Micronization and Encapsulation of Functional Pigments Using Supercritical Carbon Dioxide

Abstract

This research involves experimental studies of supercritical fluid (SCF)-based micronization and encapsulation processes exploiting both solvent and antisolvent properties of supercritical CO2 for diverse functional pigments to extend the application of these natural functional pigments. First, the reliability of homemade experimental apparatuses designed and constructed by our research group was tested. Quercetin and b-carotene were used as model substances in the micronization process via supercritical antisolvent (SAS). Bixin-rich extract with polyethylene glycol (PEG) 10,000 as encapsulant material was used in the encapsulation process via SAS, while rutin and anthocyanin-rich extract with PEG 10,000 and ethanol as cosolvents were applied to the formation of polymeric microcapsules via rapid expansion of supercritical solutions (RESS). The processing parameters and the used levels were based on the literature data. SAS process successfully reduced the particle size of quercetin by 4.1 times, while conventional micronization process only reduced the particle size by 1.8 times. Furthermore, it was demonstrated that SAS process can be successfully utilized to coprecipitate microparticles of PEG loaded with bixin-rich extract. RESS process using ethanol as cosolvent was employed effectively to encapsulate rutin and anthocyanin-rich extract in the PEG matrix. The data obtained in this study are in good agreement with the previous values reported by several authors using similar operational conditions and equipment. Core material : encapsulant material ratio, core material physical properties, such as solubility in supercritical CO2 and in CO2 + ethanol, and viscosity were key parameters for these processes.

Production of stabilized quercetin aqueous suspensions by supercritical fluid extraction of emulsions

“…Due to the low solubility of quercetin in supercritical carbon dioxide [12], Supercritical Antisolvent (SAS) experiments have been particularly successful. By SAS processing of pure quercetin, crystalline particles with particle sizes in the micrometer range (1 -6 m) have been obtained [13,14,15]. Fraile et al [16] produced quercetin particles encapsulated with Pluronic F127 by SAS technology.…”

Applications of Supercritical Fluids in Latin America: Past, Present and Future Trends

“…Afterwards, in 2008, Franceschi et al [8] and Franceschi et al [9] studied the encapsulation of β-carotene and precipitation of theophylline, respectively. By July 2013, 8 other scientific documents had been published on this issue in LA [4], [6], [10][11][12][13][14][15], which indicates significant growth in this line of research.…”

Methods and Trends of Applying Supercritical Micronization

“…Alternatywą jest wytrącanie w warunkach nadkrytycznych nośnika na wcześniej utworzonych kapsułkach substancji aktywnej, często przy użyciu złoża fluidalnego [28]. Mikrokapsułki uzyskiwane tą metodą przyjmują kształt cienkich igieł, a ich długość waha się od 1 do 5 m w przypadku cholesterolu [22], płaskich niekształtnych mikrokapsułek o długości od 9 do 42 m w przypadku rutyny (w zależności od parametrów procesowych) [21] albo zbliżonych do kuli o średnicy 0,5 m w przypadku mikrokapsułek astaksantanu [19].…”