The Effect of Ohmic, High-Pressure Carbon Dioxide (HPCD), and Maceration Extraction methods on Bioactive Compounds of Iranian Brown Algae (Nizimuddinia zanardini)

Marine algae are a rich source of bioactive compounds with promising applications as nutrients, functional food ingredients, and therapeutic agents. This study aimed to investigate the effects of temperature and time variables in ohmic, HPCD, and maceration extraction methods on extraction yield, total phenolic content, total phlorotannin content, total flavonoid content, and antioxidant activity (DPPH radical scavenging) of the Iranian brown seaweed Nizimuddinia zanardini. The results showed that the highest and lowest total phenolic and phlorotannin contents were obtained using ohmic (45°C for 120 min: 960.7 mg GAE/g, 1016.17 mg PGE/g) and maceration (45 °C for 24 h: 307.96 mg GAE/g, 281.83 mg PGE/g) methods, respectively. Moreover, the maceration method at 45 °C for 24 h yielded the highest total flavonoid content (242.67 mg QE/g). The HPCD method at 30 °C for 60 min exhibited the highest antioxidant activity (DPPH scavenging: 83.08%). In terms of extraction yield, the ohmic method at 45 °C for 120 min achieved the highest value (33.21%). The findings of this study indicate that among the three extraction methods, the ohmic method demonstrated the highest efficiency in extracting bioactive compounds from Nizimuddinia zanardini.