Effects of ultra-high pressure treatment on ACE inhibitory activity, antioxidant activity, and physicochemical properties of milk fermented with Lactobacillus delbrueckii QS306
Orthogonal Experiment On the basis of single-factor tests, optimal pressure, treatment time, and sample fermentation duration of ACEI activity of UHP fermented milk (UHPFM) were selected for an orthogonal test. An L9 (34) orthogonal table was selected for experimental design, with optimal process parameters for UHP fermentation of milk determined through use of ACEI activity as the evaluation index. The factor levels are displayed in Supplemental Table S1. Effect of UHP on ACE Inhibitory Activity in Fermented Milk Based on the single-factor testing for pressure, duration of pressurization, and duration of fermentation for UHP treatment, an optimal orthogonal level was determined from ACEI activity, namely treatment pressure of 400 MPa, pressurization for 10 min, and fermentation for 60 h. The test results and variance analysis are displayed in Supplemental Table S2.