Optimisation of ultrasound-assisted extraction conditions for phenolic content and antioxidant activities of the alga Hormosira banksii using response surface methodology

Dang et al. optimized ultrasonic conditions for highest yield of TPC and higher antioxidant activity; optimum conditions were 30 °C, 60 min, and 60% (150 W).

“Dang et al. [49] optimized the ultrasonic conditions for obtaining the highest yield of total phenolic content (TPC), and, consequently, higher antioxidant activity. They concluded that optimum conditions were temperature of 30 °C, time of 60 min and power of 60% (150 W).”

Available data of UAE extraction of macroalgae shows polyphenols and antioxidants are the main extracted compounds, using solvents such as ethanol, distilled water, and methanol with different solid:solvent ratios.

“Available data of UAE extraction of macroalgae shows that polyphenols and antioxidants are the main extracted compounds from macroalgae (Table 2). Various solvents were used, such as ethanol, distilled water, and methanol with different solid:solvent ratio [7,49,50].”

Antioxidant activity increased as TPC increased because phenolic compounds contribute most to antioxidant activity.

“Also, these studies showed that antioxidant activity increased as TPC increased because phenolic compounds contribute most to the antioxidant activity.”

Higher amount of TPC is shown by Kadam et al. because they used acid (0.03 M HCl) as solvent, while Dang et al. used ethanol; both authors used various species, which explained difference.

“The higher amount of TPC is shown by Kadam et al. [52], because they used acid (0.03 M HCl) as solvent, while Dang et al. [49] used ethanol. But, both authors used various species of macroalgae, which explained the difference between amounts of extracted polyphenols.”

According to Dang et al., temperature exhibited strongest influence on extraction yield and amount of extracted phenolic compounds, while Topuz et al. concluded solvent:seaweed ratio exhibited most influence on TPC.

“According to Dang et al. [49] the temperature exhibited the strongest influence on the extraction yield and amount of extracted phenolic compounds, while Topuz et al. [51] concluded that the solvent:seaweed ratio exhibited the most influence on TPC.”