Biorrefinaria da macroalga vermelha gracilaria birdiae (Plastino e Oliveira) visando a obtenção de r-ficoeritrina e ágar para aplicação em alimentos

Abstract

The concept of biorefinery emerged from the search for the complete use of biomass to obtain a wide range of products. Marine macroalgae are photosynthetic organisms that biosynthesize a series of compounds of commercial importance. R-phycoerythrin, a red fluorescent pigment-protein complex classified as phycobiliprotein, is present in red algae and has potential application in the food, cosmetics, health and biotechnology industries. Agar, another biomolecule extracted from these organisms, is a polysaccharide with wide application in industrialized products, analyzes and diagnostic methods. This is the first study that reports the production of R-phycoerythrin (R-FE) and agar from the red macroalgae Gracilaria birdiae under the biorefinery concept. In the first chapter, a strategy and two optimizations of extraction and partial purification of R-FE were evaluated and the most promising pigmented fractions were F25/35, F25/35 and F25/45 with indices of purity/yields 1.64/0.17, 0.71/0.44 and 0.56/1.20 mg.g-1, respectively. The colorimetric parameters showed the maintenance of color after the steps of obtaining and drying the pigment. The agar obtained from the residue from the extraction of R-FE (ARES-Gb) showed a yield of 31.64%, higher than those reported in the literature when extracted from wet or dry macroalgae and with physicochemical and rheological properties similar to commercial agar. In the second chapter, the study focused on the physicochemical characterization and antioxidant activity (ABTS•+ and DPPH) of R-FE. The pigment stability against different additives (ascorbic acid-AA; sodium benzoate; disodium EDTA and glucose) was higher in the presence of AA, reducing pigment color losses during the 30 days of storage at 25°C. Therefore, the biorefinery of the red macroalgae Gracilaria birdiae allowed a better use of algal biomass, since it made it possible to obtain two compounds of commercial interest, with R-FE with an adequate purity index for application in food, antioxidant activity and stable under storage and agar with yield and physicochemical properties similar to the commercial one.