Department of Food Science and Technology, The Ohio State University, 2015 Fyffe Rd., Columbus, OH 43210 1007, USA.
Int J Mol Sci. 2021 Jun 23;22(13):6708. doi: 10.3390/ijms22136708.
Pyranoanthocyanins are anthocyanin-derived pigments with higher stability to pH and storage. However, their slow formation and scarcity in nature hinder their industrial application. Pyranoanthocyanin formation can be accelerated by selecting anthocyanin substitutions, cofactor concentrations, and temperature. Limited information is available on the impacts of the chemical structure of the cofactor and anthocyanin; therefore, we evaluated their impacts on pyranoanthocyanin formation efficiency under conditions reported as favorable for the reaction. Different cofactors were evaluated including pyruvic acid, acetone, and hydroxycinnamic acids (-coumaric, caffeic, ferulic, and sinapic acid) by incubating them with anthocyanins in a molar ratio of 1:30 (anthocyanin:cofactor), pH 3.1, and 45 °C. The impact of the anthocyanin aglycone was evaluated by incubating delphinidin, cyanidin, petunidin, or malvidin derivatives with the most efficient cofactor (caffeic acid) under identical conditions. Pigments were identified using UHPLC-PDA and tandem mass spectrometry, and pyranoanthocyanin formation was monitored for up to 72 h. Pyranoanthocyanin yields were the highest with caffeic acid (17% at 72 h, < 0.05). When comparing anthocyanins, malvidin-3--glycosides yielded twice as many pyranoanthocyanins after 24 h (20%, < 0.01) as cyanidin-3--glycosides. Petunidin- and delphinidin-3--glycosides yielded <2% pyranoanthocyanins. This study demonstrated the importance of anthocyanin and cofactor selection in pyranoanthocyanin production.
吡喃花青素是一种花青素衍生的色素，其在 pH 值和储存方面具有更高的稳定性。然而，它们在自然界中的形成速度较慢且数量稀少，这阻碍了它们的工业应用。吡喃花青素的形成可以通过选择花青素取代基、辅因子浓度和温度来加速。关于辅因子和花青素的化学结构的影响，信息有限；因此，我们在报告有利于反应的条件下，评估了它们对吡喃花青素形成效率的影响。通过在摩尔比为 1:30（花青素：辅因子）、pH 值为 3.1 和 45°C 的条件下将不同的辅因子（丙酮酸、丙酮和羟基肉桂酸（-香豆酸、咖啡酸、阿魏酸和芥子酸）与花青素孵育，评估了不同辅因子的影响。通过在相同条件下将飞燕草素、矢车菊素、锦葵色素或二甲花翠素衍生物与最有效的辅因子（咖啡酸）孵育，评估了花青素糖苷元的影响。使用 UHPLC-PDA 和串联质谱鉴定色素，并监测吡喃花青素的形成，最长达 72 小时。咖啡酸的吡喃花青素产率最高（72 小时时约为 17%，<0.05）。在比较花青素时，锦葵色素-3-糖苷在 24 小时后产生的吡喃花青素数量是矢车菊素-3-糖苷的两倍（约 20%，<0.01）。飞燕草素和飞燕草素-3-糖苷的吡喃花青素产率<2%。这项研究表明，在吡喃花青素生产中，花青素和辅因子的选择很重要。
