Production of protein extracts from Swedish red, green, and brown seaweeds, Porphyra umbilicalis Kützing, Ulva lactuca Linnaeus, and Saccharina latissima (Linnaeus) J. V. Lamouroux using three different methods

Abstract

The demand for vegetable proteins increases globally and seaweeds are considered novel and promising protein sources. However, the tough polysaccharide-rich cell walls and the abundance of polyphenols reduce the extractability and digestibility of seaweed proteins. Therefore, food grade, scalable, and environmentally friendly protein extraction techniques are required. To date, little work has been carried out on developing such methods taking into consideration the structural differences between seaweed species. In this work, three different protein extraction methods were applied to three Swedish seaweeds (Porphyra umbilicalis, Ulva lactuca, and Saccharina latissima). These methods included (I) a traditional method using sonication in water and subsequent ammonium sulfate-induced protein precipitation, (II) the pH-shift protein extraction method using alkaline protein solubilization followed by isoelectric precipitation, and (III) the accelerated solvent extraction (ASE®) method where proteins are extracted after pre-removal of lipids and phlorotannins. The highest protein yields were achieved using the pH-shift method applied to P. umbilicalis (22.6 ± 7.3%) and S. latissima (25.1 ± 0.9%). The traditional method resulted in the greatest protein yield when applied to U. lactuca (19.6 ± 0.8%). However, the protein concentration in the produced extracts was highest for all three species using the pH-shift method (71.0 ± 3.7%, 51.2 ± 2.1%, and 40.7 ± 0.5% for P. umbilicalis, U. lactuca, and S. latissima, respectively). In addition, the pH-shift method was found to concentrate the fatty acids in U. lactuca and S. latissima by 2.2 and 1.6 times, respectively. The pH-shift method can therefore be considered a promising strategy for producing seaweed protein ingredients for use in food and feed.

Understanding the effect of temperature and time on protein degree of hydrolysis and lipid oxidation during ensilaging of herring (Clupea harengus) filleting co-products

“…The mixture was then vortexed and centrifuged (12,000 × g, 10 min). The supernatant was diluted with 0.2 M acetic acid, and analyzed by LC/APCI-MS according to a method by Özcan and Şenyuva 37 with slight modifications as described by Harrysson, et al 38 .…”

Macroalgae as a Source of Valuable Antimicrobial Compounds: Extraction and Applications

“…Accelerated solvent extraction (ASE) also referred as pressurized liquid extraction (PLE) is deemed an excellent technique for the extraction of polar compounds [ 196 , 197 ]. ASE is a solid–liquid extraction process performed at high temperatures (50–200 °C) and high pressures (10–15 MPa).…”

Effects of preservation on protein extraction in four seaweed species

“…Protein extraction from seaweed can be regarded successful either by extracting as much protein as possible or by leaving as much protein in the pellet and extracting mostly non-protein substances leaving a protein enriched pellet. Most literature focuses on extracting protein (Fleurence et al 1995;Harnedy and FitzGerald 2013;Kadam et al 2016;Vilg and Undeland 2017;Harrysson et al 2018;Kazir et al 2019); only a few researchers are able to extract more than 50% of the protein present in the biomass (Kadam et al 2016;Vilg and Undeland 2017). This means that most protein remains in the pellet after extraction, but this fraction receives little attention.…”