The antibacterial effect of silver anode treatment on raw milk

Abstract

Silver has been used as an indirect antibacterial method by the food sector. In this study, the antibacterial effect of silver on raw milk was examined using the silver anode method. The samples were divided into two groups comprising silver-containing and non-silver-containing samples. Then, the two groups were stored at 5 °C, 10 °C, and 25 °C. The changes in the bacterial flora of the raw milk samples were observed at hours 0, 12, 24, and 36. The antibacterial effect of the silver anode treatment on both groups was observed after 12 h. The antibacterial effect increased with increasing storage time. The decreases in the Pseudomonas spp., coliform bacteria, and lactic acid bacteria counts of the silver-containing group were significantly different than those of the control group after 36 h (p < 0.05). The decreases in the Pseudomonas spp. and coliform bacteria counts were greater than the decrease in the lactic acid bacteria count. The Pseudomonas spp. count decreased during the storage period depending on temperature while the growth rates of coliform and lactic acid bacteria decreased with decreasing storage temperature in the silver anode-treated group. The strongest antibacterial effect was observed at 25 °C for Pseudomonas spp. and at 5 °C for coliform and lactic acid bacteria. The results of the study revealed that the silver anode method had a strong antibacterial effect on Pseudomonas spp. and coliform bacteria and a poor antibacterial effect on lactic acid bacteria. Silver ion release into the milk samples was consistently below the legal limits at all storage temperatures.