Crop description. Cyperus esculentus L.—commonly known as tigernut, chufa sedge, yellow nutsedge, and earth almond—belongs to the family Cyperaceae and grows in warm temperate to subtropical regions of the Northern Hemisphere (see Figs. 4.17 and 4.18). It can be found in Africa, South America, Europe, and Asia. It is a perennial herb, growing up to
90 cm high [138]. Tubers contain 20-36% oil. The oil from the tuber con­tains 18% saturated (palmitic acid and stearic acid) and 82% unsatu­rated (oleic acid and linoleic acid) fatty acids [138].

Main uses. The tubers are edible and have high nutritive value. They contain 3-15% protein, 15-20% sugar, 20-25% starch, 4-14% cellulose, and trace amounts of natural resin. They are used in Spain to make a beverage named horchata, and also consumed fresh after soaking. In other countries, the tubers are used in sweetmeats or uncooked as a side dish. New products obtained can enhance the interest in this crop

Figure 4.18 Cyperus esculentus L. (Photo courtesy of Peter Chen [www. cod. edu/people/faculty/ch enpe/PRAIRIE/2005_09_20/ Cyperus_esculentus. jpg].)

as a source of dietary fiber in food technology, as a high-quality cooking/ salad oil, as a source of starch, as an antioxidant-containing food, and so forth [139]. The oil extracted from yellow nutsedge can be used as food oil as well as for industrial purposes. Since the tubers contain 20—36% oil, the crop has been suggested as a potential oil crop for the produc­tion of biodiesel [138]. Preliminary tests using pure nutsedge oil as fuel in a diesel engine have indicated that the engine operated near its rated power [140]. Currently, it is being studied as an oil source for fuel pro­duction in Africa [53].