STability and Shelf-Life of Plasma Bubbling Treated Cow Milk

Abstract

The demand of consumers for naturality of food with minimal processing was forced to the scientists for the discovery of non-thermal plasma which is now an emerging technology for the preservation and decontamination of highly perishable food such as milk. In this study, the microbial and physicochemical characteristics of plasma bubbling of raw cow milk were analysed and a comparison of boiled raw cow milk, commercially available pasteurised and UHT milk was observed. Again, shelf-life study was experimented for the plasma bubbling of milk with respect to raw cow milk sample (control). The plasma bubbling was generated at a voltage (200V), the flow rate of air 10 litres/hour (L/h) and applied to fresh cow milk for 5, 10, and 15 minutes (min) of time interval with 100 mL of the sample volume at room temperature. A significant reduction was observed in coliform and yeast at 200V, 10L/h, 15 min time interval of treatment. The pH of the milk was increased significantly to 6.85 after exposure to plasma bubbling. Whereas, a decreasing value was noticed in colour, total soluble solids (TSS) and titratable acid (TA) with respect to time given by the plasma bubbling. The result of the study indicates that plasma bubbling at (200V, 10L/h,100mL,15 min) treatment improves the quality of milk. This study shows that indirect dielectric barrier discharge (DBD) (plasma bubbling) may offer an effective microbial reduction in barley without affecting the quality attributes. The plasma bubbling processing is an initiative for cow raw milk pasteurisation, which could have a future perspective on industrial food applications.