STUDIES ON FRUIT JUICES. 9 
through a glass or block tin delivery tube reaching nearly to the 
bottom. When the desired temperature has been reached, the flow 
of carbon dioxid is momentarily increased, the delivery tube being 
withdrawn at the same time and a paraffined cork stopper, taken 
from scalding water, instantly inserted. 
In BortreEs. 
The juice is cooled to refrigerator temperatures in a cask and a 
current of carbon dioxid passed through until the product tastes 
distinctly of the dissolved gas. It is then transferred to the bottles. 
The air above the surface of the juices in the bottles is displaced by 
a rapid current of carbon dioxid after which the cork is instantly 
forced into position, tied in place and the bottles and contents given 
the necessary heat treatment. By thus lightly carbonating, excessive 
pressures due to carbon dioxid are not developed on heating. 
The principal effect of thus excluding atmospheric oxygen by 
carbon dioxid is the satisfactory retention in color observed in citrus 
and pineapple juices. The products are at the same time HD. 
in palatability by the presence of carbon dioxid. 
EXPERIMENTAL WORK. 
A condensed summary of the experimental work with the different 
fruit juices taken from the laboratory notes follows. Except where 
noted to the contrary, the conclusions are based on the work of three 
or more successive seasons. 
STRAWBERRY JUICE. 
Locally-grown berries, variety Gandy, were used in most instances. 
Pressing.—To secure good yields it was necessary to grind before 
pressing, the pressure being applied very gradually to allow time for 
drainage. The yields ranged from 63 to 88.06 per cent. 
Sterilization.—The juices were sterilized without injury to color, 
but with marked injury to fresh fruit flavor. A cooked strawberry 
taste developed. 
Keepung after stertlization.—Color and flavor changed greatly on 
keeping the juice in common storage, even in carbon dioxid. The 
beautiful, bright, red colors faded to dull brownish-red tones, and 
all distinctive flavor of strawberry disappeared, except for a slight 
cooked strawberry aroma. Disagreeable flavors developed upon 
prolonged storage at common temperatures. 
Keeping in freezing storage and concentration by freezing—Raw 
strawberry juice retained well its original color and flavor in freezing 
storage at —10°C. (14° F.) for nearly 8 months. The juice could be 
concentrated easily by freezing, but when partly concentrated be- 
came gelatinous, the juice and ice se cena with difficulty. 
91345°—Bull. 241—15——2 
