COLORING CITRUS FRUIT IN FLORIDA 13 
liable to seizure in interstate shipment and that if it does happen 
to get on the market the sale of such fruit may result in dissatisfied 
customers and consequent injury to future markets. 
TaBLE 4.—Solids-acid ratio in mixed common Florida and Davis (seedless) 
grapefruit before and after coloring 
ate Solids- ule | Solids- 
Citric | Soluble z Citric | Soluble F 
Color stage acid | solids acid Color stage acid | solids ad 
Before coloring__-_._._-_- 1.35 9. 82 7. 27 || Before coloring..__._._-_- 1.55 | 10.82 7.00 
After coloring. ........--- 1. 29 9. 82 7. 62 11 oY Bea el AR 1.49 | 10.75 Carat 
Check (not colored)_-| 1.24 9.75 7.86 || After coloring.._._....-_- 1.56 | 10.91 7. 00 
Before coloring_.____-____- 1.37 9. 85 7.18 Check (not colored)_-| 1.41] 10.61 7. 52 
After coloring. -_....-___- 1.33 9. 82 7.38 || Before coloring._._-._.__- 127, 9. 45 7, 44 
Check (not eal 1.37 9. 82 7.17 || After coloring. ...__--___- 1.32 9. 61 7. 28 
GRADING THE COLORED FRUIT 
One advantage in coloring fruit is that it can be graded much more 
easily after it is colored than while it is still green. Defects such as 
branch rubs and slight scab infections are easily overlooked on fruit 
partially green in color, especially if the blemish is on the green sur- 
face. After it is colored these defects stand out against the yellow 
background. Some types of scale which are very common in Florida 
are loosened by the coloring process and are more easily removed in 
the usual operations of washing and brushing the fruit in the pack- 
me house. This also improves the grade and makes a more attractive 
ruit. 
EFFECT OF EXPOSURE TO STOVE GAS ON STEM BUTTONS 
As has already been pointed out, the loss or retention of the 
stem button is dependent to a large extent upon the method followed 
in coloring the fruit. It was shown early in these experiments that, 
if Parson Brown oranges or grapefruit were colored at a moder- 
ately low temperature of about 70° to 80° F., the buttons could be 
retained even when the relative humidity was high. The quantity 
of gas in the room of course has some influence on the formation of 
the abscission layer at the base of this stem. At the same time a 
large quantity of gas is usually accompanied by higher temperatures, 
so that it is difficult to separate these two factors. On the early fruit 
it was found possible to loosen this button so that it could be removed 
when the fruit was washed and brushed. By raising the tempera- 
ture above 80° F. in a number of experiments carried on in various 
packing houses with this fruit these findings were corroborated, and 
there seems to be no question but that it is very easy to remove the 
buttons from the fruit by treating it from 24 to 36 hours at tempera- 
tures above 80° F. with a humidity between 80° and 90° F. With the 
late-season fruit, however, the buttons are not so easily removed, and 
late Valencia oranges, which turn green in the spring and summer, 
will retain them in most cases when treated at a temperature of 80° to 
85° I’. In the experimental work it was found that if the tempera- 
ture of the room was raised to 90° or 95° F. the formation of the 
abscission layer at the base of the stem would be accelerated, and 
that the buttons could be removed from this fruit about as readily 
