苹果汁电导率及介电损耗因子影响因素的研究.pdf

现代食品科技 Modern Food Science and Technology 2013, Vol.29, No.12 苹果汁电导率及介电损耗因子影响因素的研究 王云阳，李站龙，杨绍龙，董宇 （西北农林科技大学食品科学与工程学院，陕西杨凌 712100） 摘要：本文研究了苹果汁的电导率与可溶性固形物含量、温度、粘度和 NaCl 浓度等因素的关系，并通过电导率与介电损耗因 子的关系，确定不同频率下与离子介导相关的苹果汁的介电损耗因子。结果表明，苹果汁的电导率随可溶性固形物含量的增加呈先增 大后减小的抛物线趋势，随温度线性增大，粘度大小对电导率的影响很小，添加少量NaCl 苹果汁电导率成倍增大。借助SPASS 数据 2 2 分析软件，得出电导率同可溶性固形物含量、温度的非线性回归方程：σ=-28.69C +17.292C+0.02T+0.135，R 为0.974，拟合度良好。 通过计算获得苹果汁在不同频率下（13.56、27.12 、40.68 MHz ）与离子介导相关的介电损耗因子。这些结果和数据，可为欧姆和射 频加热技术用于苹果汁生产提供基础数据支持。 关键词：苹果汁；电导率；介电损耗因子；欧姆加热；射频加热 文章篇号：1673-9078(2013)12-2810-2815 Influencing Factors of Conductivity and Dielectric Loss Factor in Apple Juice WANG Yun-yang, LI Zhan-long, YANG Shao-long, DONGYu (College of Food Science and Engineering, Northwest Agriculture and Forest University, Yangling 712100, China) Abstract: The relationship between electrical conduct ivity and factors such as soluble solids content, temperature, viscosity and NaCl concentration was studied. Dielectric loss factors interrelated to ionic conductivity of apple juice under different frequencies was calculated according to the equation of electrical conductivity and dielectric loss factors. The results showed that electrical conductivity appeared paracurve trend which increased first and then decreased with the increase of soluble solids content of the apple juice; it was increased linearly with temperature and remarkably increased with adding little of NaCl; viscosity had little effect on electrical conductivity. Using statistical package social sciences (SPSS) data analysis software, non-linear regression equation of te