Selective Extraction of Gardenia Yellow and Geniposide from Gardenia jasminoides by Mechanochemistry.

A novel method for the selective extraction of gardenia yellow and geniposide from Gardenia Jasminoides, based on a mechanochemical method is described. Without the need of complex separation techniques, gardenia yellow compliant with the national standard could be extracted in a simple fashion. The optimal ball-milling conditions determined were as follows: 30% g/g. active carbon milling at 200 rpm in a planetary mill for 5 min. The extraction conditions of the milled mixtures were as follows: the milled mixtures were extracted with water (liquid-solid ratio 10:1) at 20 °C for 5 min with yields 85% of total geniposide, followed by extraction with 80% ethanol solution (liquid-solid ratio 5:1) and 1% g/g. Tween 20 at 75 °C for 5 min to yield 1.45% ± 0.108% g/g of gardenia yellow. The mechanism of this selective extraction was demonstrated to follow a microstructure change of activated carbon, which occurred during milling and lead to alteration of the corresponding desorption capacities. Compared with traditional extraction methods, this novel extraction technique greatly simplifies the separation process, and proves to be advantageous in terms of low organic solvent consumption, easy operation, rapid process and high efficiency.