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I N D U ST R I A L A N D E N G I N E E R I N G C H E M I ST R Y
(2) Bragg, TT'. H., and Bragg, 11'. L., "X-Rays and Crystal Structure," 4th ed., pp. 132-4, G. Bell & Sons, London, 1924. (3) Coffignier, C.. Ret. chim.ind., 18, 5-8 (1906). (4) Gardner, H. A,, "Physical and Chemical Examination of Paints, Varnishes and Colors," Chap. 5, Paint Mfrs.' hssoc. U. S., 1922. (5) Glixelli, S., 2. anorg. allgem. Chem., 55, 297-320 (1907). (6) Grohn, H., Farben-Ztg., 33, 16604 (1928). (7) Haber, F., Ber., 55B,1717-33 (1922). (8) Hallett, R. L., Proc. Am. Soc. Testing Maferials,22,Pt. 11, 52331 (1922). (9) Haslam, G. S., and Hall, C. H., J . Franklin Inst., 209, 777-89 (1930). (10) Heaton, iY., "Outlines of Paint Technology," pp. 90, 96, Charles Griffen & Co.. London. 1928. (11) Jackson, D. D., Tech. Quart., 13, 278 (1900); bluer, H. F., J. ISD. ESG. CHEW., 3,553-7 (1911). (12) Klumpp, E., Kolloid-Z., 55, 3.18-51 (1931).
Vol. 25, No. 4
(13) Larsen, E. S.,U. S. Geol. Survey, Bull. 679 (1921). (14) Levi, G. R., and Fontana, C. G., Atti accad. Lincei, [GI 7, 502-8 (1928). (15) Mellor, J. W.,"Comprehensive Treatise on Inorganic and Theoretical Chemistry," Vol. Is', p. 607, Longmans, 1923. (16) Pfund, A. H., J . Franklin Inst., 188:675-81 (1919): 196,69-7b (1923). (17) Stuckle, H. W.de, U. S. Patent 884,874 (1906). (18) Stutn, G. F., and Pfund, A. H., ISD. EKQ. CHEY., 19, 51-3 (1927). (19) Wagner, H., and Pfanner, H., Farhen-Ztg., 34,2513-14 (1929). (20) Weimarn, P. P. von, "Die Allgemeinheit des Kolloidaustandes," 2nd ed., Theodor Steinkopff, Dresden, 1925; Alexander, .J., "Colloid Chemistry," Chap. 2, Chemical Catalog, 1926. RECEIVED.iugust 29, 1932. Presented before the Division of Paint and Yarnish Chemistry a t the 84th Xeeting of the American Chemical Society, Denver, Colo., .Lugus1 2 2 t o 2 6 , 1932.
Inversion of' Sucrose by Invertase a t Low Temperatures Preliminary Report &I.A. JOSLYNAKD \I. SHERRILL, University of California, Berkeley, California U R I N G the course of investigations on the chemical and physical changes occurring in fruits during freezing and subsequent thawing, a marked inversion of sucrose was observed in certain crushed fruits packed with sugar and stored for a period of 8 months or longer a t temperatures of -16" to - 12" C. . From 10 to 50 per cent of the sucrose added to crushed Cuthbert raspberries was inverted during storage for a period of 2 years. The storage temperatures during this period mere subject to some fluctuations; temperatures as high as -4" C. were reached and held for several days. Cnder similar conditions 25 to 80 per cent of
-12" C. for a year. Practically no inversion of sucrose wa5 found in California cling peaches. Since no studies of invertase activity a t these temperatures had been reported in the literature, a preliminary study of the rate of inversion of sucrose by invertase during freezing storage was made. I n these studies, "red label" dry yeast invertase scales, free from melibiase, procured through the Xulonioline Company, were used. Cane sugar solutions of varying concentrations were prepared, cooled to 0 " C., adjusted to a pH of about 4.5, the reported optimum' pH for yeast invertase (0, and mixed in the cold with qufficient amounts of invertase suspension to yield concentrations of 0.001, 0.01, and 0.05 mg. per cc. of resulting solution, respectively. T ~ B LI.E DEGREE OF INVERSIOX OF SUCROSE IS R ~ ~ P B E R R I E S ASD STR~WBERRIES FRUIT
SUCROSE IVVERTED T h a u e d at room temp for 98 hours
RITIO OF FRUIT T h a u e d in TO SUGAR boiling u a t e r
70
I 30
DAYS
70
I 75
IW
FIGURE 1. RATEOF
DECRE.4SE OF POLARIZ.4TION IX SUG4R SOLUTIOSS OF v-ARYIVG CONCENTRdTIONS COSTAISING 0.01 MG. ISVERTASE PER cc. OF SOLUTIOS (Curve based on black dots represents decrease of reading for solution whose initial reading i s 54.4)
the sucrose added to crushed California Banner strawberries was inverted. The degree of inversion increased with decrease in the concentration of added sugar and increased with increase in time of thawing as shown in Table I. There is some indication that complete inversion of added sucrose occurred in frozen Hachiya persimmons stored a t -16" to
Although care was taken to mix the samples thoroughly, small variations in the initial concentration of the control samples and in the pH values in samples stored for 55 day; indicated that these samples were not entirely homogeneous. The variations were particularly noticeable in the samples of higher density which were fairly viscous when mixed. HOWever, considerable care was used to obtain the proper concenAt t h e present nothing I 1 This 18 the optimum a t room temperature. k n o u n about t h e possible changes in p H of t h e frozen solution and of the possible changes in t h e pH optimums of enzymes in the frozen state Thls pH value, however, approximates t h a t of t h e fruits in which inversion of sucro3e was ob-erved.
INDUSTRIAL AUD ENGINEERISG
April, 1933
CHEhlISTRY
417
TABLE11. SACCHARIMETER READIXG ASD PERCENTAGE OF SUCROSE INVERTED AT VARIOUSCOSCENTRATIOXS OF SUCROSE ASD OF ISVERTASE INITIAL SACCHARIMETER
RE&DIKG ~
IhVERTASE PER cc. O F
~~~~
AND
INITIAL
C0lvcl.r. OF
~~
11
%
. . . . . . .
. . . . . . .
. . . . . . .
. . . . . . .
,. ._ .. . . . .
64.3 68.0 66.8
. . . .
55.7
.,
..
60.4
. . . .
. . . . . . . . . . . .
0 . 7 70.0 6.9 22.0 !3.7 4.0
3.2 0.6 0.5 8.0 2.0
. . . . .
49.3 6.8 52.7 2.5 53.9 0.4 45.3 1.7 48.0 1.0 2 6 . 8 15.5 32.8 2.0 34.2 0.0 11.1 17.5 13.6 2 . 0
. . . . . . . .
PERCENTAGE SUCROSE
%
%J
..
65.8 1.6 68.3 0 . 2 66.8 0.5 59.13.8 61.1 1.2
0.05 0.01 0.001 0.01 0.001 0.05 0.01 0.001 0.01 0.001 0.05 0.01 0.001 0.01 0.001 0.05 0.01 0.001
67.3 68.5 67.2 62.3 62.0 54.2 54.4 54.1 46.4 46.4 33.7 33.7 34.0 14.4 14.2 7.8 9.6 10.2
S.
