Fabrication and characterization of citrus pectin/Dictyophora Rubrovalvata polysaccharide films: pH-cycle treatment and Penaeus vannamei shelf-life extension

Novel bioactive films were formulated via optional novel pH-cycle treatment using pectin with its weight basis of 0–8% polysaccharide from fungi Dictyophora rubrovalvata (DRP), known for its antioxidant and hypoglycemic properties. Characterizations were performed by microscopic techniques, Fourier transform infrared, X-ray diffraction, and thermal gravimetric analysis (TGA), as well as correlation analysis, etc. It was found that pectin integrated with DRP (especially those after pH-cycle treatment) exhibited significantly improved functionalities, including light barrier resistance, mechanical flexibility, thermal stability and antioxidant capacity. Notably, the elongation at break of film by incorporating 8% DRP into pectin via pH cycle reached the highest value of 20.25% as well as the strongest scavenging rates for DPPH∙ + and hydroxyl radicals at the respective rate of 75.52% and 85.71%, indicating the highest preservation efficacy on fresh Penaeus vannamei ( P <0.05). Correlational analysis offers theoretical information for the fabrication of pectin-based films as natural active packaging.