TY - JOUR
T1 - Fast cleavage of phycocyanobilin from phycocyanin for use in food colouring
AU - Roda-Serrat, Maria Cinta
AU - Christensen, Knud Villy
AU - El-Houri, Rime
AU - Fretté, Xavier
AU - Christensen, Lars Porskjær
N1 - Copyright © 2017 Elsevier Ltd. All rights reserved.
PY - 2018/2/1
Y1 - 2018/2/1
N2 - Phycocyanins from cyanobacteria are possible sources for new natural blue colourants. Their chromophore, phycocyanobilin (PCB), was cleaved from the apoprotein by solvolysis in alcohols and alcoholic aqueous solutions. In all cases two PCB isomers were obtained, while different solvent adducts were formed upon the use of different reagents. The reaction is believed to take place via two competing pathways, a concerted E2 elimination and a SN2 nucleophilic substitution. Three cleavage methods were compared in terms of yield and purity: conventional reflux, sealed vessel heated in an oil bath, and microwave assisted reaction. The sealed vessel method is a new approach for fast cleavage of PCB from phycocyanin and gave at 120°C the same yield within 30 min compared to 16 hours by the conventional reflux method (P < 0.05). In addition the sealed vessel method resulted in improved purity compared to the other methods. Microwave irradiation increased product degradation
AB - Phycocyanins from cyanobacteria are possible sources for new natural blue colourants. Their chromophore, phycocyanobilin (PCB), was cleaved from the apoprotein by solvolysis in alcohols and alcoholic aqueous solutions. In all cases two PCB isomers were obtained, while different solvent adducts were formed upon the use of different reagents. The reaction is believed to take place via two competing pathways, a concerted E2 elimination and a SN2 nucleophilic substitution. Three cleavage methods were compared in terms of yield and purity: conventional reflux, sealed vessel heated in an oil bath, and microwave assisted reaction. The sealed vessel method is a new approach for fast cleavage of PCB from phycocyanin and gave at 120°C the same yield within 30 min compared to 16 hours by the conventional reflux method (P < 0.05). In addition the sealed vessel method resulted in improved purity compared to the other methods. Microwave irradiation increased product degradation
KW - Chromophore
KW - Methanolysis
KW - Natural blue colourant
KW - Reaction mechanism
KW - Solvolysis
KW - Phycocyanin/chemistry
KW - Phycobilins/isolation & purification
KW - Cyanobacteria
KW - Food Coloring Agents/isolation & purification
UR - http://www.scopus.com/inward/record.url?scp=85026795640&partnerID=8YFLogxK
U2 - 10.1016/j.foodchem.2017.07.149
DO - 10.1016/j.foodchem.2017.07.149
M3 - Journal article
C2 - 28946325
SN - 0308-8146
VL - 240
SP - 655
EP - 661
JO - Food Chemistry
JF - Food Chemistry
ER -