Efficiency of gluconate-stabilized silver nanocoating for shelf-life enhancement of Khasi mandarin (Citrus reticulata, Blanco)

Khasi mandarin ( Citrus reticulata , Blanco) is a widely cultivated commercial fruit crop in Meghalaya, India. The present research aims to assess the potential for synthesizing and characterizing gluconate-stabilized silver nanoparticles (Glu-Ag NPs) to enhance the shelf-life of Khasi mandarin by inhibiting Penicillium italicum . Glu-Ag NPs showed the highest (58.23%) mycelial growth inhibition at 250 ppm. The lowest diseases severity index (DSI) of 13.9% was recorded in Khasi mandarins that were nanocoated for 120 s, followed by wax-coated mandarins (30.5%). The highest DSI (66.7%) was recorded in uncoated mandarins. On studying different biochemical parameters of the juice extracted from treated and untreated mandarins, the highest titratable acidity (0.061 g/100 g) was found in the juice extracted from uncoated mandarins. Similarly, the highest browning index (0.975) was recorded in the juice stored at ambient conditions (22 ± 2 °C) compared to the juice stored under refrigerated conditions (4 °C) (0.476). Nanocoated mandarins exhibited the lowest fruit weight loss at 3.008%. Thus, the antimicrobial activity of Glu-Ag NPs and their coating properties significantly enhance the shelf life of Khasi mandarin by reducing the DSI.