Strategies for Improving the Protein Yield in pH-Shift Processing of Ulva lactuca Linnaeus: Effects of Ulvan Lyases, pH-Exposure Time, and Temperature
Artikel i vetenskaplig tidskrift, 2019

Globally, there is a need for novel vegetarian protein sources. We recently showed that the pH-shift process, using alkaline protein solubilization followed by isoelectric precipitation, is an efficient way to produce extracts with high protein concentrations from Ulva lactuca (>50% on a dry matter basis). However, the total protein yield was low, and to improve this, the effects of adding ulvan lyase, preincubating the seaweed homogenate at pH 8.5 and using different protein extraction temperatures (8 °C, RT and 40 °C), were evaluated in this study. Addition of ulvan lyase reduced protein solubility but increased the precipitation. Incubation at pH 8.5, without ulvan lyase added, significantly increased both protein solubility and precipitation at 8 °C and RT. Temperature per se had no effect on protein solubility, while protein precipitation increased with decreasing temperature. Highest protein yield (29%) was achieved when keeping the process at 8 °C with a preincubation step at pH 8.5 for 1 h. By these process modifications, the yield was 3.2 times higher than achieved by the control process (9.2%).

Protein extraction

Ulvan lyase

Protein yield



Ulva lactuca


Hanna Harrysson

Chalmers, Biologi och bioteknik, Livsmedelsvetenskap

Venkat Rao Konasani

Chalmers, Biologi och bioteknik, Industriell bioteknik

Gunilla B. Toth

Göteborgs universitet

Henrik Pavia

Göteborgs universitet

Eva Albers

Chalmers, Biologi och bioteknik, Industriell bioteknik

Ingrid Undeland

Chalmers, Biologi och bioteknik, Livsmedelsvetenskap

ACS Sustainable Chemistry & Engineering

2168-0485 (eISSN)

Vol. 7 15 12688-12691

Produktionssystem för alger med högvärdiga tillämpningar

Stiftelsen för Strategisk forskning (SSF), 2015-01-01 -- 2019-12-31.


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