A comparative study on preserving milk using grass species hyperenium rufa for fumigating milk containers and pasteurisation

Abstract

Milk and dairy products form a major dietary component for many cattle rearing communities worldwide. The Banyankore, an ethnic group in Western Uganda, has over centuries used and established different methods of preserving milk and other dairy products like ghee and yoghurt. Fumigants derived from specific plant species such as Hyperenium rufa, Rhus natalensis and Molle combretum have been used when preparing vessels for storage of fresh milk and milk products. H. rufa is the most commonlyused fumigant for temporary preservation of fresh/raw milk. To date, there is no scientific literature evaluating the effectiveness of these traditional practices. We validated the use of fumigant from H. rufa to preserve the quality of fresh milk using the alcohol test, 10 min resazurin test, clot-on-boiling test and pH measurements. The total number of bacteria per milliliter of milk was determined by total plate count (TPC). Exposing raw milk to fumigant from H. rufa in wooden milk pots curtailed microbial growth for over 24 h at room temperature before sourage occurred. Results of parallel testson raw milkpreserved by fumigation compared well with those of pasteurised milk in sterilised glass vessels. We conclude that fumigation of milk pots using H. rufa can preserve milk for many hours before boiling for consumption. This method would be useful in rural communities; however, it is no substitute to pasteurisation.