2009_Book_FoodChemistry

674 15 Cereals and Cereal Products
Table 15.4. Yield per hectare in year 2000/2001/2002/2003/2004/2006 (dt/ha)
Wheat Rye Corn Rice
Germany 72.8/78.8/68.1/65.0/81.7/72.0 49.3/61.3/50.3/42.9/61.3/49.1 92.1/88.4/93.8/72.4/ 90.9/80.3 -.- / -.- / -.- / -.- / -.-/ -.-
Argentina 24.9/22.4/20.3/25.3/25.4/25.5 14.4/13.3/14.0/ 9.5/ 9.5/11.5 54.3/54.5/61.7/64.7/ 64.6/59.0 47.8/57.0/57.5/54.0/62.8/70.6
Australia 18.2/21.1/ 9.1/20.7/17.0/ 8.8 6.4/ 6.4/ 6.4/ 6.4/ 5.7/ 5.7 49.4/46.6/55.1/59.4/ 49.6/50.0 82.6/92.8/79.5/95.2/82.3/63.0
China 37.4/38.1/37.8/39.3/42.0/44.6 15.3/13.4/14.5/22.7/21.0/35.1 46.0/47.0/49.3/48.1/ 51.5/53.7 62.6/61.5/61.9/60.6/62.6/62.6
France 71.2/66.2/74.5/62.5/75.8/67.4 46.1/40.8/48.6/40.3/50.5/45.7 90.8/85.6/89.8/71.2/ 89.8/85.6 58.4/53.6/56.9/56.1/57.1/55.3
India 27.8/27.1/27.6/26.2/27.1/26.2 -.- / -.- / -.- / -.- / -.-/ -.- 18.2/20.0/16.4/19.8/ 20.0/19.4 28.5/31.2/28.9/30.8/30.5/31.2
Russian Fed. 16.1/20.6/20.7/17.0/19.8/19.5 15.8/18.8/19.9/18.6/15.4/17.1 21.2/18.1/28.6/32.2/ 40.4/36.3 34.9/34.9/37.7/31.5/37.7/43.9
Turkey 22.4/20.3/21.0/20.9/22.3/21.5 17.7/15.7/17.0/17.1/18.5/16.5 41.4/40.0/42.0/50.0/ 42.9/58.6 60.3/61.0/60.0/57.2/50.0/87.0
USA 28.3/27.1/23.7/29.7/29.0/28.3 17.8/17.2/15.5/17.0/16.9/16.5 85.9/86.7/81.6/89.2/100.7/93.6 70.4/72.8/73.7/74.5/77.8/76.9
World 27.2/27.5/26.8/27.1/29.1/28.0 20.4/23.6/23.0/21.8/25.2/22.1 42.8/44.2/43.5/44.4/ 49.1/48.2 38.9/39.4/39.1/39.1/40.0/41.1
Table 15.5. Average thousand kernel weight of cereals
(g)
Wheat 37 Oats 32
Rye 30 Barley 37
Corn 285 Millet 23
Rice 27
15.1.6 Celiac Disease
Wheat, rye and barley can cause celiac disease in
genetically predisposed persons; the role of oats
in this disease is uncertain. Celiac disease affects
both infants and adolescents, and in adults it is
also called sprue. It is associated with a loss of
villous structure of the intestinal mucosa; epithelial
cells exhibit degenerative changes and nutrient
absorption functions are severly impaired.
Incidence of the disease varies, e. g., 0.1% of
the children are affected in central Europe and
0.3% in Ireland. The prolamin fractions of wheat,
barley or rye are the cause of the disease, which
is therefore eliminated by a change of diet to rice,
millet or corn.
15.2 Individual Constituents
The role of constituents is of particular interest in
the processing of wheat and rye into bakery products.
15.2.1 Proteins
15.2.1.1 Differences in Amino Acid
Composition
The proteins of different cereal flours vary in
their amino acid composition (Table 15.10).
Lysine content is low in all cereals. Methionine
is also low, particularly in wheat, rye, barley,
oats and corn. Both amino acids are significantly
lower in flour than in muscle, egg or milk proteins.
By breeding, attempts are being made to
improve the content of all essential amino acids.
This approach has been successful in the case of
high-lysine barley and several corn cultivars.