engleski

Influence of microwave-assisted extraction parameters on brown algae Dictyota dichotoma polyphenols

Dictyota dichotoma is a species of brown algae found in rocky littoral and sublittoral zones in a wide range of habitats, from the Atlantic Ocean and the Mediterranean Sea, to the western Indian Ocean. Research has shown that Dictyota dichotoma contains a variety of chemical compounds, including pigments, phenols, flavonoids, alkaloids, steroids, tannins, coumarins, quinones, and glycosides. The presence of these biologically active molecules, especially polyphenols, is often associated with numerous health-promoting properties, which is why they are frequently used to fortify functional foods. Microwave-assisted extraction (MAE) is one of the more sustainable isolation techniques that enable rapid and more effective isolation of these substances. In this study, MAE was applied to isolate Dictyota dichotoma polyphenols in two research phases. In the first phase, the influence of different percentages of aqueous ethanol (0, 30, 50, 70, and 96%) and sample-to- solvent ratio (1:10, 1:20, and 1:30) were investigated, while temperature (60°C), irradiation time (10 min), and microwave power (800W) were kept constant. The total phenolic content (TPC) of the extracts was determined by the Folin-Ciocalteu spectrophotometric method. The choice of solvent and sample-to-solvent ratio showed significant influence on Dictyota dichotoma TPC, and the highest TPC (6.42 mg GAE g-1) was achieved when 30% ethanol and a ratio of 1:60 were applied. In the second phase of the research, temperature (40, 60, and 80°C) and irradiation time (5, 10, and 15 min) were varied, while the ethanol content (30%) and sample-to-solvent ratio (1:60) were kept constant. The results of the statistical analysis showed that temperature had a significant influence (p£0.05) on Dictyota dichotoma TPC, while the influence of irradiation time was not significant (p³0.05). The highest TPC (3.33 mg GAE g-1) was achieved at 40°C after 5 min of irradiation. The results of this study showed the influence of various MAE parameters on Dictyota dichotoma TPC and confirmed the importance of developing optimal isolation method that can lead to the most effective polyphenol recovery.

Dictyota dichotoma, polyphenols, green extraction, microwave-assisted extraction

nije evidentirano