Effect of Process and Temperature During Storage on Ultra-High Temperature Steam-Injected Milk

Milk (3.25% fat) was processed by ultra-high temperature steam injection at 138°C for 20.4 s, 149°C for 3.4 s, and was packaged aseptically.The ultra-high temperature milk was stored at 24 and 40°C.Fat soluble alkanals were analyzed at start, 8, and 24 wk.Dissolved oxygen content and acid degree values were measured at 4-wk intervals for 24 wk.Methanal, propanal, butanal, and nonanal were identified in the two ultra-high temperature samples at start.These compounds decreased during storage at both 24 and 40°C.Dissolved oxygen content increased linearly in samples stored at 24°C but decreased and remained at a minimum in samples stored at 40°C.Acid degree values increased in all samples.