朱丽娟1，刘小杰2，吴伟都1*，成官哲1，王雅琼1，吴琴1，薛玉清1，李言郡1
（1 杭州娃哈哈集团有限公司，浙江省食品生物工程重点实验室，浙江 杭州 310018；
2 上海城建职业学院，上海 201415）
摘要：本文应用快速粘度测试仪建立了测定脱脂奶粉-水混合体系在升温-保持温度-降温三阶段测试程序中粘度随温度变化的方法，通过曲线中是否存在峰及峰值粘度的大小，以及运行结束时最终粘度的大小，评价奶粉在生产加工时经历的热处理变性程度。本文研究了脱脂奶粉-水混合体系中奶粉比例、温度程序中保持温度的高低及保持时间的长短对测定结果的影响。实验结果表明：实验条件明显影响粘度随温度的变化曲线。为使奶粉中蛋白质在水中充分凝胶，同时保证凝胶强度及粘度落在一定范围，最适宜实验条件分别为：奶粉比例为44.5%（m/m），保持温度为90℃、保持时间为5min。在此最优条件下，选择了在粘度曲线中分别出现两个峰与一个峰的两批脱脂奶粉，在同一天内每隔一小时以及连续七天每隔一天分别进行奶粉-水混合体系的热致凝胶特性测定，实验结果具有较好的重复性，各个峰及最终粘度的相对标准偏差均小于5%。
关键词：脱脂奶粉；快速粘度测定仪；热致粘度变化；温度程序
Studies on the Determination of Thermo-induced Viscosity Change Characteristics for Skimmed MilkPowder-Water Mixture System
ZHU Li-juan1，LIU Xiao-jie2，WU Wei-du1*，CHENG Guan-zhe1，WANG Ya-qiong1，WU Qin1，XUE Yu-qing1，LI Yan-jun1
（1 Hangzhou Wahaha Group Company Limited，Key Laboratory of Food and Biological Engineering of ZhejiangProvince，Hangzhou 310018，China；
2 Shanghai Urban Construction Vocational College，Shanghai 201415，China）
Abstract: In this paper the method for determination of the viscosity change of skimmed milk powder-water mixturesystem as temperature in a three- stage testing program of heating- temperature maintaining- cooling using a rapidviscosity analyzer. The denaturation degree of the milk powder induced by heat treatment during production andprocessing was evaluated by examining whether the peaks were present or not and viscosity of peaks in the curve，aswell as the final viscosity at the end of operation. This article investigated the effects of the proportion of milkpowder in the skimmed milk powder-water mixture system，the high or low holding temperature in the temperatureprogram，and the length of holding time on the measurement results. The results indicated that the experimentalconditions significantly affected the viscosity curve with temperature. In order to make the protein in the milk powderfully being gelled in the water，and ensure that the strength and viscosity of the gel were within a certain range，themost appropriate experimental conditions were as below: the proportion of milk powder was 44.5%（m/m），theholding temperature was 90℃，and the holding time was 5 minutes. Under this optimal condition，two batches ofskimmed milk powder with two peaks and one peak in the viscosity curve were selected respectively. Thethermotropic gel properties of the milk powder- water mixture system were measured every hour on the same day and every other day for seven consecutive days. The experimental results had good repeatability，and the relative standarddeviation of each peak and the final viscosity were all less than 5%.
Key words: skimmed milk powder；rapid viscosity analyzer；thermo-induced viscosity change；temperature program
中图分类号：TS252.7 文献标志码：A 文章编号：1007-7871（2024）05-0034-06
2024，Vol.27，No.5