12 BULLETIN 1367, U. S. DEPARTMENT OF AGRICULTURE 
well-filled coloring room. In the operation of these rooms it is im- 
portant that the humidity should be maintained high enough to pre- 
vent any excessive shrinkage, as this not only decreases the weight 
of the fruit but makes it less attractive. 
COMPOSITION OF THE FRUIT AS AFFECTED BY COLORING 
it has been stated in earlier publications on this subject that color- 
ing apparently does not affect the composition of the juice appreci- 
ably. It is therefore important that only fruit which would pass 
the solids-acid test of 8 parts sugar to 1 of acid in the case of oranges 
O .34% 58% -32% IGS 
| Loss IN oe OF FARSON ered ca | 
| | 
| j { 
J=-d || Bee! [| fees 
id | ieee es ee 
ee cee Redes 
| 
90° <+ = | ag | 
ei lene | Nee RELATIVE HUMIDITY, PER CENT\ | 
. (CaDertss Cashin Wetnseens Sees eee | sce | | | 
goe Ls 
Fig. 5.—Loss in weight of Parson Brown oranges during coloring under humid conditions 
and at moderate temperatures 
or 7 parts sugar to 1 of acid for grapefruit should be colored. Some- 
times there is a change in the ratio during coloring, probably due to 
the evaporation of water and the concentration of juice, but it is 
usually slight. 
ce] 67% 1.02% 117% 
| | 
LOSS| IN LS SEE Oo 
90° 
| | | 
B0° La=~ | 
| B ; | 
ER Alo Pe emi ee i eS a <SYt AP [esial 
fe : | SS ee ore ~- ape caeitene ced 
70% \ ARELATIVE |HIUMY{OITS, PER CENT | | | y | 
| | | | | JEMBERAT UAE | DEGREE '£ | 
i seal | { i i i | ! j 
6 12 6 i2 S i2 6 12 6 iZ 6 12 6 12 6 
| | j | Ym. i 
| Pi. ] AM. 
j 
SS | eS i 1 
Fic. 6.—Loss in weight of grapefruit during coloring under humid conditions and at 
moderate temperatures 
Table 4 shows the results of the solids-acid test on grapefruit before 
and after coloring, and in some cases on a control sample, which was 
a collateral lot held in the packing house for the length of time the 
fruit was in the coloring room. It is evident from the table that 
there is practically no change in the solids-acid ratio which could. 
be attributed to the coloring process, which serves to emphasize the 
statement that the fruit should be of sufficient maturity to pass 
these tests before being placed in the coloring room. The point can 
not be stressed too strongly that coloring immature fruit makes it 
- 
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