April 1949
INDUSTRIAL AND ENGINEERING CHEMISTRY
(14) .Ratohford, W. P., and Faucette, W. A,, unpublished work. (15) Rehberg, C . E., and Fishq, C. H., J . Am. Chem. Soc., 66, 1203 (1944). (16) Rehberg, C. E., and Fisher, C . H., "Properties of Monomeric and Polymeric Acrylates and Methacrylates," presented before the Division of Paint, Varnish, and Plastics Chemistry, at the 109th meeting of the AM. CHEM.Soc., Atlantic City, N. J. (17) Renfrew, A., and Gates, W. E. F.,U. S. Patent 2,296,403 (Sept. 22,1942). (18) Semon, W. L.,Chem. Eny. A'ews, 24, 2900 (1946). (19) Starkweather, H. W., Bale, P. O., Carter, A. S., Hill, F.B., Jr.,
(20) (21)
(22) (23)
791
Hurka, V. I
84.7 84.6 90.4 90.4 88.4 83.8 90.0
88.5 88, R 90.4 00.4 88.4 83.8 00 0
RO
62.0 61.4 62.8
Gull1
(illl-
1 1111.
5 10 20 30 40
78.6 78.6 81.0 83.4 83.4
66.7 74.8 81 .O 83.4 81.9
69.0 76.2 78.6 82.4 81.0
64.3 60.0 73.8 73.8 76.2
54.8 59.5 54.8 64.3 66.7
2
5 10 20 30 40
86.0 86 0 89.3 88.4 90.7
84.7 86.0 87.4 89.3 88.4
85 2 86.0 88.4 88.4 88.4
83.7 83.7 86.0 88.4 87.0
83.7 83.7 90.7 76 8 86.0
Bo .i i ~ i dSulfur Dioxide, yc a t pFi 2 , 9 ? - - - p H 8 . 9 3 DH 5.02
Arabic cose, Hydrolyzate % pH 1.93
1111.
1)H 5 , 9 7
content of the hydrolyzate \\a5 deterniined by the furfural method. The experiments \\ere carried out n i t h 20-ml. solutions containing 0, 5, 10, 20, 30, 40, and 50% glucose in citrate buffer solutionq ( 4 ) adjusted to a p H of 4.0, corresponding to that of orange juice. Volumes of 1, 2 , 3, 4, and 5 ml. of hydrolyzatv containing 0.5, 1.0, 2.0, and 2.5 grams of aiabinose, respectively, were added to each of the glucose solutions. The free and bound sulfur dioxide were determined after 6 hours. Table I1 shows the percentage of hound sulfur dioxide after hydrolyzate containing arabinose was added. Table I1 shows that the maxiniuxn value of 92.570 of bound sulfur dioxide was obtained when 3 ml. of hydrolyzate, containing 1.5 grams of arabinose, vere added to a SOY, glucose solution at pH 4.0. Experiments were carried out 1)v adding guiii arabic hyd~olyzate in volumes of 1 and 2 i d . (containing 0.5 and 1 gram arabinose, respectively) to 20-ml. solutions containing 5 , 10, 20, 30, and 40YG glucose. The solutions w r e adjusted to various pH: 1.93, 2.97, 3.95, 5.02, and 5.97. The free and bound sulfur dioxide were determined after 6 hours. Table IS1 shows the percentage 01 bound sulfur dioxide after the addition of arabic gum hydrolyzate at various pH. Table 111 6hon.s that a t a pH o f about 4.0 (an aciditr corre-
T.4BLE
Ilr.
Glucose a d d e d , BoundSOz,%
GLUCOSEIh' CITRUSJUICES
INFLUENCE O F h U E D
yo
0 57.1
2.5 78.8
5 81.8
10 81.8
15 81.8
25 81.5
30 83.0
35 82
OF ADDEDGLCCOSE AXD CITRICAcm TABLE V, INFLUEKCE COXCEXTRATED CITRUSJnrcEs
A d d e d glucose, grams Added citric acid, g r a m s B o u n d SO?, %
1.0
1.5
5C.7 yl'.i 7i.i
Si.?
Added glucose, grams Added citric acid, g r a m s B o u n d Son, %
0.5 1.0 1 .O 1.0 53.0 80.1
0.5 1 .5 85.8
, , .
0.5
1.5 1.0 85.3
0.5 0.5 63.0
l,? 0.0 73.3
IN
0 56.3
1
8Q.5
ACKEOWLEUGMENT
These experiments were carried out in the Departmeiil of Biological and Colloidal Chemistry, Hebrew University, Jerusalem, with the generous cooperation of A. Fodor, director of the department. The authors acknowledge wit,h thanks the interest taken by the Scientific L4clvisory Committee, War Supply Board, Government of Paleqtine, which also sponsored t,his invcui igation.
1.5
LITERATURE CITED
0.5 82.0
1.0 1.5 1.5 1.3 90.5 96.0
TABLE VI. IKFLUEKCE OF ADDEDGuhi Anaslc HYDROLYZ TI? IS CONCESTR~TED CITRUSJUICES Added gum arabic hydrolyzate, ml. B o u n d SOZ, %,
sponding to that of cit,rus juices) when 2 ml. of hydrolysate arc added to a ZOyo glucosc solution, 88.4% of the sulfur dioxide is bound. It is possible that th? crude grim arahic hydrolyzate cont,ains small amounts of substances, such as furfural, which form a stable combination with sulfur dioxide. The results of the experiments carried out as ciescril)etl sceiri to indicate that the cornliinatiori i'n free sulfur ciioxidc with reducing sugars, such as glucose, may be influenced by mass action effect of different ionic species a t variou3 p H value.iveis set free through dilution. (C) The effect of gum arabic hydrolyzate on the bound sulfur dioxide in citrus juice concentrate mas investigat'ed as follows: T'o 20 ml. of orange juice concentrate (I t,o 6) containing 1200 p.p.m. sodium sulfite, 0, 1, 2, and 3 ml. of gum ara,bichydrnlyzatc were added. Table VI shea-s the percentage of bound sulfur dioxide determined after 6 hours when different voluniw of gum arabic hydrolyzat,e were added. Table VI shows that with the addition of 1 nil. of hydrolyzate or 0.5 grams arabinose t,o 20 xnl. of orange juice Concentrate, about 90To of sulfur dioxide is: bound. Addition of twice this volume of hydrolyzate results in only a small increase in t,he binding of sulfur dioxide and remains constant, with a furthctr increase of the hydrolyzate, Dilution of the citrus concentratc, Containing hydrolyzate, affects the bound sulfur dioxitlv only to an insignificant ext,ent.
CONCEKl'RATED
20 81.7
2
92.8
3 92.7
Vol. 41, No. 4
(4) (5) (6) (7)
nolvnel, -4. w. E., J . Soc. Chem. Ind., 62, 124 (1943). Kerp and Baur, A rb. Kais. Gesundheits amt., 26, 297 (1907) hlonier-JT7illiams. G. W., Rept. 43, hlinistiy of IIealth, 1115 Rlajesty's Stationery Office, London, 1937. Oppenheimer. C . . "Die Fermente und Ihre Wirkungen," Vol. 111 8. 616. The Haeue. W. Junk.' Or;. Synt'heses, 8,
