食品科学 ›› 2020, Vol. 41 ›› Issue (5): 57-65.doi: 10.7506/spkx1002-6630-20190228-221

• 食品工程 • 上一篇    下一篇

马铃薯燕麦复合面条热泵-热风联合干燥质热传递规律分析

屈展平,任广跃,张迎敏,段续,张乐道   

  1. (1.河南科技大学食品与生物工程学院,河南 洛阳 471000;2.粮食储藏安全河南省协同创新中心,河南 郑州 450001)
  • 出版日期:2020-03-15 发布日期:2020-03-23
  • 基金资助:
    国家自然科学基金面上项目(31671907);“十三五”国家重点研发计划重点专项(2017YFD0400901); “智汇郑州·1125聚才计划”创新领军团队项目(2016XT026)

Analysis of Mass and Heat Transfer Characteristics of Potato and Oat Composite Noodles during Combined Heat Pump-Hot Air Drying

QU Zhanping, REN Guangyue, ZHANG Yingmin, DUAN Xu, ZHANG Ledao   

  1. (1. College of Food and Bioengineering, Henan University of Science and Technology, Luoyang 471000, China; 2. Food Storage Security Henan Collaborative Innovation Center, Zhengzhou 450001, China)
  • Online:2020-03-15 Published:2020-03-23

摘要: 本研究采用新型热泵-热风联合干燥技术对马铃薯燕麦复合面条进行干燥处理,采用低场核磁共振(low field nuclear magnetic resonance,LF-NMR)技术及扫描电子显微镜分析其干燥过程中的干燥特性及水分状态迁移等质热传递规律。结果表明:热泵温度越高、转换点含水率越大、热风温度越高,越有利于干燥的进行及水分的扩散;Midilli模型适宜描述复合面条热泵-热风联合干燥行为;不同干燥条件下复合面条的有效水分扩散系数在3.82×10-10~5.12×10-10 m2/s之间;LF-NMR结果表明:干燥过程中总水分含量持续下降,弱结合水峰左移且峰值降低,即弱结合水含量下降最多,且自由度降低,大部分弱结合水向自由水迁移,部分向深层结合水迁移;到达平衡含水率时结合水占比大于自由水,干基水分含量与峰面积呈极显著正相关(P<0.01);核磁共振成像结果显示面条中部氢质子密度最大,随着干燥的进行,氢质子向外部迁移,复合面条微观结构越来越致密,深层结合水与大分子结合紧密,面筋网络更加完整。

关键词: 复合面条, 热泵-热风联合干燥, 干燥特性, 低场核磁共振, 水分迁移

Abstract: In this study, potato-oat composite noodles were dried by a new combined heat pump-hot air drying technique. Low-field nuclear magnetic resonance (LF-NMR) and scanning electron microscopy were used to analyze the drying characteristics and the heat transfer characteristics during the drying process. The results showed that higher heat pump temperature, water content at the conversion point or hot air temperature could result in higher drying efficiency and increased diffusion of moisture. The Midilli model was suitable for describing the drying behavior of noodles. Under different drying conditions, the effective water diffusion coefficient was 3.82 × 10-10–5.12 × 10-10 m2/s. The results of LF-NMR showed that the total water content decreased continuously during the drying process, and the peak of weakly bound water shifted to the left, indicating that the content of weakly bound water decreased to the greatest extent, accompanied by a simultaneous decrease in the degree of freedom; weakly bound water was mostly transformed to free water along with tightly bound water. When the equilibrium moisture was reached, bound water was relatively more abundant than free water. The moisture content on a dry basis exhibited a significantly positive correlation with peak area (P < 0.01). Magnetic resonance imaging showed that the density of protons in the middle of noodles was the largest, and protons migrated outside as the drying progressed. The microstructure became denser, and tightly bound water more tightly combined with macromolecules, thus resulting in the formation of a more intact gluten network structure.

Key words: composite noodles, combined heat pump-hot air drying, drying characteristics, low-field nuclear magnetic resonance, moisture mobility

中图分类号: