Vegetarian Gelling Agents Agar agar, Carragheen and the proprietary products Gelozone and VegeGel are the best known vegetarian gelling agents and are used in place of gelatine, aspic and isinglass.
Agar agar is derived from gelidium species of red sea vegetable.
The gelling abilities of agar agar are affected by the acidity or alkalinity of the ingredients it is applied to. Acidic fruits such as citrus fruits and strawberries require greater amounts of agar agar. Kiwi fruit is too acidic and prevents gelation. Pineapple, fresh figs, papaya, mango and peach will not set as they contain enzymes that break down gelling ability, however, cooking the fruit will negate this effect. Chocolate and spinach also prevent gelation.