Search

The production of animal and terrestrial plant proteins has environmental impacts that could limit their sustainable supply. Proteins from microalgae and macroalgae can support the growing animal-free protein demand sustainably, using non-arable land and seawater. However, current technologies and processes developed for terrestrial plant protein processing have multiple limitations when applied to micro and macroalgae, thus, providing an opportunity for emerging technologies. Here we critically review various methods used for micro and macroalgal cell disruption for protein extraction. The pulsed electric field (PEF) algal biomass process is focused on further and highlighted as a green approach for protein extraction from algae. The potential of high-voltage pulsed electric fields and electroporation technologies for algal protein processing are discussed in detail. Current state of the art, challenges, and perspectives are also discussed. The current review will aid in establishing PEF for processing algal biomass to extract valuable compounds including proteins using a non-thermal and chemical-free approach, thus providing an environmentally friendly solution for protein extraction from algae along with highlighting upscaling and processing challenges. [ABSTRACT FROM AUTHOR]

Assessment of abiotic impact on seaweed chemical composition is required for their use as crops and feedstock for biorefinery. This study investigated how seasonality and the culture age of Ulva lactuca grown in plastic sleeves in a marine photobioreactor with flow-through seawater in Mikhmoret onshore (East Mediterranean, Israel), affected the composition of the amino acids and monosaccharides. Fresh samples of young (14 days) and old (21 days) U. lactuca were sampled from the photobioreactor cultivation system from January to December 2020. DNA sequences of all studied seaweed samples, which corresponded to the U. lactuca sequence, were identified using the rbcL and ITS markers as well as phylogenetic analysis. In addition, the protein and carbohydrate contents as well as the amino acid and monosaccharide profiles were determined and quantified by thermal acid hydrolysis, silyl-based derivatization, and gas chromatography-mass spectroscopy (GC–MS) analysis. The biomass components of U. lactuca were more influenced by season than by their culture age. The total protein in the dry weight of U. lactuca was significantly higher in winter (170–237 mg g−1) than in summer (64–123 mg g−1), whereas the monosaccharide content was significantly higher in summer (117–182 mg g−1) than in winter (88–98 mg g−1). These findings indicated that seasonality is an important parameter that must be considered to predict the best time to harvest U. lactuca biomass for biorefinery and food processing. Finally, an in-vitro digestibility study indicated that U. lactuca has the potential to compete with plants as a suitable protein source. [ABSTRACT FROM AUTHOR]

Blue economy, the sustainable and effective use of ocean resources for economic growth, is a major challenge to coastal communities. Marine macroalgae are potentially sustainable feedstock for future food, materials, chemicals, and fuels. For seaweed biorefinery, the fractionation of the biomass to co-produce multiple products is crucial in the efficient valorization of the marine biomass. In this work, we developed a protocol for co-production of six different products from the green macroalga Ulva ohnoi using green extraction methods. A total of 90.31 ± 1.94% of the initial biomass was recovered in separated products. The fraction of the recovered products from initial dry weight biomass was 45.42 ± 1.91% salts, 3.67 ± 1.38% starch, 3.81 ± 1.26% lipids, 13.88 ± 0.40% ulvan, 14.83 ± 1.06% proteins, and 8.70 ± 1.87% cellulose. A potential revenue analyses, based on these experimental data and current market prices, suggests that total the revenue fluctuates between US$1.56 and US$3.93 kg−1 of dry biomass and depends on recovered products fraction in the seaweed biomass and products market value. [ABSTRACT FROM AUTHOR]