Egyptian Opuntia ficus-indica (OFI) residues: recovery and characterization of fresh mucilage from cladodes.

The utilization of biopolymers gained recent attention worldwide due to their effective rolein producing eco-friendly and economical products. Mucilage from Opuntia ficus-indica (OFI, andother succulent plants) has the capacity to absorb huge amounts of water, forming a viscous colloidwith interesting rheological properties. It also had the potential ability for use as food additivesor food technological products. We, therefore, aimed at extracting and characterizing pure liquidmucilage from the cladodes of OFI (Egyptian variety) using multidimensional approaches includingHPLC-RID, FTIR, XRD, NMR, DSC, and TGA assays. The chemical composition, total polyphenols,total flavonoids, total flavonols, and antioxidant capacity by DPPH and ABTS assays were alsomeasured. HPLC-RID analysis showed that the mucilage's sugars are composed of glucose, xylose,rhamnose, galacturonic acid, arabinose, galactose, and fucose with total sugars of 0.375 mg/mL,which were subsequently confirmed by FTIR and NMR results. The specific signals of these sugarswere also observed in 13C and 1H NMR spectra and their chemical fingerprint was obtained by FTIR.XRD patterns showed that mucilage has high calcium content, and the glass transition temperaturewas observed at 85.9 ?C. Meanwhile, total phenolic content, flavonoids, and flavonols were about7.96 mg GAE/g FW, 3.61 mg QE/g FW, and 1.47 mg QE/g FW, respectively. The antioxidant capacityof mucilage was around 26.15 and 22.5 ?mol TE/g FW for DPPH and ABTS methods, respectively. Itcan be concluded that OFI cladode mucilage showed promising properties that would improve andopen new opportunities and trends in the food, pharmaceutical, cosmetic, and other industries. Theuse of pure liquid mucilage could also be economically profitable due to its low cost, availability, andeffectiveness for many edible applications.