The combination of carbon dots/polyvinyl alcohol (CDs/PVA) active film and radio frequency (RF) was performed to improve the storage quality of fried meatball samples. The microbicidal effect of RF, and the antioxidant and antibacterial activities of CDs/PVA film were investigated. The CDs/PVA film can effectively restrain the growth of B. subtilis, S. aureus, and E. coli, and eliminate DPPH and ABTS free radicals. RF exerts inhibitory effects on C. albicans, B. subtilis, and E. coli. For meatball samples, CDs/PVA+RF20 can extend the refrigerated shelf life from 2 w to 6 w. At the sixth week, the total bacterial count (TBC) in CDs/PVA+RF20 group (3.72 log CFU/g) was remarkably lower than those in polyethylene terephthalate (PET) group (7.78 log CFU/g) and CDs/PVA (6.41 log CFU/g) group. CDs/PVA+RF20 can also inhibit the increase in TBARS and POV values. The results manifest the feasibility of CDs/PVA+RF as a novel mild pasteurization or preservation technology.
Keywords: active packaging; antimicrobial; antioxidant; carbon dots; sterilization mechanism.