Comparison of two strains of the edible cyanobacteria Arthrospira: Biochemical characterization and antioxidant properties

Chemical characterization and antioxidant potential of Arthrospira sp., Thalassiosira sp., and Raphidonema sp

Microalgae are emerging as valuable sources of bioactive compounds. This study evaluates hexane extracts from Thalassiosira sp. and Raphidonema sp., and Arthrospira sp., for their bioactive potential. Saturated fatty acids predominated in Arthrospira sp. and Thalassiosira sp. while Raphidonema was rich in polyunsaturated fatty acids. Carotenoids, such as carotenes and xanthophylls, were abundant in Arthrospira sp., while Thalassiosira sp. contained chlorophylls and fucoxanthin derivatives, and Raphidonema sp. showed high levels of chlorophylls and xanthophylls. Antioxidant assays revealed up to 70 % radical scavenging activity, 60 % iron chelation, and up to 67 (μM) ferric-reducing power. Dose-dependent protective effects were observed in Schizosaccharomyces pombe and HepG2 cells, with viability improvements up to 50 %, indicating their potential as antioxidant-rich ingredients for functional foods, promoting health and disease prevention. This study enhances our understanding of Thalassiosira sp. and Raphidonema sp. while underscoring the promising applications of microalgae extracts in functional foods.

Manufacturing processes, additional nutritional value and versatile food applications of fresh microalgae Spirulina

Spirulina is capable of using light energy and fixing carbon dioxide to synthesize a spectrum of organic substances, including proteins, polysaccharides, and unsaturated fatty acids, making it one of the most coveted food resources for humanity. Conventionally, Spirulina products are formulated into algal powder tablets or capsules. However, the processing and preparation of these products, involving screw pump feeding, extrusion, high-speed automation, and high-temperature dewatering, often result in the rupture of cell filaments, cell fragmentation, and the unfortunate loss of vital nutrients. In contrast, fresh Spirulina, cultivated within a closed photobioreactor and transformed into an edible delight through harvesting, washing, filtering, and sterilizing, presents a refreshing taste and odor. It is gradually earning acceptance as a novel health food among the general public. This review delves into the manufacturing processes of fresh Spirulina, analyzes its nutritional advantages over conventional algal powder, and ultimately prospects the avenues for fresh Spirulina's application in modern food processing. The aim is to provide valuable references for the research and development of new microalgal products and to propel the food applications of microalgae forward.

Microalgae/cyanobacteria: the potential green future of vitamin B12 production

This review summarizes the available information about potential sources of vitamin B12, especially for people who follow a vegan or vegetarian diet and inhabitants of poor countries in the developing world. Cyanobacteria and microalgae approved for food purposes can play a critical role as promising and innovative sources of this vitamin. This work involves a discussion of whether the form of vitamin B12 extracted from microalgae/cyanobacteria is biologically available to humans, specifically focusing on the genera Arthrospira and Chlorella. It describes analyses of their biomass composition, cultivation requirements, and genetic properties in B12 production. Furthermore, this review discusses the function of cobalamin in microalgae and cyanobacteria themselves and the possibility of modification and cocultivation to increase the content of B12 in their biomass.