(231ad) Solubility of Ternary Systems Containing Capsaicin + β-Carotene and Lauric Acid + Palmitic Acid in Supercritical Carbon Dioxide

The solubility data of solid mixtures in supercritical fluid (SCF) are rarely reported in literature. Capsaicin and β-carotene are both components of paprika (Capsicum annuum), one of the oldest source of natural colorants used in the food and cosmetic industries. β-Carotene is one of several carotenoids found in paprika. Capsaicin is the most important component among various capsaicinoids which causes pungency of paprika and should therefore be removed from coloring compounds (carotenoids).

On the other hand, vegetable oils contain a large number of compounds that can be classified into unsaponifiable and saponifiable fraction. The latter, accounting for about 98% of the oil, is mostly constituted from fatty acids forming esters with glycerol to produce mono-, di-, and tri-glycerides. The fatty acids composition of oils varies considerably according to the vegetable matrix (olive, sunflower, corn, palm, hazelnut, soybean, etc.) and even varies for the same vegetable matrix when considering variety, local factors, climatic condition, harvest time, extraction processes from fruits or seeds, etc.

 Supercritical extraction with CO2 seems to be a good alternative. Due to carbon dioxideâ??s relatively low critical temperature (Tc= 304.4 K), it is especially suitable for processing thermo-labile compounds. Information about solubility of solids in supercritical fluids is of great importance because supercritical fluids have several advantages over organic solvents about physical properties. Accurate experimental solubility data are fundamental to test theoretical, empirical or semi-empirical models. Semi-empirical models based on density are common approaches used to correlate experimental solid solubilities in supercritical fluids.

 The aim of this work is to present new experimental solid solubilities of the ternary systems: Capsaicin + β-Carotene + Carbon dioxide, and Lauric acid + Palmitic acid+ Carbon dioxide at 313, 323 and 333 K an pressures up to 30 MPa, based on the static-analytical method. The solubility data were correlated with the Mendez-Santiago and Teja model.