Effect of Ultra-high Temperature Steam Injection on Flavor Acceptability of Whole and Fortified Skim Milks

Abstract
Whole milk (3.25% fat and 9% solids- not-fat) and low-fat fortified milk (.9% fat and 11% solids-not-fat) were proc- essed in a No-Bac Aro-Vac equipped with an ultra-high-temperature direct steam injector. Milk was preheated to 71 C and then heated to 107, 121, 135, or 143 C and held for 1.5 or 5 s. Sam- ples were also heated to 135 or 143 C and held for 8 or 10 s. Samples were stored at 1.7 and 7.2 C and analyzed by a taste panel at 2, 9, 16, 23, and 30 days. Both triangular and prefere~ace tests were used. After 30 days of storage at 72.2 C, whole milk and fortified low-fat milk heated at 135 and 143 C for 10 s were acceptable. Storage at 1.7 C for 30 days resulted in flavor scores between acceptable and good for all processing temperatures and times. Acceptable mil': can be produced by ultra-high-tempera- ture direct stem injection.
Keywords