18 BULLETIN 241, U. S. DEPARTMENT OF AGRICULTURE. 
of other fruit juices, except in cases where the heat employed was 
excessive. 
RETENTION OF DISTINCTIVE COLORS AND FLAVORS. 
The extent to which color and flavor were retained on keeping the 
juice after sterilization varied greatly in the juices from the various 
fruits. : 
In strawberry juice the brilliant red color of the freshly sterilized 
juices in all cases faded greatly and further flavor losses occurred. 
Sterilization and subsequent keeping in carbon dioxid were not 
effective in securing color retention. 
Red currant juice very gradually lost in distinctive color and flavor 
on being kept at room temperatures after sterilization and keeping 
in carbon dioxid was not effective in securing either color or flavor 
retention. Cold storage at from 32° to 35° F. was found to be a 
very satisfactory means of controlling color and flavor changes. 
The distinctive colors and flavors of black currant, blackberry, 
and black raspberry juices were satisfactorily retained during pro- 
longed periods at common storage. The flavor of blackberries was, 
however, distinctly less well retained than that of black currants or 
black raspberries, though it did not undergo a perceptible change 
during a storage period of six months. 
In the case of red raspberries the distinctive color and flavor were 
poorly retained, even on keeping the juice in carbon dioxid in cold 
storage at from 32° to 35° F. 
When sterilized and subsequently kept in carbon dioxid the 
distinctive color of pineapple juice remained practically unchanged. 
When exposed to atmospheric oxygen at juice surfaces during and 
after sterilization, marked darkening occurred. Change in color 
was also found to be greatly, though not wholly, retarded by keep- 
ing the juice in cold storage at from 32° to 35° F. On keeping the 
juice at ordinary temperatures the distinctive pineapple flavor 
gradually lessened, though the juices remained recognizable as 
pineapple. By keeping in cold storage at from 32° to 35° F. flavor 
change was almost wholly prevented. 
The distinctive colors and flavors of peach and cherry juices were 
quite well retained while kept at room temperatures. Huckleberry 
juice, hot pressed, lost in flavor on keeping. 
Lemon juice darkened in color if sterilized and kept in the pres- 
ence of atmospheric oxygen, though the color was satisfactorily 
_ retained when the juice was sterilized and kept in carbon dioxid or 
in vacuum. In all cases an off-flavor, designated as a ‘“‘bottled 
lime-juice”’ flavor, appeared in the lemon juice after it had been 
kept for a time after sterilization, even though in cold storage at 
from 32° to 35° F. 
