《谷物食品技术 Technology of Cereals》课程教学资源（参考书籍，英文版，第四版）04 Cereals of the World：0 rig i n, CI assif icatio n, Types, Quality

Cereals of the world Origin, Classification, Types Quality Wheat derived from separate ancestors, and which differ in chromosome numbers. One classification of Origin the races, with the probable wild types, chromo- The cultivation of wheat(Triticum spp. reaches some numbers(2n)and the cultivated forms is far back into history, and the crop was predomi- shown in Table 4.I nant in antiquity as a source of human food. It ie. the lemmaand palea form a husk which remains was cultivated particularly in Persia (Iran), Egypt, around the kernel after threshing. Emmer was used Greece and Europe. Numerous examples of ancient for human food in prehistoric times(cf. p. 95) wheat have been unearthed in archaeological investigations; the grains are always carbonized, there is archaeological evidence that it was grown although in some cases the anatomical structure about 5000 B.C. in Iraq. The principal wheats of is well preserved commerce are varieties of the species Taestivum T durum(cf p. 86)and T compactum(cf p 85) Races and species of wheat Common or Bread Wheat, T. aestivum(hexa ploid 2n= 42)is an allopolyploid; three genomes, The many thousands of known species and each corresponding to a normal diploid set of varieties of the genus Triticum(wheat) can be chromosomes, are distinguishable and are known grouped into three distinct races which have been to have had separate origins in the past Wild and Cultivated Wheat Types Cultivated forms Race Wild type 2n Species Common name Small spelt T Einkorn dicoccoides T. dicoccum Emmer Macaroni wheat urum T et. Cone A

4 Cereals of the World: 0 rig i n, CI assif icatio n, Types, Quality Wheat derived from separate ancestors, and which differ in chromosome numbers. One classification of the races, with the probable wild types, chromo￾some numbers (2n) and the cultivated forms is shown in Table 4. 1. Einkorn, emmer and spelt are husked wheats, i.e. the lemma and palea form a husk which remains around the kernel after threshing. Emmer was used for human food in prehistoric times (cf. p. 95); there is archaeological evidence that it was grown about 5000 B.C. in Iraq. The principal wheats of commerce are varieties of the species T. aestivum, T. durum (cf. p. 86) and T. compactum (cf. p. 85). Common or Bread Wheat, T. aestivum (hexa￾ploid 2n = 42) is an allopolyploid; three genomes, each corresponding to a normal diploid set of chromosomes, are distinguishable and are known to have had separate origins in the past. Origin The cultivation of wheat (Triticum spp.) reaches far back into history, and the crop was predomi￾nant in antiquity as a source of human food. It was cultivated particularly in Persia (Iran), Egypt, Greece and Europe. Numerous examples of ancient wheat have been unearthed in archaeological investigations; the grains are always carbonized, although in some cases the anatomical structure is well preserved. Races and species of wheat The many thousands of known species and varieties of the genus Triticum (wheat) can be grouped into three distinct races which have been TABLE 4.1 Wild and Cultivated Wheat Types ~ Cultivated forms Race Wild type 2n Species name Common name Small spelt T. aegilopoides 14 T. mmococcum Einkorn Emmer T. dicoccoides 28 T. dicoccum Emmer T. durum Macaroni wheat T. polonicum Polish T. turgidum Rivet, Cone probably 42 T. aestivum Bread wheat T. mmococcum T. spelta Dinkel, Spelt X T. speltoides T. compactum Club x Ae. squarrosa T. sphaerococcum Indian Dwarf (durum) 1 Large spelt Dinkel 7a

CEREALS OF THE WORLD The hexaploid wheats are believed to have vitreous and mealy wheats arisen by hybridization of the diploid species T. tauschii (Aegilops squarrosa) with the tetraploid The endosperm texture may be vitreo flinty, glassy, horny) or mealy(starchy speltoides), two diploid species, with doubling of Samples may be entirely vitreous or he chromosomes. Evidence points to the spelta and mealy grains, with one type predominating group as being the oldest of the hexaploids, with Individual grains are generally completely vitreous the aestivum group having arisen from the spelta group by mutation of a single gene, and the or completely mealy but grains which are partly compactum and sphaerococcum groups having arisen vitreous and partly mealy (piebald'or 'metadine' from aestivum similarly by the mutation of single are frequently encountered. The specific gravity genes. The evidence is presented by Quisenberry of vitreous grains is generally higher than that of and Reitz (1967) mealy grains: 1.422 for vitreous, 1. 405 for mealy Cultivated varieties, which are of widely differ- (Bailey, 1916) The vitreous or mealy character is hereditary ing pedigree and are grown under varied condi- but is also affected by environment. Thus, T. tions of soil and climate show wide variations in characteristics aegilopoides, T. dicoccoides, T. monococcum and T The climatic features in countries where spring T. turgidum and many varieties of T. compactum heat is grown- maximum rainfall in spring and T aestivum are mealy(Percival, 1921).How- nd early summer, and maximum temperature in the mid-and late-summer_favour production ever, the vitreous/mealy character may be modi- of rapidly maturing grain with endosperm of fied by cultural conditions. Mealiness is favoured vitreous texture and high protein content, tradi- by heavy rainfall, light sandy soils, and crowded tionally suitable for breadmaking. Winter wheat, planting and is more dependent on these condi- grown in a climate of relatively even temperature tions than on the type of grain grown.Vitreousness and rainfall, matures more slowly, producing a can be induced by nitrogenous manuring or crop of higher yield and lower nitrogen content, commercial fertilizing and is positively correlated with better suited for biscuit and cake-making tha high protein content; mealiness is positively for bread, although in the U. K, where winter correlated with high grain-yielding capacity wheat comprises about 96% of the total (cf Vitreous kernels are translucent and appear bright against a strong light, whereas mealy p. 87), winter wheat is used for breadmaking. kernels are opaque and appear dark t under similar he yield of durum wheat(cf. p. 86), which is grown in drier areas, is lower than that of bread cIrcumstances. The opacity of mealy kernels is an optical effect due to the presence of minute The high-yielding Indian wheats, devele vacuous or air-filled fissures between and perhaps for u in the Green Revolution(cf. p 6), make within the endosperm cells. The fissures form chapatties(cf p. 270)of indifferent quality Brown internal reflecting surfaces, preventing light trans- mission, and giving the endosperm a white ance. Such fissures are absent from vitreous endosperm Wheat types The development of mealiness seems to be In a general way wheats are classified accord- connected with maturation, since immature grains ng to(1)the texture of the endosperm, because of all wheat types are vitreous, and vitreous grains this characteristic of the grain is related to the are found on plants that grow and ripen quickly way the grain breaks down in milling, and( 2) spring wheats, and those growing in dry conti he protein content, because the properties of the nental climates. Mealy grains are characteristic flour and its suitability for various purposes are of varieties that grow slowly and ha related to this characteristic maturation period

CEREALS OF THE WORLD 79 The hexaploid wheats are believed to have arisen by hybridization of the diploid species T. tauschii (Aegilops squawosa) with the tetraploid speltoides), two diploid species, with doubling of the chromosomes. Evidence points to the spelta the aestivum group having arisen from the spelta group by mutation of a single gene, and the compacturn and sphaerococcum groups having arisen Vitreous and mealy wheats The endospem texture may be viveous (steely, flinty, glassy, horny) or mealy (starchy, chalky). mealy, or may consist of a mixture of vitreous and mealy grains, with one type predominating. or completely mealy, but grains which are partly vitreous and partly mealy ('piebald' or 'metadink') are frequently encountered. The specific gravity hybrid Of T. monococcum and T. spe1toides (Ae. Samples may be entirely vitreous or entirely group as being the Oldest Of the hexap1oids, with Individual gr,&s are generally completely vitreous from aestivum simi1ar1y by the mutation Of sing1e of vitreous grains is generally higher than that of genes. The evidence is presented by Quisenberry mealy grains: 1.422 for VitreOUS, 1.405 for mealy and Reitz (1967). (Bailey, 1916). Cultivated varieties, which are of widely differ￾ing pedigree and are grown under varied condi￾tions of soil and climate, show wide variations in characteristics. The climatic features in countries where spring wheat is grown - maximum rainfall in spring and early summer, and maximum temperature in the mid- and late-summer - favour production of rapidly maturing grain with endosperm of vitreous texture and high protein content, tradi￾tionally suitable for breadmaking. Winter wheat, grown in a climate of relatively even temperature crop of higher yield and lower nitrogen content, better suited for biscuit and cake-making than The vitreous or mealy character is hereditaw, but is also affected by environment. Thus, T. aegilopoides, T. dicoccoides, T. monococcum and T. durum are species with vitreous kernels, whereas T. turgidurn and many varieties of T. compactum and T. aestivum are mealy (Percival, 1921). How￾ever, the vitreous/mealy character may be modi￾fied by cultural conditions. Mealiness is favoured by heavy rainfall, light sandy soils, and crowded planting, and is more dependent on these condi￾tions than on the type of grain grown. Vitreousness can be induced by nitrogenous manuring or with high protein content; mealiness is positively correlated with high grain-yielding capacity. and rainfa11, matures more slOwlY, producing a commercial fertilizing and is positively correlated for bread, a1though in the U.K., where winter wheat comprises about 96y0 Of the tota1 (cf. PP' 87), winter wheat is used for breadmaking' The yield Of durum wheat (cf' P' 86), which is Vitreous kernels are translucent and appear bright against a strong light, whereas mealy kernels are opaque and appear dark under similar circumStanceS. The opacity of mealy kernels is an optical effect due to the presence of minute vacuous or air-filled fissures between and perhaps internal reflecting surfaces, preventing light trans￾mission, and giving the endosperm a white appear￾ance. Such fissures are absent from vitreous endosperm. The development of mealiness seems to be of all wheat types are vitreous, and vitreous grains are found on Plants that grow and ripen quickly: spring wheats, and those growing in dry conti￾nental climates. Mealy grains are characteristic of varieties that grow slowly and have a long maturation period. grown in drier areas, is lower than that of bread wheat. for use in the Green Revolution (cf. p. 6), make chapatties (cf. p. 270) of indifferent quality (Brown, 1972). The high-yielding Indian wheats, deve1oped within the endosperm cells. The fissures form Wheat types ing to (1) the texture of the endosperm, because this characteristic of the grain is related to the way the grain breaks down in milling, and (2) the protein content, because the properties of the flour and its suitability for various purposes are related to this characteristic. In a general way, wheats are classified accord- connected with maturation, since immature grains

TECHNOLOGY OF CEREALS Vitreous kernels sometimes acquire a mealy comprised five polypeptides, but of higher M, appearance after being conditioned in various 59-149k. It has also been found that one particular ways, e.g. by repeated damping and drying, or polypeptide of the surface SGP, with Mr 15 k, is by warm conditioning(cf p 122). The proportion strongly present in all soft wheats examined, but of vitreous kernels in a sample is a characteristic only weakly present in hard(t aestivum) wheats used in grading some types of U.S. wheat(cf p. and completely absent from the very hard durum (T. durum) wheats. Hardness/softness of wheat endosperm is known to be genetically controlled Hard and soft wheats (Berg, 1947) by a gene, Ha, which is located on the 5d chromosome, and it was subsequentl Wheat types may also be classified as hard or discovered that the gene controlling the formation soft, and as strong or weak(see below). Vitreous of the Mr 15 k protein is also situated on the 5D grains tend to be hard and strong, mealy grains chromosome, and is either identical with the Ha to be soft and weak, but the association is not gene, or is located quite close to it. The Mr 15 k invariable protein has been named"friabilin'and it appears Hardness'and'softness'are milling characte- to act as a'non-stick agent, since it is strongly stics, relating to the way the endosperm breaks present in soft -endosperm wheats that fragment down. In hard wheats, fragmentation of the easily and at random, but is only weakly present endosperm tends to occur along the lines of in, or entirely absent from, hard wheats that frag- the cell boundaries, whereas the endosperm of ment only with difficulty, and generally not along soft wheat fractures in a random way. This the interface between starch granule and surround phenomenon suggests a pattern of areas of mech- ing protein matrix (Schofield and greenwell anical strength and weakness in hard wheats, but 1987; Greenwell, 1987; Greenwell and Schofield fairly uniform mechanical weakness in soft wheat. 1989) One view is that ' hardness'is related to the degree hard wheats yield coarse, gritty flour, free of adhesion between starch granules and the flowing and easily sifted, consisting of regular surrounding protein, viz. that differences in endo- shaped particles, many of which are whole sperm texture must be related to differences in the endosperm cells, singly or in groups. Soft wheats nature of the interface between starch granules give very fine four consisting of irregular-shaped and the protein matrix in which they are embedded fragments of endosperm cells (including a propor- (Barlow et aL. 1973; Simmonds, 1974). The tion of quite small cellular fragments and free interface was shown to be rich in water-extractable starch granules), with some fattened particles, proteins, although no specific biochemical com- which become entangled and adhere together, sift ponent that might control the adhesion between with difficulty, and tend to clog the apertures of starch granules surface and protein matrix was sieves (cf. p. 144). The degree of mechanical dentified(Simmonds et al., 1973) damage to starch granules produced during mill- Well-washed prime starch separated from wheat ing is greater for hard wheats than for soft(cf endosperm contains some 0. 15-0.2% by weight of pp. 62 and 149 protein-starch granule protein(SGP)-and Hardness affects the ease of detachment of the the SGP comprises about 1% of the total protein endosperm from the bran. In hard wheats the of the grain. Part of the SGP is located on the endosperm cells come away more cleanly and tend surface of the granules, the remainder is an to remain intact, whereas in soft wheats the sub integral part of the granule structure. Character- aleurone endosperm cells tend to fragment, a ization of the SGP by polyacrylamide gel electro- portion coming away while the rest remains phoresis in the presence of sodium dodecyl sulphate attached to the bran has shown that the surface SGP comprized five The granularity of four gives a measure of the polypeptides of low relative molecular mass(M_) relative hardness of the wheat, the proportion of from 5 to 30 k, while the integral SGP also the flour passing through a fine flour silk(when

80 TECHNOLOGY OF CEREALS Vitreous kernels sometimes acquire a mealy comprised five polypeptides, but of higher M,: appearance after being conditioned in various 59-149 k. It has also been found that one particular ways, e.g. by repeated damping and drying, or polypeptide of the surface SGP, with M, 15 k, is by warm conditioning (cf. p. 122). The proportion strongly present in all soft wheats examined, but of vitreous kernels in a sample is a characteristic only weakly present in hard (T. aestzvurn) wheats, used in grading some types of U.S. wheat (cf. p. and completely absent from the very hard durum 85). (T. durum) wheats. Hardnesslsoftness of wheat endosperm is known to be genetically controlled (Berg, 1947) by a gene, Ha, which is located on the 5D chromosome, and it was subsequently Hard and soft wheats Wheat types may also be classified as hard or discovered that the gene controlling the formation soft, and as strong or weak (see below). Vitreous of the M, 15 k protein is also situated on the 5D grains tend to be hard and strong, mealy grains chromosome, and is either identical with the Ha to be soft and weak, but the association is not gene, or is located quite close to it. The M, 15 k invariable. protein has been named ‘friabilin’ and it appears ‘Hardness’ and ‘softness’ are milling characte- to act as a ‘non-stick’ agent, since it is strongly ristics, relating to the way the endosperm breaks present in soft-endosperm wheats that fragment down. In hard wheats, fragmentation of the easily and at random, but is only weakly present endosperm tends to occur along the lines of in, or entirely absent from, hard wheats that frag￾the cell boundaries, whereas the endosperm of ment only with difficulty, and generally not along soft wheat fractures in a random way. This the interface between starch granule and surround￾phenomenon suggests a pattern of areas of mech- ing protein matrix (Schofield and Greenwell, anical strength and weakness in hard wheats, but 1987; Greenwell, 1987; Greenwell and Schofield, fairly uniform mechanical weakness in soft wheat. 1989). One view is that ‘hardness’ is related to the degree Hard wheats yield coarse, gritty flour, free￾of adhesion between starch granules and the flowing and easily sifted, consisting of regular￾surrounding protein, viz. that differences in endo- shaped particles, many of which are whole sperm texture must be related to differences in the endosperm cells, singly or in groups. Soft wheats nature of the interface between starch granules give very fine flour consisting of irregular-shaped and the protein matrix in which they are embedded fragments of endosperm cells (including a propor- (Barlow et al., 1973; Simmonds, 1974). The tion of quite small cellular fragments and free interface was shown to be rich in water-extractable starch granules), with some flattened particles, proteins, although no specific biochemical com- which become entangled and adhere together, sift ponent that might control the adhesion between with difficulty, and tend to clog the apertures of starch granules surface and protein matrix was sieves (cf. p. 144). The degree of mechanical identified (Simmonds et al., 1973). damage to starch granules produced during mill￾Well-washed prime starch separated from wheat ing is greater for hard wheats than for soft (cf. endosperm contains some 0.15-0.2% by weight of pp. 62 and 149). protein - ‘starch granule protein’ (SGP) - and Hardness affects the ease of detachment of the the SGP comprises about 1% of the total protein endosperm from the bran. In hard wheats the of the grain. Part of the SGP is located on the endosperm cells come away more cleanly and tend surface of the granules, the remainder is an to remain intact, whereas in soft wheats the sub￾integral part of the granule structure. Character- aleurone endosperm cells tend to fragment, a ization of the SGP by polyacrylamide gel electro- portion coming away while the rest remains phoresis in the presence of sodium dodecyl sulphate attached to the bran. has shown that the surface SGP comprized five The granularity of flour gives a measure of the polypeptides of low relative molecular mass (M,) relative hardness of the wheat, the proportion of from 5 to 30 k, while the integral SGP also the flour passing through a fine flour silk (when

CEREALS OF THE WORLD milled under standard conditions) decreasing with Protein content per se is not a factor determin increasing hardness. Greer (1949)found that the ing milling quality, except in so far as the protein percentage of the total flour passing through a no content tends to be higher in vitreous than in 16 standard silk(aperture width: 0.09 mm)under mealy wheats, and vitreousness is often associated standard conditions was 49-56% for four related with hardness and good milling quality Samples varieties of hard English wheat, whereas it was 63- of the English soft wheat varieties Riband or 71%for ten unrelated varieties of soft English wheat. Galahad may have high protein content and a The granularity of flour can also be expressed as large proportion of vitreous grains and yet mill the Particle Size Index, as determined by means of as soft wheats; on the other hand, a low-protein, an Alpine air-jet sieve. Ease of sifting, however, is predominantly mealy-grained sample of the hard affected by other factors besides hardness of varieties Hereward or mercia will mill as a hard endosperm, e.g. moisture content(cf. p. 152). wheat. The protein content of the endosperm The principal wheats of the world are arranged its quality and its chemical structure - is according to their degree of hardness as follows: however, a most important characteristicin do,, extra hard: Durum, some algerian, Indian mining baking quality(cf. p. 66) CWRS(Manitoba), American HRS Australian Prime hard Strong and weak wheats medium: Plate, Russian, some Australian American HRW, some European; Wheats yielding flour which has the ability to ft: produce bread of large loaf volume, good crumb American srw. American Soft texture, and good keeping properties(cf pp.174 White and 192) generally have a high protein content and are called'strong,, whereas those yielding Protein content four from which only a small loaf with coarse open crumb texture can be made, and which are The protein content of wheat varies over a wide characterized by low protein content, are called range(6-21%)and is influenced less by heredity weak. The flour from weak wheats is ideal for than by edaphic factors soil and climatic biscuits(cookies)and cakes, although unsuitable conditions-prevailing at the place of growth, for breadmaking unless blended with stronger nd by fertilizer treatment. Ranges of protein flour content encountered Flour from strong wheats is able to carry a wheat types are shown in Table 4.2 proportion of weak flour, i.e. the loaf maintains its large volume and good crumb structure even TABLE 4.2 when a proportion of weak four is blended with Protein Content Ranges of Wheat Types it;it is also able to absorb and retain a large Approximate q protein range The main types of wheat are classified accord ing to their baking strength HRS (United States 11,5-18 strong: CWRS (Manitoba), American HRS Russian Spring, some Australian medium: American HRW. Plate, S.E. E Russian 14.5 pean, Australian Prime Hard 8-13.5 weak: N.W. European, American SRW SRW (United States) White(United States) Hardness (milling character) and strength (baking character) are inherited separately and Sources: Schruben(1979); Kent-Jones and Amos(1947). independently(Berg, 1947). Hence, it should be

CEREALS OF THE WORLD 81 Protein content per se is not a factor determin￾ing milling quality, except in so far as the protein content tends to be higher in vitreous than in mealy wheats, and vitreousness is often associated with hardness and good milling quality. Samples of the English soft wheat varieties Riband or Galahad may have high protein content and a large proportion of vitreous grains and yet mill as soft wheats; on the other hand, a low-protein, predominantly mealy-grained sample of the hard varieties Hereward or Mercia will mill as a hard wheat. The protein content of the endosperm - its quality and its chemical structure - is, however, a most important characteristic in deter￾mining baking quality (cf. p. 66). Strong and weak wheats Wheats yielding flour which has the ability to produce bread of large loaf volume, good crumb texture, and good keeping properties (cf. pp. 174 and 192) generally have a high protein content and are called 'strong', whereas those yielding flour from which only a small loaf with coarse open crumb texture can be made, and which are characterized by OW protein content, are called 'weak'. The flour from weak wheats is ideal for biscuits (cookies) and cakes, although unsuitable for breadmaking unless blended with stronger flour. Flour from strong wheats is able to carry a proportion of weak flour, Le. the loaf maintains its large volume and good crumb structure even when a proportion of weak flour is blended with it; it is also able to absorb and retain a large Approximate quantity of water. protein range The main types of wheat are classified accord￾Wheat ("1 type 1c16.5 strong: CWRS (Manitoba), American HRS, HRS (United States) Durum Plate (Argentina) 10-16 Russian Spring, some Australian; CWRS (Manitoba) 9-18 medium: American HRW, Plate, S.E. Euro￾Russian 9-14.5 Australian 8-13.5 weak: N.W. European, American SRW, English 8-13 American Soft White, Australian Soft. Other European 8-11.5 SRW (United States) 8-1 1 Hardness (milling character) and strength (baking character) are inherited separately and White (United States) 8-10.5 independently (Berg, 1947). Hence, it should be milled under standard conditions) decreasing with increasing hardness. Greer (1949) found that the percentage of the total flour passing through a No. 16 standard silk (aperture width: 0.09 mm) under standard conditions was 49-56% for four related varieties of hard English wheat, whereas it was 63- 71% for ten unrelated varieties of soft English wheat. The granularity of flour can also be expressed as the Particle Sue Index, as determined by means of an Alpine air-jet sieve. Ease of sifting, however, is affected by other factors besides hardness of endosperm, e.g. moisture content (cf. p. 152). The principal wheats of the world are arranged according to their degree of hardness as follows: extra hard: Durum, some Algerian, Indian; hard: CWRS (Manitoba), American HRS, Australian Prime Hard; medium: Plate, Russian, some Australian, American HRW, some European; soft: Some European, some Australian, American sRw7 American 'Oft White. Protein content The protein content ofwheat varies Over a wide range (621%) and is influenced less by heredity than by edaphic factors - soil and climatic conditions - prevailing at the place of growth, and by fertilizer treatment. Ranges of protein content encountered among samples of various wheat types are shown in Table 4.2. TABLE 4.2 Protein Content Ranges of Whear Types* ing to their baking strength as follows: 11.5-18 pean, Australian Prime Hard; HRW (United States) 9-14.5 * Sources: Schruben (1979); Kent-Jones and Amos (1947)

ECHNOLOGY OF CEREALS possible, through breeding, to combine good C(mainly Canadian). Proportionately more milling quality with, for example, the type of ' imported, non-EC wheat is used for breadmak gluten associated with weak wheats, to produc ng and less (possibly none) for making biscuits a good milling biscuit wheat. The varieties Slejpner, and cakes, for household flour, and for four for Haven and Maris Huntsman are hard but pos- other purposes. Thus, in 1978-1980 the average sess no particular baking strength; Minaret and composition of the grist used for breadmaking in Flanders are soft wheats which are generally the U. K. was 41% home-grown, 9% other EC acceptable for breadmaking and 50% imported, non-EC However, since 1981 there has been a consider. Grain size and shape able reduction in the quantity of imported wheat used for breadmaking(for reasons explained in The maximum yield of white flour obtainable Ch.8,p 193). Thus, in 1990/91, while the total from wheat in milling is ultimately dependent wheat milled in the U. K. comprised 87% home- upon the endosperm content, and the latter is grown, 6%other EC, and 7% imported non-EC affected by the size and shape of the grain, and the average composition of the breadmaking grist by the thickness of the bran. was approximately 79% home-grown, 10% other The specific(bushel) weight(bu wt)measure- EC, and 11% imported non-EC(see also Fig 8.1) ment(test wt per bu in the U.S.A. hectolitre wt or natural wt in Europe) estimates the weight of a fixed volume of grain, and gives a rough America indication of kernel size and shape Wheats of The principal wheat-producing countries of the high bu wt are usually considered to mill the more American continent are Canada, U.S.A. and readily and to yield more flour. However, these Argentina measurements can be misleading, as soft mealy wheats often have high bu wt. Moisture content also affects bu wt Canada Shellenberger(1961)found that the volumetr The wheat grown in western Canada is segre oran content is lower in large than in small grains, gated into five classes according to season of viz. 14. 1%and 14.6%, respectively, from samples sowing(spring or winter), grain colour(red or of the same types of wheat, showing the economic white), grain texture(hard or soft), and species importance of large kernel size (T. aestivum or T. durum). Spring-sown types predominate-over 95% of the Canadian wheat World wheats crop is spring sown-and there is more red than white, and more hard than soft. The classes U. K.-grown and imported wheats cover a further described as follows wide range in quality and characteristics. In an endeavour to produce four of regular quality the Canada Western Red Spring/CWRS British flour miller makes milling grist' by blending together various types of wheat so that CWRS wheat-formerly known as ' Manitoba particular properties lacking in one component is grown in the provinces of Manitoba, Sas- of the grist may be provided by another. katchewan and Alberta. It is a high protein wheat In recent years, the sources of imported wheat of excellent milling and baking qualities. It can used by U. K. four millers have been more be used alone, or in blends with lower-protein restricted than formerly, and comprise principally wheat, to produce hearth breads, noodles, flat the EC countries(mainly France) and Canada. breads and steam breads. CWRS wheat is marketed Of the total wheat milled in the U.K. in 1978- in three grades, of which the primary grade 1980(5 million t per an ) 56% was home-grown, characteristics are shown in Table 4.3. The mini- 7% was other EC wheat, and 37% imported, non- mum content of hard vitreous kernels is 65%for

82 TECHNOLOGY OF CEREALS possible, through breeding, to combine good EC (mainly Canadian). Proportionately more milling quality with, for example, the type of ‘imported, non-EC’ wheat is used for breadmak￾gluten associated with weak wheats, to produce ing and less (possibly none) for making biscuits agoodmilling biscuit wheat. Thevarieties Slejpner, and cakes, for household flour, and for flour for Haven and Maris Huntsman are hard but pos- other purposes. Thus, in 1978-1980 the average sess no particular baking strength; Minaret and composition of the grist used for breadmaking in Flanders are soft wheats which are generally the U.K. was 41% home-grown, 9% other EC, acceptable for breadmaking. and 50% imported, non-EC. However, since 1981 there has been a consider￾able reduction in the quantity of imported wheat used for breadmaking (for reasons explained in Grain size and shape The maximum yield of white flour obtainable Ch. 8, p. 193). Thus, in 1990/91, while the total from wheat in milling is ultimately dependent wheat milled in the U.K. comprised 87% home￾upon the endosperm content, and the latter is grown, 6% other EC, and 7% imported non-EC, affected by the size and shape of the grain, and the average composition of the breadmaking grist by the thickness of the bran. was approximately 79% home-grown, 10% other The specific (bushel) weight (bu wt) measure- EC, and 11% imported non-EC (see also Fig. 8.1). ment (test wt per bu in the U.S.A.; hectolitre wt or natural wt in Europe) estimates the weight of America a fixed volume of grain, and gives a rough indication of kernel size and shape. Wheats of The principal wheat-producing countries of the high bu wt are usually considered to mill the more American continent are Canada, U.S.A. and readily and to yield more flour. However, these Argentina. measurements can be misleading, as soft mealy Canada wheats often have high bu wt. Moisture content also affects bu wt. Shellenberger (1961) found that the volumetric The wheat grown in western Canada is segre￾bran content is lower in large than in small grains, gated into five classes according to season of viz. 14.1% and 14.6%, respectively, from samples sowing (spring or winter), grain colour (red or of the same types of wheat, showing the economic white), grain texture (hard or soft), and species importance of large kernel size. (T. aestivum or T. durum). Spring-sown types predominate - over 95% of the Canadian wheat crop is spring sown - and there is more red than white, and more hard than soft. The classes are World wheats wide range in quality and characteristics. In an endeavour to produce flour of regular quality, the British flour miller makes a ‘milling grist’ by blending together various types of wheat so that particular properties lacking in one component of the grist may be provided by another. In recent years, the sources of imported wheat used by U.K. flour millers have been more restricted than formerly, and comprise principally the EC countries (mainly France) and Canada. Of the total wheat milled in the U.K. in 1978- 1980 (5 million t per an.), 56% was home-grown, 7% was other EC wheat, and 37% imported, non￾U.K.-grown and imported wheats cover a further described as follows. Canada Western Red Spring (C WRS) CWRS wheat - formerly known as ‘Manitoba’ - is grown in the provinces of Manitoba, Sas￾katchewan and Alberta. It is a high protein wheat of excellent milling and baking qualities. It can be used alone, or in blends with lower-protein wheat, to produce hearth breads, noodles, flat breads and steam breads. CWRS wheat is marketed in three grades, of which the primary grade characteristics are shown in Table 4.3. The mini￾mum content of hard, vitreous kernels is 65% for

CEREALS OF THE WORLD 83 TABLE 4.3 Grade Characteristics of Canada Westen Red Spring Wheat and Canada Utihty Wheat, 199/ Maximum limits(%)of test Other than Contrasting Ib/bu cereal grains Total Canada Western Red Spring No. I CWRS 0.2 1.0 No. 2 CWRS 10.0 Canada Western Utility 0.3 CW Feed no mIn mit but not me than 10% amber durum Source: Official Grain Grading Guide, 1991 edition. Canadian Grain Commission, Winnipeg No. I CWRS, and 35% for No. 2 CWRS. no being grown on only 6% of the wheat area in minimum is prescribed for No. 3 CWRS western Canada The protein content of CWrS wheat ranges The grading(Table 4.3)includes a maximum limit 18%, but Nos l and 2 CWRS can be supplied at for wheat of other classes. Until recently, wheat guaranteed minimum protein levels of 11.5%, of other classes'meant wheat of classes or varieties 12.5%, 13.5% and 14.5%(on 13. 5% m.c. basis). not equal to Marquis, but marquis was replaced The average yield in 1989 was 18 gha(22 ha in as the standard variety by Neepawa in 1987. 1986), the yield and protein content tending to be Neepawa was bred from(Thatcher X Frontana)x related inversely. The moisture content at harvest (Thatcher x Kenya Farmer)x( Thatcher x is usually 11-13%, and for inclusion in the straight Frontana-Thatcher), and is superior to marquis in grades the moisture content must not exceed resistance to stem rust. The variety of CWRS most 14.5%. Wheat with 14.6-17.0% m.c. is graded widely grown at present is Katepwa: it is resistant tough; with 17. 1% m.c. or over, 'damp to stem rust (Puccinia graminis tritici)and common Marquis is a variety of CwrS wheat which was root rot, and moderately resistant to leaf rust grown extensively for a long period It was bred (Puccinia triticina) and loose smut, though modera- by crossing Red Fife, a good milling variety which tely susceptible to speckled leaf disease( septoria was liable to frost damage, with Hard Red The Export Standards for the CWRS grades Calcutta, an Indian early-ripening variety. Marquis shown in Table 4.4, are somewhat stricter than the inherited the good milling and early ripening primary grade characteristics, shown in Table 4.3 characters of its parents. However, Marquis was Early frosts may reduce the yield of grain and susceptible to rust(cf. p. 7)and has been largely lower its milling quality by increasing the propor replaced by other varieties, such as Thatcher, tion of small shrivelled grains with low endosperm bred from the double cross(Marquis x Iumillo) content, and adversely affect baking quality X(Marquis x Kanred), and Selkirk, bred from because the milled flour is of high maltose content (McMurachy X Exchange)x Redman. The variety and produces a fiowy dough elkirk is equal to Marquis in breadmaking ty and Canada Western Utility (CWU) wheat and race 15B. In 1958 Selkirk comprised over 80% Feed wheat of the spring wheat area in Manitoba and 28%of Red Spring Wheat which does not attain the that grown in Saskatchewan, but by 1969 it was required standards for Nos 1-3 CWRS may be

CEREALS OF THE WORLD 83 TABLE 4.3 Grade Characteristics of Canada Western Red Spring Wheat and Canada Utility Wheat, 1991 * Maximum limits (Oh) of Foreign material Wheat of other classes Minimum test weight Other than Contrasting Grade 1 bibu kgihl cereal grains Total classes Total Canada Western Red Spring No. 1 CWRS 60.1 75.0 0.2 0.75 1 .o 3.0 No. 2 CWRS 57.7 72.0 0.3 1.5 3.0 6.0 No. 3 CWRS 55.3 69.0 0.5 3.5 5.0 10.0 Canada Western Utility No. 1 CWU 60.1 75 .O 0.3 2.0 3.0 10.0 No. 2 CWU 57.7 72.0 0.5 4.0 5.0 20.0 CW Feed no min. 1 .o 10.0 no limit, but not more than 10% amber durum * Source: Official Grain Grading Guide, 1991 edition. Canadian Grain Commission, Winnipeg. No. 1 CWRS, and 35% for No. 2 CWRS. No being grown on only 6% of the wheat area in minimum is prescribed for No. 3 CWRS. western Canada. The protein content of CWRS wheat ranges 9- The grading (Table 4.3) includes a maximum limit 18%, but Nos 1 and 2 CWRS can be supplied at for ‘wheat of other classes’. Until recently, ‘wheat guaranteed minimum protein levels of 11 Soh, of other classes’ meant ‘wheat of classes or varieties 12.5%, 13.5% and 14.5% (on 13.5% m.c. basis). not equal to Marquis’, but Marquis was replaced The average yield in 1989 was 18 q/ha (22 q/ha in as the standard variety by Neepawa in 1987. 1986), the yield and protein content tending to be Neepawa was bred from (Thatcher x Frontana) x related inversely. The moisture content at harvest (Thatcher X Kenya Farmer) x (Thatcher x is usually 11-13%, and for inclusion in the straight Frontana-Thatcher), and is superior to Marquis in grades the moisture content must not exceed resistance to stem rust. The variety of CWRS most 14.5%. Wheat with 14.6-17.0% m.c. is graded widely grown at present is Katepwa: it is resistant ‘tough’; with 17.1% m.c. or over, ‘damp’. to stem rust (Puccinia graminis tritici) and common Marquis is a variety of CWRS wheat which was root rot, and moderately resistant to leaf rust grown extensively for a long period. It was bred (Puccinia triticzna) and loose smut, though modera￾by crossing Red Fife, a good milling variety which tely susceptible to speckled leaf disease (Septoria). was liable to frost damage, with Hard Red The Export Standards for the CWRS grades, Calcutta, an Indian early-ripening variety. Marquis shown in Table 4.4, are somewhat stricter than the inherited the good milling and early ripening primary grade characteristics, shown in Table 4.3. characters of its parents. However, Marquis was Early frosts may reduce the Yield of grain and susceptible to rust (cf. p. 7) and has been largely lower its milling quality by increasing the Propor￾replaced by other varieties, such as Thatcher, tion Of smafl Shrivelled grains With low endosFm bred from the double cross (Marquis x Iumillo) content, and adversely affect baking quality, x (~~~~~i~ x Kanred), and Selkirk, bred from because the milled flour is of high maltose content (McMurachy x Exchange) x Redman. The variety and produces a flowy dough￾Selkirk is equal to Marquis in breadmaking Canada Western Utility (CWU) wheat and quality and, in addition, is resistant to stem rust Feed wheat race 15B. In 1958 Selkirk comprised over 80% of the spring wheat area in Manitoba and 28% of Red Spring Wheat which does not attain the that grown in Saskatchewan, but by 1969 it was required standards for Nos 1-3 CWRS may be

TECHNOLOGY OF CEREALS TABLE 4. 4 Export Standards For Canadian Wheats, 1991-1992* Wheat of other classes Other than Grade Ib/ bu kg/h Total Total Canada Western Red spring 0 I CWR 78.0 0.3 1.5 Red winter o00 0 1.0 3.0 3.0 10.0 Canada Western Soft White Sprin No. 1 CWSWS No. 2 CWSWS No. 3 CWSWS 2 1.5 Canada prairie Spring 61.7 77.0 75 No. 2 CPS Canada Western utility 2.0 Canada Western amber durum 80.0 0.5 No. 2 CWAD No, 3 CWAD 71.0 3.0 10.0 15.0 Canada Western feed Wheat 0.5 5.0 Source: Grains from Western Canada, 1991-1992. The Canadian Wheat Board, winnipeg graded as Nos l or 2 Canada Western Utility kernel characteristics, suitable for the production wheat or as Feed Wheat, the grade characteristics of French-style hearth breads and of noodles, fat for which are shown in Table 4.3, and the export breads and steam breads. Export Standards are Standards in Table 4.4. Canada Western Feed listed in Table 4.4 Wheat may contain up to 10% of Amber durum and up to 5% of heat-damaged grains. CWu Canada Western Soft White Spring(CWSWS wheat is a medium protein red wheat with hard kernel characteristics. It can be used to make pasta southern regions of western Ontario and in British n under or, when blended with other wheat, to make bread Colombia. The protein content of the top grades Glenlea, Wildcat and Bluesky. The Cw Feed normally ranges from9.0 to 10.0%(14%m c basis), Wheat, as its name implies, is suitable, alone and the four is suitable for making cakes, biscuits blended with other grains, for feeding to animals and crackers, and also, either alone or in blends for making flat bread and noodles. See Table 4.4 Canada Western Red winter(CWRW) Canada Prairie Spring /CPS) CWRW wheat is grown in southern Alberta. CPS wheat is a relatively new class of Canadian It is a medium protein, strong wheat with hard wheat, now available as CPs White wheat and

84 TECHNOLOGY OF CEREALS TABLE 4.4 Export Standards For Canadian Wheats, 1991-1 992* Maximum limits (“h) of Foreign material Wheat of other classes Minimum test weight Other than Contrasting Grade lblbu kglhl cereal grains Total classes Total Canada Western Red Spring No. 1 CWRS 62.5 78.0 0.2 0.4 0.3 1.5 No. 2 CWRS 61.7 77.0 0.2 0.75 1.5 3.0 No. 3 CWRS 60.1 75.0 0.2 1.25 2.5 5.0 Canada Western Red Winter No. 1 CWRW 62.5 78.0 0.2 1 .o 1.0 3.0 No. 2 CWRW 59.3 74.0 0.2 2.0 2.0 6.0 No. 3 CWRW 55.3 69.0 0.2 3.0 3.0 10.0 Canada Western Soft White Spring No. 1 CWSWS 62.5 78.0 0.2 0.75 - 1.5 No. 2 CWSWS 60.9 76.0 0.2 1 .o - 3.0 No. 3 CWSWS 60.1 75.0 0.2 1.5 - 5.0 Canada Prairie Spring No. 1 CPS 61.7 77.0 0.2 0.75 3.0 5.0 No. 2 CPS 60.1 75.0 0.2 1.5 5.0 10.0 Canada Western Utility No. 1 CWU 62.5 78.0 0.2 1.0 3.0 5.0 No. 2 CWU 60.9 76.0 0.2 2.0 5.0 10.0 Canada Western Amber Durum No. 1 CWAD 64.2 80.0 0.2 0.5 2.0 3.0 No. 2 CWAD 63.8 79.5 0.2 0.8 2.5 5.0 No. 3 CWAD 62.5 78.0 0.2 1.0 3.5 7.0 No. 4 CWAD 56.9 71.0 0.5 3.0 10.0 15.0 Canada Western Feed Wheat 59.3 74.0 0.5 5.0 - - * Source: Grains from Western Canada, 1991-1992. The Canadian Wheat Board, Winnipeg. graded as Nos 1 or 2 Canada Western Utility wheat or as Feed Wheat, the grade characteristics for which are shown in Table 4.3, and the Export Standards in Table 4.4. Canada Western Feed Wheat may contain up to 10% of Amber Durum and up to 5% of heat-damaged grains. CWU wheat is a medium protein red wheat with hard kernel characteristics. It can be used to make pasta kernel characteristics, suitable for the production of French-style hearth breads and of noodles, flat breads and steam breads. Export Standards are listed in Table 4.4. Canada Western Soft White Spring (CWSWS) cwsws wheat is grown under irrigation in the southern regions of weStern Ontario and in British Or, when b1ended with Other wheat, to make bread. Acceptab1e reference varieties for cwu wheat are Glenlea, Wildcat and Bluesky* The cw Feed Colombia. fie prolein COntent of the top grades nomdy ranges from 9.0 to 10.0% (14% m.c. basis), and the flour is suitable for m&ng c&es, biscuits and crackers, and also, either alone or in blends, Wheat, as its name implies, is suitable, alone or b1ended with Other grains, for feeding to animals* for mhg flat bread and noodles. See Table 4.4. Canada Western Red Winter (CWRW) CWRW wheat is grown in southern Alberta. It is a medium protein, strong wheat with hard Canada Prairie Spring (CPS) CPS wheat is a relatively new class of Canadian wheat, now available as CPS White wheat and

CEREALS OF THE WORLD CPS Red wheat. It is a semi- hard wheat with Hard Red Winter(HRW) 12-13% protein content(13. 5%m c. basis) of hRW wheat is grown in Texas, Oklahe excellent milling quality, suitable for making Kansas, Colorado, Nebraska,Montana,South French-type breads and in blends, for making Dakota and California. hRw wheat is used for noodles, steam breads, pan breads, crackers and making yeasted bread and hard rolls. Grading of elated products. See Table 4.4 HRW wheat, according to content of dark, hard and vitreous kernels, as formerly practised, was Canada Western Amber Durum/CWADI officially discontinued in December, 1979 CWAD wheat, a tetraploid (2n= 28), has a Soft Red Winter (SRW) particularly hard grain and is milled to provide emolina(cf. p 154) for making pasta products SRW wheat is grown in (see Ch. 10). The flour is unsuitable for bread- Ohio, Indiana, Arkansas and Michigan States making. CWAD wheat is graded into four grades That grown east of the great Plains region is according to test weight, content of foreign mate called Red Winter; the remainder is Western rial, other cereal grains and seeds, content of Red srW wheat mills well but is a weak wheat, wheat of other classes and varieties of durum not low in protein content. The flour is used for equal to Hercules, and content of immature biscuits(cookies)and crackers, cakes and pastries. kernels(see Table 4.4) The wheat known as Canada Eastern is low in Hard Red Spring(HRS) protein content(about 9%): it is suitable for high HRS wheat is grown in Minnesota, North ratio cake flour(cf. p 178)and for biscuits, when Dakota. Montana and South Dakota. The milling mixed with more extensible wheats. Being low in diastatic power,it is also suitable for sausage rusk, quality is only slightly inferior to that of CWRS which requires four of low maltose content and and the protein content is comparable. HRS high absorbe wheat is graded according to content of dark hard and vitreous kernels into Dark northern Spring(75%or more), Northern Spring(25-75%) o Five principal types of wheat are grown in the used for quality yeasted bread and roll heat United States and Red spring (less than 25%). HRS S.A. their names, the proportion that each contributed to the total crop in 1991/92, and their White wheat bu wt ranges are shown in Table 4.5 This includes hard and soft types. Hard White must contain 75% or more of hard kernels. Soft White, also known as Pacific White in britain TABLE 4.5 contains less than 75% of hard kernels White Characteristics of U.S. Wheat Types wheat is grown in the west coast States and in Michigan and New york States. The four from Bushel Hectolitre White Wheat is unsuitable for breadmaking, but Ty is ideal for biscuits(cookies), crackers, cakes and pastries. The Soft White is similar to Canada Hard Red winter(hRW) 44 Soft Red winter (SRW) 17 62-6477.3-79.8 Eastern White wheat, but slightly stronger and 60-6474.8-79 Hard Red Spring(HRS 63-64. 8 higher in protein content. The diastatic power 61-63 76. 1-78.6 tends to be low Data from Dahl (1962), Johnson( 1962), Shell (1961), Milling and Baking News( 19 Feb. 1980),U. llenberger Club wheat Reviews, HGCA (199 Club wheat or Triticum compactum, is a hexaploid t llb/bu= 1. 247 kg/hl white wheat grown principally in Washington

CEREALS OF THE WORLD a5 CPS Red wheat. It is a semi-hard wheat with 12-13% protein content (13.5% m.c. basis) of excellent milling quality, suitable for making French-type breads and, in blends, for making noodles, steam breads, pan breads, crackers and related products. See Table 4.4. Canada Western Amber Durum (CWAD) CWAD wheat, a tetraploid (2n = 28), has a particularly hard grain and is milled to provide semolina (cf. p. 154) for making pasta products (see Ch. 10). The flour is unsuitable for bread￾making. CWAD wheat is graded into four grades according to test weight, content of foreign mate￾rial, other cereal grains and seeds, content of wheat of other classes and varieties of durum not equal to Hercules, and content of immature kernels (see Table 4.4). The wheat known as Canada Eastern is low in protein content (about 9%): it is suitable for high ratio cake flour (cf. p. 178) and for biscuits, when mixed with more extensible wheats. Being low in diastatic power, it is also suitable for sausage rusk, which requires flour of low maltose content and high absorbency. United States Five principal types of wheat are grown in the U.S.A.: their names, the proportion that each contributed to the total crop in 1991/92, and their bu wt ranges are shown in Table 4.5. Hard Red Winter (HRW) HRW wheat is grown in Texas, Oklahoma, Kansas, Colorado, Nebraska, Montana, South Dakota and California. HRW wheat is used for making yeasted bread and hard rolls. Grading of HRW wheat, according to content of dark, hard and vitreous kernels, as formerly practised, was officially discontinued in December, 1979. Soft Red Winter (SRW) SRW wheat is grown in Missouri, Illinois, Ohio, Indiana, Arkansas and Michigan States. That grown east of the Great Plains region is called Red Winter; the remainder is Western Red. SRW wheat mills well but is a weak wheat, low in protein content. The flour is used for biscuits (cookies) and crackers, cakes and pastries. Hard Red Spring (HRS) HRS wheat is grown in Minnesota, North Dakota, Montana and South Dakota. The milling quality is only slightly inferior to that of CWRS, and the protein content is comparable. HRS wheat is graded according to content of dark, hard and vitreous kernels into Dark Northern Spring (75% or more), Northern Spring (25-75%) and Red Spring (less than 25%). HRS wheat is used for quality yeasted bread and rolls. White wheat This includes hard and soft types. Hard White must contain 75% or more of hard kernels. Soft White, also known as Pacific White in Britain, contains less than 75% of hard kernels. White wheat is grown in the west coast States and in Michigan and New York States. The flour from White Wheat is unsuitable for breadmaking, but Type % (1b) (kg) is ideal for biscuits (cookies), crackers, cakes and pastries. The Soft White is similar to Canada Eastern White wheat, but slightly stronger and Hard Red Winter (HRW) 44 Soft Red Winter (SRW) 17 60-64 74.8-79.8 Hard Red Spring (HRS) 23 63-64 78.6-79.8 higher in protein content. The diastatic power White 11 61-63 76.1-78.6 tends to be low. TABLE 4.5 Characteristics of US. Wheat Types* Proportion Bushel Hectolitre (1991192 crop) wtt wtt 62-64 77.3-79.8 Durum 5 63-64 78.6-79.8 * Data from Dah1 (1962), Johnson (1962), Shellenberger (1961),MiZlingandBakingNms(19 Feb. 1980), U.S. Wheat Reviews, HGCA (1991). t llb/bu = 1.247 kgihl. Club d7eat Club wheat or Triticum compactum, is a hexaploid white wheat grown principally in Washington

TECHNOLOGY OF CEREALS State, U.S.A. The flour milled from it is similar sample grade designation alone(Federal Register, in characteristics to that milled from white wheat 30 June, 1987) of T aestivum, and is used for making biscuits The(U.S. Food and Drug administration (cookies) announced in July 1977 that grain is subject to seizure if it contains 32 or more insect-damaged Durum wheat kernels per 100 g or 9 mg or more rodent pellets Durum wheat or'Triticum durum, is a tetraploid Wheat so adulterated may be used for animal fee wheat grown in North Dakota(85% of the crop but not for human food (Federal Register, 12 July in 1990)and California, and is used for making 1977) pasta products( see Ch ard Amber durum d vitreous kernels of amber colour: Amber durum has 60-75%: Protein testin Durum has less than 60% The U.S. Federal Grain Inspection Service authorized the official protein testing of hrW U.S. wheat grading and hrs wheats under the grain Standards Act on 1 May 1978 and for all other classes of U.s The main classes of wheat are graded according wheat except mixed and unclassed from 1 May to test wt per bu, content of damaged and 1980. Protein content will be determined eithe shrunken kernels, foreign material and wheat of by near-infra red reflectance (NiR)method or other classes, as shown in Table 4.6. Parcels which by the Kjeldahl method(U.S. Wheat review do not fall within the limits of grades U.S. Nos May 1980 1-5, or are of low quality in certain respects, and durum wheat of over 16% m.c., are designated sample grade. 'Ergoty wheat,contains more U.S. wheat surplus than 0.3% of ergot(cf. p. 15). 'Smutty wheat The surplus of wheat left over at the end of contains more than 30 smut balls per 250g(cf. the season in the U.S.A. when the new crop is p. 8).Garlicky wheat' contains more than 2 coming in is known as the ' carry over. Since green garlic bulbils per kg. 'Infested wheat'is 1952 the carry over has greatly increased, and by wheat infested with live weevils or other insects 1962 amounted to 37 million tonnes, considerably injurious to stored grain (cf. p. 106)."Treated more than one entire U.S. wheat harvest (31.3 wheat has been scoured, limed, washed, sulphured, million t in 1962). Subsequently the carry over or treated in such manner that the true quality is deceased, partly because of wheat-area restric not reflected by either the numerical grade or tion, and partly because of increased exports to LE4.6 Grade Characteristics of U.S. wheat Minimum test wt Maximum limits(%)of HRS Other Heat- Damaged Shrunken Wheat of /hite Club classes damaged kernels Foreign and broken Defects other classes kg/hl lb/bu kg/hl terial kernels (total) Contrasting Total 74.8 3 U.S,No.466. US.No.562.3 63.651 5.0 ource: U.S. Dept. Agric. (1991). I Ib/bu =1. 247 kg/hl

86 TECHNOLOGY OF CEREALS State, U.S.A. The flour milled from it is similar in characteristics to that milled from white wheat of T. aestivum, and is used for making biscuits (cookies). Durum wheat Durum wheat OrTriticum durum, is a tetraploid wheat grown in North Dakota (85y0 Of the croP in 1990) and California, and is used for making pasta products (see Ch. 10). Hard Amber Durum has 75% or more of hard and vitreous kernels of amber colour; Amber Durum has 60-75%; Durum has less than 60%. U.S. wheat grading The main classes of wheat are graded according to test wt Per bu, content of damaged and shrunken kernels, foreign material and wheat of other classes, as shown in Table 4.6. Parcels which do not fall within the limits of grades U.S. Nos. 1-5, or are of low quality in certain respects, and durum wheat of over 16% m.c., are designated ‘sample grade’. ‘Ergoty wheat’ contains more than 0.3% of ergot (cf. p. 15). ‘Smutty wheat’ contains more than 30 smut balls per 250g (cf. p. 8). ‘Garlicky wheat’ contains more than 2 green garlic bulbils per kg. ‘Infested wheat’ is wheat infested with live weevils or other insects injurious to stored grain (cf. p. 106). ‘Treated wheat’ has been scoured, limed, washed, sulphured, or treated in such manner that the true quality is not reflected by either the numerical grade or sample grade designation alone (Federal Register, 30 June, 1987). The (U.S.) Food and Drug administration announced in July 1977 that grain is subject to seizure if it contains 32 or more insect-damaged kernels per 100 g or 9 mg or more rodent pellets and/or fragments of rodent excreta pellets per kg. Wheat so adulterated may be used for animal feed but not for human food (Federal Register, 12 July, 1977). Protein testing The U.S. Federal Grain Inspection Service authorized the official protein testing of HRW and HRS wheats under the Grain Standards Act on 1 May 1978 and for all other classes of U.S. wheat except mixed and unclassed from 1 M~~ 1980. Protein content will be determined either by a near-infra red reflectance (NIR) method or by the Kjeldahl method (u.s. Wheat ~~~i~~, M~~ 1980). U.S. wheat surplus The surplus of wheat left over at the end of the season in the U.S.A. when the new crop is coming in is known as the ‘carry over’. Since 1952 the carry over has greatly increased, and by 1962 amounted to 37 million tonnes, considerably more than one entire U.S. wheat harvest (31.3 million t in 1962). Subsequently the carry over deceased, partly because of wheat-area restric￾tion, and partly because of increased exports to TABLE 4.6 Grade Characteristics of US. Wheat* Minimum test wt Maximum limits (%) of HRS, Other Heat- Damaged Shrunken Wheat of White Club classes damaged kernels Foreign and broken Defects other classes kgihl lbibu kgihl lbibu kernels (total) material kernels (total) Contrasting Total Grade U.S. No. 1 72.3 58 74.8 60 0.2 2 0.4 3 3 1 3 US. No. 2 71.1 57 72.3 58 0.2 4 0.7 5 5 2 5 U.S. No. 3 68.6 55 70.0 56 0.5 7 1.3 8 8 3 10 U.S. No. 4 66.1 53 67.3 54 1.0 10 3.0 12 12 10 10 US. No. 5 62.3 60 63.6 51 3.0 15 5.0 20 20 10 10 * Source: U.S. Dept. Agric. (1991). 1 lbibu = 1.247 kgihl

CEREALS OF THE WORLD TABLE 4.7 Composition of U.s. Wheat Carry Over*(million bu t Year HRW SRW HRS Durum Total 19767 72 1112 19899 Sources: Milling and Baking News, 19 February 1980; 15 August, 1989; 17 December, 1991 t I million bu of wheat 27, 223 metric tonnes of wheat ountries, such as the former Soviet Union, India making noodles and ethnic breads. the grains and China, which had suffered loss of crops. In are large, brittle and slightly elongated with thin million tonnes, the carry over was 22. 3 for 1969, bran of white or yellow colour. The moisture 9.2 for 1973/74, 32.0 for 1977/78, 18.9 for 1989/ content is seldom above 11%, and the grain is 90 and 11.3 for 1991/92. Composition of the carry millable up to 16%m c Nos l and 2 Prime Hard over for 1976/77, 1979/80, 1989/90 and 1991/ 92, wheat are traded with guaranteed protein levels by wheat type, is shown in Table 4.7. of 13.0%, 14.0% and 15.0%(natural m c basis) Attempts to raise the protein content by under Argentina sowing with clover have produced promising Argentina is the main producer of bread wheat in South america. The wheat is classified as hard Red Winter and is known as ' wheat. The Former Soviet Union rain is hard, red and semi- vitreous, small, thin Good-quality Hard Red Spring, Hard Red and elongated in shape. In quality, the wheat is Winter and Durum wheats are produced in the strong, with about 12% protein content, but the former Soviet Union. The grains of the hRS and gluten has limited extensibility, and the wheat is HRW wheats are small, red, hard and horny, and low in diastatic power and suitable only as a filler the wheat may contain frosted grains and grains in breadmaking grists damaged by wheat bug (cf. p. 9). The big The types of Plate wheat are named after the climatic variation within the former Soviet Union ports of shipment: Rosafe, grown in the north gives rise to a wide range of wheat quality from around Rosario, and Santa Fe are shipped from very strong to medium strong. Average russian Rosario; Baril, grown in the central area, from wheat is weaker than Cwrs in baking strength Buenos Aires; Barusso, grown in the south, from and is suitable as a filler-wheat. The protein Bahia blanca. Barusso is a softer wheat, with averages 12% lower protein content, than the other types Britain Australia Winter and n, although Wheat is grown in the relatively high rain- winter wheat comprised about 97% of the total fall areas of New South Wales, Victoria, South in 1991. Average yield of wheat in the U.K. in Australia and Queensland There are two classes: 1991 was 72 q/ha(H-GCa, 1991). The bran colour hard and soft wheats. The hard type is of medium is generally red. Much of the grain is harvested trength, and is suitable as a filler in breadmaking at relatively high moisture contents ( 16-20%)and rists. The soft type is weak, and the flour is good needs drying. Varieties grown in 1991 that were for biscuits and pastry production. Australian suitable for inclusion in breadmaking grists were wheat exports are mostly of the soft type and are Avalon, Camp remy, mercia and Urban(winter marketed mainly in the Mid- and Far-East for wheats ) Alexandria, Axona and Tonic(spring

CEREALS OF THE WORLD 87 TABLE 4.7 Composition of U.S. Wheat Cay Over* (million bu)f Year HRW SRW HRS Durum White Total 1976177 605 72 250 92 93 1112 1979180 45 1 39 317 78 89 974 1989190 297 40 216 60 81 694 1991192 151 46 117 50 50 414 * Sources: Milling and Baking News, 19 February 1980; 15 August, 1989; 17 December, 1991. t 1 million bu of wheat = 27,223 metric tonnes of wheat. countries, such as the former Soviet Union, India making noodles and ethnic breads. The grains and China, which had suffered loss of crops. In are large, brittle and slightly elongated, with thin million tonnes, the carry over was 22.3 for 1969, bran of white or yellow colour. The moisture 9.2 for 1973/74, 32.0 for 1977178, 18.9 for 1989/ content is seldom above 11%, and the grain is 90 and 11.3 for 1991/92. Composition of the carry millable up to 16% m.c. Nos 1 and 2 Prime Hard over for 1976/77, 1979/80, 1989/90 and 1991/92, wheat are traded with guaranteed protein levels by wheat type, is shown in Table 4.7. of 13.0%, 14.0% and 15.0% (natural m.c. basis). Attempts to raise the protein content by under￾sowing with clover have produced promising results. Argentina Argentina is the main producer of bread wheat in South America. The wheat is classified as Hard Former Soviet Union Red Winter, and is known as 'Plate' wheat. The grain is hard, red and semi-vitreous, small, thin Good-quality Hard Red Spring, Hard Red and elongated in shape. In quality, the wheat is Winter and Durum wheats are produced in the strong, with about 12% protein content, but the former Soviet Union. The grains of the HRS and gluten has limited extensibility, and the wheat is HRW wheats are small, red, hard and horny, and low in diastatic power, and suitable only as a filler the wheat may contain frosted grains and grains in breadmaking grists. damaged by wheat bug (cf. p. 9). The big The types of Plate wheat are named after the climatic variation within the former Soviet Union ports of shipment: Rosafe, grown in the north gives rise to a wide range of wheat quality from around Rosario, and Santa Fe are shipped from very strong to medium strong. Average Russian Rosario; Baril, grown in the central area, from wheat is weaker than CWRS in baking strength Buenos Aires; Barusso, grown in the south, from and is suitable as a filler-wheat. The protein Bahia Blanca. Barusso is a softer wheat, with averages 12%. lower protein content, than the other types. Britain Winter and spring types are grown, although Australia Wheat is grown in the relatively high rain- winter wheat comprised about 97% of the total fall areas of New South Wales, Victoria, South in 1991. Average yield of wheat in the U.K. in Australia and Queensland. There are two classes: 1991 was 72 qha (H-GCA, 1991). The bran colour hard and soft wheats. The hard type is of medium is generally red. Much of the grain is harvested strength, and is suitable as a filler in breadmaking at relatively high moisture contents (16-20°/0) and grists. The soft type is weak, and the flour is good needs drying. Varieties grown in 1991 that were for biscuits and pastry production. Australian suitable for inclusion in breadmaking grists were wheat exports are mostly of the soft type and are Avalon, Camp Remy, Mercia and Urban (winter marketed mainly in the Mid- and Far-East for wheats); Alexandria, Axona and Tonic (spring