Enhancing circular bioeconomy: Alginate-cellulose nanofibre films/coatings functionalized with encapsulated pomegranate peel extract for postharvest preservation of pomegranate arils
Noluthando Makhathini, Nishant Kumar, Olaniyi Amos Fawole
Abstract
This study investigated the properties of alginate-cellulose nanofiber (AL-CNF) bio-composite coatings functionalized with pomegranate peel extract powder (PPEP) at 0.1, 0.3, and 0.5 % (w/v) and their effects on the postharvest shelf life of pomegranate arils stored at 5 °C and 95 ± 2 % RH for 15 days. The results demonstrated that PPEP incorporation enhanced the physical, functional, and antioxidant properties of the coatings while reducing their mechanical strength. Microstructural analysis revealed that CNF contributed to a rougher surface, whereas PPEP addition improved homogeneity and smoothness. The 0.5 % PPEP concentration exhibited the highest thickness, antioxidant activity, and phenolic content. Application of AL-CNF bio-composite coatings significantly (p < 0.05) reduced weight loss, delayed respiration, and maintained firmness compared to the control. PPEP incorporation increased total soluble solids (TSS) and preserved the visual quality of arils. Additionally, 0.5 % PPEP retained higher phenolic content, anthocyanin levels, and DPPH activity while reducing microbial growth. These findings suggest that AL-CNF nanocomposite coatings enriched with PPEP (0.1-0.5 %) effectively preserve quality and extend the shelf life of minimally processed pomegranate arils, offering a sustainable postharvest preservation strategy.