Comparison of heat processing on milk quality: Direct steam infusion and indirect plate-type treatment

Direct steam infusion (DSI) can achieve an extended shelf life while maintaining high nutritional value of the milk, which has potential advantages over conventionally processed traditional Indirect plate-type treatment (IP). However, there is limited research systematically comparing DSI-treated milk and IP-treated milk, leading to confusion among consumers when selecting dairy products. This study systematically evaluated the effect of three industrially used DSI treatment and a series of IP treatment on the milk quality. The DSI-treated milk samples exhibited superior microbial inactivation compared to all IP-treated milk samples and better plasmin inactivation compared to IP63 and IP72, indicating the superiority of DSI over IP in extending milk's shelf life. The furosine content of DSI-treated milk samples (7.43–11.4 mg/100 g) was slightly higher than that of IP72, IP80, and IP85 samples (4.9–5.6 mg/100 g) and similar to that of IP63 sample (11.9 mg/100 g), suggesting that the intense thermal treatment used in DSI was comparable to that of IP. Furthermore, DSI-treated milk retained higher levels of native β-lactoglobulin and lactoferrin than IP85 milk, but lower than IP72. These results highlighted the potential of DSI treatment as an alternative to conventional pasteurization treatment. The study provided valuable insights into understanding the market positioning of DSI-treated milk. • DSI milk had longer shelf life with similar furosine content to IP milk. • DSI preserved nutritional proteins comparable to IP treatment. • DSI shows promise as a pasteurization alternative.