The biological values of the proteins of oats, barley, wheatbran and pollard

Onderstepoort Journal of Vete1'inary :icience amd Anim,al lndust1·y, T'olunt,e 15, Numbers 1 and 2, July and October, 1940.

Printed in the Union of South Africa b~· tha Government Printer, P!·etoria.

The Biological Values o f the Protein s of Oats, Ba rley, Wheatbran a nd Poll a rd.

By J. S. C. :MARAIS and D. B. S:MUTS, Section of Nutrition, Onderstepoort.

THE value of cereals in human anu animal nutrition is fully recog- nizeu and appreciated. In fad it has become a regular and prominent portion of the daily dietaries of man and an inseparable portion in the balanced rations of stoc·k.

Similarly its by-produ<.:ts han• through years of experienee attained an increasing popularity in the nutrition of farm animals.

Late,ly the Yalue of "·beaten 1ran as a 1wtural means of stimulating veristalsis in human beings has been recorded. Although these products as a group are not high in protein and therefore generally regarued as energy producing nutrients, they neYertheless contribute a fair quantity of protein to the daily aggregate of protein intake of both man and stock. It is eonsequently of importance that a detailed knoTI"ledge about the constitution and availability of the proteins container] in cereals anrl their by-products should be available, in order to assess their true nutritional value and to supplement in a practical way the indispensablE> amino acic1s "·hich may be de:ficien t.

For this reason the above cereals and by-products were investigated by means of the Thomas-Mitchell nitrogen balance method for the estimation of their H'spective biological ,-alues.

In determinations on the biological Yalues of vroteins at different levels of protein intakE' Mjt('hell (1924) obtained values of 79 and 65 for oats at 5 and 10 per cent. protein levels. Smuts and Malan (1938) determined the biological value for rolled breakfast oats at 8 per cent. level as being 84, which is very near the value of 83 for pre-cooked oatmeal as determiner] by ~furlin anu :Mattill (1938). In a comparison between barley and oats Osborne and Mendel (1920) could not assign any difference in the nutritive Yalue hetTI"een the two proteins. K either oats nor barley can meet the growth requirements

<l.ccording to Steenbock and Gross (1918). Similar are the results of Hughes (1937) namely that barley as the only source of protein in the ration of pigs allows only slow growth, with a high food intake per unit bodyweigbt increase. For wheathran and barley Gaucher and Popov (1936) determined the biological values 82 and G2 respectiYely. The proteins of bran and of the embryo are superior

205

JJIOLOGICAL VALUES O:F PROTEINS.

to that Df the endosperm according to Johns and I<'inks (1920), Osbome aud ~1endel (1919) and Boas Fixsen and Jackson (1932). A rather low biological value of 57 has. lJeen determined by Klein and co-workers (192o) for wheatbran, whilst 'Wan (1935) determined ti•e much higher value of 72. Excellent growth and reproduction were observed on rats with treated and untreated wheatbran.

ExPERIMENTAL.

In principle the method described by :Mitchell (1924) has been adopted. Male rats of 100-150 grams were used. It was found that the larger rats. gave less trouble as regards food consumption and thereby the danger of any tissue breakdown that may he caused by insufficient energy intake was greatly minimised. Only one biological value was determined on a series of six rats.. The nitrogen low period was conducted either prior to m after the protein periods. Six to seven day periods were allowed on a nitrogen low ration to estaulish constant nitrogen excretion. For the protein periods at least 10 days were allowed. The collection periods were of seven days' duration. The urine was collected in acid and the daily faeces digested by the Kjeldahl method. To distinguish between faeces of the preliminary periods and collection periods Fe2(l₃ was used as u marker. At the end of the collection period the week's digests of faeces were made up to volume and aliquots distilled for nitrogen determination. Tl1e urine collected over the period was made up to a known volume and aliquots digested for nitr<Jgen determination. The rations were made up so as to contain approximately 8 per cent. protein. The composition of the ratiDns are giYen in Table 1. All the rations were analysed for nitrogen. To prevent deteri<Jration the rations were kept in an ice chest.

RESULTS.

The nitrogen metabolism data us well as the calculations of the bioloQ'ical values are given in Table II. The standardizing periods on the nitrogen low ration preceded the protein periods in the cases of oats ancl barley and followed the protein periods directly again in the cases of wheatbran and pollard.

As can be seen from these results tl1e biological values for oats, barley, wheatbran and pollard are 83 ±2·04, 77 ±1·98, 74 ±2·82 and 84 ± 1· 66 respectively. These biological values differ only

sli~htly from the figures expressing the percentage utilizable protein which are 79 ± 2 · 73, G8 -f: 2 ·52, 72 ± 2 · 82 and 83 ± 1· 44 for oats, barley, wheatbran and pollard respectively. These small differences are due to the high digestihilities of the proteins. The digestibilities as determined are 95 ±1·25, 89 ±1·51, 98 ±1·44 anc199 ±0·82 for oats, barley, wheatbran and pollard respectively.

It is obvious from these results that these proteins are fairly well balanred and that they differ only slightly in their nutritive value; barley being the poorest and pollard the best. The explanation for the fact that pollard is better than wheatbran must be sought in the supplementary effect of tbe endosperm and epidermis. of the wheat kernel, as pollard contains a higher percentage endosperm than wheatbran.

206

J. S. C. MARAIS AND D. B. SMUTS.

SUMMARY.

The biological n lues and digestibilitie8 of the proteins of whole oats seed, unpearled barley, wheatbran and pollard have been Jetennined and a figure expressing the percentage utilizable protein calculated.

TABLE 1.

Percenta.qe Compositions of Rations.

Ingredients.

[

^{S ~Low. Heed. Oats Ruley. 'Wheat Bran.}

I

^Pollard.

Whole oats seed 69·6

Whole barley .. 82·5

Wheat britn . ... ...

..

.. 69·6

Pollard. +5· ,)

Butterfat( 1 ) . . . ... .. . .

..

. . 8·0 8·0 8·0 8·0 8·0

Cod liver oil ... 2·0 2·0 2·0 2·0 2·0

Sucrose. ^•• • • • • • ••• •• 0 0 . 10·0 10·0

·I

2·5 10·0 10·0

Harris yeast(²) . . • • . . • • . . . • . • 2·0 2·0 2·0 2·0 2·0 Salt mixture(") . ....

..

. . .

.

. . 2·0 2·0 2·0 2·0 2·0 Whole egg(') .... ....

..

... . . 3·8

NaCl.. ^{• • • • • • • • • • • • • • • • • 0 • • •} 1·0 1·0 1·0 1·0 1·0 Agar ...... 2·0

Starch ( dextrinized). 69·2 5·+ 5·-i 29·.5

TOTAL .... 100·0 JOO·O 100·0 100·0 100·0

PERCENTAGE N. 0·64 l·-!6 l· 59 1·56 1·58

( 1 ) The butter fat has been filtered through a course filter paper to remove casein.

( 2 ) Vitamin B. prepamtion prepared by "The Harris Laboratories". Cuckahoe, New

York.

(") A new salt mixture described by Hubbcl, H .. :'lfendel, .r. H. and \\"akeman . .A. J.

(1937), J. Nutr. Vol. 14, pp. 273-285.

( 4 ) The whole egg has been dried on a waterbath and cxtradecl with ether.

REFERENCES.

BOAS FIXSEN, M. A., AND JACKSON, H. M. (1932). The biological Yalues of protein. IV. The biological values of the proteins of wheat. maize and milk. Biochem. J., Vol. 26, p. 1923.

GAUCHER, G., AND POPOV, T . .D. (1936). The biological value of some protein feeds used in Bulgaria. .4.nn. Univ. Sofia. 5, Fac. AgTon. Sylvicult, Vol. 14, pp. 209-238.

HUGHES, E. H. (1937). Biological Yalue of casein as a supplement to the protein of barley Jll rations for pigs. J. AgTic. Res., Vol. 55, pp. 461-465.

JOHNS, C 0., AND FINKS, A. J. (1920). Studies in nutrition. VI. The nutritive value of peanut flour as a supplement to wheat flour. J. Biol.

Chem., Vol. 42, p. 569.

KLEIN A., HARROW, B., PINE, L., AND FUNK, C. (1926). The nutritive value of various lavers of the wheat and corn kernel. A mer. J.

l'h!J8iol., Vol. 76, p: ~37.

207

lliOLOGICAL VALl:ES Ol' PHOTEINS.

MITCHELL, H. H. (192-!). A method of determining the biological value of protein. J. Bioi... Chem., Vol. 58, p. 873-903.

MITCHELL, H. H. (1924). The biological values of proteins at different levels of intake. J. Biol. Chem., Vol. 58, pp. 905-925.

MURLIN, J. R., AND MA'l."ffLL, H. A. (1938). Digestibility and nutritional value of cereal proteins in the human subject. J. Nutr., Vol. 16, pp.

15-3:3.

OSBORNE, T. B., AKD .Jlg~DEL, L. B. (1919). The nutritive Yalue of the wheat kernel and its milling products. J. lJiol. Chem., Vol. 37, p. 557.

OSBORNE, T. B., AKD MENDEL, L. B. (1920). Nutritive value of the proteins of the barley, oats, rye and "·heat kernels. J. Biol. Chern., Vol. 41, p. 2.75.

SMUTS, D. B., A:"D MALAN, A. l. (1938). Plant Proteins II. The biological values of lucorncmeal, sesamemeal, peanutmenl, coprameal, cottonseed- meal and oatmeal. Onderstepoort J. Tl et. 8~:i. and Animal Industry, Vol. 10, pp. 207-219.

STEENBOCK, H .. Al\D GHOSS, E. G. (1918). Dietary qualities of barley . . ] . Biol. Chem., Vol. 35, pp. 62-74.

\VAN, . (1935). The biological value of proteins and the digestibility of food constituents of mixed vegetarian diets containing processed wheat brans.

Chinese J. Physiol., Vol. 9, pp. 125-]40.

1\:) 0 <:.:)

l~at No. 7 8 9 10 11 12 7 8 9 10 ll 12 7 8 9 10 ll 12 7 8 9 LO Ll 12

Initial Wgt. Gm. 120 164 144 132 107 134 13~ 177 160 147 130 152 1.40 I 137 138 132 142 127 125 1.24 130 120 140 120

Aver- Final Wgt. age Wgt. Gm. Gm. 119 120 157 161 135 140 127 130 107 107 132 133 139 139 179 178 168 164 153 150 140 135 1.60 156

I

138 [ 139 135 136 140 139 134 133 144 143 132 130 1551 140 150 137 158 144 1421 131 156 148 1 :~6 128

T_,_Jji_E

:2.

Nitrogen LlfMalJol·is-rn lJola ond the Catculat'i(m of the /J1olo[Jical Value. N-Lo1c Petiod.

I

Metabolic Endogenous Daily N. Daily N. Daily Daily ~~"ood Food N Food Nin-Faecal N in Absor-Ur-i-J:'er N in N Re-B In-Per bed N. 100 tained. lan~~-take. N. J:'er Faeces. nary Per Urine. take. Gram Day. N. Gram Day. Food. \Vgt. I Gm. Mgm. ?11gm. Mgm. i\lgm. Mgm. Mgm. Mgm. Mgm.[ Mgm. J\Jgm. l\Jgrn. J\Jgrn. 11·7

-

39·6 3·70

- -

-18·5 15·4 ---- 11·0 -37·0 3·36

-

--24·6 15·3 ---- 9·0 -31·4 3·49 ---26·4 18·9 ---

-

10·1 -33·2 3·29 ----19·2 14·8 ---- 9·1 -30·2 3·32 ---16·0 15·0 -

-

--- 10·1 -31·6 3·13

- -

-19·3 14·5 -

-

-- I Whole Oots ,_",eed l'enorl (1·4(j per tent .. \"). 10·4 151·8 51·6 3·70 38·5 13·1 138·7 4:1· 2 15·4 21·4 21·8 ll6·9 +57·0 ll· 7 170·8 46·8 3·36 39·3 7·5 163·3 66·4 15·3 27·2 39·2 124·1 -t-57·6 ll·9 173·7 47·4 3·49 41·.~ 5·!) 167·8 46·4 LS · ~~ 31 ·0 15·4 152·4 +79·9 10·6 154·8 39·6 3·29 34·9 4·7 I fiO·I iii ·6 14·8 22·2 29·4 120·7 +63·6 12·1 ] 76· 7 47·4 3·32 40·2 7·2 1.69·5 47·2 15·0 20·3 26.9 142· 6 +82·1 12·7 185·4 51i·8 3·13 39·8 16·0 160·4 .50·4 14·5 22·6 27·8 141 6 +79·2

I

J\'-/,ol( Pniod. 9·3 -35·8 3·85 I ---21.6 J5·ii -I -I -

I

-- I 8·9 -33·0 3· 71 ----20·0 14·7 -

-

i -

-

I 8·7 -30·2 3·47 ---19·2 13·8 ---- 8·8 -34·4 3·91 ---18·4 13·8 -

-

I

-- 9·9 -38·2 3·86 -. --17·6 12·3 ---- 9·6 -:34·1 3·55 ---19·6 15·1 -- I -- Wlwle lJw·ley !'l'norl (l·fJH ;_er l'l'lif .. \ ). 16·3 259·2 82·4 3·85 62·7 19·7 239·5 73·6 15·5 21·7 51·9 187·6 +103·2 15·9 252·8 87·2 3·71 59·0 28·2 224·6 81· 6 14·7 20· 1 61·5 163·1 + 84·0 15·4 244·9 79·2 3·47 53·4 25·8 219·1 70·4 13·8 19·9 50·5 168·6 + 95·3 13·6 216·2 69·6 3· 91 53·2 16·4 199·8 72·0 13·8 18·1 53·9 145·9 + 64·6 14·6 232· I 82·4 3·86 ii6·4 26·0 206·1 53·6 12·3 18·2 35·4 1.70·7

+

96·1 14·2 22!i·8 88·8 3·iili fi0·4 38·4 187·4 64·0 l!i·1 1.9·3 44·7 142 . 7

II

73 . 0 I I

I

Per Appa- True cent- rent Biolo-age Diges-Diges- gical utili- tibi-. tibi-Value. zable lity. Jity. Pro- tein. ---- ---- ---- --

-

- ---- ---

-

66 91 84 76 73 96 76 i3 75 97 91 88 74 97 80 78 73 96 84 81 70 91 84 76

---n-

95"' ~ ~ ·-----

--

-- ---- --

-

- --

-

- ---- ---- ---- 68 I 92 78

I

72 I 68 89 73 65 68 89 77 69 68 92 73 67 64 I 89 83 74 _Jl.l:_~ 76 63 66 1 89

i

77 68 -=,=---==.---=--.=

'-< [JJ (": ~ 1>- ~ > 1-' (/; >

:3

'¥ tl l:r [JJ '-'

§

(/l

~ 1-' 0

ltat No.

I

13 14 15 16 17 18 1 14 15 16 17 18 19 20 21 22 23 24 --- 19 20 21 22 23 24

Initial Wgt. Gm. 129 126 143 141 130 125 122 118 125 127 116 110 118 113 ll4 135 129 145 121 109 105 123 129 13!i

:Final Aver- Wgt. <tge Wgt. Gm. Gm. 130 130 130 128 144 144 139 140 129 130 125 125 140 I:H 136 J 27 145 135 155 141 130 123 122 116 ' 116 117 115 114 110 112 139 137 129 129 149 147 121 121 119 114 121 113 144 134 143 136 160 148

TABLE 2--(cont·inued). .Vitmgen Metabolism /Jata and the Ualcnlatio11 of bhe Rio/o,qiral Value. 1\i-Lotc l'eriuJ.

I

Metabolic Endogenous D11ily N. Daily N. App<t· Food Daily Daily Food Absor-Uri-Per_l __ l!'oo<l N He-N rent ln-NJn-Faecal Per N in bed N. 100 Per N in taim•cl. Ba-Diges- ta.ke. N. .Pe1· F'aeces. nary Urine . lance. tibi- take. Gram N. Gmm D Food. D>ty.l Wgt. ay. lity.

I

Gm. Mgm. Mgm. Mgm. Mgm. Mgm. Mgm. Mgm. Mgm. Mgm. Mgm. Mgm. Mgm. 10·2 -36·6 3·59

-

--17·2 13·2

- - -

-- 8·4 --28·8 3·43

- -

-19·6 15·3

-

--

- -

12·2 -36·0 2·9fi

-

-

-

28·8 20·0 ----

-

8·4

-

31·8 3·79 ---26·4 ]8·9 --

-

-- 7·5

-

27·2 3·63

-

--18·4 14·2

- -

-

-

- 10·3 -37·8 3·67

-

--14·8 ll-8

-

-

-

-- Wheathran Petiod (1·:)() Jit>r i'CIIf. .\ ). 13·8 215·3 49·6 3·59 49·5 0·1 215·2 70·4 13·2 17·3 53· I 162· I + 95·3 77 12·7 198·1 46·4 3·43 43·6 2·8 195·3 82·4 15·3 19·4 63·0 132·3 + 69·3 77 13·9 216·8 60·0 2·95 41·0 19·0 197·8 74·4 20·0 27·0 47·4 150·4 + 82·4 72 16·0 249·6 68·0 3·79 60·6 7·4 242·2 70·4 18·9 26·6 43·8 198·4 +lll-2 73 11· 7 182·5 44·8 3·63 42·5 2·3 180·2 72·8 14·2 17·5 55·3 142·9 + 64·9 75 10·5 163·8 38·4 3·67 38·5 -0· I 163·8 58·4 ll-8 13·7 44·7 119·1. + 67·0 77

Tn1e Diges-J3io1o- t.ibi-gica1 Va.hm. lity. --

- -

--· --- ---

I

^-

--- ----- 100 7!) !)9 68 !)1 76 97 82 100 73

---os- ---u- I

-~ ==-~

, I '"

====-= N-Lo·w Period. 9·3 -39·3 4·23

-

--17·6 150·

- I

----

I

-- 9·7 -29·0 2·99

-

--23·6 20·7 -----

- -

7·7 -26·6 3·45

-

--19·2 17·1 ------- 10·0 -36·4 3·64 ---12·4 9·1 ---

I

^-

-·-- 9·3

-

37·2 4·00 ---21·6 16·7

-

------ 10·8

-

41' 8 3·87 --

-

22·4 15·2

- -

----

-

lJollard Period (1 ·58 f1P1' r·e11f .. \'). 13·2 208·6 55·2 4·23 55·81-o-6 208·6 51·2 15·0 18·2 33·0 175·6 -/ 102·2 7+ 100 84 9·8 154·8 37·6 2·99 29·3 8·3 145·6 40·8 20·7 23·6 17·2 129·3 + 76·4 76 95 88 ll-4 180· 1 41·6 3·45 39·3 2·3 177·8 5-'i. 2 17' 1 19·3 35·9 141·9 + 83·3 77 99 80 13·0 205·4 48·0 3·64 47·3 0·7 204·6 38·2 9· 1 12·2 26·0 178·6 +119·2 77 100 87 12·2 192·8 46·4 4·00 48·8 -2·4 192·8 60·8 16·7 22·7 38·1 154·7 + 85·6 76 100 80 15·3 241 ·7 !)7' 6 3·87 59·2 -1-fi 241 ·8 62·4 15·2 22·5 39·!) 201·9 + 121·7 76 100 83 ~-99-84

Per cent- age utili- zablc Pro- tein. - - -

- -

_{-- -} - 7ii 67 69 80 68 73 -72-

-- -

- - - - 84 84 79 87

so

83 83 I ==..;;,...._ ----=,;;;.._ --·-=-

~ 0

b

a')

...

(') > t" <j ~ q t:'i UJ 0 "1 '1:1 !:::1 0

..,

t:'i

... z

f/l