| 摘要: |
| 【目的】研究超高温灭菌乳货架期理化特性变化及超滤对其品质稳定性的影响，为防止超高温灭菌乳货架期品质变化提供理论基础。【方法】取贮存1～6个月超高温灭菌乳，静置分层后，测定上、下层乳脂肪、蛋白质、总固形物含量、脂肪厚度及黏度。将原料乳超滤处理后制备超高温灭菌乳，测定其上层脂肪含量，并对其固形物颗粒进行原子力显微镜观察。【结果】随着超高温灭菌乳货架期的延长，上层乳脂肪含量上升，下层乳脂肪含量下降，脂肪上浮率达68.91%；上、下层乳液蛋白质含量均下降，下层下降幅度相对较小，蛋白质下沉率为16.18%；上、下层乳液总固形物含量均有少量下降，总固形物下沉率为1.45%；上层乳液的黏度高于下层；原料乳经过超滤处理后，超高温灭菌乳上层脂肪含量降低，大颗粒固形物减少，且颗粒大小均匀一致。【结论】超高温灭菌乳货架期理化特性发生显著变化，主要表现为脂肪上浮；超滤处理是提高超高温灭菌乳货架期品质稳定性的一种有效途径。 |
| 关键词: 高温灭菌乳 货架期 理化特性 超滤 |
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| 基金项目:国家“十一五”科技支撑计划奶业重大专项(2006BAD04A11)；教育部“长江学者与创新团队发展支持计划”项目（2010 ZDGC-01） |
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| Studies on physicochemical properties change of ultra-high temperature sterilization milk during shelf-life and role of ultrafiltration on its quality stability |
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LI Linqiang1, TIAN Wanqiang2,3, ZAN Linsen,et al3
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1.College of Food Engineering and Nutritional Science ,Shaanxi Normal University;2.Department of Animal Engineering ,Yangling Vocational ＆ Technical College;3.College of Animal Science and Technology ,Northwest A＆F University
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| Abstract: |
| 【Objective】The objective of this research was to determine the physicochemical properties change of ultra-high temperature sterilization milk during shelf-life and the role of ultrafiltration on its quality stability in order to provide theoretical basis to prevent UHT sterilization milk from quality changing during shelf-life.【Method】The fat content of UHT sterilization milk with 1 to 6 months storage,protein,total solids (TS),and the up and low viscosity was determined.The content of up fat in UHT sterilization milk was determined as raw milk treated with ultrafiltration (UF),and the solid particles was observed by atomic force microscopy.【Result】The results showed that fat content of up UHT sterilization milk increased during storage,while contrary to that of the low,with floating rate of 68.91%.The content of the up protein decreased during storage,and the same with the low,but relatively small,with sinking rate of 16.18%.The content of up and low total solids(TS) both decreased,with sinking rate of 1.45%.The up viscosity was higher than that of the low.The content of up fat decreased after raw milk treated with UF.【Conclusion】The physicochemical properties of UHT sterilization milk were significantly changed during shelf-life,mainly fat floating.UF is an effective way to improve UHT sterilization milk shelf-life quality stability. |
| Key words: UHT sterilization milk shelf-life physical and chemical properties ultrafiltration |
