Posgrado en Ciencia e Ingeniería de Materiales, Centro de Física Aplicada y Tecnología Avanzada (CFATA), Universidad Nacional Autónoma de México (UNAM), Blvd. Juriquilla 3000, Querétaro, Mexico.
Independent Researcher, El Canto, Zibatá 76269, Querétaro, Mexico.
Molecules. 2018 Oct 24;23(11):2744. doi: 10.3390/molecules23112744.
Anthocyanins are used for food coloring due their low toxicity and health benefits. They are extracted from different sources, but black carrot has higher anthocyanin content compared with common fruits and vegetables. Here, we study alcoholic anthocyanin extracts from black carrot to enhance their stability. The objective of our research is to determine if microencapsulation with tetraethyl orthosilicate (TEOS) is a feasible option for preventing black carrot anthocyanin degradation. Extraction solvents were solutions of (1) ethanol/acetic acid and (2) ethanol/citric acid. Samples were purified through a resin column and microencapsulated using TEOS. Fourier Transformed Infrared Spectroscopy (FTIR) spectra of samples were obtained, and degradation studies were performed under different conditions of UV radiation, pH and temperature. Antioxidant activity was evaluated with radical 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging and electrochemical cupric reducing antioxidant capacity (CUPRAC). Color evaluation on food models were performed with CIE Lab at the beginning of experiments and after 25 days of storage. Results indicate that the more stable extracts against pH media changes are samples obtained with ethanol/acetic acid solution as extraction solvent. Extract purification through resin and TEOS microencapsulation had no significant effect on extract stability. In conclusion, although TEOS microencapsulation has proven to be effective for some dried materials from natural extracts in our previous research, we do not recommend its use for black carrot extracts considering our results in this particular case.
花色苷由于其低毒性和健康益处而被用于食品着色。它们可以从不同的来源中提取出来,但与常见的水果和蔬菜相比,黑胡萝卜的花色苷含量更高。在这里,我们研究了黑胡萝卜的醇溶性花色苷提取物,以提高其稳定性。我们研究的目的是确定使用正硅酸乙酯(TEOS)进行微胶囊化是否是防止黑胡萝卜花色苷降解的可行选择。提取溶剂为(1)乙醇/乙酸和(2)乙醇/柠檬酸溶液。样品通过树脂柱进行纯化,并使用 TEOS 进行微胶囊化。获得了样品的傅里叶变换红外光谱(FTIR),并在不同的 UV 辐射、pH 和温度条件下进行了降解研究。使用自由基 2,2-二苯基-1-苦基肼(DPPH)清除和电化学铜还原抗氧化能力(CUPRAC)评估了抗氧化活性。在实验开始时和储存 25 天后,使用 CIE Lab 对食品模型进行了颜色评估。结果表明,在 pH 介质变化下更稳定的提取物是用乙醇/乙酸溶液作为提取溶剂获得的。通过树脂纯化和 TEOS 微胶囊化对提取物稳定性没有显著影响。总之,尽管 TEOS 微胶囊化在我们之前的研究中已被证明对某些天然提取物的干燥材料有效,但考虑到我们在这种特殊情况下的结果,我们不建议将其用于黑胡萝卜提取物。