Effect of direct steam infusion technology on the microorganism sterilization, heat intensity indicators, and nutrients of milk

• INF milk showed superior sterilization with furosine content similar to pasteurized milk. • INF milk retained more nutritional proteins than cUHT milk. • INF treatment at 130°C/0.5s is optimal for microbial inactivation and nutrient retention. Direct Steam Infusion (INF) represents a promising method for extending milk's shelf life while preserving its nutritional properties due to its brief holding times. However, the impact of INF on the milk quality, particularly at low heating intensities, remains unexplored. This study investigated the effect of INF using different heating temperature-time combinations on the milk quality. The INF-treated milk exhibited longer shelf life compared to indirect plate-type pasteurized milk. Meanwhile, the furosine (FUR) content of INF milk was comparable to that of indirect plate-type pasteurized milk and significantly lower than in conventional indirect tubular ultra-high-temperature treated milk, indicating that INF can extend milk's shelf life at a lower heat intensity. Among all INF-treated milk, the sample treated at 130°C for 0.5s exhibited higher microbial inactivation and better retention of nutritional native proteins, including α-lactalbumin, β-lactoglobulin, and lactoferrin. In contrast, milk treated at 119°C for 6s showed significantly lower protein retention and higher FUR content compared to other INF samples. These results indicate that INF processing at 130°C for 0.5s can be recommended as a highly recommended parameter for dairy production. These findings offer valuable insights for developing dairy products with extended shelf life and improved nutritional properties.