4 COLORING SATSUMA ORANGES IN ALABAMA, on 
(2) Add 5 to 10 drops of the indicator solution from the dropping 
bottle to the j juice.® 
_ (8) Fill the burette with the standard solution until the top of the 
iquid is level with the zero line. 
__ (4) Add the solution from the burette to the juice in the titration 
| flask slowly, shaking the flask constantly until the juice assumes a 
yellow color and finally attains a pinkish tint, which indicates that 
b the end point is reached and that all the acid in the solution is neu- 
~ tralized. 
_- (5) As soon as the pink color is observed, stop the flow of solution 
from the burette. Note the quantity of solution used from the 
_ burette. This is indicated by the figure at the point opposite the 
height of the solution. 
_ (6) To ascertain the percentage of acid in the 25 cubic centimeters 
_ of juice taken, multiply the quantity of solution used by the factor 
for 1 cubic centimeter of the solution which was used, either standard 
or normal, then divide by 25 plus one-tenth of the Brix reading. 
Taste 14.—Corrections for temperature differences from 15° to 31° C. in deter- 
_minations of the percentage of total soluble solids by the Brix hydrometer. 
_ [Examp.e: Reading of Brix hydrometer=8, temperature of juice=29° C. By referring to the table the 
f total soluble solids is found to be 8.74 per cent.] 
Brix reading. 
Temperature. 
6 7 8 9 10 11 12 
59.0° F. (15° C.)......per cent... 5. 89 6. 89 788 8. 88 9. 88 10. 88 11. 87 
labia ae Av... 5. 93 6. 93 7. 92 8. 92 9.92] 10.92 11. 92 
ee 6172) hoo oss - do.. 5.98 6.98 7.97 8. 97 9. 97 10. 97 11.97 
PL CODE GO CS aeons ees doz: 6. 03 Os 8. 03 9. 03 10. 93 11. 03 12. 03 
ee BOG” 6 yee. oo! do.. 6. 08 7.08 8. 08 9. 08 10. 08 11. 08 12. 08 
gle 1 oe pee ain do.. 6.14 7.14 8. 15 9.15 10. 15 11.15 12. 16 
| eee ae do... 6. 20 7.21 8. 21 9, 22 10. 22 11593 12. 23 
eG? I (22°C2) >) es rik do.. 6. 26 DOT 8, 28 9. 29 10. 29 11. 29 12. 30 
Ets ee do.. 6. 32 723 8. 34 9. 35 10. 35 11.35 12. 36 
Bares ra (24 Gee eo hse do. 6. 38 (33 8. 40 9. 4 10. 41 11. 41 12. 42 
enh 95" CO.) <1 2.2.4 - do 6. 44 7.45 8. 46 9. 47 10. 47 11. 47 12. 48 
| eC eae do 6. 51 7.52 8. 53 9. 54 10. 54 11. 54 12.55 
mee E27 Coy do 6.58 7.59 8. 60 9. 61 10. 61 11. 61 12. 62 
eet” F.(28° 0). do 6. 65 7. 66 8. 67 9.68 10. 68 11. 68 12. 69 
sto? F(29° C2). do 6.72 1218 8.74 9.75 10. 75 11. 75 12. 76 
fees. 0° F. (30° C.)_.. 2. do 6.79 7. 80 8. 81 9. 82 10. 82 11. 83 12. 85 
ees? W--(31° C.)2.. 2-3... do 6. 86 T8i 8. 88 9. 89 10. 90 11.91 12. 92 
Example: When titration was complete, as shown by the change in color of 
the juice to a pinkish tint, the height of the column of solution in the burette 
— had fallen from zero to 23.3. This is multiplied by 0.01, the factor for 1 c. ¢. of 
- the standard solution. The result is then divided by 25.87 (this figure is ob- 
tained by adding one-tenth of the Brix reading 8.74 to 25, the quantity of juice 
used). 
23.3 X 0.01 + 25.87 = 0.9 per cent acidity. 
If a tenth normal solution is used, the height of the solution in the burette 
will fall to 36.4. Multiply this by 0.0064, the factor for 1 ¢« ¢. of a tenth normal 
solution. This result is then divided by 25.87. 
34.6 X 0.0064 = 25.87 = 0.9 per cent acidity. 
6A better end point can be obtained if two volumes of water are added to the juice in 
the titration flask before titrating. Care must be taken, however, that the water is 
neither acid nor alkaline. This may be determined by adding a few drops of the indicator 
- solution to the water. It should neither turn pink nor should it require more than a 
_few drops of the standard alkali to turm a pink color. Keep the standard solution 
tightly stoppered when not in use. Wash out the burette and invert it iM the support 
when not in use. Before measuring out the juice in the pipette rinse it with a small 
quantity of the sample you are about to run. 
