Effects of partial debranching and storage temperature on recrystallization of waxy maize starch

Waxy maize starch was debranched using an isoamylase (hydrolysis for 24 h or 48 h), and then the debranched starches were recrystallized for 96 h at different temperatures (4, 25, and 50 °C). The structural and crystalline characteristics of the recrystallized samples were analyzed. The longer debranching time (48 h) produced the smaller chains containing more of linear dextrins. Crystallinity and thermal stability were much higher for the starch crystals prepared with the higher level of debranching. The starch chains recrystallized at 4 and 25 °C were recovered at 84-93% yield with B-type crystals whereas those at 50 °C induced a lower yield (11-31%) with A-type crystals. The slow recrystallization (50 °C) induced the selective association of the long chains which led to the formation of A-type crystals having a good thermal stability. The recrystallization temperature was a determining factor for the crystalline arrangement of debranched starch chains.