Recovery of ellagitannins from mesocarp of pomegranate fruits of the Syrian Laffan cultivar

Pomegranate is cultivated around the world with different microclimate. Well known producers of pomegranates are Iran, Turkey, Egypt, Italy, and Syria. Iran contributed to at least half of the total world production (more than 700.000 tons/years; FAOSTAT, FAO 2010) and the market has steadily grown presumably due to the increasing consumer awareness of the potential health benefits of this ancient fruit and phytochemicals thereof. Moreover it is well known the wide biodiversity among different cvs as recently confirmed by a study on 15 Spanish cultivars of pomegranate[1]. Nevertheless, to date scant data are available on the composition of the mesocarp, a large part of the fruit, often close to 50% of the whole weight, that often is discharged during the juice preparation. In this context, our work is aimed at studying pomegranate extracts obtained from the Syrian cultivar Laffan widely used by the local population but never characterized to date. The ellagitannins of different extracts obtained treating the discharge parts (mesocarp and peel) of the pomegranate fruits have been evaluated and compared to define the best extractive processes (higher yields and lower extraction time) suitable to recover these bioactive molecules[2]. Our results highlighted the hot water as a good solvent to recover the ellagitannins, mainly and  punicalagins with comparable yields to those obtained using hydro-alcoholic solutions. The optimum ratio water/dried mesocarp was 1g/40 mL and only by one extractive step was possible to recover almost the 90 % of the total tannins. At the same time was pointed out the thermal stability of these phenols that remain unaltered also after several minutes of boiling. In terms of ellagic tannin content the hot-water extracts showed values close to 120 mg/g dried extract. The main advantages of the proposed extractive method are the use of water as solvent, the optimal reproducibility in terms of total tannins (RSD below 3,5%) and the applicability on large scale. These results highlighted the mesocarp of Laffan cv. as a rich source of ellagic tannins and suitable to be use as food ingredient or component of food supplements.