Red Seaweed Extracts (Agar, Carrageenans, Furcellaran)

Abstract

In Japan, the agar-bearing seaweeds are gathered from rocks between mid- and low-tide marks, or else divers collect them from the sublittoral regions. For centuries, agar was produced by simply boiling seaweeds to obtain a gelatinous mass. The modern methods of preparation and purification was discovered by accident. The harvesting of carrageenan-bearing seaweeds uses a traditional, manual type of operation. Much of the raw material is harvested by workers in boats using special rakes to scrape the seaweeds from their attachments to rocks and ocean floor. The carrageenans are quite stable at pHs of seven or higher, but at lower pHs their stability decreases, especially at elevated temperatures. Carrageenan has been used in the preparation of fabricated protein fibers from soy, peanut, casein, and other proteinaceous materials. Both carrageenan and furcellaran have been used to prepare low calorie and/or sugarless versions of such custard and flan-like puddings.