August, 1930
I S D U S T R I A L AND EIVGINEERI9G CHEMISTRY
P a p e r T r a d e J . , 83, 43 (December 23, 1926). P e a n u f J . , 8, No. 1, 39 (1928). P e a n u t P r o m o t e r , 1, No. 8, 52 (1918). Ibid., 1, No. 8, 49 (1918); 3, No. 5, 20 (1920). Ibid., 2, KO.15, 28 (1919). Ibid., 2, No. 1, 141 (1919). Redgrdve, P a p e r M a k e r s Monlhly, 64, 391 (1926). Rommel, ISD. Exc. CHEX., 20, 716 (1928). (2.5) Schorger. “Chemistry of Cellulose and Wood,” p. 512 (1926).
(17) (18) (19) (20) (21) (22) (23) (24)
907
(26) Schorger, I b i d . , p. 539. (27) Shaw a n d Bicking, Bur. Standards, T e c h . Paper 340, 323 (1927). (28) Sieber a n d Walter, Papier-Fabr., 11, 1179 (1913). (29) Spirindelli, Notia. c h i m . ind., 1, 412 (1926). (30) Sweeney, U. S. Patent 1,639,152 (August 16, 1927). (31) U. S. Dept. Agr., Bull. 1401, 76 (1926). (32) Webber, IHD. EKG.CHEM., 21, 270 (1929). (33) Yamamoto, U. S. Patent 1,436,747 (November 28, 1922)). (34) Yamamoto, Cellulose I n d . Tokyo, 4, 53 (1928).
Colloids in Granulated Sugar‘ C . F. Bardorf S T . LAWREXCE SUGAR
REFISEEIES,?.fONTREAL,
T
HE question of colloids (highly dispersed cane wax) in granulated sugar was brought to the attention of the author by the claim of certain soft-drink manufactcrers that some granulated sugars tend to coagulate the flavoring extract used in the preparation of aerated Leverages. This coagulation becomes apparent in one of two ways-the bottled product loses its brilliancy or some of the extract forms a flocculent collar on the surface of the liquid. It is the contention of these manufacturers that some quality in the granulated sugar is the primal cause of this phenomenon. Strange to say, granulated sugars of superior quality, from a refiner’s point of view, have proved more troublesome in this respect than those of admittedly inferior quality. For the purpose of rapid comparison, granulated sugars were subjected to three tests: (1) by observation of the brilliancy and color of the crystals under a daylight lamp, ( 2 ) by observation of a 50 per cent solution in a white glass tube (Nessler, 3/4 X 18 inches; depth of liquid, 12 inches), and (3) by a percolation test. The percolation test is made in a 1 X 4 inch glass tube. The tube is filled with the sugar to be examined and slightly tapped to settle the grains, and then 5 to 10 ml. of cold distilled water are dripped slowly on the sugar. As the water percolates through the crystals. it carries with it any coloring matter and also much of the colloidal wax. When the water has penetrated about 2 inches ( 5 cm.) of the crystals, a ring IS formed in the tube a t the bottom of the descending column of water. This ring may be light yellow, or brownish, and when colloids are present to an appreciable extent, mill have a decidedly gray tinge. From the character and intensjty of the ring a fair estirnate can be made of the relative quality of the sugars under examination. Though admittedly crude, this method does enable the refiner to establish the variation in the so-called standard granulated sugars. Experimental With the cooperation of an aerated beverage manufacturer ten samples of granulated sugar were tested by preparing simpleasirups from the sugars and then adding an emulsified preparation which had previously been known to separate from the finished beverage. The usual trade bottles were filled with properly diluted extract and sirup and set aside for observation. After 2, 3, or 4 days a record was made of the condition of the beverage with respect to the absence or presence of coagulated or flocculated extract. Remarkable differences were to be observed; some bottles showed distinct rings of closely packed coagulated material while others exhibited loose flocculations. 1
Received April 23, 1930
Presented before t h e Division of Sugar
Chemistry a t t h e 79th Meeting of the American Chemical Society, Atldnta,
Ga , April 7 t o 11, 1930.
CAKADA
I n the accompanying table the quality of the sugars is indicated in accordance with the three tests and degree of flocculation. Percentage of ash is also given. The sugars are classed as a,b, and c, according to their relative merits, in each column. Under flocculation, a indicates little or no flocculation; b, intermediate; and c, the maximum. TEST SAMPLE
TEST
1
2
a b b b
7 8
a a b b b b
c
c
9 10
a
1 2 3
4
5 6
a a
a
a
b a b
TEST 3
a a
b b b b c a a b
FLOCCLTJRBIXTY ASH Per cent a 0.0030 a 0.0076 b C C
c a a a b
0:00i0
0.0136 0.0164 0.0104 0.0020 0.0050 0,0074
LATIOX C
b b a a
C
a b a c
A critical examination of the table throws little light on the cause of flocculation. Since sugar of inferior qualityfor example, samples 4 and &proved satisfactory, samples 1 and 2 were found unsatisfactory. Again, the average percentage of ash of sugars classed as a, under flocculation column, is 0.010, while classes b and c contain, respectively, 0.005 and 0.009 per cent of ash. It was ascertained that sugars 1, 2 , G, and 10 had been refined from Katal raws; 4 and 5 from Cuban’s, and 8 and 9 from British R e s t Indian raws. It is further to be noted that a second lot of sugar No. 7 was subjected to another experiment and test and fell into the c class under turbidity, but nevertheless maintained its status as a in flxculation column. Conclusion
It would appear, then, that so far as this preliminary investigation has gone no conclusive data have been found to suggest the cause of flocculation produced by certain granulated sugars in beverages of this kind. General excellence of a sugar does not guarantee non-flocculent tendencies in the products. Indeed, from the observation of samples 1, 2 , 8, and 9 perfectly satisfactory beverage products would be expected. But since all granulated sugars ( S o . 2 excepted) refined from S a t a l raws fall into the c class as regards floc production, it is to be inferred that the colloid dispersion in this sugar has some adverse influence. That the nature of the dispersions, rather than the quantity of colloids present in the granulated sugar, is a determining factor is suggested by the fact that sugars 4 and 5 gave the most turbid solutions of the ten lots examined, and strange to say, produced no flocculation. Finally, samples 1, 2, 3, and 9 are to be regarded as very fine examples of standard granulated and are fully up t o the best comxercial products of their class.
