materials such as dust, soil particles and weed seeds. Among other requirements for export, the amount of mixture of brown seeds inside the white tef is also given due consideration. Pure white seeds are exported more than the mixed or the pure brown tef.

    1.3 Primary Product

    Tef if a very fruitful plant, yielding from 1 000 to 10 000 seeds per plant. From this data one can state that tef produces more grains per square unit of area as compared to other food grains. But due to its minute seeds (2 500-3 000 seeds in a gram), there is a great loss of seeds in the field during harvesting, carrying the bundles to the threshing field, and in the threshing field itself. During threshing it is not possible to get all the grains out of the straw (Seyfu, 1997).

    During a six-year period (1992/93 to 1997/98), the average national yield of tef was estimated to be 8.9 q/ha. However, farmers who use improved varieties and their management practices can easily get 17 to 25 q/ha (Table 2), which is a little more than two fold. Yields higher than 25 q/ha have been reported from several regions in recent extension package activities. The production had increased due to increased productivity. At the experimental plot level tef yields up to 34 q/ha in the presence of lodging that reduces yield by 17 to 25 percent. Study conducted under non-lodging condition has demonstrated that yield can further be increased up to 46 q/ha (Table 4). A record of 50 q/ha in some research plots has also been noted in the past. Some researchers of tef believe that tef yield can be increased to 6 tonnes/ha through an intensive research programme Seyfu (1993).

    Table 4. Yielding ability of three different tef varieties under different growthconditions.

    Variety

    Farmers'

     Condition

    (kg/ha)

    Experimental Lodged Condition

    (kg/ha)

    Experimental

    Non-lodging

    Condition (kg/ha)

    DZ-01-94

    DZ-01-354

    DZ-Cr-37

    National Average

    2 000-2 500

    1 700-2 200

    1 700-2 200

    890

    2 400-3 400

    2 400-3 200

    1 800-2 800

    4 600

    4 100

    4 200

    Source: EARO 1999.

     

    1.4 Secondary & Derived Products

    Tef is predominantly grown in Ethiopia as a cereal crop and not as forage crop. However, the straw after the grain is threshed, is used as fodder. Farmers highly value the straw of tef and it is stored and used as a very important source of animal feed, especially during the dry season. Tef straw is called Ch'ed (Figure 4). Farmers feed tef straw preferentially to milking cows and working oxen. Cattle prefer tef straw than the straw of any other cereals and its price is also higher than that of other cereals. According to Lulseged and Jamal (1989), the quantity and quality of residues from various cereal crops vary greatly depending on the crop species. Wheat and barley give high straw yields, though these are of inferior quality. Among cereals, the straw of tef is relatively the best and is comparable to a good natural pasture. The same source indicated that the performance of animals on residue diets is also known to vary depending on the crop species.

     Figure 4: Tef straw called Ch'ed.

    Table 5. Amount of tef grain exported and values (Birr) obtained in 1997/98 and 1998/99

    Year

    Amount Exported (quintals)

    Value

    (Birr)*

    1997/98 (1990 E.C.)

    1998/99 (1991 E.C.)

    17 976.8

    18 402.8

    8 869 168

    14 571 827

    Source: Custom Authority, 1999
    * 1USD = 8.141 Ethiopian Birr (January 2000 Exchange rate).

    The highest daily weight gain was obtained using tef straw. ?Table 8? shows the weight gains of steers fed for 116 days on a ration composed of 50 percent residue, 20 percent molasses, 25 percent Niger cake (Guizotia abyssinica), 4 percent bonemeal and 1 percent salt. Dry-matter intake and daily weight gain were lowest for wheat straw, 5.0kg and 352g/head, respectively. For tef straw it was 6.9kg and 628g for dry-matter intake and daily weight gain, respectively. Daily feed intake was the highest for tef (IAR, 1975). It was also reported that a tef plant produced an average of 12 899 lbs. of green material per acre within three months (The Agriculture of Ethiopia, 1956).

    Tef has been used for many years in the Republic of South Africa for hay. Here extensive studies have been conducted for some years. According to the experiments carried out in other countries, tef has proved to be good forage grass. Some of its greatest advantages are the ease with which it is harvested, the way it can be dried in summer rain and its high nutrition quality. Burt-Davy (1913), cited by Seyfu (1997) had also indicated that the chief value of tef as a hay crop lies in its palatability, high nutritive value, narrow albumin ratio (for a grass hay), high yield, rapid growth, drought resistance and ability to smother weeds. According to Taddesse (1969), tef produces more than twice as much forage as weeping Lovegrass (Eragrostis curvula), producing an average of 14.5t/ha of green material in three months. This again shows that tef has a great potential to serve as a forage crop. Hence it can be used as a dual or multipurpose crop, i.e. for both cereal and forage. Tef is grown as a forage crop in various parts of the world.

    Milling of Tef
    The preparation of tef grain for making Enjera is as follows: Ordinarily, the grain is first cleaned by sifting and then ground into flour on Wefcho in households in very remote areas or in modern flour millings. In the homes of the wealthy, after the grain is cleaned by sifting, it is soaked or moistened for a few hours, and then pounded lightly in a Mukachcha (a mortar with a pestle) to remove the thin seed coat. Soon after, it is dried in the sun on a finely woven mat, and then ground into flour on Wefcho, which is placed in the house. The Wefcho is made of two hard pieces of stone, which are hand hewn. The bottom stone, about 45-50 cm long and 20-30 cm wide has a flat slightly cupped surface. This stone is set in a slightly inclined or elevated position and the edges are usually cemented with mud reinforced with tef straw.

    The edges are smooth or curved upward so that the grains will not roll off on the ground. The upper part is round and smooth. At the lower end, mud is made in a form of a pot called a Kuwat or kodakomby to catch flour. Other utensils may be placed at the lower end to catch the flour. The top stone called a Megg is about 10 to 20 cm wide on the flat side and the upper part is curved to fit the woman. s hand. The woman moves it forward and backward when grinding. While grinding the woman is in a kneeling position, behind the Wefecho with the weight of her body on her forearms. Then she adds small amount of grain on the upper side and rolls the grain to the centre with her fingers and grinds it by crushing it between the two stones. After some use, the Wefecho becomes slippery and fails to grind well. Beating with a round or oval stone called a Mawkariya or a hammer roughens the Wefecho.

    People living in and around towns, take their grain to the gristmill. In some villages they now have gristmills which are run by waterpower. Diesel engine milling facilities are available in areas where electric power is unavailable. (Figure 5). In towns and cities electrical powered milling machines are used for milling. These are much more efficient than any of above mentioned milling facilities.

     Figure 5: Diesel engine operated milling machine.

    Studies have shown that in milling, tef gives a 99 percent return in flour, whereas wheat yields 60-80 percent (Ciferri and Bakdrati, 1939). Analytical Data physical characteristics of the grain or flours from tef or a combination of tef seeds, grain flour and ash are given in Tables 6 and 7, respectively.

    Table 6. Analytical Data physical characteristics of tef grain or flour

    As by Visco (1936)

    Flour %(mg/100g)

    As by Borasio(1937)

    Flour %(mg/100g)

    As by Camis
    (1930)

    % whole seed

    (mg/100g)

    Flour %

    (mg/100g)

    Water

    10.360

    8.64

    8.84

    2.85

    Nitrogen

    1.550

    -

    -

    -

    Protein matter

    9.725

    9.93

    10.43

    8.56

    Fatty matter

    3.470

    2.00

    2.20

    3.22

    Soluble sugars

    1.440

    -

    -

    -

    Starch

    64.920

    -

    -

    -

    Cellulose

    6.540

    4.07

    4.32

    4.30

    Pentosans

    3.478

    -

    -

    -

    Ash

    2.396

    2.53

    2.65

    2.94

    N-free extract

    -

    72.83

    71.56

    -

    Source: (Ciferri et al, 1939 and Baldrati, 1950)

     

    Table 7. Composition of tef grain flour and ash according to Visco (1936)

    % of the flour

    (g/100g)

    % of the ash

     (g/100g)

    Sodium

    .050

    2.089

    Potassium

    .244

    10.193

    Calcium

    .149

    4.528

    Magnesium

    .175

    7.327

    Iron

    .033

    1.382

    Sulphur

    .127

    5.050

    Phosphorus

    2.277

    11.572

    Chlorine

    .082

    3.480

     

    Making Different Kinds of Tef Enjera
    The main use of tef is for making Ethiopian bread, called Enjera of which there are many kinds. Enjera is the most popular type of bread, which is circular, thin, porous and pancake-like with numerous eyes. It has a sour taste. The average thickness is about 5mm and the diameter is 35 to 50cm. To make this kind of Enjera the flour is mixed with warm water and then worked by hand until the dough becomes hard. The water should not be either boiled or cold as this can result in an Enjera of very poor quality. The numerous eyes are the indication of good quality Enjera (Taddesse, 1969; Seyfu, 1993).

    Making Enjera is mostly work for women. Enjera is prepared both in the rural areas, villages, towns and cities. Enjera is baked in a circular; almost flat earthenware pan called a Metad or Elle chabetta. This is a baking oven made from local materials, which is about 60cm in diameter. It is put on the open fire and heated gently. The Metad is raised slightly on three small stones at the corners called Gulecha. Then it is polished or greased by rubbing with ground Gommanzar (Brassica integrifolia) seed; or kalawa (Maesa lanceolata) seed; or Gullo (Ricinus communis) seed, cotton seed, or animal fat in a piece of cloth. People living in rural areas where electricity is unavailable or even in towns and cities where the electrical powered Mitad is too expensive, use the one which is heated by burning wood, animal dung, shrubs, etc. (Figure 6). Nowadays the Mitad is heated by electrical power in areas where electricity is available. Most of the families living in cities, towns and villages use an electrical powered Mitad (Figure 7).

     Figure 6: Mitad, an oven like used for baking Enjera, which is heated by wood, animal dung, shrubs etc. Please note that the concave shape lid of the Mitad called Akambalo, grey in colour.

     Figure 7: Mitad which is heated by electric power.

    Below is the procedure and recipe for preparing tef Enjera (Ethiopian Nutrition Institute, 1980). The flow chart is shown in Annex 2a.

    1. Procedure and recipe for preparing tef Enjera

    Ingredients Weight

    Tef flour 3 kg

    Ersho* (local yeast) 480 g

    Water for dough 6 litres

    * Ersho is starter, which is dough, saved from a previous fermentation and used as a starting fermentation in every new dough preparation.

    Cooked product

    Number of Enjera 18

    Weight of one Enjera 450g

    Preparation of the Dough

    Baking the Enjera

    After fermentation the batter is thinned again by adding a small amount of water. The fermented batter is then taken in a small can, or a gourd, called Mazoria or Masfiya from the Buhaka, and poured on to the Metad with a circular motion beginning at the outer perimeter and working towards the centre. It is covered with a Metad cover called an Akambalo. This is convex in shape. The edges of the Akambalo rest on the Metad, on the outer circle of the Enjera. Cracks or the openings between the lid and the griddle are covered with a strip of moist cloth. After 3-6 minutes the Enjera will be baked depending on its thickness and heat intensity (Figure 8). The Enjera comes loose from the Metad if the latter is well polished and well greased. Otherwise it may stick to the Metad. The baked Enjera is lifted up by hand and placed on a Sefed or lifted with the help of a Sefed, which is a kind of basket made of grass stems. The housewife makes Enjera either for one meal or for 2-3 days at one time. Enjera is used for all meals especially in the countryside.

     Figure 8: Baked Enjera on the hot Mitad.

     

    Other important points to be followed in preparing Enjera are:

    The dough should never be fermented for more than 3 days, or it will become too sour and might cause gastritis. Besides, the longer the fermentation time the higher the destruction of nutrients.

    Traditionally the flour is mixed with water in earthenware, wooden or metal container called Buhaka. During mixing, water is added to the flour little by little until the desired thickness or texture is obtained. About three litres of water are added to two kilograms of flour. To this mixture a small amount of yeast which is called Ersho is added, and the whole content is thoroughly mixed by hand to form hard dough. The dough is next immersed in water and left for 2-3 days to ferment. The rapidity with which it ferments depends on the altitude of the area and the concentration of Ersho, (Stewart and Asnake, 1962). The Buhaka is not washed very often or thoroughly, so the fermenting agent is maintained in the container continuously. After baking, the batter on the inside of the Buhaka is washed down and left for subsequent use. As the batter ferments a gas is produced and as it rises, a thin yellowish liquid settles over the paste. This yellowish liquid is the Ersho. It is poured off and saved for the next batch. Sometimes, to make a clean looking thin Enjera with numerous eyes, a small amount of the fermented paste is mixed with water (1 part to 3 parts of water), boiled, and added to the fermented batter, called Lit.

    The fermented paste is called Absit. According to Stewart and Asnake (1962) the primary agent responsible for fermenting flour in making Enjera has been identified as Candida guilliermondii (Cast) Longeron and Guerra. This yeast is known to occur naturally in the flour and seed of tef.

    After baking is over, Enjera is placed on a Messob, which is a slender splendid basket with a flat top, and a base made from grass stems (Figure 9). Large flat plates may be used on Messob. It may also be placed on a Gebata, a container with a rather flat top, smooth or curved edge, and flat base made of wood, or on a flat plate. Then some Wot is put in a bowl of black clay called a Wachett, or in a wooden or metal dish and set in the middle of a Messob or a Gebata on Enjera. Wot may also come in a small earthenware bowl called Dest in which Wot is made. It is scooped out with a wooden or metal dipper, called Chelfa and spread over or placed at the centre of the Enjera (Figure 10). Then a piece of Enjera is broken off with the fingers, dropped on the Wot upside down, to absorb the Wot, folded and shaped with the fingers and placed in the mouth (Figure 11).

     Figure 9: Baked Enjera transferred on to the Messob.

     Figure 10:The sausage called Wot spread over Enjera.

     Figure 11: Eating Enjera with Wot.

    Enjera can be broken into very small pieces to make Fetfet. Cutting Enjera into small pieces and dipping in to Wot or other sausages makes Fetfet. Enjera is eaten with the fingers except when Fetfet is prepared. Fetfet is eaten with spoon made from cattle horn, wood or silver.

    Other types of Enjera are called Aflangna or Chumbo, or Bekuo. It is a very heavy cake 3-4cm or thicker near the edge, thinner nearer to the centre, and 40-70cm in diameter. It is baked from relatively unfermented dough, 12-14 hours, on a bigger and heavier Metad than that used for ordinary Enjera. This kind of Enjera is quite common in rural areas, especially at Debo, that is, work projects with neighbours helping each other on the farm, building a house, etc., or for large families where making thin Enjera is very time consuming. In baking Chumbo, a large Metad called an Elle Chumbo, small concave Metad called a Bedde, and the cover called Akembalo are used. Bedde is placed on the fire upside down and heated until it is very hot. Then the Elle Chumbo is turned upright and cleaned by rubbing it with a piece of cloth. Bedde is placed in the centre of the Elle Chumbo upside down. In baking Aflangna, Bedde is not used. Then batter somewhat thicker than that is used for Enjera is poured onto the back of the Bedde. There it spreads out. Next a cover known as Akembalo is placed on the Elle Chumbo and cemented together along the edge with cloth or mud reinforced with tef straw. This is done to prevent the steam from escaping. It requires 1-3 hours to bake depending on its size. Chumbo is eaten with Wot made from pulses, other vegetables, and cheese. Meat Wot is not usually used with Chumbo. Chumbo is almost always made from red tef.

    Hongochy; is heavier and larger than Chumbo. It is made from rather unfermented batter, and baked for similar occasions or purposes as Chumbo, a small Metad called Bedde, and an Akembalo is needed. These are heated until very hot. Then the bigger Metad is turned upright, cleaned by rubbing with a piece of cloth, and the thick batter is poured in the centre. Next the small hot Metad is set in the centre upright on the batter and hot coals are added to it. An Akembalo is placed on the Metad and the two cemented together along the edges with mud reinforced with tef straw. Hongochy is baked slowly for 2-4 hours and eaten like Chumbo. It is almost always made from red tef. The flow chart is shown in Annex 2b.

    Annababaro or Chabetta or Hansa. This type of Enjera is made by doubling two ordinary thin Enjera. First, one thin Enjera is baked and removed from the Metad and batter for the second one is poured on the Metad. The baked Enjera is then placed on it usually upside down and baked for five to ten minutes. It is made from a fermented batter of either red or white tef and eaten like thin Enjera. The flow chart for baking Annababaro or Chabetta or Hansa is shown on Annex 2c.

    Other types of enjera are usually made in rural areas, where farmers and farmers. cooperatives are found. They are not well known in the cities and large towns. Their methods of preparation follow.

    Making Tef Porridge

    Porridge, which is locally called Ganfo, is made directly from flour or from fermented batter called Marka Buko (meaning porridge from batter). To make this porridge the housewife puts the Tuwe Marka, (a pot for porridge) onto an open fire. This is raised with three stones at the corners, water is boiled and flour or batter is added. Stirring is done with a piece of wood with a flat end, known as Bogeto. The pot is held in place with a piece of Y shaped wood that is called Ejeta. It takes about 20-40 minutes to cook porridge. Porridge is eaten with cheese or with soup made from thin, well-fermented batter. In eating the porridge women usually use their hands, children use plates, and husbands use spoons. The wife puts pieces of porridge flavoured with cheese or soup on the husband. s spoon. Often porridge is eaten in the morning. It can be prepared either from white or red tef. It is also prepared from maize, sorghum, barley, etc. (The flow chart is shown in Annex 2g).

    Making Tef Soup Muk

    In some parts of the country, namely Wollega, soup known as Muk is made from thin fermented batter. When it is cooked, salt and spices are added and it is eaten with a spoon. Muk is prepared when there is very little food available or for a sick person. It can be prepared from red or white tef. The flow chart is shown in Annex 2h.

    Making Tef As A Local beverage Called T'ella

    T' ella is a native beer made from grains such as finger millet (Eleusine coracana), grain sorghum, corn, barley, etc. Occasionally red tef is used for kitta; bread made from unfermented hard dough. This is especially used in brewing a native alcohol called Katikalla. T' ella prepared from red tef is very strong. It is called Embushbush or Bawuza.

    Making Tef Bread Bolls (Grains) Called Hunkuro (Dabbo Kolo)

    Hunkuro also known as Dabbo Kolo are bread grains cut with scissors in small sizes. Wheat is preferred for Dabbo Kolo, but in areas where wheat is not grown, white tef is used. Warm water is added to the flour to moisten it. The cereal is then roasted on a Metad over an open fire. It is stirred constantly with a piece of flat wood until small hard bread balls are formed. This is usually seasoned with spices and butter. Because it keeps for a long time without spoiling, travelers use it. White tef is preferred to red tef for the preparation of Dabo Kolo. A flow chart for making of Dabo Kolo is shown in Annex 2i.

    Fermentation of Tef

    Studies conducted using tef as the sole source of microorganisms indicate that a metabolically associated heterogeneous group of fermentative, aerogenic, gram-negative rods, lactic acid bacteria, Bacillus spp. and yeasts growing in succession were involved in the fermentation process of tef. This is reported to be unlike the fermentation process in wheat where a single organism is involved in the breadmaking process (Berhanu et al. 1982). The initial fermentation activity is performed by a group of microorganism (gram-negative aerogenic rods) such as Enterobacter, Hafnia, Citrobacter, Klebsiella, Escherichia and Proteus. Their population as a group increases substantially during the first 36 hours of fermentation and decreases thereafter. The yeast Saccharomyces spp., even though present during the whole of the fermentation process, becomes abundant after the pH level reaches below 5. This yeast become the predominant group of organisms in the liquid layer after 50 hours of fermentation, i.e. after the complete separation of the liquid/solid and is responsible for the . rising of the dough. during the second stage of fermentation (Berhanu, et al. 1982).

    According to Chaltu and Abreham (1982), out of the 22 identified yeasts isolated. 14 were the type most commonly found during the peak time of fermentation. The dominant yeast flora at the peak of fermentation of tef dough comprises two physiological groups belonging to the general Saccharomyces and Torulopsis. Yeast of the general Candida and Pichia become prominent in the yellow fluid that settles on top of the dough in the latter stages of fermentation Table 8.

    It is important to note that in studies conducted by Berhan et al. (1982) the fermentation of tef, the whole process is done without making use of Ersho (yeast) at the beginning . Whereas according to Chaltu and Abreham (1982), Ersho was added at the beginning of the fermentation process, since their experimental samples were taken from private homes and food processing enterprises that mass produced tef Enjera and where Ersho is traditionally practiced. Ersho is traditional yeast added to tef dough and used as a starter to enhance fermentation; it is usually obtained from previously fermented tef dough. This may account for the difference in the reports of the two studies cited above, regarding the population density of the various microflora observed at different times during the fermentation process.

    The studies of both Berhanu et al. (1982) and Chaltu and Abreham (1982) agree that the yeast genera Saccharomyces are involved in the fermentation process of tef, although their reports vary concerning the population density and prime time of occurrence of these genera during the process of fermentation. Both of these studies also reported that they did not find Candida guillermondii as the yeast responsible for the fermentation of tef dough, as earlier reported by Stewart and Asnake (1962).

    Enjera showed no aflatoxin contamination when prepared and handled and fermentation of the dough or storage of Enjera for prolonged periods did not increase aflatoxin B1 contamination (Besrat and Gebre, 1981).

    Effect of Fermentation on the Nitrogen of Tef

    During the latter part of the fermentation process of tef this separates into dough that settles down forming a liquid layer at the top. Because of the acidic nature of this liquid that remains at the top, it is discarded just before Enjera is baked. In the process of pouring off this liquid layer, other soluble compounds (amino acids, sugars, and minerals) and a large portion of the microorganisms involved in the fermentation process are also removed. Moreover, a significant quantity of tef nitrogen is lost at the end of the fermentation process. The nitrogen loss in tef, which amounts to 4 to 13 percent, can however, be avoided by stopping the fermentation process at about 31 hours, just before the liquid/solid separation. Enjera with minimum acidity and no or minimal loss of nitrogen, can be baked before the liquid/solid separation occurs in the fermentation tank for about 31 hours (Berhanu, et al. 1982 as cited by Seyfu, 1993). The nitrogen content of the various fractions of fermenting tef flour are presented in Table 9.

    Effect of Fermentation on the iron, phosphorus and zinc content of tef.

    The effect of fermentation on the bioavailability of iron, phosphorus and zinc was studied, in tef and in wheat. Samples were cleaned and washed in the laboratory using tap water and 25 hydrochloric acid. Fermentation at room temperature was followed by dialysis of the batters. Fermentation of tef and wheat decreased pH of the dough from 6.8 ± 0.1 to 4.5 ± 0.1, with partial breakdown of soluble starch. This also increased the dialyzable portions of their Fe, P and Zn contents from 9.0 percent ± 0.4, 16 percent ± 2.0 and 7.0 percent ± 1.0, respectively, to 24.0 percent ± 0.7, 60.0 percent ± 3.0 and 43.0 percent ± 2.0. The increase in dialyzable Fe may have a positive effect on its bioavailability, and may thus explain the rarity of iron-deficiency anaemia among tef-eating populations in Ethiopia (Ramachandran and Bolodia, 1984).

    Table 8. Yeast flora of fermenting tef dough

    Source

    Type of yeast isolates

    Fermenting tef dough (22-25hr old)

    Saccharomyces exiguus

    Saccharomyces dairensis

    Torulopsis holmii

    Yellow fluid (48hr old)

    Candida krusei

    Candida lambica

    Candida sorbosa

    Pichia kudriavzevii

    Source: Chaltu and Abreham, (1982)

    Effect of Fermentation on the carbohydrates in tef

    In an experiment carried out by Umeta and Faulks (1988), indicated that the fermentation is generally spontaneous but may also be initiated by the addition of a starter culture from the previous fermentation. The changing pattern of free sugars during fermentation was the same in both varieties. A change in the microbial population dynamics also resulted in changes in the pH of the dough. Fructose was the main free sugar in the fermenting dough and cooked product. After 72 hours of fermentation, the microbial population utilized 9 percent of the starch in both varieties. The non-starch polysaccharides (dietary fibre) were not affected.

    New Recipes for the Utilization of tef

    Many people are showing great interest in introducing tef into their countries. Hence, efforts are being made to discover and introduce other methods of utilizing tef. Ten new food recipes have been developed and introduced for the utilization of tef in the United States (Wood, N.D., cited by Seyfu, 1993). These recipes are given below.

    The recipes for some of the above mentioned new methods of using tef are presented below:

    Tef Breakfast Cereal

     Yields: 3 cups

    Time: 15 minutes

    Tef breakfast cereal is a good diversion from oatmeal breakfast. It is quick to cook breakfast cereal that is nutritionally and energetically superior to oatmeal. Most importantly, it is delicious. It takes only 15 minutes to prepare 3 cups of this breakfast cereal.

    Tef cooks well in varying amounts of water. For a firm cereal, cook a cup of tef in two cups of water. Cooked tef, regardless of the water proportion sets up firm and lends itself to panfrying.

    Ingredients

    Boil water and salt in a pan. Add tef, cover the pan, and simmer for 15 to 20 minutes, or until the water is completely absorbed. Towards the end of cooking, stir it intermittently and serve it with milk, maple syrup, or honey.

     

    Table 9. Nitrogen content of the various fractions of fermenting tef flour Nitrogen content on dry weight basis (percent) 

    Duration of fermentation in hours.

    Sample

    0

    24

    48

    72

    96

    Tef

    1.59

    1.59

    1.60

    1.58

    1.59

    Fresh dough

    1.60

    1.58

    1.59

    1.59

    1.60

    Fermented dough

    1.60

    1.58

    1.51

    1.46

    1.40

    Liquid layer

    -

    -

    0.07

    0.13

    0.20

    Total loss of starting nitrogen in the liquid layer (%)

    -

    -

    4.40

    8.10

    12.5

    Source: Berhanu et al. (1982)

    Variations

    Tef Banana Bread

    Yield: 9-inch tube cake

    Time: 50 minutes

    It just takes one taste to know how great this tef bread is. Tef's full range of blandly sweet earth flavour gives depth and adds to its unique and tender crumb.

    Ingredients

    Preparation

    Variations

    Grated carrot can be substituted for banana. The anise also can be replaced with cardamom, and raisins can replace dates and currants.

     

    Tef Waffles

    Yield: 6 waffles

    Time: 30 minutes

    Tef waffles are superior to wheat waffles. Tef. s superbly delicate crumb and full flavour offer so much more than wheat (whole or white), which demands sugar to make it palatable. Red tef is used.

    Ingredients:

    Preparation

    Variations

    Chocolate Cake

    Yield: 18-inch round layer cake

    Time: 25 minutes

    This recipe is a special alternative for people have allergies to the gluten in wheat. Tef. s light and tender crumb, plus its full range of subtly sweet earth flavours make a very good chocolate cake.

    Ingredients:

    Icing and filling

    Preparation

    Variations

    Double-Tef Butter-Pecan Tea Cakes

    Yield: 18, 1 ½ inch cakes

    Time: 30 minutes

    Rich but not too sweet, small but filling, lavish but nourishing, these dainty shortbread are very delicious. Tef teacakes keep well for a week when thoroughly cooled and then placed into an airtight container.

    Ingredients

    Preparation

    Variations

    Whole Grain Muffins

    Yield: 12 muffins

    Time: 45 minutes

    Three different grains make these nutritious muffins extra tasty. The oat brand and wheat germ add nutty flavours and the tef contributes to the fine texture.

    Ingredients

    Preparation

    Variations

    Jalapeno Tef fillets

    Yield: 4 servings

    Time: 30 minutes

    For those who enjoy Italian polenta but who do not want to spend 45 minutes standing over a stove stirring it, the tef potential is a good change. Polenta is similar to the southern version of fried cornmeal mush.

    Tef takes a fraction of the time to cook and requires stirring once or twice. Compared to corn, tef sets quickly and holds together equally as well.

    Ingredients

    Preparation

    Variations

    Utilization for Animal Feed

    According to the FAO Production Yearbook of 1985, Ethiopia had an estimated 26 million head of cattle, 17.26 million head of goats and 23.5 million head of sheep. This clearly indicates the heavy requirement of animal feeds as well as its importance to the agricultural economy of the country. However, the production of forage crops is not widely practiced. Hence, crop residues play a significant role as a source of livestock feeds.

    Tef is not grown as a forage crop in Ethiopia. However, when grown as a cereal, its straw is stored and used as a very important source of animal feed, especially during the dry season. Cattle prefer tef straw than straw from any other cereal and its price is higher than that of other cereals. For example, tef straw costs about 40-50/100 Birr/kg while the price of wheat is about 30-40/100 Birr/kg in the Ada region (Seyfu, 1993).

    The national average grain yield of tef is nearly 1 tonne ha-1. With a national average of biomass production of 4.1 ha-1 and a harvest index of 24.4 percent on 1.38 million hectares of land currently under production, the country produces on average 4.3 million tonnes of tef straw annually. The price of tef straw varies depending on the region as well as the season. However, taking the price in Ada region as a base, it is possible to roughly estimate that the national price tef straw produced per annum is between 129 million Birr and 172 million Birr. Both the amounts of tef straw produced as well as its price clearly indicates the important role tef straw plays as a crop-residue for livestock feed in Ethiopian agriculture.

    According to Lulseged and Jemal (1989), the quantity and quality of residues from various crops vary greatly depending on the crop species. Wheat and barley usually give high straw yields though of inferior quality. Among cereals, straw of tef is relatively the best and is comparable to good natural pasture-hay. Indication of the relative importance of various crop residues is given in the Table 4. According to Lulseged and Jemal (1989), the performance of animals on residue diets is also known to vary depending on the crop species.

    According to Burt-Davy (1913), the chief value of tef as a hay crop lies in its palatability, high nutritive value, narrow albumin ration (for a grass hay), high yield, rapid growth, drought resistance and ability to smother weeds. In South Africa tef is grown as a forage crop.

    According to Taddesse, (1969), tef produces more than twice as much forage as weeping love-grass (Eragrostis curvual), producing on average of 14.5t ha-1 green material in three months. This again shows that tef has a great potential as a forage crop. Hence it can be used as a dual or multipurpose crop, i.e., both as a cereal and as forage feed (Seyfu, 1993).

    1.6 Consumer Preference

    Consumers prefer white tef followed by mixed tef and red (brown) tef. Poor farmers usually sell the white tef at reasonably higher prices, while buying either the mixed or brown tef for their own consumption. The grain is ground into flour which is mainly used for making a popular pancake-like bread locally called Enjera.There are three main commercial classes of tef based on the prevailing colours of the grain. Nach (meaning white) or Manngna is very white or medium white tef and Sergagna is a mixture of white and red or reddish brown tef without any standard proportions from each. Kayy tef is red or brown red tef. Tekur tef also called Taffy Dimma is a deep vivacious or red grained tef. Sometimes there may be as many as five classes of tef. (Taddesse, 1969). White tef is more expensive than the red tef. People who can afford the price usually consume white tef or Manngna tef, while the medium and poor families consume the mixed and/or red tef. Farmers who grow white tef often do not consume it. Instead they sell the white tef and buy the red tef for home consumption.

    In the Nach class, usually red grains are found and in the kayy class white grains occur mixed with red. In samples taken from Dire Dawa, Harar, Addis Ababa, Nekemte, Jimma, Asmara and Bahre-Dar markets, it was found that from 0.1-5 percent red caryopsises were mixed in the white class and from 0.1-0.8 percent white caryopsises mixed in the red class. The principal cause of this mixture is attributed to the common threshing ground, the use of common utensils in handling the grains, run-off water carrying tef seeds from field to field, and possibly to unsatisfactory storage facilities.

    Table 10. Amino acid content of tef (g/16g N) compared with other cereals, the FAO pattern and whole egg

    Amino acid

    Tef

    Barley

    Maize

    Oats

    Rice

    Sorghum

    Wheat

    Pearl

    Millet*

    FAO

    Pattern*

    Whole egg***

    Lysine

    3.68

    3.64

    2.67

    3.71

    3.79

    2.02

    2.08

    2.89

    4.2

    6.6

    Isoleucine

    4.00

    3.58

    3.68

    3.78

    3.81

    3.92

    3.68

    3.09

    4.2

    7.5

    Leucine

    8.53

    6.67

    12.50

    7.26

    8.22

    13.30

    7.04

    7.29

    4.8

    9.4

    Valine

    5.46

    5.04

    4.85

    5.10

    5.50

    5.01

    4.13

    4.49

    4.2

    7.2

    Pheny-lalanine

    5.69

    5.14

    4.88

    5.00

    5.15

    4.90

    4.86

    3.46

    2.8

    5.8

    Tyrosine

    3.84

    3.10

    3.82

    3.30

    3.49

    2.67

    2.32

    1.41

    2.8

    4.4

    Tryptophan

    1.30*

    1.54

    0.70

    1.26

    1.25

    1.22

    1.07

    1.62

    1.4

    1.4

    Threonine

    4.32

    3.31

    3.60

    3.31

    3.90

    3.02

    2.69

    2.50

    2.8

    4.2

    Histidine

    3.21

    2.11

    2.72

    2.10

    2.50

    2.14

    2.08

    2.08

    - -

    2.1

    Arginine

    5.15

    4.72

    4.19

    6.29

    8.26

    3.07

    3.54

    3.48

    - -

    6.9

    Methionine

    4.06

    1.66

    1.92

    1.68

    2.32

    1.39

    1.46

    1.35

    2.2

    3.8

    Cystine*

    2.50

    3.19

    2.0

    2.4

    * Jansen et al. (1962).
    ** Amount of amino acid content considered adequate by FAO standards.
    *** Alemayehu (1990).

    Table 11. Chemical composition of tef seed compared with spring wheat, winter wheat, winter barley and sorghum (Melak Hail, 1966)

    Chemical Element

    Purple

    tef

    White

    tef

    Spring

    Wheat

    Winter Wheat

    Winter

    Barley

    Sorghum

    K (%) (g/100g)

    0.36

    0.20

    0.37

    0.33

    0.44

    0.44

    P (%) (g/100g)

    0.44

    0.46

    0.51

    0.40

    0.48

    0.52

    Ca (%) (g/100g)

    0.18

    0.17

    <0.10

    <0.10

    <0.10

    <0.10

    Mg (%) (g/100g)

    0.18

    0.19

    0.15

    0.12

    0.13

    0.18

    Mn (ppm)

    21.20

    30.00

    53.00

    36.00

    12.00

    29.00

    Fe (ppm)

    196.00

    115.00

    78.50

    40.00

    35.00

    66.50

    B (ppm)

    14.00

    13.00

    12.00

    11.50

    11.00

    16.50

    Cu (ppm)

    53.00

    36.00

    20.00

    11.00

    14.00

    23.50

    Zn (ppm)

    67.00

    67.60

    60.00

    39.50

    45.00

    44.00

    Al (ppm) %

    83.00

    0.12

    <0.10

    <0.10

    <0.10

    <0.10

    Sr (ppm) %

    <0.10

    <0.10

    <0.10

    <0.10

    <0.10

    <0.10

    Mo (ppm)

    0.78

    0.74

    0.55

    0.55

    0.40

    0.45

    Co (ppm)

    0.52

    0.64

    0.55

    0.55

    0.30

    0.30

    Na (ppm)

    220.00

    212.20

    168.50

    168.50

    392.00

    141.50

    Ba (ppm)

    19.00

    23.50

    6.00

    6.00

    7.00

    <0.10

    SiO2 (%)(g/100g)

    0.31

    trace

    trace

    trace

    trace

    <0.10

     

    Table 12.