I N D U S T R I A L A N D ENGINEERING CHEMISTRY
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Free Water Removed from Thawed Batters
Eighty grams of yolk batter were divided into four 20-gram samples. To each of the first three samples 2 grams of sucrose, dextrose, or levulose were added and to the fourth no protective agent was added. The samples were placed in tightly stoppered flasks and frozen a t - 15" C. for 72 hours. After thawing the samples were transferred to four ultrafilters. The ultra-filters were made by coating alundum extraction thimbles with collodion. The thimbles were fitted into thistle tubes with sections of rubber stoppers. Into the bell part of the thistle tubes side tubes were sealed to serve as connections to suction pumps. The stems of the thistle tubes were cut off short and 5-cc. tubes graduated to 0.01 cc. sealed on in their place. When the thimbles were fitted into the apparatus and suction was applied, water from the batter flowed down the walls of the thistle tubes and into the calibrated tubes. The volumes of water collected in the graduated tubes were determined by hanging the pieces of apparatus in a thermostat bath a t 20" C. for 1/2 hour and then reading the levels in all the tubes simultaneously. During the applcation of suction the tubes were immersed in an ice bath to minimize evaporation. The amounts of water recovered from the various samples are given below: BUGAR
WATERRECOVERED
cc.
Sucrose Dextrose Levulose No sugar
3.80 3.00 2.95 3.92
The results indicate that dextrose and levulose are more effective than sucrose in preventing the formation or liberation of free water in the process of egg preservation by freezing. Fermentation in Thawed Batters Following Use of Sugars
The yolks of fifty eggs were stirred into a batter, which was then divided into three equal portions and each portion transferred to a sterile flask. To each portion 10 per cent by weight of one of the sugars was added. The flasks were plugged with cotton and frozen a t -15" C. for 72 hours. The three samples were then incubated a t 22" C. and samples were withdrawn periodically for the determination of alcohol
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and for bacterial counts (at 37" C. on agar). The results are given below: SUGAR Sucrose Dextrose Levulose
PERIOD ALconox. Hours % y vol. . - b. 48 0.20 48 0.10 48 0.10
BACTERIA
ODOR
12,000 8,000 7,800
Fermentative Fermentative Fermentative
Sucrose Dextrose Levulose
72 72 72
0.45 0.25 0.25
980,000 210,000 200,000
Fermentative Fermentative Fermentative
Sucrose Dextrose Levulose
96 96 96
0.80 0.50 0.48
28,800,000 1,600,000 1,800,000
Putrid Fermentative Fermentative
Sucrose Dextrose Lev u 1ose
120 120 120
1.05 0.80 0.75
No count 24,000,000 26,000,000
Putrid Putrid Putrid
The results indicat that th dextrose- and levulose-treated batters resist fermentation and bacterial decomposition more vigorously than do those to which sucrose is added. It is thought that these differences are due to the greater osmotic pressures developed by the monosaccharides, the osmotic pressure of the dextrose solution being 1.75 times greater than that of a sucrose solution of equal concentration. Conclusions
The white portion of eggs suffers no breakdown as the result of freezing. The physical character of the yolk portion is altered on freezing, owing to the separation and coagulation of the lecithin. The coagulation of the lecithin may be prevented by the addition of 10 per cent by weight of dextrose or levulose, either of which is a much more effective anti-coagulant than sucrose. None of these sugars form permanent combinations with the egg materials or lecithin during the freezing. The watery and ropy condition of thawed yolks may be eliminated if the yolks are frozen with dextrose or levulose and to a lesser extent with sucrose. From the standpoint of the prevention of the fermentation and bacterial decomposition of the thawed batters, dextrose or levulose is much more effective than sucrose. Literature Cited (1) Plimmer, "Practical Organic and Bio-Chemistry," pp. 175, 176, and 463.
Purification of Normal Paraffin Hydrocarbons b y Chlorosulfonic Acid Treatment' Alvin F. Shepard and Albert L. Henne CHEMISTRY DEPARTMENT, THE OHIO STATE UNIVERSITY, COLUMBUS, OHIO
H E preparation of pure hydrocarbon samples from petroleum by fractional distillation is generally considered an impractical task. Young (6) isolated pure n-pentane, but was unable to purify its higher homologs completely by distillation. No other liquid normal paraffin hydrocarbon, except hexane (6), has ever been isolated in a state of purity from such a source by any method. Fractional distillation will separate a normal paraffin hydrocarbon from most of its isomers; the sample thus obtained may boil over a very narrow range, but its density will be much higher than that of synthetic preparations (2). The presence of naphthenic hydrtrcarbons has been demonstmted and the existence of azeotropic mixtures suggested but never proved.
T
1
Received January 27, 1930.
The writers have studied several chemical methods of' purification, but have obtained satisfactory results only by treatment with chlorosulfonic acid. The principle of. the method is due to Aschan (1) and has been emphasized by Young (?). They have shown that hydrocarbons (naphthenic as well as paraffinic) containing a tertiary carbon atom are rapidly attacked, whereas the normal paraffin hydrocarbons and cyclohexane are only slowly affected. This method has consequently been used to remove hydrocarbons with side chains. Fractional distillation has been employed to eliminate cyclohexane and cyclopentane. Large samples of each normal hydrocarbon from hexane to dodecane have been prepared. Their physical properties compare favorably with those of the best synthetic prepara-
April, 1930
INDUSTRIAL AND ENGINEERING CHEMISTRY
tions and will be reported later. The purification is described to show the effectiveness of the method and the degree of purity attainable. Experimental Procedure
Special gasoline with a normal paraffin hydrocarbon content of about 70 per cent was obtained from the Standard Oil Company of Indiana. It was roughly separated into its main constituents by a single fractionation. Three liters of the decane fraction were rectified three times a t 30 mm., with an improved 18-inch (46-em.) Midgley column, a t a draw-off rate of 2 to 3 cc. per minute. A sample of 1700 cc. was thus obtained with a density, d:5, of 0.739. This sample was placed in a 3-liter flask equipped with a stirrer and vent tube and treated with 300 grams of chlorosulfonic acid. Acid vapors were immediately evolved. T o promote the reaction the mixture was vigorously stirred during the day. Every 3 or 4 days the used acid was replaced by a fresh batch; about 3 kg. were required to complete the purification. The density of the hydrocarbon was determined regularly on washed, distilled samples. It decreased rapidly a t first; in the course of about 4 weeks no further drop could be detected. The batch (900 cc.) was then washed, dried, and rectified thrice under reduced pressure through a 2-inch (5-em.) Midgley column. During the last rectification the distillate was cut in several fractions; four successive cuts, amounting
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to a total of 640 cc., had a density, d:6, of 0.72643;the maximum discrepancy was 1 unit of the fifth decimal place, which was within experimental error. This compares favorably with the densities, di6, measured on synthetic samples by Simon (c), 0.72686, and Krafft ( 3 ) ,0.7266 (both values are interpolated). DURATION OF TREATMENT
DENSITY OF DECANE
Days Start
3 7 10 24
30
37
The melting point of the decane was measured to 0.01 ' @. Then fractional crystallization was attempted, but the melting point of each fraction checked within 0.01' C. and did not differ from the melting point of the entire batch. This is to be regarded as a satisfactory criterion of purity. Literature Cited (1) Aschan, Bey., 31, 1801 (1898). (2) Brown and Carr, IND. ENG.CHEM.,18, 718 (1926) (3) Krafft, Ber., 15, 1695 (1882). (4) Simon, Bull. SOC. chim. Belg., 38, 66 (1929) (5) Young, J . Ckem. Soc., 71, 440 (1897). (6) Young, I b i d . , 73, 906 (1898). (7) Young, I b i d . , 76, 172 (1899).
Absorption of Atmospheric Oxygen b y Limed Cane Juice',' J. A. Ambler CARBOHYDRATE DIVISION, BUREAUOF
CABHISTRV AND SOI1.S.
ELSON and Browne (BI), while pursuing their study of Winter's glucic acid, isolated from the products of the reaction of calcium hydroxide on glucose, a t 67' C. in the absence of air, a calcium salt which rapidly absorbed oxygen from the air with decomposition and the evolution of heat. This interesting observation raised the question of the absorption of oxygen by cane juices during the processes of liming and defecation. Preliminary experiments showed that oxygen is absorbed by limed cane juices, and after refining the method somewhat it was possible to obtain data which yielded a series of characteristic curves by plotting the quantity of oxygen absorbed a t varying degrees of alkalinity against, the time. As in all work on mixtires such as cane juices, the problem resolved itself into the question of how much of the observed absorption is to he attributed to the sugars themselves and how much to the non-sugars.
N
Absorption of Oxygen by Limed Cane Juices
Although it is common in practice to mix the lime with the juice by agitation with air, the only mention in the literature of the use of air in this way is one by Coombs (?), who recognized only the loss in lime due to the absorption of carbon dioxide in the air. Oxidation of Sugars i n Alkaline Solutions by Air
The oxidation of sugars per se in alkaline medium has been extensively studied by many investigators. As early 1 Received January 11, 1930. Presented before the Divi5ion of Sugar Chemistry at the 78th Meeting of the American Chemical Society, Minneapolis, Minn., September 9 t o 13, 1929. 2 Contribution No. 89 from the Carbohydrate Division, Bureau of Chemistry and Soils, U. S. Department of Agriculture.
WASHINGTON. D .
c.
as 1835 Malaguti ( I ? ) reported experiments on the destruction of sugar in both acid and alkaline solutions by the oxygen of the air and made two observations which are worthy of note in this place: (1) The oxidation of sucrose takes place only after its inversion and then but slowly a t ordinary temperatures; (2) the alkalinity of the solution decreases during the oxidntion. All subsequent work in this field has confirmed hlalaguti's results. Because most of the work has been directed more especially toward the study of the mechanism of the reaction from the theoretical and biological viewpoints, it is not feasible to present here a complete bibliogrnphical review of the subject. Only so much of it as has a direct bearing on the results reported herewith will be given. In 1895 and 1897 appeared a series of articles by Lohry de Bruyn and van Ekenstein (6)in which the transformation of the sugars under the influence of alkalies was reported. in Ten years later appeared the classical work of Nef (%I), which was advanced the hypothesis that these changes were brought about in alkaline solution by enolization of the aldehydic form of the sugars. This hypothesis is now being strengthened by the 6ndings of Evans and co-workers ( I g , 1 1 , l Z ) on the mechanism of carbohydrate oxidation (1). Mathews (18) studied the spontaneous oxidation by air of sugars in solutions of sodium hydroxide, and reported that all the reducing sugars oxidize rapidly, that fructose shows the greatest rate of oxidation, that the rate slowly accelerates, and that in the absence of air there is, in addition to an activation of the sugar, a molecular rearrangement into acidic products with consequent fall of alkalinity of the solutions. He also studied the effect of change of concentration of alkali and showed that the rate of oxidation increases with increasing alkalinity until, with normal sodium hydroxide i L
