Abstract
Algae comprise different inherent antioxidants. Among them, phenolic compounds can serve as potential antioxidants. Hence, in this review, phenolic compounds and their relationships with antioxidant activity are discussed. Based on published studies, phenolic compounds showed antioxidant activity that even outperformed positive controls in some cases, depending on the type of compound and type of assay such as BHT and l-ascorbic acid. Also, it was found that the degree of antioxidant activity of phenolic compounds, belonging to a specified category, depends on various factors. Besides, it would be interesting to review the efficacy of these compounds in real foods since antioxidant activity in vitro may differ from that in real foods. Accordingly, the addition of seaweeds in various forms to different food products is surveyed. It was found that phenolic compounds delayed lipid or protein oxidation. However, several factors governed their efficiencies in foodstuffs, like food type (food matrix), type of extractant for seaweed extract, presence of other compounds, and oligomeric or polymeric nature of phlorotannins. Ultimately, it is noted that seaweed phenolic compounds can effectively act as antioxidants, but serious limitations must be regarded.