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Suggested Citation: "Appendix H: Notes on Nutritional Charts." National Research Council. 1996. Lost Crops of Africa: Volume I: Grains. Washington, DC: The National Academies Press. doi: 10.17226/2305.

Appendix H
Note on Nutritional Charts

In the earlier chapters we have included tables of nutritional information, as well as charts that show how this information compares with that of a standard cereal such as maize or rice. They appear on the following pages.

Crop	Page
African rice	27
finger millet	44, 45
fonio	64
pearl millet	86, 87
sorghum	134, 135
tef	222, 223
kram-kram	263
shama millet	268
Egyptian grass	269
wadi rice	270

These tables and charts should be taken only as rough indications of the lost crop's merits, not the definitive word. Some species in this book are so neglected that their nutritional components have been reported merely once or twice. It is thus probable that the figures we have used are not representative of average samples, let alone especially nutritious forms. Moreover, natural variation can occur in the nutritional content of grain from any particular species as a result of nongenetic factors such as climate and the availability of nutrients in the soil. It could be, therefore, that even better types will be discovered and developed.

The bar graphs provide what we think is a simple, but visually powerful, representation of the relative nutritional merits of two foods. With them nutritional figures between two foods (or between a food and a recommended daily allowance) can be compared almost instantly. This technique, in which the relative merits can be seen at a glance,

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was devised specifically for this project, but comparable approaches could be employed equally well in Africa.*

The maize and rice values against which the African grains are compared in the bar graphs are taken from U.S. Department of Agriculture tables. The actual figures (converted to a dry-weight basis) are given below.

Component	Maize	Rice
Food energy (Kc)	408	406
Protein (g)	10.5	8.1
Carbohydrate (g)	83	90
Fat (g)	5.3	0.7
Fiber (g)	3.2	0.3
Ash (g)	1.3	0.7
Thiamin (mg)	0.43	0.08
Riboflavin (mg)	0.22	0.06
Niacin (mg)	4.1	1.8
Vitamin B6 (mg)	0.58	0.02
Folate (µg)	0.0	9.1
Pantothenic acid (mg)	0.47	1.15
Calcium (mg)	8	32
Copper (mg)	0.35	0.25
Iron (mg)	3.0	0.9
Magnesium (mg)	142	130
Manganese (mg)	0.55	1.1
Phosphorus (mg)	234	130
Potassium (mg)	320	130
Sodium (mg)	39	6
Zinc (mg)	2.5	1.2

In each of the essential-amino-acid bar graphs, the figures were compared on the basis of the amounts occurring in the protein of each grain (that is, grams per 100 grams of protein). In the other bar graphs, all nutrients were compared on a dry-weight basis so as to eliminate the distortions of different (and varying) amounts of moisture. Digestibility and other metabolic factors were not factored into the calculations. For vitamin A, the values for Retinol Equivalents were derived using standard formulas to convert literature figures given for carotenoids, ß-carotene, or International Units.

*	The bar graphs were plotted electronically, so their resolution exceeds the standard error of the data (which is at minimum 10 percent). Duplicate data were discarded, and ranges were treated as separate values.

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Amino Acid	Maize	Rice
Cystine	1.8	2.0
Isoleucine	3.6	4.3
Leucine	12.3	8.3
Lysine	2.8	3.6
Methionine	2.1	2.4
Phenylalanine	4.9	5.3
Threonine	3.8	3.6
Tryptophan	0.7	1.2
Tyrosine	4.1	3.3
Valine	5.1	6.1
Total	41.1	38.1
Grams per 100 g protein.

In most of the charts in the chapters we have compared the native grains in their whole-grain form with whole-grain rice and maize. A more realistic comparison might have been against polished rice and maize meal (in which the germ has been removed). This is the form in which rice and maize are normally consumed, whereas the native grains—pearl millet, fonio, finger millet, tef, and (in most cases at least) sorghum—are eaten as whole grains. Comparing nutritive values for the forms in which each is actually eaten creates an even more graphic picture of the nutritional superiority of the native grains.