Australian Research Council Training Centre for Innovative Wine Production and Waite Research Institute, The University of Adelaide, PMB 1, Glen Osmond, South Australia 5064, Australia.
Australian Research Council Training Centre for Innovative Wine Production and Waite Research Institute, The University of Adelaide, PMB 1, Glen Osmond, South Australia 5064, Australia.
Food Res Int. 2024 May;183:114195. doi: 10.1016/j.foodres.2024.114195. Epub 2024 Mar 11.
Anthocyanins are polyphenolic compounds that provide pigmentation in plants as reflected by pH-dependent structural transformations between the red flavylium cation, purple quinonoidal base, blue quinonoidal anion, colourless hemiketal, and pale yellow chalcone species. Thermodynamically stable conditions of hydrated plant cell vacuoles in vivo correspond to the colourless hemiketal, yet anthocyanin colour expression appears in an important variety of hues within plant organs such as flowers and fruit. Moreover, anthocyanin colour from grape berries is significant in red winemaking processes as it plays a crucial role in determining red wine quality. Here, nonlinear ordinary differential equations were developed to represent the evolution in concentration of various anthocyanin species in both monomeric (chemically reactive) and self-associated (temporally stable) forms for the first time, and simulations were verified experimentally. Results indicated that under hydrating conditions, anthocyanin pigmentation is preserved by self-association interactions, based on pigmented monomeric anthocyanins experiencing colour loss whereas colour-stable self-associated anthocyanins increase in concentration nonlinearly over time. In particular, self-association of the flavylium cation and the quinonoidal base was shown to influence colour expression and stability within Geranium sylvaticum flower petals and Vitis vinifera grape skins. This study ultimately characterises fundamental mechanisms of anthocyanin stabilisation and generates a quantitative framework for anthocyanin-containing systems.
花色苷是一种多酚化合物，在植物中提供色素，这反映在 pH 依赖性结构转化之间的红查耳酮阳离子、紫查耳酮碱、蓝查耳酮阴离子、无色半缩酮和浅黄色查耳酮物种。体内水合植物细胞液泡的热力学稳定条件对应于无色半缩酮，但花色苷的颜色表达在植物器官如花朵和果实中呈现出重要的色调多样性。此外，葡萄浆果中的花色苷在红酒酿造过程中非常重要，因为它在决定红酒质量方面起着关键作用。在这里，首次开发了非线性常微分方程来表示各种花色苷单体（化学活性）和自缔合（时间稳定）形式的浓度演变，并进行了实验验证。结果表明，在水合条件下，花色苷的色素化通过自缔合相互作用得以保留，基于着色的单体花色苷经历颜色损失，而颜色稳定的自缔合花色苷随时间非线性增加浓度。特别是，证明了黄烷酮阳离子和醌式碱的自缔合会影响天竺葵花瓣和葡萄皮中的花色苷表达和稳定性。这项研究最终描述了花色苷稳定的基本机制，并为含花色苷的系统生成了一个定量框架。
