脱脂乳的不同热处理对其酸奶凝胶流变学性质的影响  

Effect of forewarming on rheological properties of acid skim milk gel

作　　者：周志伟[1] 许永红[1] Merete Faergemand Jeanette Otte Karsten Bruun Qvist 

机构地区：[1]北京市食品工业研究所,北京100075 [2]丹麦皇家兽医与农业大学乳品技术研究所

出　　处：《中国乳品工业》2000年第5期6-9,共4页China Dairy Industry

摘　　要：研究了复原脱脂乳经不同加热处理后其酸奶凝胶形成过程中流变学特性的变化。复原脱脂乳经 70～ 90℃处理 10～ 2 5min ,用D 葡萄糖 δ 内酯酸化成胶。用流变学方法动态监测凝胶性能 ,并监测酸化过程和成胶时间。结果显示 ,不同条件下处理后的脱脂乳在酸化过程中 ,pH值并未改变 ,但凝胶储存模量 (G′)和损失模量 (G″)随受热程度的增加而增加 ,只是当加热温度为 90℃时反而随加热时间的延长而降低。在 85℃加热 2 5min或 90℃加热后 ,脱脂乳酸性凝胶的流变学曲线呈现出异常情况 ,这时G′和G″的增长出现两个迟缓期。Rheological properties of differently forewarmed acid reconstituted skim milk(RSM)gel were investigated. Preheated at different temperatures (70～90?℃) for varying periods?(10～25?min),acid RSM gels were induced by acidification with 2% glucono δ lactone,and gel properties, along with pH changes and gelation time, were monitored during gel formation. Results show that there was little difference in pH profiles during acidification,but both storage moduli (G′) and loss moduli (G″) increased with heat load of forewarming at temperature below 90?℃. Gels originated from RSM pretreated at 90?℃ exhibited different characteristics instead of steady increase of G′and G″with heating time, a trend of decrease was observed.Nontypical rheograms were obtained for gels prepared from RSM previously heated at 85?℃ for 25?min or at 90?℃, in which the development of G' and G'' showed two lag phases or two linear phases. Gelation time decreased with the severity of heating.

关 键 词：热处理 脱脂乳 流变学性质 酸奶凝胶 

分 类 号：TS252.54[轻工技术与工程—农产品加工及贮藏工程] TS252.4[轻工技术与工程—食品科学与工程]