Enzymatic browning reduction in white cabbage, potent antibacterial and antioxidant activities of biogenic silver nanoparticles

To produce economically benign and nontoxic enzymatic browning reducing and antimicrobial agents is the goal of nanotechnology. In this study we synthesized environmentally friendly silver nanoparticles (AgNPs) using Longan fruit juice as reducing and stabilizing agent. Silver nanoparticles synthesis was monitored by UV-vis spectroscopy showing localized surface plasmon resonance at 443 nm. XRD (X-ray diffraction analysis), HRTEM (high resolution transmission electron microscopy) and EDX (energy dispersive X-ray analysis) were used to characterize crystalline structure, size (4-10 nm), shape and elemental composition of silver nanoparticles. Surface capped phytochemicals were characterized by FTIR. Silver nanoparticles have significant enzymatic browning reduction (p < 0.001) using white cabbage as a model system. No research has been reported on the Enzymatic browning reduction of biosynthesized silver nanoparticles. The silver nanoparticles showed prominent antibacterial activity with MIC values of 31.25 μg/ml against Staphylococcus aureus and Basillus subtilus while 62.5 μg/ml against Escherichia coli. High cells constituents' release was exhibited by B. subtilus with 2 × MIC value of silver nanoparticles. Silver nanoparticles exhibited no hemolytic activity against Red blood cells of male Wistar albino rat. Silver nanoparticles also showed significant DPPH free radical scavenging activity. This research would have an important implication for the synthesis of more efficient antimicrobial, antioxidant and anti-enzymatic browning agents for food preservation, processing and other biomedical applications.