靛蓝是一种古老的植物染料，也是一种具有抗菌、抗炎和抗癌特性的著名中药。传统工艺中，需要进行数千次人工搅拌将优质的靛蓝与粗糙浆料分离。然而，这种方法耗时费力，质量不稳定且产量低，无法满足现代工业化生产的要求。本研究采用泡沫分离技术提高了优质靛蓝的工业适用性。基于活性成分含量、皮肤刺激效果和抗氧化应激活性，对工序参数进行了优化。结果显示，泡沫分离的最佳工艺实现了40厘米的液位差和0.35兆帕的泡沫强度。与原样相比，纯化靛蓝中靛蓝素和靛紫素的含量分别提高了1.6倍和3倍，总灰分含量从86%降至70%，pH值从12.18降至9.71，淋洗倍增。动物实验表明，泡沫分离后的靛蓝明显减少了刺激作用（p < 0.01），并增强了抗氧化应激活性（p < 0.01）。因此，本研究开发的泡沫分离设备实现了靛蓝中活性成分的提纯，大大提高了生产效率和品质。

Indigo Naturalis is not only an ancient plant dye but also a famous herbal medicine with antibacterial, anti-inflammatory, and anticancer properties. In traditional processes, thousands of manual stirring separate the high-quality Indigo Naturalis from the crude pulp system. However, this method is time-consuming and labor-intensive, resulting in an unstable quality and low yield, which cannot meet the requirements of modern industrial production. In this study, foam-separation technology was used to increase the industrial applicability of high-quality Indigo Naturalis. The process parameters were optimized based on the content of active ingredients, skin irritation effects, and antioxidative stress activity. The results showed that the optimal process of the foam separation achieved the liquid level difference of 40 cm and the foaming intensity of 0.35 MPa. Compared with the original sample, the indigo and indirubin contents in purified Indigo Naturalis were 1.6 and 3 times higher, the total ash content decreased from 86 to 70%, the pH value decreased from 12.18 to 9.71, and the leachate doubled. Animal experiments suggested the significantly reduced irritation (p < 0.01) and enhanced antioxidative stress activity (p < 0.01) of Indigo Naturalis after foam separation. Therefore, the foam-separation equipment developed in this study enabled the refinement of active ingredients in Indigo Naturalis, which greatly improved the production efficiency and quality.