See X. F ertilisers.—See XVI
X VIII.— FERMENTATION INDUSTRIES
Constituents of dried y ea st and yeast extracts.
Application in hum an nutrition. S. G. W i l l i m o t t
and F. W o k e s (Lancet, 1928, 2 1 5 , 668—673).—Any deficiency of vitam in-5 in white flour can be remedied by the correct addition of dried yeast. About 80% of the vitam in-5 content of fresh yeast can be extracted by heating at 98° with a saline solution for several hours.
The addition of dried yeast to bread is recommended, an amount equivalent to 2— 4% of the flour being sufficient to furnish more vitam in-5 than is present in whole-wheat flour. Potato starch may contain suffi
cient vitam in-5 to vitiate an a ssa y ; rice starch appears
to be free from this contamination. D ata of the per
centage composition and vitam in-5 content of various yeast products are tabulated. L. S. T h e o b a l d .
Ferm entation of rice straw b y B . a c e to e th y lic u s.
V. N. P a t w a r d h a n (J. Indian Chem. Soc., 1930,7 , 531—
536).—The yields of reducing sugar obtained by hydro
lysis of Bangalore rice straw are proportionately in
creased by increase of the concentration of the sulphuric acid used from 2% up to a t least 6%, these results being a t variance with those of Thaysen (“ Fuel for Motor Transport,” H.M. Stationery Office, 1927) for Burma rice straw. 5 . acetoethylicus may be trained to ferment pentoses (such as are obtained by processes similar to the above) a t concentrations up to 7%, but the yields of alcohol and acetone, which are somewhat variable (cf. Thaysen and Galloway, B., 1929, 272), generally decrease continuously as the concentrations of sugar are increased above 3%. Change of the nutrient mixture from ammonium phosphate and peptone to.
combinations of ammonium nitrate, disodium hydrogen phosphate, and yeast water does not materially affect the yields. The presence of small quantities of hexoses, e.g., dextrose, facilitates the growth of the bacterium and ferm entation of the pentoses. H. A. P i g g o t t .
E xtractives of w h iskey. W. P a r t r i d g e (Analyst, 1931, 5 6 , 177—178).—Of 44 samples examined, the total solids of 29 exceeded 0-15% wt./vol. (the lim it usually mentioned in the literature), 4 samples of which gave 0-41—0-53%. Sherry appears to be a safe and profit
able adulterant. T . M c L a c h l a n .
T reatm ent of w ine w ith ozonised air. P. M a r s a i s
(Rev. Viticult., 1930, 73, 311—314; Chem. Zentr., 1931, i, 375).—The alcohol, volatile acid, and non
volatile acid content was scarcely affected ; the sulphur dioxide diminished. White wine gave a tannin-iron precipitate. The effect of the treatm ent on the taste is described. A. A. E l d r i d g e .
Addition of am m oniu m sa lts to vinegar. C. A.
M i t c h e l l (Analyst, 1931, 5 6 , 178—179).—These salts are added to spurious vinegars to give the nitrogen figure obtained from a normal m alt vinegar. Less than one tenth of the total nitrogen should be present as ammoni- acal nitrogen, whilst one fifth to one tenth, should be precipitable on saturation with zinc sulphate.
T. McLa c h l a n.
Sterilisation of en zy m es. F erm ents in honey.—
See XIX.
See also A., April, 522, Selective ferm entation of dextrose-laevulose m ixtu res. R ole of iron and copper in grow th and m etab olism of yeast.
Pa t e n t.
W ater-soluble vitam in .—See XIX.
X IX .— FOOD S.
Sterilisation of flour and of en zy m es in pow der form . A. J. J. V a n d e V e l d e (Bull. Acad. roy. Belg., 1930, [v], 1 6 , 585—591).—The carbon disulphide trea t
m ent previously developed for the sterilisation of flour (cf. B., 1910, 1129) has been applied to amylase and
512
B r i t i s h C h e m ic a l A b s t r a c t s — B .
C l. X IX .—Fo o d s.
pepsinase. By treating with pure carbon disulphide in P etri dishes at ordinary temperatures and subsequently removing the last traces by a current of dry sterile air, the enzymes were obtained in a sterile form without alteration to their hydrolytic powers. II. J. D o w d e n .
D eterm ination of starch in flour by d iastase- acid hydrolysis. B. 6. H a r t m a n n and F. H i l l i g
(J. Assoc. Off. Agric. Chem., 1931, 14, 112—116).—
Modifications have been made in the official A.O.A.C.
diastase-acid hydrolysis method (cf. B., 1927, 90).
Sugar and fat are extracted by solvents, followed by centrifuging; the residue is subm itted to pepsin diges
tion in acid solution. I t is neutralised, treated with m alt extract for 20 min. a t 65°, and then hydrolysed with hydrochloric acid ; the sugar is determined in the normal maimer. E. B. H u g h e s .
Baking quality of w heat. F. S c h n e l l e (Pflanzen- bau, 1929, 1, 471—555; Chem. Zentr., 1931, i, 377).—
Comparative tests with 33 varieties were made, the results being correlated with the season, time of ripening, geographical source, and nitrogen content.
A. A. E l d r i d g e .
Role of m ilk constituents in breadm aking. L. A.
A l l e n and J. B e l l (J. Roy. Tech. Coll., Glasgow, 1931,
2 , 550—563).—Experiments were made on the use of
separated milk, dried and separated milk, whey, and albumin-free whey in bread dough (4 lb. of strong spring and 1-25 lb. of soft winter wheat flours, sugar 0-5 o z .;
lard 0-5 oz., salt 1-5 oz., yeast 2 oz., water 1500 c.c.).
The increase in volume during fermentation was stimu
lated by albumin-free whey, bu t was slightly depressed by separated milk, and to a greater extent by whey.
The theory th a t albumin is a determining and adverse factor in volume increase was confirmed from the depressant effect obtained on addition of a suspension of egg-albumin to an albumin-free control dough, and from the appreciable increase in volume obtained if the albumin was coagulated by boiling the milk under reflux for 15 min. before mixing. Dried (pressure-spray system) separated milk lowers the loaf volume, unless i t has been preheated, when the effect is largely counter
balanced ; lactose or rennin has no influence, but small amounts of lactic acid effect an improvement. Whey, boiled whey, and albumin-free whey increase, and raw or boiled separated milk decrease, the rate of gas evolution. This may be explained in terms of a balance between the stimulating effects of phosphates and the inhibitory effects of albumin (vide infra) and of casein.
In all cases the colour, texture, and flavour of the final loaf were improved by addition of whole milk, separated milk, or whey, the first being superior in this respect.
The increase in volume of fermenting dough is best measured by placing the standard whisked dough (strong spring wheat flour 225 g., yeast 22-5 g., salt 9 g., water 250 c.c.) in graduated cylinders immersed in
water a t 29°. J. G r a n t .
Direct determ ination of available carbon dioxide in baking powder. M. R. Coe (J. Assoc. Off. Agric.
Chem., 1931, 1 4 , 99—101).—The A.O.A.C. gasometric method (ibid., 1923, 6, 453) is modified to give a direct determination of the available carbon' dioxide by using a 5% solution of ammonium sulphate as the reacting
liquid, heating the reaction flask to boiling to evolve all gas, and then cooling it to room temperature.
E . B . Hu g h e s.
D ispersoid-chem ical study of m ilk . III. Separa
tion of cream . A. S c h n e c k [with E. M u t h ] (Milchwirt.
Forsch., 1930, 10, 1—29 ; Chem. Zentr., 1930, ii, 1154;
cf. A., 1930, 1204).—The mechanism of the process is discussed. The speed diminishes a t first quickly and then slowly ; it is unaffected by movement of the milk, and hence by agglomeration of the fat. The separability of milk heated a t 61° is greater than th a t of unheated milk ; the effect of various temperatures was examined.
A. A. E l d r i d g e .
S m all-sca le research on spray-drying of m ilk.
A. W. S c o t t (J. Roy. Tech. Coll., Glasgow, 1931, 2, 456—460).—The engineering problems associated with spray-drying of milk are briefly reviewed, and a detailed description is given of an experimental plant. The principal feature is the low-pressure atomiser in which the milk under a pressure of about 4 lb./in.2 issues vertically upwards from a nozzle 0-005 in. in diam. in an annular chamber, while air a t 4—6 lb./in.2 is directed by means of a curved cap so as to impinge tangentially on the issuing jet. The atomised milk meets a down
ward stream of hot air in a chamber of tinned sheeting, and passes out a t the bottom through filter-bags which collect the milk, recondensation of water vapour being avoided by ensuring an outlet temperature of a t least 55°. Separated milk gave a fine powder with an average solubility of 99-5%. J. G r a n t .
D eterm ination of m ilk proteins. III. Proposed m odified m ethod for casein. G. M. Mo ir (Analyst, 1931, 5 6 , 147—149; cf. B „ 1931, 413).—The casein is precipitated from warm diluted milk a t p ^ 4-6 by the successive addition of acetic acid and sodium acetate, filtered, and the nitrogen determined by the Kjeldahl method. The result is returned as casein-nitrogen on account of uncertainty of the structure of the protein
molecule. T. M c L a c h l a n .
D eterm ination of the f.p. of m ilk . A. H e i d u s c h k a
and A. K e r n (Milchwirt. Forsch., 1930, 1 0 , 165—172;
Chem. Zentr., 1930, ii, 1153).—Requirements for unan
im ity are discussed. Watering of milk is more T e a d ily
detected by means of the f.p. than by means of the density of the serum. A. A. E l d r i d g e .
Surface tension of m ilk . W. M o h r and C. B r o c k - j i a n n (Milchwirt. Forsch., 1930, 1 0 , 72—96; Chem.
Zentr., 1930, ii, 1153).—Semi-dynamic (drop method) values are always higher than, bu t generally parallel with, static values; the surface tension falls with increasing fat content, owing to concentration of capil
lary active substances a t the fat globules. The depres
sion differs for solid and liquid fats. Structural pheno
mena and film formation account for anomalies with skim milk. Pasteurisation, boiling, sterilising, ageing, freezing, and addition of formaldehyde are practically without effect on the surface tension. Increased air content increases and souring diminishes the value.
A. A. E l d r i d g e .
Indications of dextrose in m ilk . C. H . W h i t n a h
(J. Amer. Chem. Soc., 1931, 5 3 , 300—304).—Small amounts of dextrose in milk are determined by clarifying
B ritish C h e m ic a l A b s t r a c t s — B .
C l. X IX .—Fo o d s. 513
the milk with mercuric nitrate, measuring the rotatory power of the solution, removing the dextrose by fer
mentation with yeast, and again measuring the rotatory power. Application of the method to normal milk indicates the presence of 0—O'35% of dextrose.
H . Bu r t o n.
M icroscopical exam ination of m ilk for tubercle bacilli. D. R. W o o d (Analyst, 1931, 5 6 , 1 7 9—180).—
From a simple calculation it is shown that, without concentration, the test is about 500 times less sensitive than the biological test, and is limited to the detection of not less than 10—500 per c.c., or, in the case of milks with less than 2-5 c.c. deposit per 100 c.c., 10—50 bacilli
per c.c. T . McLa c h l a n.
Vitam in content of m argarine. K. H. Co w a r d
(Lancet, 1928, 215, 726—727).—Data, showing the vita
min content of “ Viking,” “ Silver Tray,” “ Welcome,”
and “ Gold-Chain ” margarine are recorded. The margarines are equal to best summer butter in their vitamin-A and -D contents and show more constant values than the latter. The vitamin-2) content averaged 1'25 units per g. L. S. Th e o b a l d.
Vitam in-C content of com m ercially canned sauerkraut ; observations on its v ita m in -/! con
tent. B. Cl o w, H. T. Pa r s o n s, and I. St e v e n s o n
(J. Agric. Res., 1930, 41, 51—64).—The vitamin-C content of six commercial brands of sauerkraut varied within wide limits, protection against scurvy of guinea- pigs being afforded a t levels of 2 |, 5, 7 | g. and over of the various makes. A satisfactory technique for the determination of vitam in-/! was not achieved.
E . Ho l m e s.
Use of acetaldehyde in th e storage of fruit.
S. A. Tr o u t and R. G. To m k i n s (J. Counc. Sci. Ind.
Res., Australia, 1931, 4, 6—11).—The sound condition of stored fruit may be prolonged in an atmosphere containing small proportions (1 in 250—1000 vols.) of acetaldehyde. The margin of safety between con
centrations necessary to prevent mould growth and those causing injury to fruit are small. Dipping the fruit in solutions of acetaldehyde was unsuccessful.
A. G. Po l l a r d.
Corrosion b y fruit preserves. H. Se r g e r (Kon- serven-Ind., 1930, 17, 621—622 ; Chem. Zentr., 1931, i, 540).—The P.D. (b) a t 22° between a tantalum dish containing an infusion of the fruit and a zinc plate, and that (a) using 0 • 12V-oxalic acid are measured ; then d = 106/a. Values of d, the corrosiveness, ranged from 3-93 to 14-43. A. A. El d r i d g e.
Determ ination of pectins. A. Me h l i t z(Konserven- Ind., 1930,17, 624—626, 640—645, 654—657, 671—673 ; Chem. Zentr., 1931,. i, 378).—In the determination of methoxyl by Zeisel’s method the error is 2;5% , by Fellenberg’s method 2-8% , and by a simplification of the latter 4-6% . F or LiieTS and LochmulleT’s breaking test the error is 10%. Fiedler’s method a t 3 • 0 and nearly equal pectin concentration gives reproducible values.
The ash, as well as the methoxyl, content should be determined. The am ount of calcium pectate in the precipitate obtained with alcohol characterises the origin (apple 60—70%, citrus 90—95%). In Liiers and
Loclimiiller’s tension test mercury is used instead of
shot. A. A. El d r i d g e.
B ehaviour of th e diastatic ferm ents in honey on heating. H . W. d e Bo e r (Chem. Weekblad, 1930, 27, 646—648).—No destruction of the ferments is observed below 60°. The number falls by one unit for every 7 hrs.5 heating at 65°, for every 4—5 hrs. a t 70°, for every 2—2£ hrs. a t 75°, for every 10 min. a t 80°, and for every 45 sec. a t 95°. The rate of fall diminishes with time, the last traces disappearing only slowly. S. I. Le v y.
Colour of m eat. A. A. Be n e d i c t (Proc. Iowa Acad.
Sci., 1929, 3 6 , 301—302).—Change in the colour of meat is prevented by placing the sample between glass plates immediately after cutting. The intensities of the light diffusely reflected from various cuts were compared spectrophotometrically in the region 500—700 mjx.
Ch e m i c a l Ab s t r a c t s.
R em oval of the astringent taste of coffee by treatm ent of the raw beans with ozone in vacuo.
H . Jo r d t (Chem.-Ztg., 1931, 55, 161).—The raw beans are placed in a chamber which is evacuated to 10 mm., and ozonised air saturated with moisture is then intro
duced until the inner and outer pressures are the same.
In this way the ozone is able to penetrate through the cellular tissue to the interior of the b ea n s; a pretTeat- ment with a suitable solvent to remove the external wax layer is also advantageous. After several hours’
treatm ent the beans are removed from the chamber and roasted as usual. F . R. En n o s.
Parchm ent packing.—See V. Solubilities of m etals in m ilk .—See X. D eterm ination of fat.
Indian ghee.—See X II. Anthocyan [in cereals].—
See XVI. R ye m eal in flour.—See XVII. Dried yeast etc.—See XVIII.
See also A., April, 498, T rigonelline [from coffee beans], 508, D eterm ination of sterol and ergo- sterol in co w ’s m ilk . 529—531, V itam ins. 531, Antiscorbutic potency of apples. 537, Proteins of Indian foodstuffs.
Pa t e n t s.
Treatm ent of cereal flour or dough. Br i t. Ar k a d y Co., Lt d., and H . He w i t t (B.P. 342,697 and 343,677, [a] 2.11.29, [b] 7.1.30).—(a) Leguminous flour is added to the dough in the proportion of 2% or less of the wheat flour, and the exposure of the dough to the air during mixing causes subsequent bleaching.
Persulphates, bromates, iodates, or organic peroxides may be added, (b) The leguminous flour is added as an extract prepared by soaking in water, filtering, and concentrating the filtrate in vacuo a t 50°.
E . B. Hu g h e s.
Preparation of bread. G. Ch a u d e t ( B .P . 342,657, 29.10.29. Switz., 10.6.29).—A solution of iron and calcium bicarbonates, calcium and sodium chlorides, magnesia, and lactic acid in mineral water is added to the dough to replace the yeast wholly or in part.
H . Ro y a l- Da w s o n.
Baking powder. A. H . Fi s k e, Assr. to Ru m f o r d Ch e m. Wo r k s (U.S.P. 1,775,037, 2.9.30. Appl., 2.3.28).
—Improvers, of the type used in flour for bread-making,
B r i t i s h C h e m ic a l A b s t r a c t s — B .
C l. X X .— Me d i c i n a l Su b s t a n c e s ; Es s e n t i a l Oi l s.
including persulpliates, perborates, and peroxides, are added to baking powder and the proportion of tbe acidic reagent is increased so as to leave a neutral residue after reaction is complete. E. B. Hu g h e s.
E lectrotherm al treatm ent of cheese. C. H.
Pa r s o n s and W. D. Ri c h a r d s o n, Assrs. to Sw i f t & Co.
( U .S .P . 1,774,610, 2.9.30. A ppl, 29.6.27).—Emulsified cheese is pasteurised by forcing the product between suitably arranged electrodes in a cylindrical vessel. I t is claimed th a t uniform heating is thus obtained.
E. B. Hu g h e s.
Manufacture or treatm ent of coffee. W. E.
C l i f t o n (B.P. 3 4 2 ,7 7 8 , 8 . 1 1 . 2 9 ) .—The sealing of the volatile constituents and essential oils of coffee is achieved by grinding the beans in an edible, water- soluble, viscous liquid (e.g., sugar solutions, condensed milk). An apparatus is described. E. B. Hughes.
Concentrating the w ater-soluble vitam in of a m aterial containing such vitam in. A . B. 0 . No r r-
b i n, and Ak t i e b. As t r a Ap o t e k a r n a s Ke m is k a Fab e.
(B.P. 343,086, 13.11.29).—In a dilute acid extract of a vitamin-containing material, e.g., yeast, is dissolved at least one substance which, on neutralisation of the solution, forms a compound which is precipitated, carrying the vitamin with it. E.g., calcium carbonate is dissolved in a dilute acetic acid extract of yeast and a'f'-sugar is added to the solution. On neutralisation with alkali, the sugar-calcium compound is precipi
tated ; this is separated and stirred with sufficient dilute sulphuric acid to transform all the calcium into calcium sulphate. Alcohol is then added to the mixture and the dilute alcoholic extract is separated and concentrated to'give an emulsion which contains the vitamin.
E. H. Sharples. Freezing of food products. A. E. W hite. From
Fr o s t e d Fo o d sC o ., I n c . ( B . P . 3 4 5 , 6 1 8 , 1 8 . 1 2 . 2 9 ) .
Preparing anim al m eats for the m arket. W. W.
Tr i g g s. From Sw i f t& Co. (B.P. 345,328—9, 16.12.29).
N itrosylsulphuric acid .—See VII. N itrogenous substances.—See XVI. V itam in-D ,—See XX.