Carrageenans are gel-forming hydrocolloids extracted from the cell walls of marine red algae, such as Eucheuma, Chondrus, Gigartina, Hypnea.

卡拉胶是一种红藻多糖，主要存在于红藻纲中的麒麟菜属、角叉菜属、杉藻属和沙菜属等生物的细胞壁中。