168 U. S. BUREAU OF FISHERIES 
TaBLe 25.—Free fatty-acid content of fry-bath oil samples from the first and second 
runs of frying experiments } 






Date, | Per cent,| Per cent, Date, | Per cent,| Per cent, 
Run 1921’ | BathI’| Bath IL Run 1921 | BathI’| Bath i 
| 
inshore Bose ds Start 0.1 0.1 Second—Contd. 
(aja, SPP Seer Fans ly) 2 -1+ 1D ee ee Sete Feb. 16 3+ ae, 
1D Yih be Pe ee ean Jan. 18 2 -1-+ Doles ase Feb. 17 5 2+ 
Doh Asa. Jan. 20 2+ 2+ Doser eee Feb. 18 5+ 24+ 
1D Yo)S2 es et ees Jan. 21 2+ 2+ 1B oj f eran os Mar. 4 5 =o 
1D hie eee @ Jan. 29 3+ 3+ Do. ee Mar. 6 5 Sa 
1) GL Soe bee Feb. 2 44+ 44 DOL Sees Mar. 7 5 -3+ 
DOE Se 2 ee Feb. 3 4+ 4 Dor veeesess S| Mar. 8 5 ai 
DQelss: Bese Feb. 4 4 50 1D Ys)-; Aa Se Mar. 10 .6 aii 
IDOL See ref Feb. 9 6 .6 1D oe Le See Mar. 17 6+ ~o+ 
Seconds: aon 22 Start. 2+ mall 1D Ore eee Mar. 18 6+ .5-+- 
1D {cps ee 2 Feb. 11 24+ 1 
DoF tas Se Feb. 15 8+ 2 






1 Analyses conducted as follows: Sample taken with pipette, which delivered 8.6 grams of oil. Hot 
neutral alcohol (50 c. c.) was added and the acidity neutralized with N/10 sodium hydroxide, using phe- 
nolphthalein as an indicator. Percentage of free fatty acids calculated as oleic acid. 
TABLE 26.—First set of heating tests on oils used in frying sardines. Color and 
viscosity comparisons } 










COLOR 
S Color comparison of sample with original sample 2 
3 : ia 
: ~ oC 
iS 3 S iS} 3 Apr. 15 | Apr. 22 Apr. 27 (1921) 
2 2)/a¢}]e3/¢ ; 
a °o jo) — 
Bisa. ies deel Open toair| ©!0S¢d to | Open toair| Closed to air | Open to air | Closed to 
a| ° a 3 air air 
NM | ie) = ie) mM 
TF 200 YE Oe bea ee Nochange_| Nochange_} Slightly Slightly lighter] Same____-__- Same. 
lighter. 
Dil ae DOO he eon Cee do2 5 =e 2 dotea way Sdgeeres Same____._.._| Very slightly Do. 
lighter. 
| Peete | eae G/T 1G at a es do-ee-2|*- do s2 seas GOs se Very slightly |__-_- do=s42 5 Slightly 
darker. darker. 
Ci reel Ng Sede a 2007-22002) = --s|Eeado4a eee Reddish __| Same___-_----- Red-t22 2234 Same. 
Ba PLOO |= 2 || sea 100, |222d0r= 2] A= doe Dark yel- |__--- do_______.| Reddish tinge Do. 
ow. 
G),| sae (GEOOu Eee 100) E@dowee55| ts doss ses s|o- dose aes banees dows se eae dole aaa 08 
7h Ae [omeeh 100')|:100) |. -doL st |25 dota eh 2|22-do-2 22) Slightly lichten|penes do. Slightly 
| lighter. 
tote! Sa 5, 0)5 | eee es 50l)|| = Sd Oa Seale eo eee SEA00 886222 ee nee cea E eee dos 2232.2 






1 Samples to be exposed to air were placed in 250-cubic centimeter beakers with glass stirring rod. Other 
samples were placed in the same sized bottles, having ground glass stoppers. Beakers and bottles were 
then partly buried in the sand or a sand bath placed on an electric hot plate and the oils kept at a tempera- 
pare of 212 to 240° F. Ten cubic-centimeter samples were taken at the beginning of the run and at three 
other times. 
? Heating began on Apr. 14, 192). All original samples were yellow in color. Colors were observed in 
12 cubic-centimeter test tubes, each of which held slightly over 10 cubie centimeters of oil. 
§ Lighter than sample 5. 
VISCOSITY 
Rough visual comparison of the viscosities of the oils heated to April 27 showed 
the following: Pure oils, in order of decreasing viscosity, 4, 2, 3, and 1 the same; 
mixed oils, 8, 5, 6, and 7, 
ARE OT EEO NCE NG NE 

DEO ti 

