Mesocarp and Exocarp of Laffan and Wonderful Pomegranate Cultivars: by products as a Source of Ellagitannins

Pomegranate peel (exocarp and mesocarp), which constitutes about 50% of the whole fresh fruit, is extensively used in folk medicine but discarded in large quantities as by-product, after the juice production. The objective was to valorize this by-product derived from Laffan and Wonderful varieties, by improving the knowledge on its composition and by applying sustainable extraction processes. The extraction was performed separately on exocarp and mesocarp, using water at different temperatures, and 70% ethanol; the ellagitannins were determined by HPLC-DAD and MS- TOF. The polysaccharide fraction was extracted and determined by weight (yields). The profiles of mesocarp and exocarp separately of the two varieties were very similar and characterized by the same ellagitannins (ETs) of pomegranate juice. The highest ETs amount was obtained from mesocarp (140 - 150 mg/dried matter) via decoction and hydroalcoholic extraction. No ETs degradation was observed during decoction, α and β punicalagins were always 59 – 78 % of the total ETs. Decoction as a green process easy to apply can help to valorize these by-products as it is able to recover polysaccharides as well as ellagitannins. A Nutritional label was prepared for the whole dry decoction from Wonderful mesocarp