Supercritical carbon dioxide extraction of chamomile flowers: extraction efficiency, stability, and in‐line inclusion of chamomile–carbon dioxide extract in β‐cyclodextrin

Abstract

The extraction of chamomile flowers using supercritical carbon dioxide was investigated with respect to extraction efficiency and compared with solvent extraction. The stability of matricine, a sensitive constituent of the essential oil of chamomile, in these extracts was studied during storage at different temperatures over 6 months. Matricine was stable at -30 degrees C. A slight decrease (80-90% recovery) occurred at +5 degrees C, whereas complete decomposition of matricine took place within 3-4 months at room temperature and at +30 degrees C, respectively. An in-line inclusion of chamomile constituents in beta-cyclodextrin (beta-CD) during the extraction process was assessed and inclusion rates between 40 and 95% were obtained depending on the amount of beta-CD and the type of chamomile constituent. No further stabilization of matricine in the carbon dioxide extract/beta-CD complexes was achieved. High residual water contents in the complexes even after freeze-drying were identified as accelerating the decomposition. In addition, the extractability of flavonoids, such as apigenin and apigenin-7-glucoside, was determined. Apigenin-7-glucoside, the more hydrophilic substance, was not extractable with pure carbon dioxide and showed a recovery of 11% using methanol modified carbon dioxide (18%, w/w) at 60 degrees C and 380 bar. Extraction conditions in the two-phase region of the binary mixture carbon dioxide-methanol (70 degrees C, 100 bar) led to a drastic change in fluid polarity and hence extractability increased to 92-95%.

A review on cyclodextrin encapsulation of essential oils and volatiles

“…[108,115] b-CyD inclusion complexes with carvacrol, thymol and eugenol, and also citral flavours were prepared by the SC-CO2 technique [88,116] and also b-farnesene and matricine. [84] …”

“…The extent of the protection depended on the applied mass of b-CyD. [84] Carvone and limonene, constituents of caraway essential oil, were complexed with b-CyD. The b-CyD inclusion complex seemed to protect volatile substances from evaporation more efficiently during storage whereas microcapsules with modified starches as wall material were more heat tolerant.…”

Carbon dioxide deliming in leather production: a literature review

“…The first technological application of SCCD is caffeine extraction from coffee beans and raisin from hops (Zosel, 1978). To date, SCCD is widely used in food (Teberikler et al, 2001;Jokic et al, 2011;Yu et al, 2012), aroma (Hamburger et al, 2004;Kaiser et al, 2004) and polymer synthesis, etc. Skins degreasing was achieved with SCCD as a cleaner solvent (Marsal et al, 2000;Vaquero et al, 2006).…”

Application of supercritical fluid extraction for separation of nutraceuticals and other phytochemicals from plant material

“…Because of the polarity of flavonoids, polar modifiers have to be added to SC-CO 2 to increase solubility. Numerous researches were performed, where the influence of modifiers was investigated [84,90,[94][95][96][97][98][99][100][101][102][103][104][105][106][107]. These studied showed that the addition of a modifier generally increases the efficiency of extraction by increasing yields.…”