Macroalgae are an emerging alternative source of various chemicals and materials due to their unique structure, biochemical composition and high photosynthetic rates. They are promising feedstocks for the sustainable supply of commodities and specialties for food, feed, materials and energy.
SMART SEAWEED aims at maximizing the extraction of high-value components from macroalgae through a cascade biorefinery. A conscious biorefinery concept applied to marine algae effectively directs every fraction towards high added-value products thus promoting a sustainable exploitation of marine algal resources. In this project we specifically propose the valorization of the protein and the carbohydrate seaweed fractions.
Valorization of seaweed proteins
Seaweed represents a novel and promising protein source.
Protein from seaweed contains all essential amino acids, having thus a high nutritional value, comparable to that of the common poultry egg. Some seaweed species have higher protein content than conventional protein-rich foods such as soybean (35% on dry-weight basis). Due to the intrinsic quality of seaweed protein it is important to find ways to improve its bioavailability for food and feed applications. Three different technologies namely heat processing, fermentation and protein extraction will be attempted in this project aiming to improve the bioavailability of proteins and other nutrients.
Extracted proteins/peptides and protein-rich processed seaweed will be tested as ingredients in aquafeed and the effect of their incorporation on seabream growth will be assessed.
Valorization of seaweed carbohydrates
The carbohydrate fraction in macroalgae can represent up to 75 % of the total dry-weight. Seaweed polysaccharides such as agar, carrageenan and alginate are commercially valuable products currently extracted from seaweed resources. The seaweed phycocolloids industry uses only 15–30% of the total dry mass while the remaining is mostly considered waste. Recent studies have shown that seaweed´s residues still contain a considerable amount of insoluble carbohydrates, i.e. cellulose, which can be upgraded to biofuels or biomaterials through fermentation. The production of two different added-value products based on algae carbohydrates is proposed: polyhydroxyalkanoates (PHAs), which are biodegradable bioplastics, and cosmetic ingredients.
Three different seaweed species very common in the Portuguese coast and with high protein content were chosen as model.
Identify the best method of processing seaweeds to increase the potential interest of this feedstock as food and feed ingredient by evaluating the bio-availability of nutrients and proposing lower and upper limits of incorporation.
Deliver a protein-rich ingredient derived from seaweed to be incorporated in aquafeed and understand its effect on the growth and quality of seabream.
Determine the best protocol for extraction of the protein fraction in the three model seaweeds.
Determine the best hydrolysis protocol to attain a sugar-rich hydrolysate from seaweed residues after protein extraction.
Select the best technologies for PHA and cosmetic ingredients production based on seaweed hydrolysates.