Lannie A. Alava, Ann Margaret D. Diaz, Glorieaster B. Sabando (February 2007)
Philippine Science High School Western Visayas Campus – Department of Science and Technology (DOST-PSHS WVC), Brgy. Bito-on, Jaro, Iloilo City 5000, Philippines
ABSTRACT
Majority of the milk producers in third world countries have no ability to install a cold room or to buy a refrigerator for storage that is already available in rich countries. Thus, there is an apparent need in the development of a natural preservative of raw milk, especially in in an underdeveloped country like the Philippines. This study made use of liquid Korean Propolis, a substance collected by honeybees that was found to have antioxidants that can preserve food. The raw goat’s milk was divided into 3 replicates, each having 2 setups. The first setup was without liquid Korean Propolis and the second setup was added with 1 ml of liquid Korean Propolis and the second setup was added with 1 ml of liquid Korean Propolis for ever 200 ml of the milk sample. Presence of spoilage causing organisms and physico-chemical properties of milk were determined by conducting quality tests every hour-organoleptic analysis, determination of specific gravity using a hydrometer, determination of the percentage of lactic acid through titration, determination of pH using pH strips, and Methylene Blue Reduction test. Sensory evaluation was used to determine the acceptability of the milk samples. The presence of the liquid Korean Propolis delayed the spoilage of the milk sample at a difference of 3 hours. Thus, propolis has the potential to be a natural preservative in milk. However, the results of the sensory evaluation of the panelists showed that rawgoat’s milk without liquid Korean Propolis was liked moderately than the milk with liquid Korean Propolis.