Book review

Elsayed Abdel-Aal and Peter Wood, editors. Speciality

grains for food and feed (2005, American Association of

Cereal Chemists, Inc., St Paul, Minnesota, USA), 412

pages hardcover, 6 in.!9 in., price $159.00

ISBN 1-891127-41-1.

Few cereal science professionals can have failed to

notice the increasing popularity of multi-grain breads and

crispbreads, wholegrain breakfast cereals, snack bars and

other health-food products, yet until now the key reference

books have been limited to mainstream cereal grains: wheat,

rice, corn, barley, sorghum and oats. This new title brings

together information on many other grains that are finding

new applications, including: einkorn, emmer, spelt, waxy

wheat, hulless barley, hairless canary seed, hulless oats,

specialty rye, specialty sorghums, blue and purple grains,

amaranth and buckwheat. Production of grains for the

‘organic’ food sector is also discussed and the book

concludes with a summarising discussion of the potential

value of specialty grains for their health benefits.

First impressions on opening the book are of extensive

text and tables but surprisingly few illustrations. Many

references are provided at the end of each chapter; however

there is no overall author index for these. The short

introduction by the editors reminds us that almost half the

world population’s energy and more than 40% of its protein

intake comes from cereal foods. Nearly two billion tonnes

are grown annually, of which half is used for food, 35% for

feed and the rest for industrial processing, seed, etc. To meet

global population growth, predominantly in Asia, cultiva-

tion will have to increase every year by about 15 million

tonnes.

Before progressing into specialty grain varieties, the

book covers a market area of significance largely in

developed countries, that of production to ‘organic’ food

standards. Certification, accreditation and crop management

are discussed and detail is provided on organic food

markets, price premiums and profitability. Nutritional

value, safety and technical quality are also considered and

it is noted that mycotoxin content is highly variable

regardless of the agricultural system used, but that the

lower protein content of organic wheat leads to inferior

bread volume.

Chapter 3 covers einkorn, an early-domesticated

wheat (Triticum monococcum) found in Near-East archae-

ological sites from 10,000 years ago. Origin, genetics

doi:10.1016/j.jcs.2005.02.003

and morphology are described, but there is no illustration of

the grain, also known as ‘small spelt’. It is a late maturing,

non-free threshing, soft milling, high protein grain, having a

yellow endosperm and poor rheological properties. No

specific health benefits have been reported, although

einkorn could provide a genetic resource for future

development of a high-lutein wheat.

The next and by far the longest chapter is devoted to

another specialty wheat, emmer (T. dicoccon), also

cultivated from ancient times and widely distributed from

the Middle-East as far as Russia, India, North Africa and

Italy. Emmer is good for cultivation in marginal areas.

There are now over 2000 world accessions, which are being

used to improve agronomic and technological properties of

common and durum wheats. Detailed tables are given of

agronomic performance and protein composition. Protein

content is variable from 9 to18% but the glutenin content

and level of high molecular weight subunits is very low,

hence giving a weak gluten and poorer bread quality than

spelt, although having a distinct flavour. Emmer gluten has

high sequence homology with coeliac-toxic sequences of

wheat and is therefore not safe for coeliac patients. This

chapter also provides extensive information on emmer

processing, including details of a novel application of

‘parboiling’ hydrothermal treatment to improve milling

performance, nutrient retention and cooking quality. It is

possible to make pasta, cookies and extruded snacks from

emmer, but the real potential lies in its genetic contribution

in breeding programs, especially adaptability to marginal

areas, biotic and abiotic stress resistance, etc.

Spelt is covered in Chapter 5. Hexaploid and originally

classified as Triticum spelta it is now regarded as a subgroup

of common wheat. It is hulled and useful in cold soils where

it is resistant to common bunt fungus. Before milling, the

grain must be de-hulled, losing about a quarter of its weight.

The flour, of intermediate gluten strength, has applications

in the expensive health-foods market in bread, pasta and

breakfast cereals. As for emmer, claims have been made that

these ancient wheats could be non-toxic to coeliac patients,

but this is not true—identical toxic peptide sequences

having recently been isolated from spelt and common

wheat.

Waxy wheat, a modern specialty grain (amylose-free)

described in Chapter 6, is a recent development using

biochemical and molecular genetic techniques to produce

lines with triple nulls to the amylose synthase enzyme,

GBSS1. This is necessary since spontaneous mutation in all

Journal of Cereal Science 42 (2005) 135–137

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Book review / Journal of Cereal Science 42 (2005) 135–137136

three genomes is very unlikely and no native fully waxy

wheat mutants have been found. Ability to modify the ratio

of amylose to amylopectin in wheat starch and hence to vary

the gelling, pasting and retrogradation properties, offers the

possibility of novel applications and an alternative for

chemically modified starches. Texture control in diverse

types of Asian noodles is especially dependent on starch

properties. Modified wheat starch also has the potential to

retard staling of bread, produce better extruded snacks and

easy-cook instant products and alternative thickeners for

soups and sauces. Millers should note that the Hagberg

falling number test to detect sprout damaged grain cannot be

applied to waxy wheat owing to the changed pasting

properties.

Hulless barley (naked or huskless) is described in

Chapter 7 as an ancient grain with modern applications.

Both hulled and hulless varieties were cultivated 8000 years

ago and share the same genetic background. Although little

hulless grain is produced at present, it has a potential

advantage for human food in that pearling is not necessary,

so giving a greater retention of beneficial minor nutrients.

Barley products also tend to have greater resistant starch

content than wheat products and together with their high

soluble-fibre, (1/3,1/4)-b-glucan), content produce a

very low glycemic index (GI) response. The chapter also

contains a section on feed uses for pigs and poultry.

A short description of hairless canary seed is given in

Chapter 8. Annual canarygrass (Phalaris canariensis L.)

is grown primarily for caged birds. Most cultivars are

unsuitable for food use because the attached hulls are

covered with small siliceous hairs (trichomes, 98%

silicon), which are irritating to skin and have been

linked to oesophageal cancer. Recently a hairless cultivar

has been developed in Canada by mutagenesis and is

currently undergoing assessment as a novel food. The

starch content is about 60% in the form of very small

granules (2 mm) having high pasting temperature, shear

and heat stability. The average protein content is very

high for a cereal crop (O18%) and consists mainly of

alcohol-soluble prolamins (O45%). The lipid content is

also relatively high (11%). The crop is considered to

have promise mainly for fractionation and novel

utilisation of these constituents.

Oat hulls cannot be digested by non-ruminant animals

and since the demise of the work-horse, cultivation of

traditional covered-seeded oats has greatly declined.

Chapter 9 considers the successful breeding of naked oats

to provide significant opportunities for feed, human food

and industrial use. It gives a lot of detail on breeding and is

the only chapter to show clear photographs of seeds,

spikelets, groats, etc. and give the reader a good idea of the

nature of the specialty grain under discussion. There is also

a long description of coeliac disease with evidence

referenced that pure oats are safe for coeliac patients,

contrary to other views. The chapter also describes

experiences of feeding oats to poultry, pigs, horses, dairy

and beef animals, lambs, rabbits and other domestic

animals.

Rye, discussed in Chapter 10, accounts for only about

5% of world cultivated cereal grains. Most varieties are

cold-hardy and drought-tolerant. With the exception of

ergot problems, which are due to the long-opening florets,

rye is a relatively disease-resistant crop and these traits

have been exploited in wheat through inter-specific

crosses. Rye contains relatively high levels of non-starch

polysaccharides (arabinoxylans) which give high water-

extract viscosity and because of their ferulic acid content

can be cross-linked through oxidation to form gels. Both

soluble and insoluble fibre is good for humans, but the

soluble fibre causes digestibility problems in poultry. The

water-extractable arabinoxylan also has pharmaceutical

and cosmetic uses.

Chapter 11 describes sorghum as the fifth most important

world cereal crop for food, feed and industrial uses. With

over 40,000 accessions, there is very wide diversity in

composition and processing properties. Food use of white

sorghum includes porridges, non-leavened bread, couscous

and beverages. Waxy-starch varieties are excellent for

extrusion-expanded snacks and flaking. Black sorghums are

rich in tannins (proanthocyanidins with antioxidant activity)

and anthocyanin pigments. Detail is provided on tannin

levels and structure. This diversity of phytochemicals has

potential for significant impact on human health, including

cholesterol-lowering phytosterols, anti-mutagenic polyphe-

nols, antioxidant activity, etc.

The appearance of purple and blue colours of grains is

mainly due to the presence of phenolic flavonoid com-

pounds, particularly anthocyanins. Only a small proportion

of world cereal crops are selected positively for colour

features, however the health benefits of flavonoid com-

pounds are increasingly being recognised and such grains

provide opportunities for cultivar development. Chapter 12

provides a wealth of information on genetics, grain and flour

characteristics, pigment composition and current and

potential uses of pigmented varieties of barley, buckwheat,

maize, oats, rice, rye, triticale, sorghum, millet, quinoa,

amaranth, wheat and wild rice.

Evidence for the importance of the non-cereal grain,

amaranth (Chapter 13) has been found from as early as

8000 BC in Central America. It has a much higher protein

content than cereal grains and the proteins, salt-soluble

11S and 7S globulins, are of better nutritional value

(approaching casein). This dicotyledonous plant is hardy

and can be grown in places unsuited to cereals, although

seed shedding during harvesting may be a problem. Wide

genetic variation is providing accessible resources for the

development of improved lines. This chapter provides

extensive detail on the composition of amaranth lipids

(high in total unsaturates) and starch which is present as

extremely small granules (1–2 mm diameter) of low

amylose content (only 4–8%) and may provide unique

Book review / Journal of Cereal Science 42 (2005) 135–137 137

functional properties for both food and non-food

applications.

Buckwheat, Chapter 14, is another non-cereal crop,

originating from North-Eastern Asia, and produces grains

which are grey-black triangular dry fruit up to 9 mm long.

After dehulling, the endosperm can be milled to flour

containing 11–15% protein, rich in lysine, 60–70% starch,

with a high amylose content (up to 50%) and around 2%

lipids. The hulls contain polyphenolic compounds, provide

significant antioxidant activity and are a source of

pharmaceutical products such as rutin, hyperin and

quercetin. Traditionally buckwheat has been used to make

alcoholic beverages, vinegar and noodles or as coarse-

milled groats. Modern applications include an extruded

ready-to-eat corn-buckwheat breakfast product of high

nutritional value and buckwheat has a potential wider use

for its therapeutic benefits.

Overall this is a very interesting reference book and

will undoubtedly be widely purchased, although many

readers may only require specific parts. Inevitably, being

multi-authored, there are differences in style and layout

between chapters. The editors could perhaps have done

more to impose unifying constraints on the headings and

avoid some of the repetition, for example on coeliac

disease. However, my main concern is the shortage of

illustrations. Without seeing pictures of many of these

novel crops and grains, it is difficult to fully appreciate

their characteristics.

Peter J. Frazier*

School of Food Biosciences, University of Reading,

Whiteknights, Readings, RG6 6AP, UK

E-mail address: pfrz@dsl.pipex.com

* Tel.: +44(0)118 378 8700; fax: C44 (0) 118 931 0080.