A n alyses of potable sp irits m ade from w ine and from vin asse, and of raw and rectified spirit.
F. Pir a n i (Annali Chim. Appl., 1927, 17, 176—187).—
Results are given of determinations (1) of the usual components in 190 samples of brandy made from Italian wine and vinasse, and (2) of the proportions of methyl alcohol in 17 samples of rectified spirits from wine and vinasse. In the determination of the acidity, use is made, not of phenolphthalein, bu t of tincture of litmus (cf. Barbet, Proc. V lth Internat. Congress Appl. Chem., 5, 645), the solubility being increased by diluting the spirit with boiled distilled water. In determining the esters, it is essential to effect the saponification with calcium saccharate (Barbet, loc. cil., 648), which does not resinify the aldehydes, since otherwise the coloration developed obscures the colour change of the indicator.
Even when kept away from the air, calcium saccharate solutions vary in titre, so th a t a blank test is necessary : 25 c.c. of the spirit are boiled for 2 hrs. in a reflux apparatus with 50 c.c. of about 0 • liV-calcium ¡saccharate solution, the quantity of 0-liV-sulphuric acid required to neutralise such 50 c.c. being added immediately after the boiling, and the excess of acid then measured by titration with 0-liV-alkali. Deniges’ colorimetric deter
mination of the formic acid produced on oxidation of the methyl alcohol present seems the best adapted for determining the methyl alcohol in spirits ; the test is best made on 1 c.c. of the liquid, and the comparison tube should have the same alcoholic strength as th a t tested. Alcohol from the distillation of wine never contains more than 0-35 vol. of methyl alcohol per 100 vols. of anhydrous ethyl alcohol, whereas with vinasse spirit up to 4 vols. are found. In rectified spirits from wine and vinasse, the proportions are trace—-0-25 and 0-54—1-90 respectively. T. H. Po p e.
T otal iron content of w in es. J. H. Fa r bre and E. Bbemond(Ann. Falsif., 1927,20, 213—217).—Ferrous salts are always present to the extent of about 10—14 mg./litre in wine manufactured from grapes pressed by treading and fermented and matured in wooden and glass vessels. An abnormally high iron content may produce ferric tanuate, which im parts a bitter taste and a blue-black tin t to the wine, rendering it unsaleable.
B r itis h C h em ica l A b s tr a c ts — JB.
Cl. X I X —Fo o d s. (501
Tt is shown th a t dressing the vines with ferrous or ferric sulphate does not affect the iron content of the resultant wine. Wines from machine-pressed grapes, and which were fermented in ferro-concrete vats, were found to contain as much as 60 mg. of iron per litre and exhibited the “ iron complaint ” to a marked degree. The conclu
sion is drawn th a t the sulphur dioxide added to the wine during fermentation attacks the cast iron door fittings and the iron reinforcements of the walls of vats, by permeating the cement facings. The amount of iron thus introduced into the wine is sufficient to cause the spoiling of the wine. This could be avoided by the use of copper or enamelled fittings and glass storage vessels.
H . J . Dow den. Influence of p otassium hydrogen tartrate and of tartaric and m alic acids on th e precipitation of protein su bstan ces, in relation to th e defecation and clarification of m u sts. E . Er iu ciielli (Annali Chim. Appl., 1927, 17, 221—244).—The coagulation of proteins in presence of sufficient tannin to precipitate them is favoured by addition of tartaric acid up to about 0-005% , but hindered by larger proportions, 0 ’015% of the acid completely preventing precipitation. Malic acid and potassium hydrogen tartrate exert a similar influence. The bearings of these observations on the defecation of grape m ust and on the clarification of wine
are discussed. T. II. Po pe.
Presence and detection of furfuraldehyde in vinegar. L . H . La m p it t, E . B. Hu g h es, and L. H . Trace (Analyst, 1927, 52, 260—265).—Vinegar gives rise to furfuraldehyde on heating a t 80°, and in com
mercial distillation the amount of distillate increases as the process proceeds, and a t the same time there is a reduction in the pentosan content. Furfuraldehyde may be determined in light-coloured vinegars by Youngburg and Pucher’s method (cf. B., 1924, 1028), but for dark vinegars 6 c.c. of redistilled aniline are dissolved in 24 c.c. of glacial acetic acid and made up to 60 c.c. with pure amyl alcohol. To 10 c.c. of this mixture 20 o.c. of the vinegar are added, shaken, and allowed to remain in the dark for 15 min. The amyl alcohol which separates is deep red in colour if furfuraldehyde is present, 0 • 1 pt.
of furfuraldehyde in a million being thus detectable.
D . 6 . He w e r. Effect of pre-treatm ent on the properties of top- y east and b ottom -yeast. H. Fin k and H. von Euler
(Z. physiol. Chem., 1927, 163, 193—201 ; cf. von Euler, Fink, and Nilsson, A., 1926, 1176).—The removability of the co-enzymes in dry yeast preparations by lixiviation depends on the conditions of growth, especially on the composition of the nutrient material used. If bottom- yeast is cultivated in liquor containing sucrose, the co-enzymes can no longer be removed by washing ; the same condition results in top-yeast grown in beer-wort.
The capacity to hydrolyse raffinose is shown, on the other hand, to be independent of the conditions of growth or of the nutrim ent used, and does not run parallel with the removability of the co-enzymes by washing. Only after prolonged intensive culture is a top-yeast able to hydrolyse raffinose, and this is the result of much more profound change than the solubilising or insolubilising of the co-enzymes. C. Ho l l in s.
R um anian alcohol. Za ha riaand Motzoc.—See XX.
Paten ts.
Manufacture of yeast. J. We b e r, Assee. of H. Claas- SEN (E.P. 264,795, 1.11.26. Conv., 21.1.26. Addn. to E.P. 230,098 ; B., 1925, 897).—Ammonium salts are added to a portion of the nutritive solution containing organic nitrogen, and the yeast fermentation is carried on until the greater portion of the inorganic nitrogen has been absorbed. The resulting yeast crop, with or with
out separation from the liquid medium, is then added to the remaining quantity of the original nutritive
solution. C. Rank en.
Vitam in preparation (U.S.P. 1,624,154).—See XIX.
XIX.—FOODS.
Com parison of som e physical and chem ical tests for determ ining the quality of gluten in w heat and flour. D. A. Colem an, H. B. Dix o n, and H. C.
Fellow s (J. Agric. Res., 1927, 34, 241—264).—A study of the results obtained by several methods in use for determining gluten quality, and comparison of these with the baking data on the same samples of flour.
The highest coefficient of correlation with baking strength, as shown by the loaf volume and crumb texture, was given by the crude protein content. Next in order ranked the washed gluten test, the viscosity determination of one concentration of flour and water, the kernel texture of the wheat, and the water-absorbing power of the flour. Determinations of the quality angle b (cf. Sharp and Gortner ; B., 1924, 29), and of the vis
cosities of flour suspensions containing the same amount of protein were of no value as a measure of gluten quality, but the lack of agreement between these and the volume of the loaf was probably due in part to variations in baking procedure. F . R. Ennos.
Rapid determ ination of the [w eight of] dry gluten. Marion (Ann. Falsif., 1927, 20, 210—213).—
The dry weight of gluten is determined by introducing a known weight (w) of the moist material into a small, wide-mouthed, stoppered bottle of known volume (F), and measuring the volume of water (E) now required to fill the bottle. The dry weight (IF) is then given by the equation: W — w — 0-72 (V — E). The figure 0-72 is an empirical factor derived from the observation th a t the volume of moist gluten is 3-56 times th a t of the dry
material. H. J. Dow den.
B iochem ical m ethod for detecting watering of m ilk . G. Rim in i (Annali Chim. Appl., 1927, 17, 214—
220).—The following test appears to indicate infallibly the addition of 10% or more of water to goat’s or cow’s milk. The milk is boiled for some minutes and allowed to cool to 50°, 50 c.c. being then introduced into a wide
mouthed phial, into which 1 c.c. of well-shaken, cold, acidified milk (yoghurt) is next pipetted. The vessel is closed with a ground stopper, thoroughly shaken for a few seconds, and immersed in a bath kept at 40—45"
so th a t the surface of the milk is just beneath th a t of the bath. If the milk is genuine, a compact coagulum forms without separation of serum ; if, however, 10%
of water had been added to the milk, the coagulum obtained is soft and a shallow layer of whey ajipea
B ritish C hem ical A b s tra c ts— B .
502 C l. X IX .—Fo o d s.
The time required for coagulation varies with the pro
portion of added water. Observation of the tube should commence 90 mill, after addition of the acidifying organism, the tube being withdrawn from the bath and slightly inclined, being carefully replaced if the milk is still liquid. Further observations are made a t intervals of 10 min., and when coagulation is noted, the tube is allowed to cool to room temperature and examined.
Coagulation occurs rather more rapidly in watered than in genuine milk. Milk sold as “ sterilised fresh milk ” answers to this test, giving a compact coagulum with
out separated serum, but the resulting product exhibits no acid taste, so th a t in this case the coagulation is effected by the casease without the help of lactic acid.
T. H . Po p e. U se o f lim e in butter m ak ing. 0 . R. O v e rm a n (Ind. Eng. Chem., 1927, 19, 571—573).—B utter made from cream of high acidity develops an unpleasant flavour on keeping, and on pasteurising such cream the casein is coagulated. The use of such substances as sodium carbonate or bicarbonate to neutralise the acidity is convenient, and the carbon dioxide evolved is said to remove undesirable flavours and odours, but a soapy taste is imparted to the butter. Calcium carbonate is unsuit
able owing to its insolubility, but in the United States the use of dry hydrated lime is extensive. I t is applied as a suspension of 2 lb. of hydrated lime in 1 gal. of water, the cream being violently agitated and the lime water introduced as a fine spray. The acidity is reduced to about 0-3% and not below 0-2% , titrations being made with 0 • 1 JV-sodium hydroxide and phenolphthalein.
W. G. Ca r ey. Apple juice i n “ pure fruit ’’ j a m s . C. F. M u t t e l e t (Ann. Falsif., 1927, 20, 208—210).—The detection by microscopical methods of the illegal addition of apples to so-called “ pure fruit ” jams, has been evaded by using filtered apple juice. I t is shown th a t such addition can be proved, either by the presence of malic acid (cf. B., 1922, 726 a), or by the relative proportions of lamilose and dextrose present (cf. B., 1927, 122). In apple juice, lsevulose always predominates, whilst in other fruits used for making jams the dextrose content either equals or exceeds th a t of IsBvulose. Application of the second method to the investigation of oranges and mandarins has shown th a t in 100 c.c. of juice, the dextrose exceeds the lsevulose by 0-08—0-5 g. according to the variety.
Home-made marmalade showed a dextrose excess of 3%, but two commercial samples containing, respectively, 1-75% and 2 '25% excess of leevulose had clearly been adulterated with apple juice. H. J. Dow d en.
Occurrence of g la ss fragm ents in foods packed in g la ss containers. G. C. Hancock (Rep. Public Health and Medical Subjects, 1927, No. 37. 36 pp.).—The evidence accumulated shows th a t the occurrence of glass fragments of considerable size is rare, but not unknown.
The source of such fragments may be in the manufacture of the container itself, especially in the case of hand
made bottles, or in the filling of the container with food.
Glass particles of microscopic size are of frequent occurrence, but they are not necessarily caused by the containers, the dust in the air having been proved to be a fruitful source of such impurities. Glass particles
may be distinguished from sand or other mineral m atter by their appearance in polarised light. Under the polaris
ing microscope with crossed nicols, glass particles are invisible, whilst crystalline particles appear bright on a dark field and often show interference colours. Amor
phous quartz etc. has a mottled appearance.
H. J. Do w d en. D eterm ination of benzoic acid in foodstuffs.
G. W. M o n ier-W illiams (Rep. Public Health and Medical Subjects, 1927, No. 39. 57 pp.).—Methods for the determination of benzoic acid fall into two classes, («■) extraction by solvents and (b) steam distillation.
To avoid the formation of emulsions in the extraction method, it is necessary to remove proteins by precipi
tation with acetic or phosphotungstic acids, or mercuric nitrate. The coagulum is liable to retain some benzoic acid. The precipitation may be performed by a saturated solution of sodium chloride, bu t in this case owing to the low solubility of benzoic acid in strong salt solution (0-08% in the saturated solution), free benzoic acid may be precipitated. Removal of proteins may also be effected by prolonged boiling with caustic alkali or hydrochloric acid. Benzoic acid may be extracted from materials containing fats by shaking with a weak solution of sodium bicarbonate, bu t if the fat is present in large quantities it should first be removed before extracting the benzoic acid. In methods of the second class it is established that, in the presence of saturated sodium chloride solution, benzoic acid is completely volatile in steam. Whether obtained by extraction or distillation, the benzoic acid is always impure and m ust be purified by washing with water, by oxidation with alkaline permanganate, by sublimation, or by precipi
tation of metallic benzoates, but each of these processes has its limitations. The most sensitive test for benzoic acid is th a t proposed by Mohler (cf. B., 1890, 770).
The buff-coloured precipitate produced by addition of ferric salts to neutral solutions of benzoates is very delicate, as is also Jonescu’s test (cf. B., 1909, 670).
The method recommended by the author for the determination of benzoic acid consists in distilling the material in steam after saturation with sodium chloride and adding phosphoric acid. The distillate is evaporated to small bulk and impurities are oxidised by treatm ent with alkaline permanganate. The acid is then extracted by a m ixture of equal volumes of m ethylated ether and light petroleum (b.p. 30—50°), after first saturating with sodium chloride. The extract is drawn over into specially-arranged test-tubes, and the solvent removed by aspirating air. The crude solid benzoic acid is purified by mixing with pure sand and subliming in a special oven a t about 160°, a layer of filter paper preventing contamination of the sublimate by the sand. After cutting off the lower end of the tube containing the sand, the sublimate is weighed
in situ. H . J. D o w d e n .
D eterm ination of sulphur d ioxid e in dried fruit.
P. May (Analyst, 1927, 52, 271—273).—100—200 g. of a fruit of the class in which 2000 pts. of sulphur dioxide per million are allowed, or 40 g. of moister fruits in which 750 pts. per million are allowed, are weighed into a flask containing 25 g. of marble and connected by a
B r itis 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. 5 0 3
splash-head to a condenser with its adapter dipping into 100 c.c. of saturated bromine water. 25 c.c. of concentrated hydrochloric acid diluted to 300 c.c. are added to the contents of the flask, and, after the evolution of carbon dioxide has slackened, the flask is heated until all the gas has been evolved, after which 200 c.c.
are distilled over. The distillate is then evaporated to about 120 c.c. and the barium sulphate precipitated and weighed. Eesults were consistent, and likely sources of error tend to give low results. A considerable number of tests with unsulphured fruits gave consistent
zero results. D. G. He w e r.
Form ation of hydrocyanic acid from linseed m eal, and its dependence on the hydrogen-ion concentration. P. Ha n sen (Dansk Tidsskr. Farm., 1927, 1, 382—388).—Linseed meal contains a glucoside which, in the presence of water, can be split up by enzyme action into sugar, acetone, and hydrocyanic a c id ; the am ount of the acid formed may reach 0-4%, and many cases of cattle poisoning have been traced to this source. Collins and Blair (A., 1915, i, 110) showed th a t the production of hydrocyanic acid was hindered by the presence of quite small amounts of an acid. Experiments now show th a t the optimum tem perature for the production of hydrocyanic acid from linseed meal lies between 40° and 50°, and, further, th a t the optimum hydrogen-ion concentration for the reaction lies about j)It 5. No liberation of hydrogen cyanide took place with p H values greater than 8 or less than 2. The observed p s values for suspensions of linseed meal, measured with a quinhydrone electrode using a Yeibel normal electrode for comparison, exhibit a marked deviation from those calculated from the strength of the hydrochloric acid employed. The differences are probably due to adsorption effects, although buffer effects and the presence of ampholytic substances may also be responsible. H . F. Harwood.
L im e-treatm en t o f pea cannery w a ste s. Wa r w ic k.
—See X X III.
Pa t e n t s.
Production of bread. E . Rosenbaum (Swiss P.
115,100, 10.12.25).—After leaving bran in contact with water until fermentation begins, the liquid is poured off from the residue, worked up with flour into dough,
and baked. F. R . En no s.
S terilisation , p asteu risation , or lik e treatm ent of m ilk and other liq u id s. R. L. Munday (E.P.
269,678, 25.1.26).—The liquid is exhausted of air by spraying or filming it or by agitating it in bulk within a vacuum chamber, whence it is taken by a positive- action vacuum pump to a series of heat exchangers, in which it is sterilised. Further, it may be subjected to the action of ultra-violet rays, or impregnated with sterile air or a flavouring or odorising gas, a continuous vacuum being sustained throughout the whole process.
F. R . Enno s. M aking a self-preservin g acid m ilk product esp ecially adapted for th e low er a n im als. A. P.
Hu n t (E.P. 269,610, 24.11.25).—Skimmed milk is treated with a suitable culture, e.g., B. Bulgaricus, until a total acidity of 0-78—1 '5 % is developed, after which
it is agitated and heated, first gradually to 52° and then rapidly to 85° in order to precipitate the casein and milk albumin in t h e ' form of non-adherent particles. The product is then evaporated in m a w a t a low temperature (60—65°), until it contains about 28% of solids, and its lactic acidity, which acts as a sterilising agent, is increased
up to 6%. F. R. Ennos.
Manufacture of oleom argarine. H . Lero u d ier
(E.P. 252,369, 18.5.26. Conv., 20.5.25).—The primary mass of melted oleomargarine fats and oils, either pure or emulsified with not more than 5% of water, is mixed with a suspension of fats or oils in a much larger quantity of water, the use of natural or artificial milk being
excluded. F. R. Ennos.
Preservation of liquid eg g s or egg constituents.
Un it e d Yea st Co., Lt d., W. Salmon, and F. Jackson (E .P . 270,052, 18.3.26).—The liquid eggs, or their con
stituent yolk or albumin, are mixed below 21° with 1% ammonia solution in such amount, which is varied according to the length of time it is desired to preserve the eggs, th a t the free ammonia remaining when they are required for use shall be approximately 0-25% . The mixture is then transferred to air-tight containers which are hermetically sealed. F. R. Ennos.
Apparatus and continuous m ethod fo r cooking cheese. C. Do er in g and H. H. Doerin g(E.P. 270,046, 8.3.26).—The cheese, which is cut into small particles in one chamber, is moved by means of a worm screw- conveyor to the second chamber, where it is cooked a t about 60° by introduction of steam a t various points, the worm-screw in this chamber being hollow to permit the circulation of steam therein. The mass, after mixing and removal of excess of moisture, is treated with flavouring and ageing ingredients and passed through a third or blenSing chamber maintained a t 60°. Thence it is delivered in a continuous stream, from which solid particles are separated by reticular means, to an agitating vessel, in which it is aerated with oxygen or carbon
Apparatus and continuous m ethod fo r cooking cheese. C. Do er in g and H. H. Doerin g(E.P. 270,046, 8.3.26).—The cheese, which is cut into small particles in one chamber, is moved by means of a worm screw- conveyor to the second chamber, where it is cooked a t about 60° by introduction of steam a t various points, the worm-screw in this chamber being hollow to permit the circulation of steam therein. The mass, after mixing and removal of excess of moisture, is treated with flavouring and ageing ingredients and passed through a third or blenSing chamber maintained a t 60°. Thence it is delivered in a continuous stream, from which solid particles are separated by reticular means, to an agitating vessel, in which it is aerated with oxygen or carbon