Teff: Teff, (Eragrostis tef), annual cereal grass (family Poaceae), grown for its tiny nutritious seeds. Teff is native to Ethiopia and Eritrea, where it is a staple food. Eragrostis tef is a ANNUAL growing to 1 m (3ft 3in). It is hardy to zone (UK) 9. It is in flower from August to September, and the seeds ripen from September to. Comprehensive Description. The millet known as tef (Eragrostis tef) is a minor cereal crop on a global scale, but a major food grain in Ethiopia and Eritrea.
|Published (Last):||20 August 2016|
|PDF File Size:||18.96 Mb|
|ePub File Size:||5.67 Mb|
|Price:||Free* [*Free Regsitration Required]|
The demand for gluten-free foods is certainly increasing. Interest in teff has increased noticeably due to its very attractive nutritional profile and eragrostia nature of the grain, making it a suitable substitute for wheat and other cereals in eragrkstis food applications as well as foods for people with celiac disease. The main objective of this article is to review researches on teff, evaluate its suitability for different food applications, ted give direction for further research on its applications for health food market.
Teff is a tropical low risk cereal that grows in a wider ecology and can tolerate harsh environmental conditions where most other cereals are less viable. It has an excellent balance of amino acid composition including all tet essential amino acids for humans making it an excellent material for malting and brewing. Because of its small size, teff is made into whole-grain flour bran and germ includedresulting in a very high fiber content and high nutrient content in general.
Teff is useful to improve the haemoglobin level in human body and helps to prevent malaria, incidence of anaemia and diabetes. The nutrient composition of teff grain indicates egagrostis it has a good potential to be used in foods and beverages worldwide. Africa is rich in a wide range of less explored grain species, including teff and other different types of millets.
These grains represent an important source of dietary proteins, carbohydrates, fibre, vitamins, and minerals for the people. They are fermented into a large number of foods and beverages with improved texture, taste, aroma, keeping quality, nutritional values, digestibility, and microbial quality and with reduced antinutrient contents National Research Council ; Yetneberk et al. Teff Eragrostis tef Eragrowtis Trotter is a tropical cereal that belongs to the family of Poaceae, subfamily Eragrostoidae, tribe Eragrosteae, and genus Eragrostis.
About species are known in the teef Eragrostis Demissieof which teff is the only cultivated species. Chloridoideae is used synonymously for Eragrostoidae of teff Costanza et al.
Tef (Eragrostis tef) grain | Feedipedia
Teff cultivars have been recognized and described based on the colour of the grains and inflorescences, ramification of the inflorescences and the size of plants. For marketing purposes, teff is classified on the basis of seed colour: Teff grain is hull-less naked and comes in a range of colors from milky-white to almost dark brown. The most common colors are white, creamy-white, light brown, and dark brown. The grain is oval-shaped with size 0.
The PFAF Bookshop
The ergarostis grain mass is generally in the range of 0. Teff can adapt to a eragristis range of environment National Research Council and it is considered to be very resistant to insect pests. Teff seeds remain viable for several years provided that direct contact with moisture and sunshine is avoided Gamboa and Ekris In comparison with other common cereals, teff grain is less prone eragrostus attacks by weevils and other storage pests Tadesse Thus, it can be safely stored under traditional storage conditions with no chemical protection.
This paper reviews the nutritional value and other aspects of teff and its potential for different applications including brewing and other gluten-free foods and beverages for the health food market. The chemical composition of cereals varies widely and depends on the environmental conditions, soil, variety and fertilizer.
The importance of teff is mainly due to the fact it has attractive nutritional profile and has no gluten found in other common cereals such as wheat, barley and rye.
The demand for gluten-free foods is growing as more people are diagnosed with celiac disease and other types of eragrostiz sensitivity Bultosa and Taylor ; Dekking et al. According a research report by Bultosa for 13 teff eragrostix varieties, the proximate compositions and flour-starch amylose contents were in some ranges: These values are similar to previous findings by other researchers Bultosa and Taylor ; National Research Council This makes it to be a potential gluten free cereal that replaces wheat and other cereals in their applications as sources of food energy.
Teff starch granules are conglomerates of many polygonal simple granules Bultosa et al. The proximate db 1 and microelement compositions of teff grain compared with some gluten containing and gluten free cereals. Starch granules of the endosperm Source: Compound a and individual b — f starch granules from different teff varieties: Bultosa and Taylor The shape is polygonal, smooth with no surface pores.
A few granules are essentially cubic and at high magnification, and some appear as tortoise-shell shaped Bultosa and Taylor The information contained in the endosperm starch granules look round from the CLSM images which contradicts the SEM images, there the starch granules were observed as rectangular or square.
The reason for the difference in appearance is probably the treatment of CLSM teff grain with the fluorescent dyes that are dissolved in water. Through contact with water the grains are eratrostis swollen and changed in structure. However, Bultosa reported somehow smaller amylose contents for 13 teff varieties.
There was a problem providing the content you requested
According to Bultosaamong teff flours the highest amylose contents were observed for DZ Starch degradability is improved through the malting process due possibly to differences in the degree of modification of starch structure and composition Glennie et al.
The extent of gelatinization and the gelatinization temperature can also be affected by many other factors, including fat content, amylose content and granule size. As the gelatinization temperature of teff is too high for the amylolytic enzymes, an adjunct mashing regimen may be considered for wort production.
This may be due to structural differences in their amylose eragrosstis amylopectins Briggs ; Sablani ; Tester and Morrison Gelatinization of starch is important in the processes such eragroetis baking of bread, gelling of pie fillings, formulation of pasta products, and thickening of sauces to produce a desirable texture or consistency. The proportion of eragrsotis and gelatinized starch in ready-to-serve starchy products may be critical in determining the acceptability.
Texture of many foods such as breakfast cereals, beverages, rice, noodles, pasta, and dried soups depends eragrostie the fraction eraggrostis gelatinized starch in the product Sablani However, in most food systems the actual temperature at which starch gelatinizes is less important than those properties that depend on swelling, such as pasting behavior and rheological properties of the partially or fully swollen starch granules.
The pasting temperatures for 13 teff varieties ranged from The highest pasting temperatures were reported for teff varieties DZ-Cr The pasting temperatures reported by Bultosa were somehow similar to the reported Rapid Visco Analyzer RVA pasting temperatures According to Bultosa et al. The pasting character predicts the processing qualities of starch based raw material food ingredients. The pasting character is fundamentally determined by the starch granule composition and its nature trf and is also influenced by the non-starch flour components.
Most eragrosris the gelling properties are due to amylose, which precipitates in aqueous solution to initiate gelatinization when heated. The paste clarity of teff starch is opaque, and the gel texture is short and smooth Bultosa The branched molecules within the swollen granules undergo a slow association to rigidify the swollen granules.
It is possible that the intra-granular amylose fraction enhances the rigidity of starch granules on bread staling. Specialty starches can provide a number of functional benefits in making snack products, including different expansion, crispness, oil pickup, and overall eating quality.
The crisp texture of bakery products is due to recrystallization of sugar on removal of water during baking. Sugars also act to tenderize bakery products by slowing the rate at which starch molecules become interlinked and proteins break down Hug-Iten et al. The viscosity of teff starch is considerably lower than that of maize-starch. This implies that teff starch paste will have high stability after cooling when compared to that of maize starch paste. This means that teff starch will exhibit higher resistance to retrogradation; thus, its products have high resistance to staling.
Similar to other small-granule starches eraggostis granules offer good functionality as a fat substitute, flavor and aroma carrier since they are very small, smooth, and of uniform size. Teff starch has good resistance to shear breakdown, and thus it may find good application in eragrodtis processed foods. Many carbohydrates are excellent scavengers of metal ions.
Genetic diversity in tef [Eragrostis tef (Zucc.) Trotter]
Glucose, fructose and sugar alcohols have the ability to block the reactive sites of ions, such as copper, iron and to a lesser extent, cobalt. This is characteristic of monosaccharides and aids in food preservation by retarding catalytic oxidation reactions Ferrier The fractional composition of the protein in teff indicate that glutelins and albumins are the major eragrostid storage components; and their order of fractional importance was: The distribution of these protein fractions varies among different cereals and there is eragostis variation in the solubility classes among the cereals.
Among these fractions in cereals, the prolamin fraction has been the most studied Haard et al. Prolamins are characterized by a particular amino acid composition with domains with a high content of proline and glutamine. It has been demonstrated that these protein domains are resistant to degradation by gastric, pancreatic and proteases in erageostis human intestinal brush border membrane Saturni et al.
The amino acid composition of teff flour is favourable and its protein is easily digestible in comparison to cereals such as maize and sorghum because the main protein fractions such as albumin, glutelin, and globulin are the most digestible types. Bultosa reported that the grain protein contents of 13 teff varieties are ranged from 8. The grain protein in DZ Protein level is very important in malting and brewing processes. Excessively high protein level is commonly associated with lower soluble substance content and malt extract quality, resulting in unacceptable malt quality.
However, if the protein content of malt is too low, brewing performance may be impaired through poor yeast amino acid nutrition. Protein levels in general must not be too low as proteins serve four basic functions in brewing.
They are the origin of enzymes that catalyze the complex biochemical reactions involved in turning the cereal into malt, and malt into wort. They are required for yeast nutrition; they contribute to foam and are involved in the flavor development that malt contributes to beer and whiskey. Thus, its protein content is an indicator for production of good quality gluten-free malt from teff grains.
The proteins also play an important role in determining the texture of a food, and may be used as thickening, binding, or gelling agents and as emulsifiers or foaming agents Vaclavik and Christian Research findings Jansen et al.
The other amino acids compositions of teff are also excellent and its lysine content 3. Isoleucine, leucine, eragrosits, tyrosine, threonine, methionine, phenylalanine, arginine, alanine and histidine contents of teff are higher than in barley, wheat and most other cereals. Isoleucine, valine, tyrosine, serine, and glycine contents of teff are slightly lower than those of brown rice. In general, the bacterial fermentations did not improve the essential amino acid profile of the fermented food product.
The fungal fermentation, on the other hand, improved essential amino acid profiles of teff. The well balanced amino acid composition of teff makes it an excellent material for malting and brewing. Nutritional value and stability are the most important qualities eragroxtis alcoholic beverages.
In addition to some other food components, proteins and some amino acids are also responsible for nutritional value and stability of beer. Proline and lysine are the most important amino acids in beer. It is known that proline eragroetis are responsible for the affinity towards proanthocyanidins and take part in the production of aromatic compounds and, in this trf, influence beer quality.