title: The chemical and antioxidant stability of isolated low molecular weight phlorotannins.
abstract: Due to their high anti-oxidant activity, phlorotannins represent potential natural alternatives to synthetic preservatives currently used within the food industry. However, their successful integration into food products requires research into their chemical integrity, particularly when selecting appropriate storage conditions. Subsequently, this study aims to investigate the stability of low molecular weight phlorotannin fractions from Fucus vesiculosus (L.). Powder and aqueous fractions were stored under five different conditions for 10weeks. Phlorotannin stability was determined using Q-ToF-MS and UPLC-TQD-MS/MS and a DPPH assay. After 10weeks of storage, fractions suspended in an aqueous matrix underwent oxidation when exposed to continuous atmospheric oxygen and thermal degradation when exposed to a constant temperature of 50°C, resulting in decreases in radical scavenging activity (p<0.001). Phlorotannins remained stable under all other storage conditions. This study highlights phlorotannins as highly stable polymers, under certain storage conditions, with an excellent capacity for scavenging radicals.
authors.affiliation: Botany and Plant Science, School of Natural Sciences, Ryan Institute for Environmental, Marine and Energy Research, National University of Ireland Galway, Galway, Ireland; Food Biosciences, Teagasc Food Research Centre, Ashtown, Dublin 15, Ireland.
authors.forename: D A
authors.initials: DA
authors.lastname: Kirke
authors.affiliation: Department of Life Science, Institute of Technology Sligo, Ireland. Electronic address: Smyth.thomas@itsligo.ie.
authors.forename: T J
authors.initials: TJ
authors.lastname: Smyth
authors.affiliation: Food Biosciences, Teagasc Food Research Centre, Ashtown, Dublin 15, Ireland.
authors.forename: D K
authors.initials: DK
authors.lastname: Rai
authors.affiliation: Institute of Food and Health, University College Dublin, Belfield, Dublin 4, Ireland.
authors.forename: O
authors.initials: O
authors.lastname: Kenny
authors.affiliation: Botany and Plant Science, School of Natural Sciences, Ryan Institute for Environmental, Marine and Energy Research, National University of Ireland Galway, Galway, Ireland.
authors.forename: D B
authors.initials: DB
authors.lastname: Stengel
mesh_terms: D000975:Antioxidants / Q000737:chemistry* / Q000302:isolation & purification; D001713:Biphenyl Compounds / Q000737:chemistry; D005520:Food Preservatives / Q000737:chemistry* / Q000302:isolation & purification; D044645:Fucus / Q000737:chemistry*; D015394:Molecular Structure; D008970:Molecular Weight; D010851:Picrates / Q000737:chemistry; D053719:Tandem Mass Spectrometry; D013634:Tannins / Q000737:chemistry* / Q000302:isolation & purification
chemical_list: D000975:Antioxidants; D001713:Biphenyl Compounds; D005520:Food Preservatives; D010851:Picrates; D013634:Tannins; C004931:1,1-diphenyl-2-picrylhydrazyl
keywords: Oxidation; Phlorotannins; Profiling; Q-ToF-MS; Radical scavenging activity (RSA); Stability; Storage; UPLC-TQD-MS/MS