Title : The potential of Porphyra umbilicalis from the Atlantic coast of Spain to obtain new proteins via microbial fermentation
Abstract:
Macroalgae (red and brown seaweeds) are feedstocks very rich in carbohydrates (up to 60% content), but generally low in protein content (< 20%) and digestibility. However, macroalgae seem a very promising substrate for biomass fermentation to increase protein content. This study aims to evaluate the nutritional composition and antioxidant potential of 5 macroalgae species collected in the Atlantic Coast of Spain to evaluate its fermentation properties to obtain new proteins via microbial fermentation. For this, a comprehensive nutritional analysis was conducted in terms of total content of carbohydrates, protein, and lipids together with the total phenolic content (TPC). In addition, the amino acid, the phenolic and fatty acid profile were determined using LC-MS/MS or GC-FID. The results indicate that macroalgae species exhibit abundant nutritional components and diverse bioactive compounds, with significant differences in the content of macronutrients and micronutrients. Particularly, Porphyra umbilicalis (P. umbilicalis) shows relatively high accumulation levels of both protein and carbohydrates, reaching 31% and 55%, respectively. The fatty acid profile reveals that P. umbilicalis contains a high level of polyunsaturated fatty acids (PUFAs) and the highest amount of eicosapentaenoic acid (EPA, C20:5n3). The proportion of non-essential amino acids (NEAA) is relatively elevated. Moreover, the TPC of P. umbilicalis was three times higher than that obtained from other macroalgae, demonstrating extremely strong antioxidant properties, which was related to the abundant content of flavonoids (such as tricin, apigenin, amentoflavone) substances. In conclusion, P. umbilicalis is rich in protein content and has the potential to serve as a sustainable source of functional compounds, highlighting its value for industrial fermentation applications.
