食品科学 ›› 2020, Vol. 41 ›› Issue (7): 117-123.doi: 10.7506/spkx1002-6630-20190403-045

• 食品工程 • 上一篇    下一篇

射频处理对红枣中短波红外干燥动力学及品质特性的影响

王坤华,李佳美,彭飞,刘昱迪,马琦,李梅,徐怀德   

  1. (西北农林科技大学食品科学与工程学院,陕西 杨凌 712100)
  • 出版日期:2020-04-15 发布日期:2020-04-20
  • 基金资助:
    陕西省重点研发计划项目(2019NY-108)

Effects of Radio Frequency Treatment on Short- and Medium-Wavelength Infrared Drying Kinetics and Quality Characteristics of Red Jujubes

WANG Kunhua, LI Jiamei, PENG Fei, LIU Yudi, MA Qi, LI Mei, XU Huaide   

  1. (College of Food Science and Engineering, Northwest A & F University, Yangling 712100, China)
  • Online:2020-04-15 Published:2020-04-20

摘要: 为缩短红枣干燥时间、提高红枣干燥品质,将射频技术(radio frequency,RF)应用于红枣干燥前处理,运用中短波红外干燥技术在不同干燥温度(50、60、70 ℃)下干燥红枣,研究RF处理红枣的干燥动力学及品质特性,并选取8 个常用的薄层干燥数学模型,采用非线性回归的方式对实验结果进行拟合,得出最适于RF处理后红枣中短波红外干燥的数学干燥模型。结果表明:RF处理组红枣的干燥时间较未处理组红枣缩短了21.2%~29.3%,水分有效扩散系数提高了16.7%~49.6%,干燥活化能降低了13.13%;比较各数学模型的决定系数、均方根误差和卡方值,发现Weibull distribution模型拟合效果最好,可用于描述、预测RF处理后红枣的中短波红外干燥过程;经RF处理后干燥的红枣较未处理红枣色差值降低了19.3%~31.4%,总酚含量提高了14.9%~19.1%,环磷酸腺苷含量提高了27.5%~31.9%。与未处理红枣相比,RF处理红枣的干燥效率高,干燥后产品质量好,表明RF处理是一种优良的红枣干燥前处理方法。

关键词: 红枣, 射频处理, 中短波红外干燥, 干燥动力学, 品质, 数学模型

Abstract: Radio frequency (RF) technology was applied as a pretreatment for drying to shorten the drying process and improve the quality of dried red jujubes. Specifically, short- and medium-wavelength infrared drying was performed at 50, 60 or 70 ℃ to explore the drying kinetics and the quality characteristics of the dried red jujubes. In addition, the experimental results were fitted to eight common thin-layer drying models by nonlinear regression analysis and the optimum model was selected from these models. The results indicated that the drying time was shortened by 21.2%-29.3%; the effective diffusion coefficient of moisture was increased by 16.7%-49.6%; the activation energy of drying was reduced by 13.13% after RF treatment. In terms of correlation coefficient (R2), root-mean-square error (RMSE), and chi-square values (χ2), Weibull distribution was found to be the best model for describing and forecasting the short- and medium-wave infrared drying process following RF treatment of red jujubes. Comparatively, the color difference (ΔE) of dried jujubes after RF treatment decreased by 19.3%-31.4%, total phenol content increased by 14.9%-19.1%, and cyclic adenosine monophosphate content increased by 27.5%-31.9%. Compared with untreated jujubes, RF treated jujubes showed higher drying efficiency and better quality of dried products, indicating that RF is a promising pretreatment for dried jujube processing.

Key words: Ziziphus jujuba Mill., radio frequency treatment, short- and medium-wavelength infrared radiation drying, drying dynamics, quality, mathematical model

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