Cover Image
close this bookFood and Nutrition Bulletin Volume 07, Number 4, 1985 (UNU, 1985, 86 pages)
close this folderFood science
View the documentComparison of relative energy costs of village-prepared and centrally processed weaning foods
View the documentHigh-protein biscuits made with ragi flour and oil-seed flour blends
View the documentA simplified procedure for calculating amino-acid scores of blended foods or dietary patterns
View the documentA simple field kit for testing iodine in salt

A simple field kit for testing iodine in salt

A simplified procedure for calculating amino-acid scores of blended foods or dietary patterns

G. Richard Jansen and Judson M. Harper
Colorado State University, Fort Collins, Colorado, USA

Amino-acid scores provide a useful estimate of the protein quality of blended foods or dietary patterns and are an acceptable substitute for the biological assays [1]. The most recent international recommendations for an aminoacid reference pattern are given separately for infants and pre-school children [2] . None are given for adults because amino-acid pattern is rarely a factor limiting the utilization of protein in the diets of adults. For persons of all ages, however, the digestibility of the protein must be taken into account. The calculations that follow are for children of two to four years of age and need to be further adjusted for the digestibility of the dietary protein. In the absence of specific data it can be assumed to be 90 per cent or more for mixed blended foods containing animal protein and 80 per cent or more even for diets that are entirely of vegetable origin [3] .

The following procedure has been simplified by including only those amino-acids likely to be found limiting in weaning foods and diets and by providing a standard format for entering the required data and calculating net protein value. Calculation of the protein value of formulas for infants by this procedure would require use of the aminoacid pattern proposed for this age group in the FAO/VVHO/ UNU report. Because it is often difficult to locate data on the aminoacid content likely to be used in weaning food mixtures, values provided by the Agency for International Development are given in table [4].

DIRECTIONS

1. Record on the work sheet (fig. 1 ) the reference number and the weight in grams for each of the components of the mixture.
2. Record the amounts of nitrogen (N), protein, Iysine,
threonine, tryptophan and sulphur amino acids (methionine plus cystine) by multiplying the corresponding handbook values by the weight of the component in grams divided by 100 (see table 1, note a).
3. Add up the weight and amounts of N. Iys, tier, try, and SAA in the total mixture.
4. To obtain mg/gN divide the amounts (mg) of Iys, tier, try, and SAA by the amount (9) of N in the mixture.
5. To obtain amino-acid scores divide the mg/gN for each amino acid by the corresponding values in mg/gN listed for the 1983 FAOtWHO/UNU pattern x 100 [2] .
6. To calculate per cent protein, g protein in mixture should be divided by the weight of mixture (g) x 100.
7. To obtain net protein value (NPV) multiply the lowest amino-acid score by the per cent protein divided by 100.

Figure 1. Sample work sheet

Ref.no.

Component

Wt(g)

N (g)

Prot (g)

Lys(mg)

Thr(mg)

Try(mg)

SAA(mg)

9 Maize 70 1.06 6.6 178 239 47 230
280 Full-fat soya flour 20 1.34 8.4 538 328 118 176
283 Non-fat dry milk 10 0.57 3.6 260 151 51 126
Total   100 2.97 18.6 976 718 216 532
mg/gN in mixture       329 242 73 179  
FAO/WHO/UNU pattern (mg/gN)         344 250 63 156
A Amino-acid score (per cent)       96 97 116 115  
B Protein (per cent)     18.6          
C NPV (AxB/100) (per cent)     17.8          

 

TABLE 1. Amino-acid scores of floodsa

No. Name N Prot (g) Lys (mg) Thr Try (mg) SAA
(g) (mg) (mg)
  Cereals and grain products
1. Ache 1.26 7.90 205 315 111 622
2. Barley 1.88 11.00 406 389 180 463
3. Buckwheat 1.95 12.20 464 439 152 476
4. Combe fringe 2.51 15.70 236 472 - 0 439
5. Foxtail millet 1 69 10.60 233 328 103 296
6. Iburu 1.89 11.80 225 389 215 616
7. Job's Tears 2.21 13.80 285 409 99 506
8. Koda millet 0.91 5.70 171 176 35 85
9. Maize 1.52 9,50 254 342 67 329
10. Millet 1.55 9.70 332 374 189 468
11. Oats 2.23 13.00 517 462 176 606
12. Proso millet 1.39 8.70 262 204 68 222
13. Quinoa 1.92 12.00 672 420 127 240
14. Ragi millet 1.18 7.40 213 310 107 421
15. Rice (brown or husked) 1.26 7.50 299 307 98 267
16. Rice (polished) 1.13 6.70 255 234 95 258
17. Rice (parboiled) 1.19 7.10 261 343 87 387
18. Rye 1.89 11.00 401 395 87 397
19. Sandbar 2.85 17.80 214 658 - 0 3,932
20. Sorghum 1.62 10.10 204 306 123 293
21. Teff 1.57 9.80 273 334 146 472
22. Teosinte 3.81 23.80 308 712 91 549
23. Wheat (whore grain) 2.09 12.20 374 382 142 528
24. Wheat (germ) 3.95 22.90 1,608 1,047 261 996
25. Wheat (bran) 2.16 13.60 583 482 173 583
26. Wheat (flour 80%-90%) 2.05 11.70 326 394 139 459
27. Wheat (flour 70%-80%) 1.91 10.90 248 321 128 478
28. Wheat (flour 60%-70%) 1.61 9.20 182 246 93 369
29. Wheat (parboiled) 1.92 11.20 309 340 127 420
30. Wheat (gluten) 13 40 76.40 1,193 2,131 844 3,095

 

  Starchy roots, tubbers
31. Cassava (meal) 0.26 1.60 67 43 19 45
32. Cassava (meal fermented) 0.16 1.00 26 24 7 21
33. Giant arum 0.38 2.40 107 93 - 0 88
34, Hausa potato 0.21 1.30 75 75 13 39
35. Lotus, Egyptian 0.83 5.20 260 192 - 0 99
36. Potato 0.32 2 00 96 75 33 38
37. Sweet potato 0.21 1.30 45 50 22 36
38. Tacca 0.26 1.60 81 47 13 32
39. Taro 0.29 1.80 70 74 26 71
40. Tigernut 0.56 3.50 175 133 35 77
41. Yautia 0.35 2.20 70 65 30 79
42. Yam 0.38 2.40 97 86 30 65

 

  Dry legumes and legume products
43.African locust bean 5.17 32.30 2,089 1,008 289 693
44. Bambarra groundnut 2.83 17.70 1,141 617 192 496
45. Bean 3.54 22.10 1,593 878 223 422
46.Bonavist Niger 3.65 22.80 1,591 755 164 339
47. Broad bean 3.74 23.40 1,513 786 202 359
48. Chickpea 3.22 20.10 1,376 756 174 447
49. Cowpea 3.74 23.40 1,599 842 254 528
50. Gemsbok bean 4.37 27.30 1,119 822 219 275
51. Ground bean 3.10 19.40 1,280 738 155 462
52. Groundnut 4.69 25.60 1,036 764 305 704
53. Lentil 3.87 2 4.20 1,739 960 231 415
54. Lima bean 3.15 1 9.70 1,466 823 199 445
55. Lupine 4.99 31.20 1,652 1,138 314 669
56. Mung bean 3.82 23.90 1,927 799 191 294
57. Pea 3.60 22.50 1,692 914 202 457
58. Pigeon pea 3.34 20.90 1,607 608 117 311
59.Sesbania 5.12 32.00 1,219 768 - 0 404
60. Soya bean (seed) 6.65 3 8.00 2,653 1,603 532 1,077
61. Soya bean (cake) 8.06 46.00 3,063 2,152 774 1,555
62. Soya bean (soya milk) 0.56 3.20 195 128 48 107
63. Soya bean (fermented) 2.98 17.00 1,120 742 235 542
64. Sword bean 3.92 24.50 1,348 1,078 - 0 627
65.Tamarind 3.01 18.80 1,111 394 57 169
66. Velvet bean 5.25 32.80 2,037 1,313 - 0 688
67. Vetch 4.13 25.80 1,490 863 - 0 537
68. Yam bean 2.96 18.50 1,258 758 - 0 630

 

  Nuts and seeds
69. African fan palm 0.17 0.90 53 45 17 37
70. African mammee-apple 0.38 2.00 95 71 22 19
71. Almond (dry) 3.24 16.80 454 492 172 690
72. Amaranth 3.13 16.60 970 676 160 344
73. Baobab 5.66 30.00 1,307 1,132 - 0 458
74. Bombax 3.64 19.30 1.023 728 167 251
75. Brazil nut 2.71 14.80 474 442 322 1,339
76. Cashew 3.28 17.40 942 666 378 309
77. Chirauli nut 5.53 29.30 1,316 1,040 382 553
78. Coconut 1.25 6.60 275 265 85 245
79. Colewort 5.12 32.00 1,587 1,393 481 1,397
80. Cotton (seed) 3.81 20.20 1,052 785 297 679
81. Cotton (cake) 5.17 27.40 1,339 1,060 460 941
82. Deccan hemp 5.64 29.90 1,528 1,151 - 0 1,258
83. Desert date 5.00 26.50 1,015 780 155 1,640
84.Dika nut 1.62 8.60 496 386 173 638
85. Dum palm 0.74 3.90 226 125 - 0 190
86. Gabon nut 1.60 8.50 490 400 - 0 340
87. Hazelnut 3.75 19.90 690 623 263 289
88. Heisteria 2.09 11.10 627 510 - 0 458
89.Jacktruit 1.70 9.00 617 457 117 192
90. Kola 1.09 5.80 491 239 34 109
91. Linseed 3.40 18.00 806 813 330 823
92. Lotus, Egyptian 1.58 9.90 246 346 - 0 228
93. Manketti 4.00 21.20 1,176 900 244 716
94. Melon 4.87 25.80 833 1,076 458 1,008
95. Meni-oil tree 3.08 16.30 1,214 829 -0 290
96. Niger seed 3.26 17.30 903 789 - 0 649
97. Oysternut tree 4.57 24.20 1,001 1,257 - 0 343
98. Palm 1.24 6.60 305 275 78 356
99. Panda 5.21 27.60 1,141 1,042 - 0 422
100. Papo-Canary tree 4.08 21.60 738 816 -0 792
101. Parinarium 8.46 52.90 1,580 812 677 1,936
102. Pecan 1.24 7.80 348 275 97 274
103. Pistachio 3.57 18.90 1,080 613 225 752
104. Raffia palm 1.47 7.80 523 322 - 276
105. Safflower 2.38 12.60 464 455 143 343
106. Sesame 3.42 18.10 585 763 287 988
107. Slugwood 1.32 7.00 347 182 -0 149
108. Sopei 1.87 9.90 597 468 -0 176
109. Sorleh 0.51 2.70 162 156 -0 13
110. Sunflower(seed) 2.38 12.60 536 547 202 504
111. Sunflower (cake) 7.60 40.30 1,756 1,733 576 2,006
112. Tallowtree 0.81 4.30 167 182 -0 258
113. Tropicalalmond 3.84 24.00 553 695 -0 215
114. Turnip seed 6.94 43.40 2,387 1,672 562 1,783
115. Walnut 2.94 15.60 285 494 185 247
116. White and black mangrove 1.24 6.60 224 241 -0 257

continue