PDF(Pubmed)
Abstract：
Beyond the key bitter compound kaempferol 3-O-(2‴-O-sinapoyl-β-d-sophoroside) previously described in the literature (1), eight further bitter and astringent-tasting kaempferol glucosides (2-9) have been identified in rapeseed protein isolates (Brassica napus L.). The bitterness and astringency of these taste-active substances have been described with taste threshold concentrations ranging from 3.3 to 531.7 and 0.3 to 66.4 μmol/L, respectively, as determined by human sensory experiments. In this study, the impact of 1 and kaempferol 3-O-β-d-glucopyranoside (8) on TAS2R-linked proton secretion by HGT-1 cells was analyzed by quantification of the intracellular proton index. mRNA levels of bitter receptors TAS2R3, 4, 5, 13, 30, 31, 39, 40, 43, 45, 46, 50 and TAS2R8 were increased after treatment with compounds 1 and 8. Using quantitative UHPLC-MS/MSMRM measurements, the concentrations of 1-9 were determined in rapeseed/canola seeds and their corresponding protein isolates. Depending on the sample material, compounds 1, 3, and 5-9 exceeded dose over threshold (DoT) factors above one for both bitterness and astringency in selected protein isolates. In addition, an increase in the key bitter compound 1 during industrial protein production (apart from enrichment) was observed, allowing the identification of the potential precursor of 1 to be kaempferol 3-O-(2‴-O-sinapoyl-β-d-sophoroside)-7-O-β-d-glucopyranoside (3). These results may contribute to the production of less bitter and astringent rapeseed protein isolates through the optimization of breeding and postharvest downstream processing.
摘要：
除了文献（1）中先前描述的关键苦味化合物山奈酚3-O-（2-O-芥子酰-β-d-槐苷）之外，在菜籽蛋白分离物（BrassicanapusL.）中已鉴定出另外八种苦味和涩味山奈酚葡糖苷（2-9）。已经描述了这些味觉活性物质的苦味和收敛性，味觉阈值浓度范围为3.3至531.7和0.3至66.4μmol/L，分别,由人类感官实验确定。在这项研究中,通过定量细胞内质子指数分析1和山奈酚3-O-β-d-吡喃葡萄糖苷(8)对HGT-1细胞TAS2R相关质子分泌的影响.用化合物1和8处理后,苦味受体TAS2R3、4、5、13、30、31、39、40、43、45、46、50和TAS2R8的mRNA水平增加。使用UHPLC-MS/MSMRM定量测量，在油菜籽/油菜种子及其相应的蛋白质分离物中测定了1-9的浓度。根据样品材料，化合物1、3和5-9在选定的蛋白质分离物中的苦味和收敛性均超过剂量阈值（DoT）因子。此外,在工业蛋白质生产过程中（除了富集）观察到关键苦味化合物1的增加，允许鉴定1的潜在前体为山奈酚3-O-（2-O-芥子酰-β-d-槐苷）-7-O-β-d-吡喃葡萄糖苷（3）。通过优化育种和采后下游加工，这些结果可能有助于产生较少苦味和涩的菜籽蛋白分离物。
