Application of catechin nanoencapsulation with enhanced antioxidant activity in high pressure processed catechin-fortified coconut milk

The efficiency of ultrasonic nanoemulsion to improve physical stability and antioxidant activity of catechins when exposed to stress conditions imitating food process was investigated. The catechin nanoemulsions (CaNE) were fabricated using ultrasonication and subjected to different stress conditions including pH (2-8), ionic strengths (200-1000 mmol/L NaCl) and temperatures (pasteurization, sterilization, and high pressure processing; HPP). Physical stability (droplet size and polydispersity index; PDI) and antioxidant activity (DPPH and FRAP values) of the CaNE were investigated during storage at 4 degrees C for 28 days. The developed CaNE showed good physical stability at various pH (2-8) and ionic strengths (200-600 mmol/L NaCl), whereas DPPH and FRAP values of the CaNE significantly decreased at pH > 6 and NaCl > 600 mmol/L. Pasteurization and sterilization induced an increase in droplet size and a decrease in antioxidant activity, whereas HPP had no effect on the CaNE. The efficiency of nanoemulsion to stabilize catechins in a high pressure processed catechin-fortified coconut milk (HPP-CM-CaNE) was investigated in comparison to HPP-CM and HPP-CM containing catechin solution (HPP-CM-Ca) during storage at 4 degrees C. The decrease in pH and antioxidant activity of HPP-CM-CaNE was less than those of HPP-CM-Ca, indicating that the nanoemulsion could enhance catechin stability in HPP-CM.

Automated summary

The efficiency of ultrasonic nanoemulsion in improving the physical stability and antioxidant activity of catechins under stress conditions was investigated. The study showed that nanoemulsions could enhance the stability of catechins, but the antioxidant activity decreased significantly at high pH and ionic strengths.