Abstract:

Mung bean, potato, sweet potato, rice and corn starches were isolated and their physico-chemical properties were compared respectively. Amylose leaching and setback (SB) are the highest for mung bean starch, and they are both highly correlated to apparent and total amylose content. Though mung bean starch has the highest amylose content, yet it does not show thermalpaste stability. The results showed thatduring heating sweet potato starch granules swell rather freely with bad thermal-instability and low retrogradation, indicating hign swelling power, peak viscosity (PV) and breakdown (BD), and low syneresis of the sweet potato starch, while rice starch shows the inverse. The gel consistency is also different among various starches, with potato starch the highest, and rice starch the lowest. The syneresis shows no obvious correlationship with amylose content and seems to be affecfed by other factors.

Key words: starch, amylose, physico-chemical properties, retrogradation