EFFECTS OF VARYING PASTEURIZATION TEMPERATURES ON PHYSICO- CHEMICAL PROPERTIES OF MILK FROM WEST AFRICAN DWARF GOATS

Abstract

Raw West African Dwarf goat milk (800 mL) was purchased to determine its physical and chemical properties after undergoing varying pasteurization temperatures. The milk sample was divided based on pasteurization temperatures into four treatments (0, 65, 75 and 85 °C) containing 200 mL of milk each. Each treatment was further sub-divided into four replicates containing 50 mL each. After heating, milk samples from each replicates were cooled and physical and chemical properties were determined. The data obtained were subjected to analysis of variance in a completely randomized design. The results revealed a pH range of 6.21 to 6.33; viscosity and total solids were significantly (p<0.05) higher in milk samples heated at 85 °C (270.00 (m2/s) and 30.38%, respectively) than 107.67 (m/s) and 15.64%, respectively recorded at 0 °C. Also, the value of titratable acidity of milk samples was highest at 65°C (0.59). In addition, moisture, crude protein and ash contents were significantly (p<0.05) highest (84.36, 0.47 and 2.26%, respectively) at 0 °C and lowest (69.62, 0.27 and 0.66%, respectively) at 85 °C. However, Ether Extract and calcium contents of heated milk were significantly (p<0.05) highest (16.32% and 552.53 mg/L, respectively) at 85 °C and lowest (8.90% and 310.43 mg/L) at 0 °C. It was concluded that West African Dwarf goat milk pasteurized at 65 °C had better milk pH and acidity.