10.5.2.
I N D U S T 1l I A 1, A N D E N G I N I$ E I( 1 N G C 1%E M I S 'T H Y
stimulating substances contained nitrogen, were organic, and were soluble in 80 per cent alcoliol. Further studies on the relation of the growth-proniating factors to known growth stimulants of plant oridn, on the possible importance of carbons, fitter aids, etc., as~wellas the importance of such stimulants to bacteriological fermenbation tests, arc now under invcstigation. ACKNOWLEDGMENT
A11 of the sugar samples used in this investigation wcre furnislied by the Carbohydrate Division of this bureau. The
Voi. 25, No. 9
authors appreciate the advice a.nd asvistalice given by H. S. Paine, J. A. Ambler, aiid ot.her members of the Carbohydrate Division. I>lTEllATURE
Clren
(1) Ucuareux. E. I>,, and T1~imer.F.C., 1.Bacl., 14, 317-33 (1927). (2) Fulrnor. E. 1.. Nelson. V. 13,. arid Sherrrood, F. F..J . d m . Ckem. Soe.. 43,186--91 (1921). ( 3 ) Funk. C., and Freedmun. 1... 1.B i d . ('hem., 56, X51.-80(1923). ~ t r c r ~ February vs~ 1 1 . 1933
Beating Properties of Egg White W. C. HENRYAND A. D. BAHBOUR, Ontario Research Fouridat,ion, T ~ r o i i l .Ontario, ~, Canada
1
K TUE course of an irivestigation the use of beaten egg white in a commercial candy product, it \\-as necessary to deterlninet~le effect of various conditions on volume of the heat.cii white and tiicrelativestabilityof the foam. There is litt.le iiiforniation of a q u a n t i t a t i v e character to he found in the literature and no
Mdhods huce been devised for studying lhe iricrease in c&me of egg while on beating, and the stabilily of the beaten product. The efects of rate and time of beating, temperalure, hydrogen-ion concentration., and additions of water and oil have been determined, and also the ~mmparative resulls obtairiuble ruilli ,fresh and defrosled storage white.
foam for tile lrieasurelnell~ of ,.olumeor foam St. Jolin F ] (6)~ used ~ amethocl which consisted in beating the egg white with a hand beater llntilan apparentmaximum volume was obtained, drying tho foam in an oven at 60" C. to a solid condition, breaking it into sniall pieces, and measuring the volumc approximately in a graduated cylinder. They obtained better results with the thin than with the thick white, and better results with storage than
bfwnions AND d r r a i t ~ ~ u s It was felt that ll,ucll more couid be obtained with a m e c h a n i c a l beater with speed control, in place Of the hand beater by the preceding workers. The a p p a ' a t n s used i n a l l the folloving determinations was a Sunheani Mixmaster k i t c h e n beater, manufacturett by the Chicago Flexible Shaft Company. It, was provided with a rheost.at permitting its use at four different speeds. The increasc in volume on beating the egg white was determined as follows: smd1 glass cylinders, upm at both eads, of inside dimensions shout 17 X 50 mm., were used for the determinations. The volume of these cyiinders was carefully measured, and the weight of liquid egg white which they X-ould contain was caleulrtted, assuming t,he specificgravity of the white t,o be 1.035. To determine the volume increase oi the egg white after heating, one of these tubes was pushed into the heaten ~ R B S unt,il eomplet,ely 6llui, care bein taken to exclude large sir hubbles and to leave no part, of t i e tube unfilled. The excess w m removed from the ends of the tube by scraping off with a
FIGURE 1. APPARATUS fresh eggs. They also found that contamination of the wliitcs with a trace of yolk has a detrimental efect on the beating qualities, a fact which has long been known in corniriercial practice. Peter and Bell (J), using a penetrometer method, compared tlie stability of foanls made by beating solutions of dried whey protein and of dried egg albumin. In the case of tlie ~vheyprotein they obtained increased stability by small additions of calcium hydroxide and subsequent neutralization; by successivesmall additions of acid or alkali during whipping; and hy the addition of tannic acid, saponin, sodium sulfite, or sodium disulfite. KO attempt was made by these workers to measure the beaten volume. So far as can be learned from their published results, none uf the abovc investigators attempted to determine the most satisfactory time of beating, speed of agitation, or temperature during heating, and to standardize their procedure accordingly. d i i
s
600
$
8
TOO
zoo
% ffINUTE5
TOTAL
2
nfl€Of
4
6
BLr/lT/NG
Fx~une 2. COXPAHATWEVOLUME INCKEI~E or F i i ~ s eEGGWHITEA N D DEFROSTED %OHAGE EGG W H m :
;I
Egg white:
N E li, R 1 N G
c FI E M I S 'r 1< Y
tlie resultti could be checksd froiii time to time. T h e speed giving the greatest volun~eincrease was thus 1080 r. p. m. and this speed, and the time intervals of 2,4, and I3 minutcn were adopted for all further tests.
7 10
1080
1220
2 6 5.0 7.5
12.02 11.91 12.85
2.19 2.11 2.18
447 465 488
2 4 6
12.02 11.91 12.88
1.76 1.41 1.44
741 788
1
12.M ll.Sl 12.83
1.77 1 66 1.73
675 616 641
2 3
FlGUllE
3.
Fnssw DEFHOYTEI> STOMQEEoo
C o m P A H ~ r I v lST*BlUTY ~ OF
EGG W w r ~ t i ANI)
WHITE
sharp-edged spatidit, the outside OS the tube was carefully wiped dry, iind the tube and contanis were weighed. Since the increase i n volume on beating is proportional t.o'the decrease in weight of a given volume, this incroase may be expressed ns LI percentage of the original volume as follows:
ins5
582
E OF T E M l ~ E l l a l ~ u a E Severity-five cubic centimeter samples were adjusted t.o IO", i s o , Z O O , and 25' C. and bea,ten as described above. The results at Iso, 2O", and 25" C. were within tho experimental error of t,lie niethod. The results at 10" C . appeared to be somewh-hat.lower. TIE temperature of 20" C. was adopted for subsequent experiments. A rise of temperature of about 3" C. was foiind to occur during tire bea.ting. CoM1~.4111~0hUFhESH
EGGW H I T E AND I h U L E N (uESll< Eoc WHITE
STORAGE:
111 view OS tlie results reported by Ht. John and Plor (d), the results obtained by the present method on two commercial egg white samples from different sources, which had been frozen and held in storage in this coiiditioli for a consider100 - 100 100 :( - 1) able time, were compared with $ determinations on p e r f e c t l y $, fresh eggs. At the same time, htests were made separately on the thick and thin fractions of : s ~ m n l ewas ?hen illlowed to dry alowlv at room temwrature. the fresh white. -', Whin dry, t,he material, which-was more 01' less collapsed in Fresh eggs, graded "extras" some cases, was sectioned trarisvrrsely with a razor blade, and tam^ 71nr or Brrrms, m w r m tho sections photographed to show the structure of The product by the Canadian Government F~~~~~ 4. E ~ ~OFCT~~ T and the degree to which collapse had taken place. The q u i p - standard, were broken, and or BEATING ON STABILITY OF ment used is shown in Figure 1. (Unless otherwise stated all the white carefully separated J h 4 T E N FImsH EGG W H I T E det,erminatioris were made on frozen stor%aeegg white, after froin the yolk. The further defrosting.) separation into thick and thin white was carried out on a EFFECT ON \-OLUME INClhE OP ll*:.m~(;SPEED A N D TIME g-mesh screen by thc method of IIolst and Almquist ( I ) . The proportions of thick arid thin white in the various saitiO P UEATINC ples are shown in Table 11. The results on beating are given Seventy-five cubic centimeters of the egg white were placed in k'ignrc 2. in the mixing bowl at 20" C. Tlie beaters were started while still raised out of the material: when constant speed was TABLE11. ~'I~oPORTIUN OF THICK AND THINWHITE: IN FxssH AND F n o a ~ (DEFBUBTED) ~ STORAGE EGGWIIITE attained, as tcst.ed with a tactiometer, the beaters were S*MPLE Tmca Wuirr: TaiN >v~nW lowercd siirldenly into t.he egg white arid the stop watch was started. At the end of the first time interval shown, the beatr Fieab extras ers ere stoppcd and a sarnple taken. (.The sauipling re€?roeen stursae h prosen RLoraXL I3 quired about 011e minute.) The beat.crs werc again started and the procedure repeated. Time intervals vero chosen in The results indicate that the tliiri white has considerably proportion to the speed of beating in order to give approximately maximum volume before the end of the longest inter- better initial beating properties than the thick fraction, but that the former tends to lose volume 0x1 continued beating. val. The results obtained are shown in Table 1. Duplicate runs The properties of the mixed fresh white are intermediate were matlc at 1220 T. p. m. in order to determine how closely between the two, as would be expected, wliile the mixed de-
-
' ~
1056
INDUSTRIAL
AND ENGINEERING CHEMISTRY
frosted storage whites give results which are much inferior to the mixed fresh white. On these samples, stability tests were made by the method already described. The photographed sections of the dried cylinders of beaten white are shown in Figure 3. It is evident that the beaten fresh white is much less stable than the storage white, and that the stability becomes less and less with continued beating.
Vol. 25, No. 9
It is apparent that mixtures of water and egg white, containing up to 40 per cent of water by volume, show volume increases on beating equal to the volume increase of undiluted egg white. The stability of the beaten mixtures is also nearly as great as for the undiluted white, as is shown by Figure 7, although the structure of the water-containing samples appears, in general, to be more porous. With the samples containing 60 and 80 per cent of water by volume, watery liquid ran out of the beaten samples on standing, before drying took place, and there was a decided tendency for the structure to break down with continued beating. The increases in volume obtained, when calculated on the basis of the actual egg white content of the samples, show a tremendous increase with increasing amounts of water in the mixture up to 80 per cent. EFFECTOF ADDITIONS OF OIL
As it is generally supposed that the presence of traces of oil has a detrimental effect on the beating properties of egg white, this was tested experimentally. Amounts of refined cottonseed oil varying from 0.01 to 1.00 per cent by volume were added to egg white samples before beating; the results are shown in Figure 8.
Iy//YurEs 2 4 6 TOTAL nME O f B€A7/NG FIGURE5. EFFECTOF FREEZING AND DEFROSTING ON VOLUME IIVCREASEOF FRESHEGGWHITE
This effect of beating time on the stability of the beaten fresh white was checked by a penetrometer method similar to that used by Peter and Bell ( 5 ) , with the results shown in Figure 4. These correspond well with the indications of the photographic method. COMPARISON OF FRESH EGGWHITEAND THE SAMEMATERIAL FROZEN FOR VARIOUS LENGTHS OF TIME The volume increase on beating was determined on a sample of a large quantity of egg white separated from fresh % 20 40 60 80 extras. The remainder of the material was frozen solid a t -3' C. and held in this condition. Small samples were TEA IN flit W e € removed after 5 hours, 3 days, and 1 month, and the volume EFFECT OF ADDITIONS OF WATER FIGURE 6. increase on beating determined a t 20" C., after defrosting. ON VOLUME INCREASE The results are shown in Figure 5 . It is evident that freezing and frozen storage exerts a negligible effect on the beating The effect of adding oil to the mixture is to reduce the properties over the period of the test. The changes in the beaten volume, and the reduction in volume is directly frozen product which affect the beating quality must acproportional to the percentage of oil added, within the excordingly be very slow. permental error of the method. The tendency for the structure to break down on continued beating also increases in EFFECT OF ADDITIONS OF WATER It has long been a popular belief among housewives that proportion to the amount of oil added. The stability of the beaten product is apparently unthe addition of a small quantity of water to egg white has affected by additions of oil up to 0.2 per cent. There is a the effect of improving its beating properties. It has already been noted that the beaten volume of thin white is definite breakdown with 0.5 per cent, and with 1 per cent greater than that of thick white, although Holst and Alm- of oil the structure breaks down completely on standing. quist (1) find that the thick and thin fractions have the EFFECT OF HYDROGEN-ION CONCENTRATION same content of total solids. These tests were carried out using fresh egg white, with Mixtures of egg white with water in various proportions, from 98:2 to 20:80, were beaten and the volume increase the normal equilibrium pH of 9.37. The samples were determined. This has been calculated in two ways: (1) prepared by diluting varying amounts of standard sulfuric as the increase in volume over the volume of liquid beaten, acid and sodium hydroxide solutions to exactly 5 cc. and by and (2) as the increase in volume over the actual volume of adding 70 cc. of egg white, 5 cc. of distilled water and 70 cc. egg white in the mixture. The results appear in Figures of egg white were used as the control, In the case where the largest amount of acid was added (resulting in a p H of 6 and 7.
w!
I N D U S T R I A L A N D E N G I N E E R I N G C 1%E M IS T R Y
Srpt,ember. 1933
5.47), a slight precipitate \
