Scoping Australian macroalgae for health and nutritional applications

Macroalgae are an abundant and diverse group of organisms. Their polysaccharides are successfully utilised in industry due to their rheological properties, but the diverse and unique functional metabolites in macroalgae are still poorly exploited. This holds a lot of promise for health and nutritional applications. However, the variability across taxa and shifting metabolites in response to environmental conditions has resulted in an inconsistent or complex story of nutritional and health opportunities from macroalgae. In addition, the methods used to analyse metabolites from sources other than macroalgae may not be directly transferable, due to peculiarities of the algal organic tissue matrix. Therefore standardising the methods for characterisation of important macroalgal metabolite profiles and the cultivation effects on metabolites of target taxa are two of the aims of this work. Consistent and validated metabolic and compositional metabolite profiles will be required to deliver traceable, quality-controlled biomass with optimal chemistries for applications in health and nutrition. South Eastern Australia is a diversity hot spot for algal flora and species endemism, yet it is poorly understood which species should be targeted for cultivation towards food and health markets. Here for the first time, typical macroalgae of the Eastern temperate coastal zone of New South Wales (NSW), Australia were explored including the taxa Hormosira banksii, Phyllospora comosa, Myriogloea sciurus, Ecklonia radiata, Solieria robusta and the green macroalgae Ulva.1 Particular attention was directed towards their fatty acid (FA) profiles, anti-inflammatory, anti-oxidant and cell toxicity or functionality. In doing so, robust methods were tested and developed to establish optimal protocols for effective metabolite extraction and characterisation.