Traditional and Emerging Feedstocks for Food and Industrial Bioproduct Manufacturing - Food and Industrial Bioproducts and Bioprocessing - page 2

or tripling of resource use efficiencies (especially of nitrogen and water productivity in
biomass production systems) will be necessary to meet the rapidly growing demand for
food, feed and industrial bioproducts over the next 20-30 years (Spiertz and Ewert, 2009).
About 224 × 10 9 tonnes of dry biomass is generated globally as a result of photosynthesis
(Champagne, 2008). Today, forestry products and agricultural crops are the major feedstocks
for bioproduct manufacturing. Utilization of agricultural residues, forestry, animal and
municipal solid wastes and marine vegetation as feedstock could ease the pressure on
agricultural land needed to grow food. However, the effect of excessive biomass removal on
ecosystems has to be examined very carefully.
In this chapter, current and potential feedstocks for food and bioproduct manufacturing
will be reviewed under three categories: grain, oilseed and lignocellulosic biomass, which
will include grasses and trees. Microalgae, emerging as a biomass source, will be covered in
another chapter of this topic.

1.2 GRAIN CROPS

Grain crops, specifically cereal crops, are major feedstocks for the food and fermentation
industry because of their high starch and protein content. Cereal crops are by far the most
important crops cultivated globally. In 2009 about 2.5 billion tonnes of cereals were
produced worldwide (FAO, 2010). Wheat, corn, barley and sorghum are the common starch
sources that have been traditionally used in food and industrial bioproduct manufacturing.
Straw and stocks from cereal crops are also important as lignocellulosic feedstock for
bioproduct manufacturing.

1.2.1 Wheat
1.2.1.1 Production

Wheat is one of the major grain crops produced, consumed and traded worldwide. About
683 million tonnes of wheat is produced globally each year (Table 1.1). China, India, the
USA and the Russian Federation are among the largest wheat growers (FAO, 2010).
It is believed that einkorn, which was developed from a wild grass native to western Asia,
was the first type of wheat cultivated (Atwell, 2001; Orth and Shellenberger, 1988). Four
species, Tiriticum : T. monococcum, T. turgidum, T. timopheevi and T. aestivum , are the
commercially important wheat cultivars today. Among these, T. turgidum and T. aestivum ,
which are mainly used for bread and pasta making, respectively, are the most widely grown
wheat species (Pomeranz, 1988). Enhancement of nutritional composition and value of
wheat through biotechnology is an area that is gaining ever increasing scientific attention. It
has been shown that a gene, GPC-B1, found in wild wheat but lost its functionality during
domestication has the potential of increasing protein and micronutrient content of cultivated
wheat by 10-15% (Uauy et al ., 2006). Novel wheat varieties with high amylose content
have been developed by using the RNAi gene silencing technique that suppresses the
expression of two wheat genes, SBEIIa and SBEIIb (Regina et al ., 2006 ). These genes
produce starch branching enzymes and play important role in the starch synthesis pathway.
The suppression of these two genes produced a wheat variety with high resistant starch
(amylose) content and low glycemic index (GI). This new wheat variety could potentially
provide health benefits to people with bowel, diabetes and obesity problems.