Department of Food Science, Faculty of Sciences, University of Copenhagen, Rolighedsvej 26, DK-1958 Frederiksberg C, Denmark.
Department of Food Science, Faculty of Sciences, University of Copenhagen, Rolighedsvej 26, DK-1958 Frederiksberg C, Denmark.
Food Chem. 2019 Sep 1;291:77-86. doi: 10.1016/j.foodchem.2019.03.136. Epub 2019 Mar 27.
Monogastric animals exhibit different biological responses to structurally diverse glucosinolates and their transformation products, depending on the dietary levels. The transformations of 2-hydroxyalkenyl and aromatic glucosinolates were examined in vitro under gastric conditions, ex vivo in ligated porcine stomachs and in vivo in a rat model. Intact glucosinolates were almost completely transformed in vitro within 1 h at pH 3 (73-88%) and at pH 5 (97-100%) upon addition of Fe ranging from two-fold molar excess. Glucosinolate transformations reached 78-99% when incubated ex vivo in ligated porcine stomachs. Rat in vivo feeding trials showed major reductions (81-84%) in the intact glucosinolate contents upon passage through the gastrointestinal (GI) tract. Non-enzymatic transformations of glucosinolates occur in the stomach, where pH and the level of Fe are primary determinants. This is the first study to show a complex formation between iron-progoitrin and iron-sinalbin, facilitating the transformation into nitriles and thionamides.
单胃动物对结构多样的硫代葡萄糖苷及其转化产物表现出不同的生物学反应，这取决于饮食水平。在胃内条件下、在结扎猪胃的离体条件下和在大鼠模型的体内条件下，研究了 2-羟烯基和芳基硫代葡萄糖苷的转化。在 pH 值为 3（73-88%）和 pH 值为 5（97-100%）时，添加两倍摩尔过量的 Fe 后，完整的硫代葡萄糖苷在体外 1 小时内几乎完全转化（73-88%）。在结扎的猪胃中离体孵育时，硫代葡萄糖苷的转化达到 78-99%。大鼠体内喂养试验表明，在通过胃肠道（GI）时，完整的硫代葡萄糖苷含量大幅减少（81-84%）。非酶促硫代葡萄糖苷转化发生在胃中，其中 pH 值和铁水平是主要决定因素。这是首次研究表明铁-前甘氨酸与铁-芝麻素之间形成复合物，从而促进转化为腈和硫代酰胺。
