2010 年 1 巻 2 号 p. 102-106
Yam Tubers were classified in the Family Dioscoreacea which is starch staple foods. This is the main source of starch supply in Africa. The original from Southeast Asia are D.alata and D.esculenta. Yam tubers were distributed to all region parts of Thailand. The aim of this research is to study some physical-chemical properties of starch obtained from three types of yam tubers from two species: water yam (mun jao diang: jd and mun lued: ld) and lesser yam (mun mue seu: ms) as alternative for food industry. Starch was extracted from fresh tubers by wet milling process and purification. Products were compared among three types of yam tubers. The yields of starch were about 17.01-41.73% for jd and ms, but ld was quite different in starch content at 95-99% (dry weight) estimated by enzymetric method. The chemical properties were not quite different, but the structural starch granule by image analysis and morphological approach by scanning electron microscope (SEM) showed that the shape of D.alata were trigonally rounded with average size of 20-26; also in D.esculenta the shape was polygonal with average size of 4.7. It was considered that some of starch granule could be destroyed by milling process. Viscosity and some functional properties were not remarkably different for all of yams starch.
