Extraction of Triterpenic Acids and Phytosterols from Apple Pomace with Supercritical Carbon Dioxide: Impact of Process Parameters, Modelling of Kinetics, and Scaling-Up Study

Abstract

Apple pomace, a byproduct of juice production, is a rich source of bioactive compounds and nutrients. Supercritical fluid extraction was proposed as a method for a fast and selective extraction of hydrophobic compounds with a pharmaceutical potential from this matrix. Chromatographic analysis showed that the pomace contained significant amounts of such substances, the most abundant of them were ursolic acid, oleanolic acid, and β-sitosterol. The solubility was chosen as a primary factor for a selection of the extraction conditions; the best results were acquired for a temperature of 80 °C and a pressure of 30 MPa. The equation proposed by Chrastil was applied for the description of the impact of the process parameters on the solubility of the analytes; the obtained values of coefficients of determination were satisfactory, despite the fact that the equation was developed for binary systems. The extraction curves obtained during the experiments were used for the description of the process kinetics using the Broken plus Intact Cell model. The impact of the temperature, pressure, and flow rate of carbon dioxide on the mass transfer phenomena was investigated. The data obtained allowed the prediction of the extraction curve for the process conducted on the larger scale.

Effect of Ethylene and Abscisic Acid on Steroid and Triterpenoid Synthesis in Calendula officinalis Hairy Roots and Saponin Release to the Culture Medium

“…Their identifications were made on the basis of the MS spectra, retention time, and chromatographic mobility of available authentic standards, as well as the comparison with the data from MS libraries and the literature ( Table S1 ). Free steroids can be unequivocally identified without derivatization by their fairly consistent mass spectra, in which a molecular ion (usually of significant intensity) was easily observed, along with other diagnostic ions produced after the loss of 3β-hydroxy group as water [M-18] + and subsequent fragmentation by a retro-Diels-Alder reaction [ 26 , 27 , 28 ]. Three compounds were most prevalent in all samples: stigmasterol (22 E -stigmasta-5,22-dien-3β-ol), sitosterol (stigmast-5-en-3β-ol), and campesterol (24 R -ergost-5-en-3β-ol), which are typical and very common plant sterols.…”

Photosensitizing Furocoumarins: Content in Plant Matrices and Kinetics of Supercritical Carbon Dioxide Extraction

“…The equation connects the solubility of an analyte with temperature and density of a supercritical fluid in the simple binary system. However, as reported in one of our earlier publications [ 34 ], the equation may be suitable to describe the complex phenomena occurring during solubilization of constituents of complex matrices. The measurements conducted using plant matrices instead of pure analytes allowed us to include the impact of other constituents of analyzed plants that can impact solubility of furocoumarins.…”

Distribution of Triterpenoids and Steroids in Developing Rugosa Rose (Rosarugosa Thunb.) Accessory Fruit

“…However, these compounds also occurred in smaller amounts in the pulp and the achenes, thus indicating that their localization in fruits is not restricted only to the surface, as it was also demonstrated in the case of other fruits, such as pear or Saskatoon berry [ 2 , 26 ]. Nevertheless, in the majority of fruits known for their significant content of triterpenoid acids, the peel remains the best source of these compounds, and various techniques of their efficient extraction are currently the subject of much study [ 28 ]. In turn, the relative small amounts of pentacyclic triterpenoids (both acids and alcohols), regarded as defense metabolites, was surprising in rugosa rose achenes, where the accumulation of protective phytochemicals could be expected.…”