title: Influence of the leaf content and herbal particle size on the presence and extractability of quantitated phenolic compounds in Cistus incanus herbal teas.
abstract: A variety of Cistus incanus products and thereof a majority of herbal teas are offered by manufacturers despite a classification as Novel Food. For a re-evaluation of this legal status, a characterization of bioactive ingredients will provide data. These teas consist of various compositions of plant parts and particle sizes. Whereas some include high leaf contents with a small particle size, others mainly consist of woody stem parts. For the consumer it is of interest which product yields the highest concentrations of bioactive phenolic compounds in the final infusions. In this study, four commercially available samples were divided into leaves and stems. Additionally, one sample was reconstituted in three mixtures of these plant parts. The amount of wood was determined by cellulose concentration. The aim was to estimate the influence of the plant parts on the concentration of phenolic compounds, which were identified by LC-DAD-ESI-MS/MS and quantitated by LC-DAD. Furthermore, one herbal tea was separated into six fractions with different particle sizes to investigate the influence of particle size on the extractability of phenolic compounds. On basis of the results, the highest concentrations of bioactive compounds in the infusions were yielded when leafy parts with a small particle size were used for brewing.
authors.affiliation: Food Chemistry, Hamburg School of Food Science, University of Hamburg , Grindelallee 117, 20146 Hamburg, Germany.
authors.forename: Peer
authors.initials: P
authors.lastname: Riehle
authors.forename: Nele
authors.initials: N
authors.lastname: Rusche
authors.forename: Bodo
authors.initials: B
authors.lastname: Saake
authors.forename: Sascha
authors.initials: S
authors.lastname: Rohn
mesh_terms: D001628:Beverages / Q000032:analysis*; D029758:Cistus / Q000737:chemistry*; D005511:Food Handling / Q000379:methods*; D013058:Mass Spectrometry; D010316:Particle Size; D010636:Phenols / Q000737:chemistry* / Q000302:isolation & purification*; D018515:Plant Leaves / Q000737:chemistry*
chemical_list: D010636:Phenols
keywords: LC-DAD; LC-ESI-MS/MS; Novel Food; TEAC; bioactivity; cellulose concentration; wood content