Enhancement of natural pigment extraction using Bacillus species xylanase

Pigment extracts from the root of Lithospermum erythrorhizon are used as natural red dyes, as well as basic drugs due to their numerous pharmacological activities. In recent years, the demand for such natural pigment materials has increased; however, in natural dye production, the pigment yield is strongly affected by the source of cultivation, extracting conditions, and solvents. Accordingly, this study proposes a method of enzymatic pigment production based on the introduction of hydrolytic enzymes prior to the usual extraction to avoid repeated pigment extraction. The matrix destruction in the epidermal layer of the root by the enzymes was found to improve the pigment extractability, that is, the increment of K(L), the mass transfer coefficient, representing the pigment mobility in the epidermal layer. The root tissue maceration by the hydrolytic enzymes was also measured to evaluate the pigment extractability, and a linear relationship was observed between the K(L) values and the tissue maceration up to the addition of 3000 units/g of xylanase, indicating that the enzymatic maceration proportionally increases the interfacial area between the pigment and the solvent. Bacillus sp. DX107 xylanase only served to increase the extractability of the pigment by loosening the root shell matrix, without affecting the contents and color properties of the pigment, as almost no difference was found in the color between the pigments extracted using xylanase and those extracted according to the traditional method.