{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,10]],"date-time":"2026-03-10T05:02:51Z","timestamp":1773118971435,"version":"3.50.1"},"reference-count":35,"publisher":"MDPI AG","issue":"1","license":[{"start":{"date-parts":[[2023,1,3]],"date-time":"2023-01-03T00:00:00Z","timestamp":1672704000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"CICECO-Aveiro Institute of Materials","award":["UIDB\/50011\/2020"],"award-info":[{"award-number":["UIDB\/50011\/2020"]}]},{"name":"CICECO-Aveiro Institute of Materials","award":["UIDP\/50011\/2020"],"award-info":[{"award-number":["UIDP\/50011\/2020"]}]},{"name":"CICECO-Aveiro Institute of Materials","award":["LA\/P\/0006\/2020"],"award-info":[{"award-number":["LA\/P\/0006\/2020"]}]},{"name":"CICECO-Aveiro Institute of Materials","award":["UIDB\/50006\/2020"],"award-info":[{"award-number":["UIDB\/50006\/2020"]}]},{"name":"CICECO-Aveiro Institute of Materials","award":["UIDP\/50006\/2020"],"award-info":[{"award-number":["UIDP\/50006\/2020"]}]},{"name":"LAQV-REQUIMTE","award":["UIDB\/50011\/2020"],"award-info":[{"award-number":["UIDB\/50011\/2020"]}]},{"name":"LAQV-REQUIMTE","award":["UIDP\/50011\/2020"],"award-info":[{"award-number":["UIDP\/50011\/2020"]}]},{"name":"LAQV-REQUIMTE","award":["LA\/P\/0006\/2020"],"award-info":[{"award-number":["LA\/P\/0006\/2020"]}]},{"name":"LAQV-REQUIMTE","award":["UIDB\/50006\/2020"],"award-info":[{"award-number":["UIDB\/50006\/2020"]}]},{"name":"LAQV-REQUIMTE","award":["UIDP\/50006\/2020"],"award-info":[{"award-number":["UIDP\/50006\/2020"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Molecules"],"abstract":"<jats:p>Chlorella vulgaris is a green microalga with a high chlorophyll content, representing a valuable source of green pigments for food applications. As the application of whole biomass can promote an unpleasant fish-like flavor, the use of chlorophyll extract can overcome this drawback. However, chlorophylls tend to easily degrade when out of the chloroplasts, decreasing their potential as a food ingredient. Thus, to study the suitable conditions for isolated chlorophylls preservation, in this work, the influence of temperature (4 to 60 \u00b0C), light (dark or 24 h photoperiod), alkaline conditions (with or without aqueous NaOH addition), and modified atmosphere (air or argon atmosphere) on the stability of the color in ethanolic solutions obtained from C. vulgaris were studied. The loss of green color with temperature followed the first-order kinetics, with an activation energy of 74 kJ\/mol. Below 28 \u00b0C and dark conditions were suitable to preserve isolated chlorophylls. The addition of NaOH and an inert argon-rich atmosphere did not exhibit a statistically positive effect on color preservation. In the case study, cooked cold rice was colored to be used in sushi. The color remained stable for up to 3 days at 4 \u00b0C. Therefore, this work showed that C. vulgaris chlorophylls could be preserved in ethanolic solutions at room or lower temperatures when protected from light, allowing them to obtain a suitable natural food ingredient to color foodstuffs.<\/jats:p>","DOI":"10.3390\/molecules28010408","type":"journal-article","created":{"date-parts":[[2023,1,4]],"date-time":"2023-01-04T02:54:55Z","timestamp":1672800895000},"page":"408","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":16,"title":["Stabilization of Natural Pigments in Ethanolic Solutions for Food Applications: The Case Study of Chlorella vulgaris"],"prefix":"10.3390","volume":"28","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-0321-2207","authenticated-orcid":false,"given":"Andreia S.","family":"Ferreira","sequence":"first","affiliation":[{"name":"LAQV-REQUIMTE, Department of Chemistry, University of Aveiro, 3810-193 Aveiro, Portugal"}]},{"given":"Liliana","family":"Pereira","sequence":"additional","affiliation":[{"name":"LAQV-REQUIMTE, Department of Chemistry, University of Aveiro, 3810-193 Aveiro, Portugal"}]},{"given":"Feliciana","family":"Canfora","sequence":"additional","affiliation":[{"name":"LAQV-REQUIMTE, Department of Chemistry, University of Aveiro, 3810-193 Aveiro, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8520-603X","authenticated-orcid":false,"given":"Tiago H.","family":"Silva","sequence":"additional","affiliation":[{"name":"3B\u2019s Research Group, I3Bs\u2014Research Institute on Biomaterials, Biodegradables and Biomimetics, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, University of Minho, AvePark-Parque de Ci\u00eancia e Tecnologia, 4805-017 Guimar\u00e3es, Portugal"},{"name":"ICVS\/3B\u2019s-PT Government Associate Laboratory, 4710-057 Guimar\u00e3es, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8898-6342","authenticated-orcid":false,"given":"Manuel A.","family":"Coimbra","sequence":"additional","affiliation":[{"name":"LAQV-REQUIMTE, Department of Chemistry, University of Aveiro, 3810-193 Aveiro, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7217-2790","authenticated-orcid":false,"given":"Cl\u00e1udia","family":"Nunes","sequence":"additional","affiliation":[{"name":"CICECO\u2013Aveiro Institute of Materials, Department of Materials and Ceramic Engineering, University of Aveiro, 3810-193 Aveiro, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2023,1,3]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"2006","DOI":"10.1007\/s13197-012-0706-z","article-title":"Optimization of Ultrasound-Assisted Extraction Parameters of Chlorophyll from Chlorella Vulgaris Residue after Lipid Separation Using Response Surface Methodology","volume":"51","author":"Kong","year":"2014","journal-title":"J. Food Sci. Technol."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"345","DOI":"10.1007\/s002170050088","article-title":"Determination of Major Chlorophyll Degradation Products","volume":"204","author":"Mangos","year":"1997","journal-title":"Zeitschrift Leb. Forsch. A"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"5129","DOI":"10.1016\/j.biortech.2011.01.078","article-title":"Horizontal or Vertical Photobioreactors? How to Improve Microalgae Photosynthetic Efficiency","volume":"102","author":"Cuaresma","year":"2011","journal-title":"Bioresour. Technol."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"312","DOI":"10.1016\/j.lwt.2012.05.006","article-title":"Isochrysis Galbana and Diacronema Vlkianum Biomass Incorporation in Pasta Products as PUFA\u2019s Source","volume":"50","author":"Fradique","year":"2013","journal-title":"LWT-Food Sci. Technol."},{"key":"ref_5","doi-asserted-by":"crossref","unstructured":"Ventura, S.P.M., Nobre, B.P., Ertekin, F., Hayes, M., Garci\u00e1-Vaquero, M., Vieira, F., Koc, M., Gouveia, L., Aires-Barros, M.R., and Palavra, A.M.F. (2017). Extraction of Value-Added Compounds from Microalgae. Microalgae-Based Biofuels and Bioproducts, Elsevier.","DOI":"10.1016\/B978-0-08-101023-5.00019-4"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"255","DOI":"10.1016\/j.jff.2011.07.001","article-title":"Biological Activities and Health Benefit Effects of Natural Pigments Derived from Marine Algae","volume":"3","author":"Pangestuti","year":"2011","journal-title":"J. Funct. Foods"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"108","DOI":"10.1016\/j.jpba.2017.09.018","article-title":"Separation, Identification and Quantification of Carotenoids and Chlorophylls in Dietary Supplements Containing Chlorella Vulgaris and Spirulina Platensis Using High Performance Thin Layer Chromatography","volume":"148","author":"Hynstova","year":"2018","journal-title":"J. Pharm. Biomed. Anal."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"101757","DOI":"10.1016\/j.algal.2019.101757","article-title":"Reserve, Structural and Extracellular Polysaccharides of Chlorella Vulgaris: A Holistic Approach","volume":"45","author":"Ferreira","year":"2020","journal-title":"Algal Res."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"609","DOI":"10.1016\/j.foodchem.2005.09.079","article-title":"Effect of PH on Chlorophyll Degradation and Colour Loss in Blanched Green Peas","volume":"100","author":"Koca","year":"2007","journal-title":"Food Chem."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"638","DOI":"10.1039\/c4pp00435c","article-title":"How Green Is Green Chemistry? Chlorophylls as a Bioresource from Biorefineries and Their Commercial Potential in Medicine and Photovoltaics","volume":"14","author":"Ryan","year":"2015","journal-title":"Photochem. Photobiol. Sci."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"595","DOI":"10.1016\/j.lwt.2013.10.011","article-title":"Effect of Heat Treatment, PH, Sugar Concentration, and Metal Ion Addition on Green Color Retention in Homogenized Puree of Thompson Seedless Grape","volume":"55","author":"Zheng","year":"2014","journal-title":"LWT-Food Sci. Technol."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"135","DOI":"10.1016\/j.jfoodeng.2003.09.021","article-title":"A Study on the Degradation Kinetics of Visual Green Colour in Spinach (Spinacea oleracea L.) and the Effect of Salt Therein","volume":"64","author":"Nisha","year":"2004","journal-title":"J. Food Eng."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"2358","DOI":"10.1111\/j.1365-2621.2007.01642.x","article-title":"Stability of Pigments and Oil in Pistachio Kernels during Storage","volume":"44","author":"Bellomo","year":"2009","journal-title":"Int. J. Food Sci. Technol."},{"key":"ref_14","first-page":"135","article-title":"Chlorophyll Changes in Thermally Processed Spinach as Influenced by Enzyme Conversion and PH Adjustment","volume":"22","author":"Clydesdale","year":"1968","journal-title":"Food Technol."},{"key":"ref_15","first-page":"11","article-title":"Relationship between Colour Improvement and Metallo-Chlorophyll Complexes during Blanching of Peas and Broccoli","volume":"4","author":"Salama","year":"2007","journal-title":"Alex. J. Food Sci. Technol."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"91","DOI":"10.1007\/s11947-007-0016-z","article-title":"Thermal Degradation Kinetics of Chlorophyll in Pureed Coriander Leaves","volume":"1","author":"Rudra","year":"2008","journal-title":"Food Bioprocess Technol."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"415","DOI":"10.1039\/ai9953200415","article-title":"Stability Studies of Chlorophyll a Using Different Storage Systems","volume":"Volume 32","author":"Araujo","year":"1995","journal-title":"Proceedings of the Analytical Proceedings including Analytical Communications"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"8056","DOI":"10.1021\/jf101214g","article-title":"Color Loss in Ethanolic Solutions of Chlorophyll A","volume":"58","author":"Shen","year":"2010","journal-title":"J. Agric. Food Chem."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"38","DOI":"10.1139\/f85-005","article-title":"Optimization of Ultrasound-Assisted Extraction Parameters of Chlorophyll from Chlorella Vulgaris Residue after Lipid Separation Using Response Surface Methodology","volume":"42","author":"Wood","year":"1985","journal-title":"Can. J. Fish. Aquat. Sci."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"F4.2.1","DOI":"10.1002\/0471142913.faf0402s01","article-title":"Extraction of Phtosynthetic Tissues: Chlorophylls and Carotenoids","volume":"1","author":"Lichtenthaler","year":"2001","journal-title":"Curr. Protoc. Food Anal. Chem."},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"Safafar, H., Uldall N\u00f8rregaard, P., Ljubic, A., M\u00f8ller, P., L\u00f8vstad Holdt, S., and Jacobsen, C. (2016). Enhancement of Protein and Pigment Content in Two Chlorella Species Cultivated on Industrial Process Water. J. Mar. Sci. Eng., 4.","DOI":"10.3390\/jmse4040084"},{"key":"ref_22","first-page":"1275","article-title":"Separation of Algal Pigments by Thin Layer Chromatography (TLC) and High Performance Liquid Chromatography (HPLC)","volume":"6","author":"Sathya","year":"2017","journal-title":"World J. Pharm. Res."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"652","DOI":"10.1007\/s12010-017-2537-x","article-title":"Investigation of Chlorella Vulgaris UTEX 265 Cultivation under Light and Low Temperature Stressed Conditions for Lutein Production in Flasks and the Coiled Tree Photo-Bioreactor (CTPBR)","volume":"183","author":"Gong","year":"2017","journal-title":"Appl. Biochem. Biotechnol."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"101790","DOI":"10.1016\/j.algal.2020.101790","article-title":"Development of a Chlorella Vulgaris Mutant by Chemical Mutagenesis as a Producer for Natural Violaxanthin","volume":"46","author":"Kim","year":"2020","journal-title":"Algal Res."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"193","DOI":"10.1016\/j.foodres.2014.05.047","article-title":"Changes in Chlorophylls, Chlorophyll Degradation Products and Lutein in Pistachio Kernels (Pistacia vera L.) during Roasting","volume":"65","author":"Pumilia","year":"2014","journal-title":"Food Res. Int."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"307","DOI":"10.1016\/S0176-1617(11)81192-2","article-title":"The Spectral Determination of Chlorophylls a and b, as Well as Total Carotenoids, Using Various Solvents with Spectrophotometers of Different Resolution","volume":"144","author":"Wellburn","year":"1994","journal-title":"J. Plant Physiol."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"2133","DOI":"10.1007\/s00217-019-03318-9","article-title":"Modulation of Infusion Processes to Obtain Coffee-Derived Food Ingredients with Distinct Composition","volume":"245","author":"Lopes","year":"2019","journal-title":"Eur. Food Res. Technol."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"956","DOI":"10.1021\/ja01245a052","article-title":"The Photo-Oxidation of Chlorophyll","volume":"65","author":"Aronoff","year":"1943","journal-title":"J. Am. Chem. Soc."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"303","DOI":"10.1016\/S1466-8564(01)00045-5","article-title":"Modelling the Change in Colour of Broccoli and Green Beans during Blanching","volume":"2","author":"Tijskens","year":"2001","journal-title":"Innov. Food Sci. Emerg. Technol."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"161","DOI":"10.1016\/0021-9673(94)00924-X","article-title":"High-Performance Liquid Chromatographic Study of Alkaline Treatment of Chlorophyll","volume":"690","year":"1995","journal-title":"J. Chromatogr. A"},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"1600256","DOI":"10.1002\/star.201600256","article-title":"Alkaline Dissolution of Native Potato Starch\u2014Impact of the Preparation Conditions on the Solution Properties Determined by Means of SEC-MALS","volume":"69","author":"Ulbrich","year":"2017","journal-title":"Starch St\u00e4rke"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"2404","DOI":"10.1021\/jf980663o","article-title":"Green Chilli Puree","volume":"47","author":"Weemaes","year":"1999","journal-title":"J. Agric. Food Chem."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"1088","DOI":"10.1111\/j.1365-2621.2002.tb09457.x","article-title":"Color Degradation Kinetics of Spinach, Mustard Leaves, and Mixed Puree","volume":"67","author":"Ahmed","year":"2002","journal-title":"J. Food Sci."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"239","DOI":"10.1016\/S0260-8774(00)00034-0","article-title":"V Rheological Characteristics and Kinetics of Colour Degradation of Green Chilli Puree","volume":"44","author":"Ahmed","year":"2000","journal-title":"J. Food Eng."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"F4.3.1","DOI":"10.1002\/0471142913.faf0403s01","article-title":"Chlorophylls and Carotenoids: Measurement and Characterization by UV-VIS Spectroscopy","volume":"1","author":"Lichtenthaler","year":"2001","journal-title":"Curr. Protoc. Food Anal. Chem."}],"container-title":["Molecules"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1420-3049\/28\/1\/408\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T17:57:03Z","timestamp":1760119023000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1420-3049\/28\/1\/408"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2023,1,3]]},"references-count":35,"journal-issue":{"issue":"1","published-online":{"date-parts":[[2023,1]]}},"alternative-id":["molecules28010408"],"URL":"https:\/\/doi.org\/10.3390\/molecules28010408","relation":{},"ISSN":["1420-3049"],"issn-type":[{"value":"1420-3049","type":"electronic"}],"subject":[],"published":{"date-parts":[[2023,1,3]]}}}