Use of Microfiltration to Improve Quality and Shelf Life of Ultra-High Temperature Milk

Abstract

The main objectives of this research were to evaluate the efficacy of microfiltration in extending the shelf life and improving the quality of ultra-high temperature (UHT) milk. Results showed that in high somatic cell counts (SCC) and low SCC raw milk, microfiltration resulted in an average 3.56 and 3.57 log reduction of total bacterial counts, and 1.52 × 106 and 2.10 × 105 to <1.00 × 103 of SCC, respectively. Microfiltered UHT milk had higher pH values and lower titratable acidity compared to nonmicrofiltered UHT control milk during storage. After 112 days and 63 days of storage, there were significant differences of noncasein nitrogen/total nitrogen between the microfiltered UHT milk and nonmicrofiltered UHT control milk in high SCC and low SCC milk (P < 0.05). Particle size distribution in microfiltered UHT milk followed monodisperse distribution during storage. The shelf life of microfiltered UHT milk made by low SCC and high SCC raw milk were effectively extended by 21 and 63 days. Practical Applications Microfiltration process was to reduce bacteria and to remove somatic cell counts (SCC) of raw milk. Compared with nonmicrofiltered ultra-high temperature (UHT) control milk, the quality of microfiltered UHT milk was greatly enhanced. Microfiltration in combination with UHT process resulted in longer shelf life of UHT milk, especially for high SCC milk.