AUGUST, 1938
INDUSTRIAL AND ENGINEERWG CHEMISTRY
Comparison of the results upon different juices emphasizes the importance of acidity in pasteurization as well as the importance of filling containers full. It is practically impossible tpsterilize the apple juices-that is, to kill both bacterial as well as mold spores and still retain a good flavor. Higher acidity favors the destruction of bacteria. It is a far more simple procedure to fill cans full so that no air is present and thus eliminate chance of mold growth, than to try to heat the product sufficiently to kill all mold spores. There may be an objection to this method of pasteurizing and canning, owing to the deposit of a sediment in the bottom of the container. The juices mentioned, with the exception of the blended clarified juice, all contain a fine amber sediment which might be considered unsightly by some. On the other hand, it does not impair the flavor of the juice. The amount of sediment or deposit in cans of juice varied. Deaeration had little effect upon the amount deposited. Juices pasteurized a t higher temperatures contained the least sediment (Table V). The amount of sediment depends upon the fineness of straining or filtering, and upon the variety and the condition of the apples when pressed. The Greening juices contained more sediment than the Baldwin juice, and the second lot of Baldwin juice which was produced from apples of firm texture deposited very little sediment (Table V). Why variations are obtained in the amount of deposit a t different pasteurization temperatures is not readily explained. It may be possible that the higher pasteurization temperatures may partially dissolve the sediment or produce a physical change which tends to keep the solids in suspension. There is also a possibility that certain enzymes are not inactivated a t the lower temperatures. The deaeration process has not proved as great a benefit to these juices as has been observed by Tucker, Marsh, and Cruess ( I @ , Arengo-Jones ( I ) , and Cruess, Aref, and Irish (6). If apples were pressed so that less oxidation occurred during pressing, the advantages of deaeration might be more evident. After 8 months of storage, the enamel of all completely filled cans is still in excellent condition. However, longer storage may show the advantage of eliminating oxygen from the juice, since partially filled cans now show slight corrosion. The canned cloudy apple juice produced by deaeration and flash pasteurization is a superior product in that there is no cooked flavor, and still the full apple flavor is retained. The
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sediment is a disadvantage in that it does not present as nice an appearance. Work is being continued in the hope that the amount of this sediment may be minimized. It should be remembered that the sediment is not harmful in any way and that many of the best fruit juices packed now are not only cloudy but contain considerable sediment which is usually mixed with the juice when served.
Acknowledgment The authors wish to acknowledge the aid of H. G. Beattie and W. F. Walsh in carrying out the analytical work reported in this paper.
Literature Cited R.W., Fruit Products J., 17,105 (1937). (2) Carpenter, D.C., Pederson, C. S., and Walsh, W. F., IND. ENQ. CHEM.,24, 1218 (1932). (3) Carpenter, D. C., and Walsh, W. F., N. Y. State Agr. Expt. Sta., Tech. Bull. 202 (1932). (4) Celmer, R. F.,and Cruess, W. V., Fruit Products J., 16, 356 (1937). (5) Clague, J. A., and Fellers, C. R.,Mass. Agr. Expt. Sta., Bull. 336 (1936). (6) Cruess, W. V., Aref, H., and Irish, J. H., Fruit Products J., 12, 358 (1933). (7) Cruess, W. V., Richert, P. H., and Irish, J. H., Hilgurdiu, 6, 295-314 11931). (8) Fabian, F. ‘W., and Marshall, R. E., Mich. State Expt. Sta., Bull. 98 (1935). (9) Kertesr, Z. I., and Willaman, J. J., N. Y.State Agr. Expt. Sta., Tech. Bull. 178 (1931). (10) Marsh, G.L.,Fruit Products J . , 16, 271 (1937). (11) Marshall, R . E . , and Kremer, J. C., Mich. Agr. Expt. Sta., Quart. Bull. 20, 1 (1937). (12) Mottern, H. H., and von Loesecke, H. W., Fruit Products J., 12, 325 (1933). (13) Pederson, C. S.,Beavens, E. A., and Goresline, H. E., Food Research, 1, 325 (1936). (14) Pederson, C. S., Goresline, H. E . , and Beavens, E . A., IND. ENQ.CHEM.,27, 1257 (1935). (15) Poore, H.D.,Fruit Products J . , 14, 170 (1935). (16) Tucker, D.A., Marsh, G. L., and Cruess, W. V., Ibid., 15,7-8 (1935). (17) Waksman, 9. A., Cunner, 54, 18,45 (1922). (18) Welsh, W. F., N. Y. State Agr. Expt. Sta., Circ. 149 (1934). (1) Arengo-Jones,
RECEIVTID April 28, 1938. Approved by the Director, New York State Agricultural Experiment Station, for publication as Journal Paper 263.
Approximate Molecular Weights of Higher Hydrocarbon Fractions F. A. L U C Y
The Richards C h e m i c a l Works, I n c . , Jersey City, N. J.
I
N A STUDY of the types of molecules present in a given lubricating oil or other complicated mixture of hydrocarbons, it is desirable to know the molecular weights of the various distillation cuts. This is usually determined accurately by careful measurements of freezing point depression. For estimation of parachors or molecular refractivities to compare with values expected for various assumed structures, an approximate value of the molecular weight is sufficient. Mair and Willingham’ published the boiling points a t 1 mm. for a number of lubricating oil cuts ranging from Czr to Cas. The writer recently measured the boiling points of 1
IND. ENQ.C H ~ M 28, . . 1457 (1936).
three other hydrocarbon oils in the range CISto Ctl. Both sets of data are fitted well by a Walker-type equation,
T
= 111.3n0*4896
where, for the writer’s data a t least, T i s the uncorrected distilling temperature in K. at 1 mm., and n i s the number of carbon atoms per molecule. In terms of molecular weight, M = (T/35)*.276
This probably holds without serious error down to (315. Lighter hydrocarbons are conveniently distilled at 1 atmosphere. RECEIVED May 20, 1938.
