Selection criteria for high-value biomass: seasonal and morphological variation of polyphenolic content and antioxidant capacity in two brown macroalgae

Abstract

The total polyphenolic content (TPC) and antioxidant capacity (AC) of brown macroalgae Macrocystis pyrifera and Lessonia spicata were studied due to the current interest of alginate industries and emerging high-value product industries. The aim of this study was to compare the morphology, TPC, and AC of these species in different seasons for establishing a selection criterion of adequate biomass. The differences between AC and TPC in different seasons and morphological structures were demonstrated by ANOVA. The results showed that M. pyrifera had great variations in both, season and morphological structure, where high concentrations in stipes and fronds were detected in winter. Regarding L. spicata, decrease of TPC and AC was observed only in spring. Significant correlation was observed between both variables using type II regression analysis, indicating that polyphenols are the main compounds responsible for antioxidant capacity in the analyzed species. It has been concluded that L. spicata shows the highest TPC and AC. Regarding morphology, the stipe in M. pyrifera is the most sustainable and abundant structure for adequate use in the food industry. Winter was the season that showed the highest polyphenolic content in both species. Finally, compatibility of alginate industries with polyphenol production was demonstrated through alginate and polyphenolic sequential extractions. In addition to this, recycling of alginate biomass was simulated in the context of bioeconomy. The impact of this study concerns macroalgae collectors, as well as chemical, pharmaceutical, and food industries, adding value to this natural resource and diversifying its use.