Effects of Flash Evaporation Conditions on the Quality of UHT Milk by Changing the Dissolved Oxygen Content in Milk

This study assessed the impact of reducing dissolved oxygen (DO) content on the quality of UHT milk using a flash deoxygenation treatment. Flash deoxygenation was designed based on preheated milk reaching boiling early under low-pressure conditions to remove DO from the milk. Two parameters were designed for flash deoxygenation: preheating temperature 65 degrees C, -0.08 Mpa, and 70 degrees C, -0.06 Mpa. The flash conditions were applied to two UHT sterilization conditions (135 degrees C for 10 s and 145 degrees C for 5 s). After deoxygenation, the total oxidation (TOTOX) value of UHT milk was reduced by 1.4 similar to 1.71, and the protein carbonyl (PC) value was reduced by 1.15-1.52 nmol/mg of protein. The maximum inhibition rates of furusine and 5-HMF were 33.23 +/- 1.72% and 25.43 +/- 3.14%, respectively. The particle size was reduced by 0.141 similar to 0.178 mu m. The ketones and stale aldehydes causing oxidized taste in the UHT milk were significantly reduced. This study showed that the oxidation and Maillard reactions of UHT milk were significantly inhibited, stability was improved, and the content of undesirable volatile flavor substances was reduced after flash deoxygenation. Therefore, reducing DO content was beneficial to improving the quality of UHT milk.