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a b s t r a c tObtaining an extract with high antioxidant activity using environmentally friendly technologies and lowcost raw materials is of great interest. In the present work, a combined extraction process developed by our research group involving ultrasound treatment and agitated solvent extraction was evaluated. This method was compared in terms of yield, composition, and economical feasibility to traditional extraction methods, including ultrasound assisted, agitated bed and soxhlet extraction with ethanol (acidified or not). The proposed method maximizes the extraction of phenolic compounds with acceptable degradation of anthocyanin pigments from an unusual source: Brazilian jabuticaba (Myrciaria cauliflora) skins. The use of ultrasonic irradiation continuously supporting a main extraction process has demonstrated increased performance but implies in high consumption of energy and consequently, money. However, the procedure described in this paper appears to be a viable option because it uses shorter ultrasonic irradiation and results in high antioxidant activity extracts, and the anthocyanin profile corroborates literature data (cyanidin-3-glucoside and delphinidin-3-glucoside).

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Supercritical fluids have become an attractive alternative due to environmentally friendly solvents. The methods that use supercritical fluids can be conveniently used for various applications such as extraction, reactions, particle formation and encapsulation. For encapsulation purposes, the processing conditions given by supercritical technology have important advantages over other methods that include harsh treatments with regard to pH, temperature, light, the use of organic solvents, etc. Unstable functional pigments such as carotenoids extracted from natural sources have been encapsulated to overcome instability problem. Thus, the most used techniques applicable to this intention are described and discussed in this review as well the recent advances and recent trends in this topic that involves the use of supercritical fluids.

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.

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