Satoimo (Colocasia esculenta) can be used as an alternative food source

By Ahmad Suhendra

Satoimo ( Sato-imo) is the name given to taro root that grows wild and is cultivated in Japan. Its name means village potato. Common taro has a long rootstock with a shape similar to a sweet potato, whereas Satoimo is smaller and roughly rounded, with tapered ends. The taste and texture of the different varieties is similar. Taro Satoimo is rich in Hyaluronic Acid (HA), a substance produced naturally within our bodies in abundance when we are young. It promotes strong joints and produces natural collagen.[1]  It also contains potassium , phosphorus, Vitamins B1, B2 and C and Rich in fibers.[2] Taro is closely related to Xanthosoma and Caladium, plants commonly grown as ornamentals, and like them it is sometimes loosely called elephant ear.[2]

Generally, commercial taro producers apply a variety of fertilizers for improved yields. Nitrogen at 100 kg N/ha is often applied as urea or ammonium sulphate, in split applications at 5, 10 and 15 weeks after planting (WAP). Where necessary, 25 kg/ha phosphorus is applied at planting as superphosphate. If potassium is low, 100 kg/ha is split, with one application at planting and the other at 10 WAP. Compound NPK fertilizer (13:13:21) is recommended at 400 kg/ha, with half applied at planting and the other half at 10 WAP. Where available, poultry manure can be used at 10 tonnes/ha, applied two weeks before planting.[1]

Table.1 Proximate Composition of the Taro Corm on Fresh Weight Basis[3]
Component	Content
Moisture	63-85%
Carbohydrate	13-29%
Protein	1.4-3.0%
Fat	0.16-0.36%
Crude fiber	0.6-1.18%
Ash	0.6-1.3%
Vitamin C	7-9 mg/100 g
Thiamine	0.18 mg/100 g
Riboflavin	0.04 mg/100 g
Niacin	0.9 mg/100 g

The main economic parts of the taro plant are the corms and cormels, as well as the leaves. The fresh weight composition of the taro corm is shown in Table 1. The fresh corm has about two-thirds water and 13-29 % carbohydrate. The composition of the carbohydrate fraction is shown in Table 2, indicating that the predominant carbohydrate is starch. The starch itself is about four fifths amylopectin and one-fifth amylose. The amylopectin has 22 glucose units per molecule, while the amylose has 490 glucose units per molecule. The starch grains are small and therefore easily digestible. This factor makes taro suitable as a specialty food for allergic infants and persons with alimentary disorders.

Table.2 Percentage Composition of Taro Corm Carbohydrate[3]
Carbohydrate	Percentage(%)
Starch	77.9
Pentosans	2.6
Crude fiber	1.4
Dextrin	0.5
Reducing sugar	0.5
Sucrose	0.1

The taro leaf, like most higher plant leaves, is rich in protein. It contains about 23% protein on a dry weight basis. It is also a rich source of calcium, phosphorus, iron, Vitamin C, thiamine, riboflavin and niacin, which are important constituents of human diet.

Ref:

1. FAO: Taro cultivation in Asia and the Pacific, 1999
2. http://shizuokagourmet.wordpress.com/2009/12/26/vegetables-facts-and-tips-15-tarosato-imo/
3. Onwueme,I.C.(1994).Tropical root and tuber crops-production, prespectives and future prospect. FAO Plant Production and Protection Paper 126,FAO,Rome.228p
4. http://en.wikipedia.org/wiki/Taro