2.4.2. pH Stability

The pH values of quercetin-loaded HZ, HZ-chi and HZ-chi/pec particles were adjusted from 2 to 9 with 0.1 mM hydrochloric acid and sodium hydroxide and then continuously stirred for 30 min [8]. Particle size and ζ-potential were analyzed by diluting them in pH-adjusted Milli-Q water [23].

## 2.4.3. Temperature Durability

Quercetin-loaded HZ, HZ-chi and HZ-chi/pec particles were incubated in a water bath at 30, 40, 50, 60, 70, 80 and 90 ◦C for 30 min and evaluated for particle size and ζ-potential [8].
