TY - JOUR
T1 - Human Sensory, Taste Receptor, and Quantitation Studies on Kaempferol Glycosides Derived from Rapeseed/Canola Protein Isolates
T2 - Journal of Agricultural and Food Chemistry
AU - Walser, Christoph
AU - Spaccasassi, Andrea
AU - Gradl, Katrin
AU - Stark, Timo D.
AU - Sterneder, Sonja
AU - Wolter, Frank P.
AU - Achatz, Felicia
AU - Frank, Oliver
AU - Somoza, Veronika
AU - Hofmann, Thomas
AU - Dawid, Corinna
N1 - doi: 10.1021/acs.jafc.4c02342
PY - 2024/6/18
Y1 - 2024/6/18
N2 - 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.
AB - 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.
U2 - 10.1021/acs.jafc.4c02342
DO - 10.1021/acs.jafc.4c02342
M3 - Article
SN - 0021-8561
JO - Journal of agricultural and food chemistry
JF - Journal of agricultural and food chemistry
ER -