Proteolysis of yogurts made from ultra-high-pressure homogenized milk during cold storage

Levels of residual α_s2-, α_s1- β- and κ-caseins in the pH 4.6-insoluble fraction of yogurts from ultra-high-pressure homogenized milk (230=200MPa at 30°C; 240=200MPa at 40°C; 330=300MPa at 30°C; 340=300MPa at 40°C) and HT+SMP milk (treated at 90°C for 90s, homogenized at 15MPa, and enriched with 3% skim milk powder) at d 1 (white bars) and d 28 (gray bars) of storage. Results are expressed as integrated area peaks (mean±SD). ^a,bDifferent letters indicate differences between d 1 and 28 in the same treatment. ^A,BDifferent letters indicate differences between treatments in the same day of storage.

Area counts of A) hydrophilic and B) hydrophobic peptides in the pH 4.6-soluble fraction of yogurts from ultra-high-pressure homogenized milk (230=200MPa at 30°C; 240=200MPa at 40°C; 330 = 300MPa at 30°C; 340=300MPa at 40°C) and HT+SMP milk (treated at 90°C for 90s, homogenized at 15MPa, and enriched with 3% skim milk powder) at d 1 (white bars), d 14 (gray bars), and d 28 (hatched bars) of storage. ^a,bDifferent letters indicate differences between d 1, 14, and 28 within the same treatment; error bars indicate standard deviation.