Phenolic Compounds Recovery from Pomegranate (Punica granatum L.) By-Products of Pressurized Liquid Extraction.

This study aimed to valorize pomegranate by-products (peel and carpelar membranes-PPCM) through their high biological potential for phenolic compounds recovery. The influence of lower temperatures (40 and 60 °C) and pressures (20, 40, 60, 80, and 100 bar) than those generally used in pressurized liquid extraction (PLE) was evaluated through global extraction yield (X0), and qualitative and quantitative composition of the phenolic compounds. Chromatographic techniques were used to analyze the two treatments with the highest X0. Temperature, pressure, and their interaction had a significant influence on X0. The best phenolic compounds extraction conditions were using pressurized ethanol at 60 °C and 40 bar (extract 1-E1, 37% on d.b.) and 60 °C and 80 bar (extract 2-E2, 45% on d.b.). Nevertheless, E1 presented a significantly higher content of α, ß punicalagin, and ellagic acid (48 ± 2, 146 ± 11, and 25.6 ± 0.3 mg/100 g, respectively) than E2 (40 ± 2, 126 ± 4, and 22.7 ± 0.3 mg/100 g). Therefore, this study could validate the use of low pressures and temperatures in PLE to recover phenolic compounds from pomegranate residues, making this process more competitive and sustainable for the pomegranate industry.

Obtaining bixin from semi-defatted annatto seeds by a mechanical method and solvent extraction: Process integration and economic evaluation.

This work involves the application of physical separation methods to concentrate the pigment of semi-defatted annatto seeds, a noble vegetal biomass rich in bixin pigments. Semi-defatted annatto seeds are the residue produced after the extraction of the lipid fraction from annatto seeds using supercritical fluid extraction (SFE). Semi-defatted annatto seeds are use in this work due to three important reasons: i) previous lipid extraction is necessary to recovery the tocotrienol-rich oil present in the annatto seeds, ii) an initial removal of the oil via SFE process favors bixin separation and iii) the cost of raw material is null. Physical methods including i) the mechanical fractionation method and ii) an integrated process of mechanical fractionation method and low-pressure solvent extraction (LPSE) were studied. The integrated process was proposed for processing two different semi-defatted annatto materials denoted Batches 1 and 2. The cost of manufacture (COM) was calculated for two different production scales (5 and 50L) considering the integrated process vs. only the mechanical fractionation method. The integrated process showed a significantly higher COM than mechanical fractionation method. This work suggests that mechanical fractionation method is an adequate and low-cost process to obtain a rich-pigment product from semi-defatted annatto seeds.