Introduction
Apart from the rice and cane sugar industries, the tapioca starch-processing industry has played an important role in the Thailand's agricultural economy. Known as the world's largest producer and exporter of tapioca starch, Thailand produced over seven million tons of starch in 2004. Approximate annual revenue from tapioca starch export is 38,805 million baht or 1060 million dollars [1]. Tapioca is produced from treated and dried cassava (manioc) root and used in the food, paper, and toothpaste industries. Only 20% of the cassava root harvested in Thailand is delivered to starch-processing plants, while the rest is used in the production of pellets and chips. Currently, Thailand has 92 tapioca processing plants with a total production capacity of native and modified starch at about 16,910 and 4350 ton/day, respectively [1]. Normally, these tapioca plants operate 24 h a day for 8–9 months, from September to May.