EFFECTS OF METAL IONS ON BENZYLGLUCOSINOLATE DEGRADATION IN LEPIDIUM SATIVUM SEED AUTOLYSATES

Article abstract of DOI:10.1016/0031-9422(82)83140-3

The effects of varying concentrations of Fe²⁺ (5E-5 - 5E-1 M) on benzylglucosinolate degradation in Lepidium sativum seed autolysates were investigated.Increased glucosinolate decomposition was observed over the whole range with a maximum effect at ca. 6E-3 M Fe²⁺, at which point glucosinolate degradation was more than three times that obtained in the absence of added Fe²⁺.Nitrile formation was especially enhanced in the presence of all concentrations of Fe²⁺ studied, and maximum amounts were obtained at ca. 6E-3 M Fe²⁺, when a more than four-fold increase over quantities produced in the absence of Fe²⁺ was observed.Thiocyanate formation was also promoted with a maximum at ca. 4E-3 M Fe²⁺, but isothiocyanate production was considerably reduced in all cases.It is suggested that Fe²⁺ inhibits isothiocyanate formation by interfering with the availability of ascorbic acid which is a proven co-factor for most thioglucosidase isoenzymes, but that an Fe²⁺-ascorbate complex might then be responsible for promoting enzymic production of nitrile.The effects of a limited range of concentrations of Fe³⁺ and Cu⁺ were also studied, and results related to those for Fe²⁺ The relevance of the findings to natural systems and to glucosinolate-containing foods is briefly discussed.Key Word Index-Lepidium sativum; Cruciferae; glucosinolate degradation.