TY  - CONF
AU  - Simović, Ana
AU  - Combet, Sophie
AU  - Ćirković-Veličković, Tanja
AU  - Nikolic, Milan
AU  - Minic, Simeon
PY  - 2022
UR  - http://cherry.chem.bg.ac.rs/handle/123456789/5133
AB  - The high content of vitamins, minerals, antioxidants, and proteins makes red algae Porphyra sp. (Nori) superfood with exceptional health-promoting benefits. Its intense colour originates from R-phycoerythrin (R-PE), phycobiliprotein containing covalently attached tetrapyrrole chromophores: red phycoerythrobilin and orange phycourobilin. The present study aims to characterize the stability of R-PE, a natural colourant with a high potential for application in the food, cosmetic, and pharmaceutical industries. We purified R-PE from dried Nori flakes with a high purity ratio (A560 /A280 ≥5). Far-UV CD spectroscopic showed that α-helix is the dominant secondary structure (75%). The thermal unfolding of α-helix revealed two transitions (Tm1 and Tm2 at 56 and 72°C, respectively), ascribed to the different subunits of R-PE. Absorption measurements showed that high pressure (HP) induces dissociation of R-PE into subunits followed by subunit unfolding. Contrary to temperature, HP treatment showed a significant advantage under applied conditions: the protein unfolding is partly reversible, and the R-PE colour bleaching is minimized. Based on the fluorescence quenching approach, R-PE's binding affinities for Cu2+ and Zn2+ ions were 6.27x105 and 1.71x103 M-1, respectively. Absorption and near-UV/VIS CD spectroscopy suggested conformational changes in protein chromophores upon metal ions binding. Far-UV CD spectroscopy did not reveal that metal binding affects R-PE structure. The obtained results give new insights into the stability of R-PE with a good use-value in replacement of toxic synthetic dyes, preservation of R-PE red colour in fortified food and beverages by HP processing, and as a biosensor for Cu2+ in aquatic life systems.
Acknowledgments: This study was financially supported by the Ministry of Education, Science and Technological Development of the Republic of Serbia, Contract number: 451-03-9/2021-14/200168 and the European Commission, under the Horizon2020, FoodEnTwin Project, GA No. 810752.
PB  - Sociedade Portuguesa de Química
C3  - Book of Abstracts of the XXI EuroFoodChem Congress, 22-24 November 2021, On-line conference
T1  - Probing the stability of the food colourant R-phycoerythrin from dried Nori flakes
SP  - 138
EP  - 138
UR  - https://hdl.handle.net/21.15107/rcub_cherry_5133
ER  - 

@conference{
author = "Simović, Ana and Combet, Sophie and Ćirković-Veličković, Tanja and Nikolic, Milan and Minic, Simeon",
year = "2022",
abstract = "The high content of vitamins, minerals, antioxidants, and proteins makes red algae Porphyra sp. (Nori) superfood with exceptional health-promoting benefits. Its intense colour originates from R-phycoerythrin (R-PE), phycobiliprotein containing covalently attached tetrapyrrole chromophores: red phycoerythrobilin and orange phycourobilin. The present study aims to characterize the stability of R-PE, a natural colourant with a high potential for application in the food, cosmetic, and pharmaceutical industries. We purified R-PE from dried Nori flakes with a high purity ratio (A560 /A280 ≥5). Far-UV CD spectroscopic showed that α-helix is the dominant secondary structure (75%). The thermal unfolding of α-helix revealed two transitions (Tm1 and Tm2 at 56 and 72°C, respectively), ascribed to the different subunits of R-PE. Absorption measurements showed that high pressure (HP) induces dissociation of R-PE into subunits followed by subunit unfolding. Contrary to temperature, HP treatment showed a significant advantage under applied conditions: the protein unfolding is partly reversible, and the R-PE colour bleaching is minimized. Based on the fluorescence quenching approach, R-PE's binding affinities for Cu2+ and Zn2+ ions were 6.27x105 and 1.71x103 M-1, respectively. Absorption and near-UV/VIS CD spectroscopy suggested conformational changes in protein chromophores upon metal ions binding. Far-UV CD spectroscopy did not reveal that metal binding affects R-PE structure. The obtained results give new insights into the stability of R-PE with a good use-value in replacement of toxic synthetic dyes, preservation of R-PE red colour in fortified food and beverages by HP processing, and as a biosensor for Cu2+ in aquatic life systems.
Acknowledgments: This study was financially supported by the Ministry of Education, Science and Technological Development of the Republic of Serbia, Contract number: 451-03-9/2021-14/200168 and the European Commission, under the Horizon2020, FoodEnTwin Project, GA No. 810752.",
publisher = "Sociedade Portuguesa de Química",
journal = "Book of Abstracts of the XXI EuroFoodChem Congress, 22-24 November 2021, On-line conference",
title = "Probing the stability of the food colourant R-phycoerythrin from dried Nori flakes",
pages = "138-138",
url = "https://hdl.handle.net/21.15107/rcub_cherry_5133"
}

Simović, A., Combet, S., Ćirković-Veličković, T., Nikolic, M.,& Minic, S.. (2022). Probing the stability of the food colourant R-phycoerythrin from dried Nori flakes. in Book of Abstracts of the XXI EuroFoodChem Congress, 22-24 November 2021, On-line conference
Sociedade Portuguesa de Química., 138-138.
https://hdl.handle.net/21.15107/rcub_cherry_5133

Simović A, Combet S, Ćirković-Veličković T, Nikolic M, Minic S. Probing the stability of the food colourant R-phycoerythrin from dried Nori flakes. in Book of Abstracts of the XXI EuroFoodChem Congress, 22-24 November 2021, On-line conference. 2022;:138-138.
https://hdl.handle.net/21.15107/rcub_cherry_5133 .

Simović, Ana, Combet, Sophie, Ćirković-Veličković, Tanja, Nikolic, Milan, Minic, Simeon, "Probing the stability of the food colourant R-phycoerythrin from dried Nori flakes" in Book of Abstracts of the XXI EuroFoodChem Congress, 22-24 November 2021, On-line conference (2022):138-138,
https://hdl.handle.net/21.15107/rcub_cherry_5133 .