Beer : Health and Nutrition

Table 3.2 Composition of barley.
Component % of total dry weight
Carbohydrates 78–83
Starch 63–65
Sucrose 1–2
Other sugars 1
Water-soluble polysaccharides 1–1.5
Alkali-soluble polysaccharides 8–10
Cellulose 4–5
Lipid 2–3
Protein 10–12
Albumins and globulins 3.5
Hordeins 3–4
Glutelins 3–4
Nucleic acids 0.2–0.3
Minerals 2
Other 5–6
Source: data derived from Harris (1962).
The Basics of Malting and Brewing 53
common with other crops, barley is susceptible to a range of infections and infestations
(Briggs 1978).
Aflatoxins originate from some members of the genus Aspergillus, namely
Aspergillus avus, A. parasiticus, A. nomius and A. ochraceoreseus (Moss 2003). (It
will be noted that these don’t include the strains such as A. oryzae that have a role in the
production of alcoholic beverages such as sake or as a source of exogenous enzymes
for brewers.) The most commonly a atoxin-contaminated foods are corn (maize) and
peanuts, but all cereals may be affected. Infection is most commonly associated with
post-harvest spoilage, when storage is under inapproporiate conditions of temperature
and moisture.
Pesticides have real value in this context. Nonetheless there has been in-depth investigation
of alternative ways of treating grain, particularly during storage, such that it
does not develop infection. These studies have included the use of anaerobic storage
(Baxter & Dawe 1990). Where pesticides are used much will be largely washed off the
surface of the grain during steeping (Miyake et al. 2002).
It must be emphasised that authorities in most countries have regulations and systems
for controlling the nature of pesticides that may be used, and those pesticides
have been widely screened for their environmental and health impacts. Any perceived
risks of using them are grossly outweighed by the very real problem that can accrue in
any cereal from contamination with those micro ora capable of producing mycotoxins
and ochratoxins (Petzinger & Weidenbach 2002). One such substance is deoxynivalenol
(DON), which is produced by the fungus Fusarium (Wolf-Hall & Schwarz 2002).
Brewers (and therefore maltsters) set rigorous standards for the level of DON in barley