6 Food and Feed Uses

As populations explode and come to demand more and better food, man's inescapable reliance on food plants has made the production of new, hardier, and better kinds of crop plants almost the only way left to fight man's ancient and universal enemy-hungers

B. S. DODGE

It Started in Eden

Triticale, like red wheat, has a brownish seed coat. It gives an offwhite flour, much like the whole-wheat flours that come from red wheats. However, the plant breeding department at Punjab Agricultural University in Ludhiana, India, has recently produced white-seeded types.

Thus, although much more research is needed, white-seeded triticales are soon likely to be available for those places where markets overwhelmingly demand white flour.

NUTRITIONAL VALUE

Compared with wheat, triticale has slightly higher levels of most of the nutritious constituents. However, whether this will be meaningful in the long run is uncertain because the levels of all constituents are extremely variable-reflecting both triticale's mixed parentage and its youthfulness as a crop. Nonetheless, the main nutritional qualities of the current types are given below.

Protein

Early triticale lines varied enormously in protein content but generally were very high. For example, in the early 1970s, protein contents were mainly in the range of 15 to 18 percent of the total grain weight.

FIGURE 6.1 Protein and Iysine contents. Early triticales were characterized by high levels of protein, averaging more than 17 percent. However, these had grains that were shriveled and unacceptable in the marketplace. Over the years, as the kernel characteristics (especially the ratio of endosperm to bran) have improved, the average protein content has drastically declined. Today, it is at near normal levels for a cereal. Nonetheless, the high level of Iysine has remained. Few wheats are in triticale's range of 3.7-4.0 percent Iysine. Most are around 2.7 percent. In Iysine content, therefore, triticale is exceptional for a cereal. (E. Villegas,CIMMYT)

Wheat, by comparison, has an average protein content of only 12.9 percent. This demonstration of triticale's apparent nutritional superiority led to much publicity and to claims of it being a "super food."

However, this was misleading. The protein levels were high only because in the shriveled seeds of that time starch deposition was unnaturally low. The underdeveloped endosperm meant that the proportion of bran and germ (high protein) was greater than is normal in a cereal grain. As subsequent breeding and selection for plump seeds increased the size of the endosperm, the proportion of germ and bran decreased. This led to an inevitable decrease in the proportion of protein and an increase in the proportion of starch to near normal levels.

Although it might seem that reducing the protein content in the grain was a retrograde step, the loss has been more than offset by the increase in overall crop yield. Thus, in 1968 (when protein contents averaged 17.5 percent and the best yields were 2,500 kg per hectare), triticale produced 425 kg protein per hectare. By 1973 (when the protein content had dropped to 13.7 percent, but the best yields were up to 8,000 kg per hectare), it was producing 1,100 kg protein per hectare . Information from E. sears.

TABLE 6.1 Amino Acid Content.

	Triticale	Wheat	Rye
Amino Acid	(Yoreme)	(INIA)	(Snoopy)
	g/100 g of protein
Lysine	3.44	2.83	4.02
Threonine	3.55	2.98	4.06
Methionine(a)	1.28	1.42	1.35
Isoleucine	3.45	2.68	3.70
Leucine	7.20	7.22	7.75
Phenylalanine	4.94	3.77	4.74
Valine	4.48	3.73	5.10
Tryptophan	1.02	1.10	ND

(a)Partial destruction during hydrolysis
SOURCE: General Laboratories, CIMMYT, 1982.

Protein Quality

A protein's biological quality is determined by its proportions of various essential amino acids. These are the building blocks of protein that cannot be synthesized by humans (and other nonruminants such as pigs and poultry) and must therefore be obtained entirely from food. In triticale, as in most cereal grains, the "first limiting" amino acid is Iysine.

Although Iysine is the amino acid most lacking in triticale' it is present in higher proportions than in commercial wheats. Of 5,500 triticale lines analyzed by CIMMYT in 1974, the protein averaged 3.4 percent Iysine. In commercial wheat, by comparison, the total protein fraction averages about 2.8 percent of Iysine. Therefore, triticale protein is almost 25 percent richer in Iysine than wheat protein is (see table 6. 1). Information from c. Qualset.

In triticale protein, the content of threonine-another essential amino acid-is approximately 10 percent higher than that in wheat protein. Beyond Iysine and threonine, there seem to be no significant differences between the amino acids of triticale and wheat.

TABLE 6.2 Vitamin Content(a)

	Triticale	Triticale
	(winter type(b))	(Spring type(c))	Wheat(d)	Rye(e)
	µg/g	µg/g	µg/g	µg/g
Thiamine	9.8	9.0	9.9	7.7
Riboflavin	2.5	2.5	3.1	2.9
Niacin	17.9	16.0	48.3	15.3
Biotin	0.06	0.07	0.06	0.05
Folacin	0.56	0.77	0.56	0.49
Pantothenic Acid	9.1	8.3	9.1	6.3
Vitamin B6	4.7	4.9	4.7	3. 4

(a) Dry basis
(b) TR 383
(c) 6TA204
(d) Chris
(e) Prolific

SOURCE: Michela and Lorenz, 1976.

Other Nutrients

In triticale, the major minerals, such as potassium and phosphorus, generally have marginally higher levels than in wheat;(5) the micronutrient elements, such as sodium, manganese, iron, and zinc, are also a little higher.

(5) Lorenz et al., 1974.

On the other hand, triticale's vitamin content is about the same as that of wheat. Triticale's most limiting vitamin is niacin (see table 6.2).

The level of digestible energy is also the same in both triticale and wheat: triticale contains

14.1 MJ per kg; wheat, 14.4 MJ per kg.

Nutritional Performance

In general, trials on living animals have shown triticale to have a biological value 15-20 percent higher than wheat's (see table 6.3). This is important because biological value measures the proportion of absorbed nitrogen that is retained by the body. The superiority is probably due to triticale's higher content of Iysine and threonine.

True protein digestibility-the proportion of food nitrogen that is absorbed by the bloodstream-is above 90 percent in triticale protein, a figure comparable to that of wheat protein and much higher than that of rye protein. True digestibilities of individual amino acids in wheat, triticale, and rye have been compared in studies with pigs. The Iysine availability in triticale (81 percent) is higher than that in wheat and other cereals.

TABLE 6.3 Percent of True Protein Digestibility, Biological Value, and Net Protein Utilization of Some Varieties of Triticale Compared with a Wheat Variety, Using Male White Rats.

	Triticale		Wheat
	Mapache	Beagle	PC-297	Hermosillo-77
True Protein Digestibility	92.7	91.0	91.5	92.0
Biological Value	66.1	69.9	59.3	57.6
Net Protein Utilization	61.3	63.7	54.2	52.9

SOURCE: Villegas et al., 1980.

In triticale, the digestibility of gross energy is also high (87 percent), fully comparable to the corresponding values in wheat and maize. Antinutritional Factors

Many early trials in which triticale was fed to animals produced responses inconsistent with expectations based on the grain's composition. Apparently, the discrepancies were caused by minor constituents that block the body from fully utilizing nutrients. Such antinutritional factors are found in many foods. They include watersoluble pentosans, enzyme inhibitors, alkyl-resorcinols, tannins, aciddetergent fiber, pectins, and protein-polysaccharide complexes. All of these have been found in small amounts in triticale, but at levels much lower than in rye.

The variable results have few or no implications for humans eating triticale because cooking probably removes and certainly reduces the antinutritional factors. Although definitive tests have not been carried out, there are no known ingredients in the grain that differ from those in wheat or rye. Thus, triticale can be used to produce foods similar to those normally made of either wheat or rye.

MILLING PERFORMANCE

Just as bread wheats vary in their genetic potential for quality, varying quality characteristics are found in different triticales. The earliest cultivars had poor milling performance, but improvement of grain plumpness has resulted in many triticales with flour-milling properties similar to those of bread wheats.

Compared with the varieties first released in the 1960s, today's grains are smooth, round, and plump. They pack well and fill space with few voids. This is obvious from the change in ''test weight," the weight of a standard volume of seed. The early varieties had test weights of about 60 kg per hectoliter. Today's varieties have test weights up to 78 kg per hectoliter-approaching those of wheat (see figure 3.2). In general, when triticale is grown on fertile sites and under unstressed conditions, researchers no longer consider shriveled seed to be a concern. However, when it is grown on marginal sites, the seeds are sometimes somewhat shriveled. Thus, at Ciudad Obregon (unstressed growing conditions) one variety may produce seed with a test weight of 78, but the same line at Toluca (stressful conditions) may produce seed with a test weight of only

65. Soon, however, even this is likely to improve. Zebra and Rhino, two CIMMYT lines with stable test weight (that is, whose grains remain plump under both good and bad conditions) are becoming available.

In the past, triticales produced a lower flour yield than bread wheat: their extraction rates were only 50-65 percent, compared with 66-72 percent for bread wheat. This was mainly because of the shriveled grains. Today the situation is quite different: many current triticales have extraction rates of more than 70 percent in laboratory mills. Flour yields of even 73 percent, fully comparable with those of wheat, are found in some advanced lines.

Triticale can be milled either alone or as a mixture with soft bread wheat. In Brazil, triticale is sold as "wheat" and blended with wheat before milling.

FOOD PRODUCTS

For baked products that require doughs or batters with low protein, low water absorption, and minimal resistance to extension, triticale can be fully substituted for wheat flour without modifying the baking methods. Thus, it is highly suited for products in which soft wheat is used. These include cookies, cakes, biscuits, waffles, pancakes, noodles, and flour tortillas.

Unleavened Bread

Unleavened products that have been produced with triticale include the following:

· Chapatis. In tests, a number of triticale lines were as good as or better than the wheat check for making chapatis, a staple flat bread of South Asia.

· Tortillas. Tortillas made from plump triticale kernels taste like those made from wheat. In

CIMMYT tests, a number of triticale lines were as good as or better than the wheat check in tortilla-making quality. The triticale tortillas were flavorful, but those made from 100 percent unbleached flour were gray-brown in colon Villagers in Michoacan, Mexico, use triticale daily and report that triticale dough is easier to flatten than wheat dough, making the preparation of tortillas easier. Also, they say, the tortillas hold together better.

· Concha. This sweet, whole grain bread, made with molasses, is popular in Mexico. Triticale has been used to make it without any problem.

· Enjera. Ethiopians (notably those living outside their native land) have found that triticale flour can be substituted for at least 50 percent of other traditional flours such as teff and buckwheat, used in making the national food, enjera. This traditional flat "pancake" can also be made from equal parts of triticale and teff.

Leavened Bread

Flour produced from triticale varieties having breadmaking properties produces rich, brown, satisfactory loaves that look like wholewheat bread and taste, as their ancestry might suggest, like a combination of rye and wheat bread.

Breads rise because of the presence of special proteins (especially glutens) that trap and hold the bubbles of gas released by the leavening agent. Triticale proteins represent a mixture of the types found in rye and in bread wheat. This is unexpected because many of today's triticales (that is, hexaploids) are made from durum wheats and lack the D-genome chromosomes that are responsible for the breadmaking quality in bread wheats (see chapter

5). Nonetheless, baking trials show that the gluten content is satisfactory and that the dough rises well, at least in some triticale lines. The resulting loaves are of normal size and porosity and have a good flavor.

If the best breadmaking varieties are used, triticale flour by itself can yield good raised breads. Baking tests on advanced triticale lines with plump grains (test weight up to 74 kg per hectoliter) have produced loaves with a volume similar to the loaf volume of the wheat control. However, the absorption, fermentation, and mixing procedures had to be slightly modified from those used with wheat flour. Lowered fermentation temperatures and slightly increased yeast concentrations (to compensate for the cooler conditions) were used. With these modifications, and with the progress made by breeders toward plumper grains, there are now many triticale lines that produce excellent loaf volumes, even when 100 percent triticale flour is used to make sandwich bread (see figure 6.2). By using normal baking methods and run-of-the-mill triticale varieties, many leavened breads can also be made from a 30:70 mixture of triticale and bread wheat with the results equaling those obtained with pure bread wheat. However, with "bread quality" triticale varieties, mixtures of up to 75 percent triticale flour can give products essentially indistinguishable from those made from pure bread-wheat flour. Such blends can be used in industrial bakeries with high-speed mixing equipment. However, as noted in chapter 4, even the best triticales cannot now be used in the pure form in high-speed mixing equipment because of the "sticky dough" problem.

Triticale can also be mixed with non-wheat flours. It combines well with quality-protein maize (QPM), for instance. Both grains contribute Iysine to the diet. Breads and muffins made with a blend of QPM and triticale have a nutty flavor and a chewy texture that make their whiteflour counterparts seem hopelessly bland by comparison.

Other Foods

Triticale has the potential for use in cereal foods that are not baked- noodles, breakfast cereals, and porridges, for instance. In Kenya, it is already more desirable than wheat for making the traditional staple food, ugali, a stiff porridge based on maize meal.

Triticale grain can also be used in the brewing and distilling industries. Based on taste-panel results, it has performed as well as maize and rice, both of which are extensively used by the brewing industry as carbohydrate sources. One large Mexican brewery is growing some 2,000 hectares of the crop near Ciudad Obregon in the state of Sonora to test triticale as a source of malt. Reportedly, triticale's cell-wall polysaccharides (derived from the rye parent) give stability to the foam on the beer.

FEED AND FORAGE

Triticale grain shows considerable potential as livestock feed. Indeed, most of today's yield is used as a feed grain. It has the advantage over rye in that it can be fed directly to animals without prior processing. For pigs, triticale is considered a potentially valuable source of energy and amino acids and is of great potential value where maize and soybeans cannot be grown (as in Poland), or can substitute for rye- which is unsatisfactory for pig or chicken feeds. Several experiments have shown that, whereas rye grain can be fed only at low levels, triticale can be included in rations at up to 50 percent. In addition to being a feed grain, triticale is particularly promising as an early crop for grazing or making hay. Its forage and silage yields, at least in some situations, can be significantly greater than those of wheat, rye, oats, or barley. It has done well in areas where oats fared poorly, notably where oats proved susceptible to rust. And it persists longer than rye in mixtures with rye grass and clover. Moreover, the protein content of triticale forage ranges between 22 and 24 percent (dry-weight basis), which is higher than that of all other forage grasses except oats.

In one comparison with other small-grain forages, triticale was reported to have the highest forage yield over two years. Grazing trials with yearling steers have shown average daily weight gains of 0.72 kg for triticale, 0.69 kg for wheat, and 0.59 kg for rye. Winter triticales are particularly promising as forages. Argentina, one of the world's largest producers of triticale for forage, has several (so far unnamed) forage lines that are used by farmers. They have been selected under heavy grazing by sheep and are derived from crosses of spring and winter triticales.

Improved forage varieties can be expected in the future. There is much potential for selecting for higher protein and better grain. There is also a possibility of combining forage production with grain production. In the Andalusian region of Spain in 1982-the driest year in the recorded history of this region-the wheat crop was so stricken it had to be abandoned. Animals were turned onto triticale instead, and allowed to graze it down twice. Then came late winter rains, and the farmers allowed the triticale to produce seed. At the end of the season, they still harvested 2.5 tons of grain per hectare.(22)

(22) Information from G. Varughese.

Because triticale is similar to other feed grains, price and yield will often be the factors to determine its utilization in animal feeds. In this respect, triticale often has a competitive advantage, especially where growing conditions are marginal for the conventional feed grains (see figure 7.1).

FIGURE