Traditional and Emerging Feedstocks for Food and Industrial Bioproduct Manufacturing - Food and Industrial Bioproducts and Bioprocessing - page 10

also contains numerous polyphenolic compounds, including catechin and proanthocyanidin
(Aastrup et al ., 1984). Proanthocyanidins cause undesirable haze in beer. Fortunately, about
600 proanthocyanidin-free barley mutants have been isolated and used in breeding programs
(Jende-Strid, 1993). Oxidation of phenolic compounds to o -quinones results in discoloration
of the products made with barley after cooking (Sapers, 1993).

1.2.3.3 Utilization

It is estimated that about 85% of the world barley production is utilized as feed (Mäkinen
and Nuutila, 2004). Malting is the second largest application for barley grain. Only 2% of
barley is used for food production in the United States. However, in regions with extreme
climates, such as Himalayan nations, Ethiopia and Morocco, barley remains an important
food source (Baik and Ullrich, 2008).
Low protein content barley grain is preferred for malting. In general, protein and starch
contents are negatively correlated in crops. Higher starch content in barley grain leads to
higher extract content in malt. Low protein is ideal for starch production while higher
protein content is desirable in feed barley. The health benefits of barley include reduction of
blood LDL cholesterol level, glycemic index and body mass, which lead to control of heart
disease and type-2 diabetes. Interest in incorporating low tannin barley in human diet is
increasing because of its high nutritional value (Newman and Newman, 2008). The beneficial
effects of barley are due to the presence of several bioactive compounds, such as -glucans,

tocopherols and tocotrienols in the grain (Baik and Ullrich, 2008). Indeed the US Food and
Drug Administration (FDA) approved a health claim verifying that barley contains high
levels of

β

-glucans which help to prevent coronary heart disease when consumed by humans
(FDA, 2005). Although today the main source of barley

β

β -glucan in functional foods is oats,

barley -glucan has a potential for new formulations. Co-products from barley milling can

be used to recover phenolic compounds and other antioxidants that can be incorporated into
functional foods and nutraceuticals, such as high performance sports drinks and dietary
supplements, anti-aging cosmetics and sun-screen lotions (Griffey et al ., 2009 ; Newman
and Newman, 2008). Barley has the potential as a platform to produce various enzymes,
therapeutic proteins and novel high value chemicals through genetic modifications (Jensen
et al ., 1996 ; Jende-Strid, 1993 ; Horvath et al ., 2000 ).
Interest in using barley, particularly winter hulless winter barley, for bioproduct and
biofuel production is growing specifically outside the Corn Belt area in the United States
(Septiano et al ., 2010 ; Griffey et al ., 2009). Ground whole barley grain and flour have been
successfully converted to bioethanol (Sohn et al ., 2007 ; Septiano et al ., 2010 ; Gibreel et al .,
2009). Production of valuable high protein content DDGS as a by-product improves the
feasibility of barley as feedstock for alcohol production for fuel and solvent uses (Ingledew
et al ., 1995 ).

β

1.2.4 Sorghum
1.2.4.1 Production

Sorghum is a member of the grass family Poaceae. It is a drought-tolerant crop that grows
well with minimal input. In regions with low rainfall, less than 900 mm annual rainfall,
sorghum out-performs corn, making it an appealing crop in semiarid regions of the world
(Zhan et al ., 2003). Total world production of barley was 66.8 million tonnes in 2008 (FAO,