46 
BULLETIN 448, U. S. DEPARTMENT OF AGRICULTURE. 
Table 3. — Behavior of colors when treated with reducing agents followed by oxidizing 
agents. 
[Numbers denoting permitted dyes are in boldfaced type; natural colors are in italics. Dyes common in 
foods are starred, three stars indicating those most often found. Statements apply in general to 0.01 per 
cent solutions.] 
No. 
Coloring 
matter. 
With sodium hydrosulphite. 
Coloring 
matter. 
Reduction product with air or potas- 
sium persulphate. 
1 
*462 
Almost decolorized. 
*462 
Color restored. 
2 
434 
Almost decolorized. 
434 
Color partially restored. 
3 
435 
Almost decolorized. 
435 
Color partially restored. 
4 
*436 
Becomes paler very slowly. 
*436 
5 
439 
Paler, slowly. 
439 
Color restored. 
6 
491 
Almost decolorized. 
491 
Some color returns. 
7 
440 
Decolorized. 
440 
Color restored. 
8 
**602 
Pale olive. 
**602 
Color restored. 
9 
**108 
Decolorized. 
**108 
Remains colorless or nearly so. 
10 
***g 
Decolorized. 
***8 
Remains colorless or nearly so. 
11 
9 
Decolorized. 
9 
Remains colorless or nearly so. 
12 
**S9 
Decolorized. 
**89 
Remains colorless or nearly so. 
13 
692 
Decolorized. 
692 
Color restored. 
14 
399 
Not decolorized. 
399 
15 
***106 
Decolorized. 
***106 
Remains colorless or nearly so. 
16 
107 
Decolorized. 
107 
Remains colorless or nearly so. 
17 
94 
Decolorized. 
94 
Remains colorless or nearly so. 
18 
*398 
Decolorized. 
*398 
Remains colorless or nearly so. 
19 
605 
Pale orange. 
605 
Color restored. 
20 
604 
Pale orange. 
604 
Color restored. 
21 
198 
Decolorized. 
198 
Remains colorless or nearly so. 
22 
***14 
Decolorized. 
***14 
Remains colorless or nearly so. 
23 
21 
Decolorized rather slowly. 
21 
Remains colorless or pale brownish. 
24 
318 
Bluer; then decolorized. 
318 
Remains colorless or nearly so. 
25 
20 
Decolorized. 
20 
Remains colorless or nearly so. 
26 
93 
Decolorized. 
93 
Remains colorless or nearly so. 
27 
***480 
Much paler. 
***480 
Color restored. 
28 
*53 
Decolorized. 
*53 
Remains colorless or nearly so. 
29 
*55 
Decolorized. 
*55 
Remains colorless or nearly so. 
30 
105 
Decolorized. 
105 
Remains colorless or nearly so. 
31 
4 
Decolorized. 
4 
Remains colorless or nearly so. 
32 
***706 
Not decolorized. 
***706 
33 
56 
Decolorized. 
56 
Remains colorless or nearly so. 
34 
*62 
Decolorized. 
*62 
Remains colorless or nearly so. 
35 
**64 
Decolorized. 
**64 
Remains colorless or nearly so. 
36 
*65 
Decolorized. 
*65 
Remains colorless or nearly so. 
37 
**103 
Decolorized. 
**103 
Remains colorless or nearly so. 
38 
139 
Decolorized. 
139 
Remains colorless or nearly so. 
39 
164 
Decolorized. 
164 
Remains colorless or nearly so. 
40 
**667 
Not changed. 
**667 
41 
*169 
Bluer; then decolorized. 
*169 
Remains colorless or nearly so. 
42 
163 
Decolorized. 
163 
Remains colorless or nearly so. 
43 
170 
Bluer; then decolorized. 
170 
Remains colorless or nearly so. 
44 
84 
Decolorized. 
84 
Remains colorless or nearly so. 
45 
146 
Bluer; then decolorized. 
146 
Remains colorless or nearly so. 
46 
287 
Slowly decolorized. 
287 
Remains colorless or nearly so. 
47 
78 
Slowly decolorized. 
78 
Remains colorless or nearly so. 
48 
***J1Q 
Decolorized, nearly. 
***710 
Color restored. 
49 
*546 
Not changed. 
*546 
50 
1 
Decolorized. 
1 
Not restored. 
51 
507 
Not changed. 
507 
52 
328 
Decolorized. 
328 
Remains colorless or nearly so. 
53 
606 
Pale yellow. 
606 
Color restored. 
54 
154 
Bluer; then decolorized. 
154 
Remains colorless or nearly so. 
55 
85 
Decolorized. 
85 
Remains colorless or nearly so. 
56 
**13 
Decolorized. 
**13 
Remains colorless or nearly so. 
57 
***86 
Decolorized. 
***86 
Remains colorless or nearly so. 
58 
97 
Decolorized. 
97 
Remains colorless or nearly so. 
59 
54 
Decolorized. 
54 
Remains colorless or nearly so. 
60 
329 
Decolorized. 
329 
Remains color jess or nearly so. 
61 
139 
Decolorized. 
139 
Remains colorless or nearly so. 
62 
157 
Decolorized. 
157 
Remains colorless or nearly so. 
63 
*95 
Decolorized. 
*95 
Colorless or slightly yellow. 
64 
88 
Decolorized. 
88 
Colorless or slightly yellow. 
65 
*92 
Decolorized. 
*92 
Remains colorless or nearly so. 
66 
101 
Decolorized. 
101 
Remains colorless or nearly so. 
67 
102 
Decolorized. 
102 
Remains colorless or nearly so. 
68 
483 
Decolorized. 
483 
Color restored. 
69 
*510 
Much paler. 
*510 
Color restored. 
70 
26 
Decolorized. 
26 
Remains colorless or nearly so. 
71 
220 
Decolorized. 
220 
Remains colorless or nearly so. 
72 
269 
Decolorized. 
269 
Remains colorless or nearly so. 
73 
512 
Much paler (with excess). 
512 
Color restored. 
74 
515 
Much paler (with excess). 
515 
Color restored. 
75 
516 
Much paler (with excess). 
516 
Color restored. 
