Universidade do Vale do Paraíba-UNIVAP, São José dos Campos, SP, Brazil.
J Fluoresc. 2011 Jan;21(1):415-21. doi: 10.1007/s10895-010-0730-1. Epub 2010 Oct 6.
Nowadays, the synthetic dyes (as erythrosine, ponceau and tartrazina) and natural colourants (as annatto, paprika, curcuma and anthocyanin) are indispensable in the food, pharmaceutical and cosmetics applications. However, the use of natural colourant has been considered safer for human consumption then synthetic dye. For practical applications of the coloring, optical properties are important for the understanding of the characteristics of them. In this work, we presented the absorption and fluorescence spectroscopic characterizations of annatto extracts obtained from the seeds of the tropical shrub Bixa orellana L. solutions and commercial colourant. The measurements were performed in annatto extracts with acetone and chloroform in different concentrations range (3.5-52.5) μg/mL. The main carotenoids detected in annatto seeds is bixin. The numerical calculus of the absorbance spectra for cis- and trans-bixin conformation is presented. In addition, for commercial colourant, the measurements were performed for six different brands and five lots each one. Modifications in the shape of the colorific fluorescence spectra were observed and it can be an indicative of differences in the industrial methods applied for obtaining annatto pigments powders and/or the possibility of the presence of other impurities added in the commercial powders.
如今，合成染料（如赤藓红、胭脂红和柠檬黄）和天然着色剂（如胭脂树橙、辣椒粉、姜黄和花青素）在食品、制药和化妆品应用中不可或缺。然而，与合成染料相比，天然着色剂的使用被认为对人类消费更安全。为了实际应用着色，光学性质对于理解它们的特性很重要。在这项工作中，我们展示了从热带灌木胭脂树种子中提取的胭脂树提取物的吸收和荧光光谱特性，以及商业着色剂。测量是在含有丙酮和氯仿的不同浓度范围内（3.5-52.5）μg/mL 的胭脂树提取物中进行的。在胭脂树种子中检测到的主要类胡萝卜素是胭脂树橙。提出了顺式和反式胭脂树橙构象的吸收光谱的数值计算。此外，对于商业着色剂，对六个不同品牌和每个品牌的五个批次进行了测量。观察到彩色荧光光谱形状的变化，这可能表明用于获得胭脂树颜料粉末的工业方法存在差异，或者商业粉末中可能存在其他杂质。
