APPLICATION OF ACCELERATED SOLVENT EXTRACTION (ASE) AND THIN LAYER CHROMATOGRAPHY (TLC) TO DETERMINATION OF PIPERINE IN COMMERCIAL SAMPLES OF PEPPER (PIPER NIGRUML.)

In this preliminary study, an attempt was made to develop a simple yet reliable overall approach to quantification of piperine in pepper (Piper nigrum L.), and also in the other piperine-containing spice compositions. Such an approach can prove useful for rapid screening of the commercially traded pepper (and other spices) in a pulverized form, with piperine as a single adulteration marker. The main features of this approach consist in a rapid (ca. 40 min) and exhaustive (as proved in a recovery experiment) extraction of plant material with use of Accelerated Solvent Extraction (ASE), followed by an easy thin-layer chromatographic quantification of piperine in the obtained extracts. Within the framework of this approach, dichloromethane (DCM) was selected as an extracting agent and the extraction temperature was fixed at 70°C. With use of the piperine standard, the calibration curve was developed and applicability of the proposed approach was tested upon the commercial samples of white and black pepper in a pulverized and peppercorn form. The piperine levels obtained with the commercial pepper samples remained in agreement with the data available from the literature. Moreover, the assumed quantification approach correctly differentiates between the lower piperine levels in an unripe (black) pepper and the higher ones in a ripe (white) pepper, and also between the lower piperine levels extractable from the whole peppercorn and the higher ones extractable from the ground pepper. Now on the basis of this preliminary study, a completely validated method of quantifying piperine in botanical matter with use of the proposed approach can be elaborated.