Research on the optimization of preparation and the application analysis of antioxidant activity of mycosporine-like amino acids derived from marine macroalgae

In recent years, mycosporine-like amino acids (MAAs) have demonstrated extensive application prospects across various fields such as food, pharmaceuticals, and cosmetics. In a previous study we conducted, the MAA extracts obtained from several macroalgae contained a large amount of pigments, which introduced numerous interfering factors to the study of the extract's activity. In this study, the extraction processes of MAAs of the six macroalgae, such as Bangia fuscopurpurea, Gelidium amansii, Sargassum fusiforme, Palmaria palmata, Sargassum sp., and Undaria pinnatifida, were optimized with the aim of reducing the pigment content in the MAA extracts. Additionally, their in vitro antioxidant activities, anti-browning effects, and mineral contents were also analyzed. Furthermore, the target MAA extracts were combined with several common food additives to explore their impact on the stability of the target MAA extracts. The results indicated that the removal of pigments along with multiple alcohol precipitation could remarkably diminish the pigment content within the MAA extracts and augment the extraction yield. Through this pretreatment method, the yields of the MAA extracts from Bangia fuscopurpurea and Gelidium amansii were elevated to 1.5 times and 1.1 times their original values, respectively. The MAA extracts from the six macroalgae predominantly consisted of palythine, palythenic acid, shinorine, and/or porphyra-334. Among them, the MAA extracts sourced from Sargassum fusiforme and Bangia fuscopurpurea exhibited stronger antioxidant capabilities and more pronounced anti-browning effects. These MAA extracts were also rich in both macro- and micro-elements essential for the human body, while being devoid of any harmful mineral elements. Carrageenan and agar proved effective in maintaining the stability of the MAA extracts from Sargassum fusiforme and Bangia fuscopurpurea. Overall, the MAA extracts from Sargassum fusiforme and Bangia fuscopurpurea demonstrated favorable potential for application in the food industry.