Use of enzymatically modified starch in the microencapsulation of ascorbic acid: Microcapsule characterization, release behavior and in vitro digestion

Microcapsules were prepared using enzyme-treated corn starch with 16 and 20 h of hydrolysis time (ETCS 16 h-GA and ETCS 20 h-GA) and coated with gum (GA). Microcapsules made only from GA were used as control. The increase in hydrolysis time caused an increase in the number and size of pores on the corn starch. The percentage of total starch decreased with the increase in hydrolysis time, while apparent amylose increased. The starch/ascorbic acid ratio in the microencapsulation process was 1/0.1 (shell/core). Particle size to ETCS 16 h-GA and ETCS 20 h-GA were 1087.44 μm and 1245.43 μm, respectively. While that for GA microcapsules was 12.71 μm. The ETCS microcapsules showed a lower percentage of retention and surface ascorbic acid (AA) than GA microcapsules. ETCS 16 h-GA microcapsules lost less AA during storage time and provided a better protection for AA during digestion in the gastrointestinal tract (GIT); these benefits were more noticeable from day 7 of storage. ETCS can be used as a wall material, as it shows greater stability in the protection of AA and allows for a controlled release in the GIT.