Barley for Food and Health: Science, Technology, and Products

76 BARLEY: GENETICS AND NUTRIENT COMPOSITION
of two hulled and two hulless barley cultivars. One of the hulless types was
waxy and was grown in a different environment and year than the other three
barleys. The concentrations of all T and T3 isomers reported in this study were
higher than reported by Wang et al. (1993), Peterson (1994), and Ehrenbergerovά
et al. (2006). The greatest differences were in α-T and α-T3 concentrations and
the sum of the eight isomers, which was 2.0 to 2.6 times greater than in the
earlier reports. In contrast to the findings of Ehrenbergerovά (2006), Cavallero
et al. (2004) and Moreau et al. (2007) reported higher levels of total tocols in
hulled barley although they also reported that hulless types had higher levels
of α-T3. The results of these four studies indicate variability in concentrations
of the various tocol isomers among different barleys. The differences may be
explained by the different laboratories, genotypes, and growing environments.
The one consistent finding in all four studies was the greater concentration of
α-T3 than of the other T and T3 isomers (Table 4.4).
There is much less recent information on the amounts of the other vitamins in
barley grain. Whole-grain cereals in general are good sources of the B-complex
vitamins. Barley contains a range of the B vitamins that act as cofactors or prosthetic
groups for various metabolic reactions in animal and microbial metabolism.
A summary of the B-complex vitamin concentrations in barley grain is presented
in Table 4.5. The data, which are from different laboratories spanning several
years, are consistent for some vitamins but vary widely for others. It was suggested
by Briggs (1978) that variation in the concentrations of vitamins reported
in barley may be attributed to differences in analytical procedures and techniques
used in different laboratories. Nicotinic acid is the most abundant of the
TABLE 4.4
Tocol Content (mg/kg) of Barley, Dry Matter Basis
Tocopherols (T) Tocotrienols (T3)
η α β γ δ α β γ δ T + T3 T3(%)
7 a 10.9 0.6 11.0 0.3 32.6 — 6.9 0.7 63.0 63.8
2 b 8.1 0.4 10.0 0.4 43.3 — 7.7 1.0 70.9 73.3
3 c 7.6 0.5 0.4 0.2 26.0 5.3 4.2 0.7 44.9 80.6
4 d 5.1 0.5 3.7 0.3 16.6 3.3 8.1 1.2 38.8 75.3
6 e 9.3 0.4 2.1 0.2 30.8 4.3 6.9 0.8 54.8 78.1
13 f 6.8 4.3 h — 1.0 29.6 11.4 h — 0.6 53.7 77.5
4 g 17.9 1.5 10.3 2.6 58.7 8.9 13.6 2.3 115.8 72.1
Weighted means 8.7 0.7 6.4 0.8 32.3 5.3 7.9 0.9 63.0 73.7
a Wang (1992).
b Wang et al. (1993).
c Peterson (1994).
d Andersson et al. (2003).
e Cavallero et al. (2004).
f Ehrenbergerova et al. (2006).
g Moreau et al. (2007).
h β and γ isomers were combined in this report and not included in weighted means.