Structural and physicochemical properties of granular starches after treatment with debranching enzyme.

The present study modified maize and potato granular starches by partial debranching treatment below the gelatinization temperature, and investigated their structural and physicochemical properties. Pullulanase was much effective (more than three times) on hydrolyzing potato starch compared to maize starch as measured from total carbohydrate values in the supernatant. The pullulanase hydrolysis decreased the amount of double helices as observed from DSC measurement. These effects were dependent upon the time of enzyme hydrolysis (24h>8h>1h) as well as type of starch (potato>maize). The pullulanase hydrolysis decreased the peak viscosity of the potato starch paste, whereas the effect was very less pronounced for maize starch. The current results showed that it is possible to achieve the starches with desired physicochemical properties by varying the starch type as well as modification process.