Department of Pharmacy, University of Salerno, via Giovanni Paolo II, 132, 84084 Fisciano, Italy.
Department of Pharmacognosy and Herbal Medicines, Wrocław Medical University, ul. Borowska, 211, 50-556 Wrocław, Poland.
Molecules. 2021 May 8;26(9):2765. doi: 10.3390/molecules26092765.
Strawberry tree honey is a high-value honey from the Mediterranean area and it is characterised by a typical bitter taste. To possibly identify the secondary metabolites responsible for the bitter taste, the honey was fractionated on a C18 column and the individual fractions were subjected to sensory analysis and then analysed by liquid chromatography coupled with high-resolution tandem mass spectrometry in negative ion mode, using a mass spectrometer with an electrospray source coupled to a hybrid high resolution mass analyser (LC-ESI/LTQ-Orbitrap-MS). A chemometric model obtained by preliminary principal component analysis (PCA) of LC-ESI/LTQ-Orbitrap-MS data allowed the identification of the fractions that caused the perception of bitterness. Subsequently, a partial least squares (PLS) regression model was built. The studies carried out with multivariate analysis showed that unedone (2-(1,2-dihydroxypropyl)-4,4,8-trimethyl-1-oxaspiro [2.5] oct-7-en-6-one) can be considered responsible for the bitter taste of strawberry tree honey. Confirmation of the bitter taste of unedone was obtained by sensory evaluation of a pure standard, allowing it to be added to the list of natural compounds responsible for giving the sensation of bitterness to humans.
树莓蜜是一种来自地中海地区的高价值蜂蜜，其特点是具有典型的苦味。为了确定可能导致苦味的次生代谢物，将蜂蜜在 C18 柱上进行分离，然后对各个馏分进行感官分析，再通过液相色谱-高分辨率串联质谱联用仪（LC-ESI/LTQ-Orbitrap-MS）在负离子模式下进行分析，使用带有电喷雾源的质谱仪与混合高分辨率质量分析仪（LC-ESI/LTQ-Orbitrap-MS）相连接。通过对 LC-ESI/LTQ-Orbitrap-MS 数据进行初步主成分分析（PCA）得到的化学计量学模型，能够识别出引起苦味感知的馏分。随后，建立了偏最小二乘（PLS）回归模型。通过多元分析进行的研究表明，unedone（2-(1,2-二羟基丙基)-4,4,8-三甲基-1-氧杂螺[2.5]辛-7-烯-6-酮）可被视为树莓蜜苦味的原因。通过对纯标准品的感官评价，证实了 unedone 的苦味，因此它被添加到了引起人类苦味感知的天然化合物列表中。
