Institute of Process Equipment, College of Energy Engineering, Zhejiang University, Zheda Road No. 38, Hangzhou, 310027, China.
Lab Chip. 2019 Jun 11;19(12):2089-2095. doi: 10.1039/c9lc00240e.
Natural colorants, which impart a vivid color to food and add additional health benefits, are favored over synthetic colorants; however, their applications are limited by their low solubility in water and low stability. Here, we develop a versatile microfluidic strategy to incorporate natural colorants in shellac nanoparticles with controlled physicochemical properties. The rapid mixing in the microfluidic channels ensures that the mixing time is shorter than the aggregation time, thus providing control over the co-precipitation of the colorant and the polymer. By introducing molecular interactions, colorant nanoaggregates are efficiently embedded in the polymer matrix, forming hierarchical colorant-loaded nanoparticles. The colorant-loaded nanoparticles dispersed in water are transparent and stable over a wide pH range and their polymer matrix also provides a favorable microenvironment that greatly improves the shelf life of the colorants. The improved solubility, stability and bioavailability of the natural colorants suggest that shellac nanoparticles are ideal carriers and the stable, transparent dispersions of biocompatible colorant-loaded nanoparticles in water are well-suited for the development of functional foods, such as natural color drinks.
天然色素为食物赋予鲜艳的颜色，并增加额外的健康益处，因此优于合成色素；然而，由于其在水中的溶解度低和稳定性低，其应用受到限制。在这里，我们开发了一种通用的微流控策略，可将天然色素掺入具有可控物理化学性质的紫胶纳米颗粒中。在微流道中的快速混合确保混合时间短于聚集时间，从而可以控制色素和聚合物的共沉淀。通过引入分子相互作用，色素纳米聚集体有效地嵌入聚合物基质中，形成分级的色素负载纳米颗粒。色素负载的纳米颗粒在水中分散时具有透明性和宽 pH 值范围内的稳定性，其聚合物基质也提供了有利的微环境，大大提高了色素的保质期。天然色素的溶解度、稳定性和生物利用度的提高表明紫胶纳米颗粒是理想的载体，而在水中具有生物相容性的色素负载纳米颗粒的稳定透明分散体非常适合开发功能性食品，如天然彩色饮料。
