title: Degradation of glucosinolates during in vitro incubations of rapeseed meal with myrosinase (EC 3.2.3.1) and with pepsin (EC 3.4.23.1)-hydrochloric acid, and contents of porcine small intestine and caecum.
abstract: Changes in the concentrations of glucosinolates from rapeseed meal and some glucosinolate degradation products during incubation in vitro with myrosinase (EC 3.2.3.1), with pepsin (EC 3.4.23.1)-HCl, and with contents of porcine small intestine and caecum were studied. When rapeseed meal was incubated with myrosinase, 5-vinyl oxazolidinethione (OZT) and butenyl and pentenyl isothiocyanates were produced; OZT concentration rose to a plateau after about 2 h. However, when incubated with caecal contents only OZT could be detected; its concentration peaked after about 4-5 h then declined. Under in vitro conditions which attempted to simulate peptic and small intestinal digestion no OZT could be detected; the individual glucosinolates differed in susceptibility to peptic conditions, losses ranging from 3 to 23%. Under the small intestinal conditions the losses of individual glucosinolates ranged from about 7 to 28%. Addition of CuSO4, ascorbic acid, tylosin or a probiotic had little effect on the outcome of peptic or small intestinal incubations but tylosin appeared to slow the degradation of glucosinolates in the presence of caecal contents.
authors.affiliation: Department of Biological and Nutritional Sciences, University of Newcastle upon Tyne.
authors.forename: I
authors.initials: I
authors.lastname: Maskell
authors.forename: R
authors.initials: R
authors.lastname: Smithard
mesh_terms: D000818:Animals; D013956:Antithyroid Agents / Q000378:metabolism; D001937:Brassica; D004063:Digestion; D005503:Food Additives; D005766:Gastrointestinal Contents / Q000737:chemistry; D005961:Glucosinolates / Q000378:metabolism*; D006026:Glycoside Hydrolases / Q000378:metabolism*; D066298:In Vitro Techniques; D008752:Methylene Chloride; D010080:Oxazoles / Q000378:metabolism; D023303:Oxazolidinones; D010434:Pepsin A / Q000378:metabolism*; D013552:Swine; D013997:Time Factors
chemical_list: D013956:Antithyroid Agents; D005503:Food Additives; D005961:Glucosinolates; D010080:Oxazoles; D023303:Oxazolidinones; D008752:Methylene Chloride; C004333:goitrin; D006026:Glycoside Hydrolases; C022739:thioglucosidase; D010434:Pepsin A