Effects of different heat treatments on the bioactive components, bactericidal and antioxidative capacity of bovine milk

Abstract

This study investigated the changes in native microbiota, representative bioactive components and functions therefrom of raw milk after heating for 15 s at different temperatures (from 72 to 100°C). When a common high-temperature short time (HTST) pasteurisation (72°C for 15 s) was applied, the total bacterial count was reduced by ~log 2 cfu/mL relative to the raw milk; the retention of native lactoferrin, IgG, vitamin C and vitamin B₂ in milk was 73.1% and 77.8%, 80.8%, and 97.8%, respectively. As the heating temperature increased, the bacteriostatic and antioxidative capacity of milk decreased with the increasing loss of bioactive components. Furosine level was significantly increased when heating above 90°C, whereas only after heating at 100°C, a limited lactosylation of both α-lactalbumin and β-lactoglobulin was found. This study provided an evaluation on the milk quality after HTST processing, providing a guidance for optimising dairy processing parameters.