AGAR AND RELATED PHYCOCOLLOIDS 85 



specific uses for each extractive for which the other two are less suitable or use- 

 less. In addition there are the overlapping uses in which two or more phycocol- 

 loids may be chosen. 



The unique gel strength of agar is responsible for its great value, although 

 the low viscosity of some agars when in melted condition is also important for 

 certain uses. While agar is the most expensive of all the phycocolloids on a dry- 

 weight basis, it is not necessarily the most expensive for some purposes, even 

 where Irish moss or algin can be used. Since considerably less agar is required to 

 obtain a gel of a given strength, the gel may cost less if made from agar instead 

 of carrageenin. 



In Foods. Among the largest users of agar in foods is the bakery industry. 

 Agar is often added to icings to prevent their becoming sticky or adhering to 

 wrappers during damp weather and to prevent excessive drying and brittleness 

 under conditions of low humidity. Agar has been used as a stabilizer in chiflFon 

 pies, meringues, and pie fillings. Except where gel strength is of importance, the 

 variety of Irish moss extractives recently developed have largely replaced agar in 

 baked goods. Agar serves as a stabilizer in sherbets, but usually in combination 

 with tragacanth or other gums. Both agar and carrageenin are used to control 

 the moisture and consistency of fruit cakes. 



In cream cheese of the Neufchatel type agar and Irish moss extractive are used 

 to reduce its tendency to exude whey at summer temperatures and to improve 

 slicing qualities and texture. 



Agar and Irish moss extractive are used in place of gelatin in many jelly candies 

 and marshmallows, as well as fillers in various types of candy bars. Tseng (1944) 

 estimated that over 100,000 pounds of agar are used annually in confections. 



Part or all of the gel-forming substance in jelly desserts, aspic salads, puddings, 

 fruit butters, jams or preserves may be agar or carrageenin. Mayonnaise and salad 

 dressings are usually stabilized by one of these phycocolloids. 



In the canning of pickled tongue, poultry, fish, or other soft meats agar or 

 carrageenin is usually added to prevent the prodvict from becoming mushy in 

 transit. Gelatin is not entirely satisfactory as it melts at summer temperature; 

 carrageenin melts at less than body temperature. Agar is preferred because of its 

 high gel strength and high melting temperature. A large portion of the agar 

 produced in Australia and New Zealand is used for this purpose. 



In Pharmaceuticals. Agar is more widely known as a therapeutic agent for 

 constipation. It is probably superior to all other intestinal "bulk producers" be- 

 cause of the absence of undesirable side effects. Bran, the most widely used 

 remedy, is sometimes irritating. Since agar is indigestible (and hence has no food 

 value), it passes through the human digestive system unchanged. If taken as a 

 suspension of the powdered form in liquid with cereals or in baked goods, it 

 absorbs moisture in the intestinal tract and provides the needed bulk. It has been 

 recommended for elderly persons and children in particular. Agar taken in the gel 

 form is less effective as it does not absorb more moisture or continue to swell. 



Emulsions of agar, water, and mineral oil are only as effective as the oil con- 

 stituent since the agar (or carrageenin) is too dilute to act as anything but an 

 emulsifier. Carrageenin is less effective than agar because it is partially digested 

 and because it absorbs so much water as to lose part of its bulk-producing effect. 



