Chalmers University of Technology
Hanna Harrysson is a PhD-student at the Division of Food and Nutrition Science at Chalmers University of Technology since November 2015. The title of the PhD-project is “Isolation of high-value ingredients from red (Porphyra umbilicalis) and green (Ulva lactuca) Swedish seaweeds”. Her main supervisor is Professor Ingrid Undeland at the Division of Food and Nutrition Science at Chalmers University of Technology and co-supervisor is Docent Gunilla Toth at the Department of Marine Science at The University of Gothenburg.
Isolation of proteins from Swedish red, green and brown seaweed
There is an increased demand for vegetable proteins and some seaweed species constitutes interesting protein raw materials. However the though polysaccharide-rich cell walls and abundance of polyphenols reduce digestibility of seaweed proteins. Therefore food grade techniques for isolating the proteins from the seaweed matrix are desirable. The aim of this study, which is part of the Swedish Seafarm and Sweaweed projects, is to evaluate the efficiency of three different protein isolation methods using Porphyra umbilicalis, Ulva lactuca and Saccharina latissima; (i) solubilization in water and subsequent precipitation with ammonium sulfate, (ii) alkaline protein solubilization followed by isoelectric precipitation (pH-shift method) and (iii) by a bio-refinery approach, were the residual remaining after pre-removal of lipids and phlorotannins is used. Highest protein yield was achieved by method (ii) for Porphyra (26%) and Saccharina (25%) and by (i) for Ulva (8%). Method (ii) gave highest concentrations of proteins in isolates (71, 51, 41%).