Khan Mohammad Imtiyaj
Department of Biotechnology, Gauhati University, Gopinath Bordoloi Nagar, Guwahati 781014, India.
Food Chem. 2016 Apr 15;197 Pt B:1280-5. doi: 10.1016/j.foodchem.2015.11.043. Epub 2015 Nov 11.
Betalains are vacuolar pigments composed of a nitrogenous core structure, betalamic acid [4-(2-oxoethylidene)-1,2,3,4-tetrahydropyridine-2,6-dicarboxylic acid]. This compound consists of a chromophore substructure 1,7-diazaheptamethin. Betalamic acid condenses with imino compounds (cyclo-DOPA or its glucosyl derivatives), or amines and/or their derivatives to form a variety of betacyanins (violet) and betaxanthins (yellow), respectively. These pigments exhibit absorption maxima in between 532-550 nm and 457-485 nm, respectively. These colors are currently in use as food additives as they are bioactive and completely safe to consume. However, owing to poor stability, their potential application in pharmaceuticals and cosmetics is severely compromised. There is a lack of scientific reports highlighting their superior tinctorial strength including fluorescence, and their excellent water solubility. For widening the color spectrum and their usage, various betalain-rich extracts have been reviewed here, focusing on their matrix effects on stability vis-a-vis purified pigments of different structural make-up. This review also encompasses work carried out in the past related to stability/stabilization of betalains and future research direction for the same.
甜菜色素是一种液泡色素，由含氮核心结构甜菜醛氨酸[4-(2-氧代亚乙基)-1,2,3,4-四氢吡啶-2,6-二羧酸]组成。该化合物由发色团亚结构1,7-二氮杂庚省组成。甜菜醛氨酸分别与亚氨基化合物（环多巴或其葡糖基衍生物）、胺和/或其衍生物缩合，形成各种花青素（紫色）和黄嘌呤（黄色）。这些色素的最大吸收波长分别在532-550nm和457-485nm之间。这些色素目前用作食品添加剂，因为它们具有生物活性且食用完全安全。然而，由于稳定性差，它们在制药和化妆品中的潜在应用受到严重影响。缺乏科学报告强调其卓越的染色强度，包括荧光以及出色的水溶性。为了拓宽色谱范围及其用途，本文综述了各种富含甜菜色素的提取物，重点关注它们相对于不同结构组成的纯化色素在稳定性方面的基质效应。本综述还涵盖了过去与甜菜色素稳定性/稳定化相关的工作以及未来的研究方向。
