SIMULTANEOUS EXTRACTION AND SEPARATION OF PHENOLIC COMPOUNDS FROM INDUSTRIAL APPLE RESIDUE BY PRESSURIZED LIQUID EXTRACTION COUPLED ON-LINE WITH AN ADSORBENT

The industrial byproduct of apple has great biological potential derived from phenolic compounds present in the fruit bagasse. Techniques of extraction and separation of these compounds should be applied to better take advantage of them from the production of concentrated extracts and to explore diverse forms of applications of these in foods. The objective of this work was to produce concentrated and purified fractions in bioactive compounds from apple industrial waste, combining the pressurized liquid extraction coupled in line with the solid phase extraction (PLE-SPE), as well as understanding the activation and functionality of different adsorbents, solvents and temperature in the retention of phenolic compounds and to compare this technique with other conventional techniques of extraction. To activate the adsorbents was used methanol or ethanol solvents, whereas for the packaging only solvent water. In the first phase of PLE-SPE extraction water was used as solvent (0 - 120 ml) for the selective extraction of acids and retention of flavonoids in the solid phase column. In the second extraction step ethanol or methanol was used as solvents (20 ml). For the development of the method, different extraction temperatures (60ºC, 70ºC and 80ºC) were evaluated using four adsorbents: Sepra, Isolute, StrataX and Oasis. The results indicate that it's possible to obtain two well-defined chemical fractions: an aqueous fraction with high concentrations of gallic acid (36292.5 µg/g to 43795.5 µg/g), and a flavonoid-rich alcoholic fraction (44061.7 µg/g to 46022.2 µg/g). The best retention of compounds was with the temperature of 70 °C and Sepra adsorbent (101355.7 µg/g). The solvent ethanol was positive for extraction/elution of flavonoid compounds (44723.5 µg/g). Thus, the PLE-SPE coupling presents a great potential for the separation and purification of the phenolic compounds present in the apple industrial waste.