Effects of Different Sterilization Processes on the Quality of Extended Shelf-Life Milk

The effects of traditional high-temperature sterilization, direct steam infusion and membrane filtration combined with pasteurization on the quality of extended shelf-life (ESL) milk were compared by measuring microbial indexes, shelf life, percentage loss of lactoferrin (LF) and immunoglobulin G (IgG) and furosine content. The process parameters for steam immersion sterilization and membrane filtration combined with pasteurization were optimized. The results showed that compared with traditional high temperature sterilization, direct steam infusion (147 ℃/0.09 s) resulted in a longer shelf life, more stable quality and lower furosine content and retained lesser amounts of active substances. Membrane filtration combined with 72 ℃/15 s sterilization retained more active substances such as LF and IgG. However, this process has higher requirements for storage temperature. The storage temperature needs to be lower than 6 ℃ to ensure the stability of product quality.