Abstract:

The preparation of microencapsulated anthocyanins from Lycium ruthenicum Murr. using spray drying was
investigated and the stability of the native and microencapsulated anthocyanins was evaluated. Single factor experiments
were used to examine the influence of proportions of arabic gum and β-cyclodextrin to coating wall, core-to-wall ratio, feed
flow rate, inlet air temperature, and total solids content on microencapsulation efficiency. The selected key parameters were
optimized using response surface methodology with Box-Behnken experimental design. The results showed that the optimal
process parameters were as follows: rotary speed of 2 000 r/min, emulsification time of 10 min, outlet air temperature of 80 ℃,
1% arabic gum and 50% β-cyclodextrin in the coating wall, feed flow rate of 330 mL/h, core-to-wall ratio of 1:2.5 (g/g), inlet air
temperature of 160 ℃, and total solids content of 22%. Under these conditions, the microencapsulation efficiency was 91.01%.
The anthocyanins microcapsules were rose-red powder with a cylinder-like shape, having average particle size of (9.16 ± 1.02) μm.
The microcapsules were more stable than the native anthocyanins when exposed to light, air and temperature.

Key words: Lycium ruthenicum Murr., anthocyanins, microencapsulation, spray drying, response surface methodology