COMPARATIVE STUDIES ON PHYSICO-CHEMICAL PROPERTIES OF STARCHES FROM JACKFRUIT SEED AND MUNG BEAN

摘要

The physico-chemical properties of starch from jackfruit seed and mung bean were investigated. Jackfruit seed starch had much higher resistant starch content (26.99%) titan that of mung bean starch (4.04%). Furthermore, jackfruit seed starch had a higher gela-tinization temperature (T_0) that required more gelatinization energy (△H) compared to mung bean starch. However, mung bean starch had higher amylose content and its gran-ules were much larger than that of jackfruit seed starch. Mung bean starch had the highest peak viscosity, breakdown, and setback whereas jackfruit seed starch had the highest pasting temperature. Amylopectin chain length of mung bean starch contained higher proportion of short chains (degrees of polymerization 6-12) but lower proportion of very long chains (degrees of polymerization ≥37 ) comparing with jackfruit seed starch. The X-ray diffraction patterns showed both starches to be Type-A crystallinity. In addition, both starch gels showed higher the storage modulus (G′) than the loss modulus (G″) designating as rubber like material. However, mung bean starch gel exhibited higher G′ and less tan δ than that of jackfruit seed starch indicating much stronger of gel structure.