Pomegranate peel extract and zinc oxide as a source of natural dye and functional material for textile fibers aiming for photoprotective properties

The use of photoprotection products is indispensable today, due to the potential harmful effects of ultraviolet (UV) rays. Textiles are a natural barrier against UV radiation and can be made more effective by applying UV blockers. The present study investigates the photoprotection properties arising from dyeing cotton fabric with pomegranate peel extract. The extract was characterized by TPC, TFC, THT, color, pH, HPLC-UV and including its antiradical activity. The dyed fabric samples were evaluated for color, color fastness to light, rubbing, washing and sweating, along with a determination of SEM, EDS, ATR-FTIR, and UPF properties. The chemical analyses of the P. granatum peel aqueous extract by HPLC-UV indicated the presence of ellagic acid, punicalagin and punicalin derivatives. The extract showed antiradical activity (11.1 ± 0.4 CI50 (mg L−1) which is consistent with a high amount of total phenols 307 ± 26 (mg GAE/g extract), total flavonoids 150.3 ± 2.3 (mg RE/g extract), and condensed tannins 632.6 ± 84.1 (mg TAE/g extract). The dyed fabric samples showed yellowish colors and good color fastness ratings. The evaluation of the Ultraviolet Protection Factor (UPF) indicated mostly values from 15 to 24, equivalent to the category of good to very good photoprotection. Bearing in mind that ZnO is often used in combination with other UV-blockers to enhance the coverage of sunscreens, an aspect of this study involved determining the UPF of the pomegranate extract mixed with ZnO. In this case, ZnO addition did not significantly enhance the UPF of the dyed cotton fabric.