FISHERY BULLETIN: VOL. 69, NO. I 



undiluted and in alcoholic solution, essential oils, 

 and imitation flavoring compositions. The ad- 

 ditives were obtained from many sources. 



METHODS 



In the initial work, 5-ml samples of menhaden 

 oil, with or without flavor additive, were held 

 in covered plastic petri dishes (100 by 15 mm) 

 for 5 days at 75° F (22° C). Preliminary tests 

 indicated that 1 part by volume of flavoring ma- 

 terial per 400 parts by volume of oil gave about 

 the proper concentration with most flavor prep- 

 arations, so this concentration was used through- 

 out the work. With the large surface of oil 

 exposed to air in this test, a fairly advanced 

 stage of rancidity was reached in 5 days. 



In some of the later work in which larger 

 samples were required, oil in both 200-ml (8-oz) 

 and 25-ml (1-oz) stoppered bottles was stored: 

 (1) at 40° F (4° C) for 8 to 12 weeks, (2) at 

 _20° F (—29° C) for 8 to 12 weeks, and (3) 

 at room temperature— that is, at 75° F (22° C) 

 for 4 weeks. 



For various aspects of this work, especially 

 in preliminary observations, paired comparison 

 tests, duo-trio tests, ranking tests and descriptive 

 tests — all described by Jellinek (1964) were 

 used. For most of this work, however, descrip- 

 tive tests and ranking tests were used; only the 

 descriptive and ranking tests will be tabulated 

 in this report. 



Samples of oil were tasted by immersing the 

 tip end of a plastic spoon into the oil and placing 

 the spoon into the mouth. This procedure 

 avoided coating the lips with oil, and it elim- 

 inated much of the objection of some panel mem- 

 bers to an undesirable oily feel during protracted 

 examination of many samples. 



The panel used in this part of the work con- 

 sisted of 5 to 7 laboratory workers all of whom 

 had had some previous experience with odors 

 and flavors of fish oils. Several preliminary 

 training sessions were held in order for them 

 to become familiar with and be able to use con- 

 sistent terminology for the odors and flavors 

 to be encountered in the experimental work. 



RESULTS 



Initial Screening Test 



In an initial screening test of all 66 flavoring 

 compounds, a degree-of -masking scale was used 

 as follows: + + , very good masking; + , good 

 masking; ±, good masking when first tasted 

 but did not mask aftertaste; ?, questionable 

 masking; — , negative masking — that is, the 

 taste was not masked (Table 1). The flavoring 

 materials are listed in alphabetical order with- 

 in each category. 



Main-Examination Test 



We then made a more detailed examination, 

 paying greater attention to the type of flavor 

 which sometimes varied at diff'erent stages dur- 

 ing the storage of the oil. The following com- 

 ments show certain limitations of many of the 

 flavor additives. 



Fkivoring materials with "green" or "floral" 

 flavor properties. — Because fresh fish oil has a 

 "green-grassy" or "green-cucumber" odor and 

 flavor, two green standards had been worked 

 out in earlier experiments (Stansby and Jellinek, 

 1965). These standards were cis-hexen-3-ol-l 

 and Green Aroma Hr (coded sample of Haar- 

 mann and Reimer, Holzminden, West Germany,' 

 probably: nona-2-enal or nona-2-dienal or a 

 mixture of both (Forss, Dunstone, Ramshaw, 

 and Stark, 1962). These two green standards 

 were tried as masking agents. 



Cis-he.xen-3-ol-l contributed a definite green- 

 grassy note to the menhaden oil and also showed 

 very good masking abilities in the exposed men- 

 haden oil. 



Gi'een Aroma HR contributed a green-cucum- 

 ber note to the fish oil but seemed to have pro- 

 oxidant qualities. In comparison with the con- 

 trol sample, the menhaden oil got rancid faster 

 and reached a higher intensity. These observa- 

 tions seem to be similar to those made about 20 

 years ago on butter with a high content of di- 



' The use of trade names is merely to facilitate de- 

 scriptions; no endorsement is implied. 



216 



