Abstract:

In-Vitro model and 76-13 standard method of the American Association of Cereal Chemistry (AACC) were used to evaluate the digestibility and enzymatic resistance of mechanical activated cassava starch and its acetylated starch. Results indicated that mechanical activation significantly improved the digestibility of cassava starch granules. Meanwhile, longer activation time could result in enhanced digestion rate and less enzymatic resistance starch. The major reason was due to the damage of crystal structure and compact granule surface of cassava starch, which improved the sensitivity of starch granule digestibility and reactivity. Acetylation also resulted in an increase in digestibility of activated starch granules, a reduction of digestibility of starch pastes, and destroyed and inhibited the formation of enzymatic resistance starch. However, decreases in digestion rate of starch granules and pastes and enzymatic resistance starch content were also observed due to increasing degree of substitution (DS).

Key words: cassava starch, mechanical activation, acetylation, digestibility, enzymatic resistance starch