title: In vitro gastrointestinal digestion study of broccoli inflorescence phenolic compounds, glucosinolates, and vitamin C.
abstract: Broccoli (Brassica oleracea L. var. italica cv. Marathon) inflorescences are a good source of bioactive compounds, such as phenolics (flavonoids and hydroxycinnamoyl derivatives), glucosinolates, and vitamin C. In this work, these health-promoting compounds were submitted to digestion under in vitro gastrointestinal conditions (pH, temperature, enzyme, and chemical conditions). This technique differentiated among the compounds associated with macromolecules in soluble and insoluble form and those that are freely soluble. In addition, it evaluates the chemical stability of the broccoli compounds under simulated physiological conditions. The gastric digestion of broccoli caused high losses in glucosinolates (69% loss), whereas phenolics and vitamin C presented higher stability under these conditions. Thus, there were no losses in flavonoids, a 7% loss of vitamin C, and a variable rate of loss (6-25%) in hydroxycinnamic acid derivatives. The stability of all of the compounds was affected by the in vitro intestinal conditions. Under the in vitro conditions, flavonoids and hydroxycinnamoyl acid derivatives were of low availability, due to their significant losses under these conditions, at the end of the experiment (84 and 80% loss, respectively). Vitamin C was the metabolite that showed the greater decrease after intestinal digestion (91% loss). Regarding the remaining glucosinolates, these compounds presented higher stability under intestinal conditions, rendering an availability similar to that found for phenolics (75% loss). Therefore, broccoli components were affected by gastric and/or intestinal conditions depending on the type of compound. Thus, glucosinolates were mainly degraded by gastric conditions, whereas phenolic compounds and vitamin C were degraded by intestinal conditions.
authors.affiliation: Departamento de Ciencia y Tecnología de los Alimentos, CEBAS-CSIC, PO Box 164, 30100 Espinardo, Murcia, Spain.
authors.forename: Fernando
authors.initials: F
authors.lastname: Vallejo
authors.forename: Angel
authors.initials: A
authors.lastname: Gil-Izquierdo
authors.forename: Antonio
authors.initials: A
authors.lastname: Pérez-Vicente
authors.forename: Cristina
authors.initials: C
authors.lastname: García-Viguera
mesh_terms: D001205:Ascorbic Acid / Q000378:metabolism*; D001647:Bile Acids and Salts / Q000378:metabolism; D001937:Brassica / Q000737:chemistry*; D003373:Coumaric Acids / Q000378:metabolism; D004063:Digestion; D004064:Digestive System / Q000378:metabolism*; D004355:Drug Stability; D005419:Flavonoids / Q000378:metabolism; D005961:Glucosinolates / Q000378:metabolism*; D006851:Hydrochloric Acid / Q000378:metabolism; D066298:In Vitro Techniques; D010194:Pancreatin / Q000378:metabolism; D010434:Pepsin A / Q000378:metabolism; D010636:Phenols / Q000378:metabolism*; D012995:Solubility
chemical_list: D001647:Bile Acids and Salts; D003373:Coumaric Acids; D005419:Flavonoids; D005961:Glucosinolates; D010636:Phenols; D010194:Pancreatin; D010434:Pepsin A; D001205:Ascorbic Acid; D006851:Hydrochloric Acid