COMPARISON BETWEEN ADSORVENTS IN THE SEPARATION OF PHENOLIC COMPOUNDS FROM POMEGRANATE PEEL EXTRACT

Phenolic compounds found in the pomegranate peel are of interest due to their nutritional and microbiological value, resulting in a high potential for food industry use. The main compounds are quercetin, ellagitannins (largely punicalagin), phenolic acids (caffeic, chlorogenic, coumaric, ellagic, gallic, and quinic), and anthocyanins (delphinidin, cyanidin, and pelargonidin). They present different structures and can promote different effects on human health. Thus, the separation and concentration are interesting for further applications considering their characteristics. Among the techniques to separate, adsorption is a selective way to isolate and fractionate phenolic compounds. Therefore, our objective was to evaluate the ability of two adsorbents, polar and non-polar, to separate phenolic compounds from pomegranate peel. The pomegranate extract was obtained using bath ultrasound applying 100 W at 37 kHz and 60 ºC for 1 h. The extract was used to evaluate the adsorption process using the adsorbents Rxn RP Bulk (PoraPak®) and C18-E (Sepra®). The adsorption process was performed using different mass percentages of adsorbent in relation to the extract (1.42, 2.85, 4.28, 5.71, and 7.14%) in an ultrasound bath for 1 hour at 100 W and 37 kHz. Analysis before and after adsorption was performed by Ultra High-performance Liquid Chromatography (UHPLC). The results show that the adsorbent Rxn RP Bulk promoted a better separation between punicalagin and ellagic acid when used at the highest proportion (7.14%). Therefore, the more polar adsorbent (Rxn RP Bulk) favored the separation of phenolic compounds present in the extract. In this way, the isolated compounds can be applied to enrich food products or produce pharmaceutical products according to their characteristics.