Electrophoretic Characterization of Casein of Refrigerated Cow and Buffalo Milk Preserved with Banana Pseudostem Juice

Cow milk, a highly nutritious food item, is amenable to quality degradation due to lipolysis and proteolysis, as a sequel to the growth of spoilage microorganisms, particularly under ambient condition in tropical countries, with consequential loss of aesthetic appeal and product output. Prescription antibiotics used for milk preservation have many undesirable side effects on the health of consumers, besides bolstering development of antibiotic resistant strains of bacteria. This paper has tried to elucidate the effect of treatment of raw cow milk and buffalo milk stored under refrigeration with Banana (Musa paridasiaca) Pseudostem Juice (BPJ), a natural antimicrobial agent on the electrophoretic profile of whole casein of milk, since BPJ can checkmate proteolysis with consequential alteration of molecular mass, on which no study has been done earlier. Fresh cow milk and buffalo milk, procured from local milk producers were treated with 0.3% (v/v) BPJ, and were kept under refrigeration at 7+2 0C for 5 days and 4 days respectively, while BPJ untreated (control) samples of cow and buffalo milks were kept at same temperature for 3 days and 2 days respectively. Sodium Dodecyl Sulphate Polyacrylamide Gel Electrophoresis (SDSPAGE) profile of control and BPJ treated cow milk samples were determined after 3 days and 5 days respectively, whereas the same was done for buffalo milk samples after 2 days and 4 days respectively. The SDS-PAGE pattern revealed that the whole caseins of BPJ treated cow and buffalo milk samples resolved in to two bands of low molecular weight components ranging between 29 kD and 43 kD. The SDS-PAGE pattern of isolated whole caseins of BPJ treated cow milk and buffalo milk did not exhibit any deviation from control cow and buffalo milk caseins. It is concluded that addition of BPJ (0.3%, v/v) to cow milk and buffalo milk did not alter the molecular configuration of milk casein under refrigerated (7+2 0C) preservation for 5 days and 4 days respectively due to its inhibitory effect on proteolysis.