54 MASS. EXPERIMENT STATION BULLETIN 449 



vestigations have been carried on to determine the percentage of the come-up 

 time which may be applied as process time for home-canned foods processed in a 

 pressure canner at 240°F. The time required, after the completion of the venting 

 period, for the pressure canner to reach the desired processing temperature was 

 taken as the come-up time. Come-up times ranging from to 60 minutes were 

 studied. The test media used were 1 and 5 percent suspensions of bentonite, 

 representing convection and conduction heating products, respectively. Pint 

 home-canning jars were used as containers. With 1 percent bentonite suspensions, 

 30 percent of the come-up time was equivalent to process time at 240°F.; while 

 50 percent of the come-up time could be applied as process time in the case of 

 5 percent bentonite. The effect of the come-up time on the length of the process 

 time was independent of the pressure canner load and of the rate of cooling in the 

 jars. 



Trimethylamine Production as an Indication of Spoilage in Fish. (C. R. Fel- 

 lers, and D. Anderson.) The effect of temperature on trimethylamine production 

 in samples of swordfish stored at 75°F., 40°F., and 32°F. was studied. Tri- 

 methylamine formation decreased with a decrease in storage temperature. A 

 correlation of trimethylamine and ammonia formation was noted only at the 

 highest storage temperature used. No correlation was observed between tri- 

 methylamine and bacterial content. 



A method was perfected for obtaining sterile fish muscle press juice, which 

 was used as a medium for determining that chemical autolysis occurring in fish 

 muscle did not reduce trimethylamine oxide to the amine. Fifty microorganisms 

 isolated from spoiled fish muscle were tested for the trimethylamine oxide re- 

 ducing characteristic. Those microorganisms which reduced the oxide were 

 identified as members of the coliform group. 



Chemical dips of a 0.3 percent solution of sodium benzoate and a 0.2 percent 

 solution of sodium nitrite inhibited the formation of trimethylamine. Acetic 

 acid and sodium chloride dips did not affect trimethylamine amine formation in 

 swordfish muscle. 



Stability of Color in Fruit Juices. (J. E. W. McConnell, E. A. Nebesky, and 

 W. B. Esselen, Jr.) The effect of length of storage, and the relationship of 

 oxygen, light, sugar, pH, and ascorbic acid to deteriorative changes in the color 

 of seven representative fruit juices (blueberry, currant, raspberry, tomato, grape, 

 strawberry, and cherry) and strawberry fountain syrup have been investigated. 

 Similar studies were made on solutions of purified anthocyanin pigments isolated 

 from strawberries and currants to observe whether deteriorative changes in 

 juices of these fruits were directly associated with changes in the pigment. 



Temperature of storage and oxygen content were the agents most responsible 

 for deterioration of color during storage of both juices and isolated pigments. 

 Exposure to light caused little deterioriation of color in the juices, but exerted a 

 measurable bleaching effect on the isolated anthocyanin pigments. Adjustment 

 of pH values had little efTect on deterioration of color in fruit juices, but some 

 effect could be observed in solutions of isolated pigments. Sugar had little effect 

 on stability of color in either juices or pigment solutions. The addition of 1-ascor- 

 bic acid (50 mg. per 100 ml. of juice) had no protective effect on color stability 

 with any of the juices except blueberry and grape. Addition of similar concen- 

 trations to strawberry anthocyanin, resulted in virtually complete decolorization 

 of the pigment. 



The Non-Enzymatic Browning of Foodstuffs, (W. B. Esselen, Jr., V. Lewis, 

 and C. R. Fellers.) A study was made of some of the reactions that result in the 



