84 



MARINE PRODUCTS OF COMMERCE 



Table 20. Temperature of Gelation and Gel Strength of Agar from Various 

 Sources and of Irish Moss Extractive.* 



Concentration Temp, of Gel 



Per Cent Gelation Strength 

 °F °C Grams 



1.0 87.8 31 15 



3.0 90 



5.0 300 



1.0 116.6 47 120 



1.5 190 



0.5 109.4 43 113 



1.0 and 407 



1.5 138.2 59 650 



1.0 114.8 46 95 



1.5 167 



1.0 98.6 37 187 



1.5 337 



1.0 100.4 38 70 



1.5 80 



1.0 102.2 39 215 



1.5 350 



Carrageenin 



Gracilaria confervoides, California 

 Gracilaria confervoides, Nortli Carolina f 



Gracilaria confervoides, Australia 

 Gracilaria confervoides. South Africa 

 Japanese Gelidium f (plus other sp.) 

 Bacto-Agar (California Gelidium?) 



4000 



q: 3500 



UJ 



^ 3000 



a 



fe 2500 

 Q 



z 

 o 



2000 

 1500 

 1000 

 500 



100 200 300 400 500 600 700 800 900 1000 

 WATER CONTENT- MG. OF H2O PER G. OF DRY AGAR. 



Fig. .5-16. Swelling of agar on absorption of water (from Clark, 1925). 



* Stoloff, L. S., "The Agar Situation," Fishery Market News, 5, 1-5 (1943). 



f The gel strength given for G. confervoides from North Carolina represents a sample 

 of unusually high gel strength; the data on gel strength of Japanese agar apparently repre- 

 sent a sample of below average strength. 



