136 U. S. BUREAU OF FISHERIES 
the hot air draws the skin tightly about the flesh and holds the oil 
under it. 
Although the drippings were small in amount, they caused trouble. 
They fell on the fish below and dried, leaving unsightly marks. The 
protein, including blood, left dark stains. The oil dried (oxidized) 
in the sense that paint does, turning dark in color. In fact, it actually 
baked on the skin as enamel is baked on an automobile fender in an 
oven. Some fat fish, upon which the marks were quite pronounced, 
did not lose the marks very soon after canning. At the end of a year, 
when examined, most of the marks had disappeared, but the oil in 
the can showed that the dark oil had mixed to some extent with the 
light yellow oil from the fish, 
It was a simple matter to prevent these difficulties. A drip pan 
was placed under the fish and this protected those below. 
Cooling.—In the experiments large ‘“‘oval’’ fish, direct from the 
cooker, always were cooled sufficiently to be handled for packing in 
15 minutes, when placed in the large cooler and treated with outdoor 
air having a velocity of about 1,400 feet per minute and a tempera- 
ture ranging from 65° to 80°. In experiments 159a and 163a fish 
were cooked, cooled in this way, and given to a girl to pack as they 
were removed from the cooler. No difficulty was encountered. 
QUALITY OF PRODUCTS 
Fish prepared by the new process were excellent, both before and 
after canning. Their physical condition was equal to and _ their 
appearance and taste better than the general run of fried fish. The 
bad effects that frying in ‘‘old”’ oil has upon quality were absent, 
of course (p. 104). These conclusions were drawn from the results 
obtained from at least 95 different cooking experiments spread out 
over the entire 1923-24 sardine season in San Pedro, Calif. A few 
lots were also prepared in Monterey during the next season. The 
fish from 40 of these experiments were canned, and of this number 27 
were compared with commercial packs of fried fish put up in a regular 
sardine cannery from the same lots of fish as were used in the experi- 
ments. In one experiment enough fish were prepared to make 304 
cans and in another 289 cans. 
Most of the work was done upon the preparation of fish for the 
pound-oval pack. Of the experiments, however, 10 were upen fish 
for the quarter-oil pack, 5 lots of which were canned. These experi- 
ments were very successful and show the possibilities the new process 
holds out to producers of quarter-oils in California. 
In one experiment fillets from large, oval-size, fat fish were used. 
They cooked rapidly, lost much water, and were excellent, except 
for two drawbacks. The exposed flesh darkened and the oil, not 
being held in the fish and protected by the skin, oxidized considerably. 
This oxidized oil gave a sort of ‘‘biting taste,’’ which persisted when 
these fish were canned. It was more pronounced when the fish were 
canned in oil than in tomato sauce. The latter seemed to mask the 
taste considerably. Lowering the air temperature, although it did 
not prevent oxidation, bettered matters.*? 


58 Part of the information given in this paragraph was obtained from some experiments not reported 
upon here. It would be possible to blow over the fish air from which most of the oxygen had been re- 
moved by combustion. Oxidation could be kept at a minimum in this way, and this should give a better 
product, s 
