Abstract: 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.

Key words: extended shelf life milk; high-temperature sterilization; direct steam infusion; membrane filtration; active proteins; shelf life

摘要： 比较传统高温热杀菌、蒸汽浸入式杀菌、膜过滤结合巴氏杀菌对延长货架期牛乳品质的影响，测定不同热处理工艺对微生物指标、货架期、活性物质乳铁蛋白和免疫球蛋白G（immunoglobulin G，IgG）损失率及糠氨酸含量的影响，并优化蒸汽浸入式杀菌、膜过滤结合巴氏杀菌的工艺参数。结果表明：与传统高温杀菌工艺比较，蒸汽浸入式杀菌（147 ℃、0.09 s）产品货架期更长，品质更稳定，杀菌后糠氨酸含量较低且保留少量的活性物质；膜过滤结合72 ℃、15 s杀菌能更好地保留活性物质乳铁蛋白和IgG，但是该工艺对贮藏温度要求较高，全程贮藏温度需低于6 ℃，才能够确保产品在货架期内的品质稳定。

关键词: 延长货架期牛乳；高温杀菌；蒸汽浸入式杀菌；膜过滤工艺；活性蛋白；货架期