食品科学 ›› 2019, Vol. 40 ›› Issue (5): 116-123.doi: 10.7506/spkx1002-6630-20171123-289

• 食品工程 • 上一篇    下一篇

利用低场核磁共振技术研究调味山药片真空微波干燥过程中水分的变化规律

李定金1,2,段振华1,2,*,刘 艳1,段秋霞1,叶寿林3,朱香澔1,2,杨玉霞1,2   

  1. 1.贺州学院食品与生物工程学院,广西 贺州 542899;2.大连工业大学食品学院,辽宁 大连 116034;3.苍梧县农产品质量安全检测中心,广西 梧州 543100
  • 出版日期:2019-03-15 发布日期:2019-04-02
  • 基金资助:
    广西特色果蔬深加工与保鲜技术研究项目(YS201601);贺州学院“果蔬深加工与保鲜团队建设”项目(YS201602);广西特聘专家专项经费项目(厅发[2016]21号);现代食品加工新技术研究岗位创新人才培养示范基地建设项目(桂科AD17195088);贺州学院校级科研项目(2016ZZZK08)

Variation in Water Content during Vacuum Microwave Drying of Flavored Yam Chips Process Analyzed by Low-Field Nuclear Magnetic Resonance Imaging

LI Dingjin1,2, DUAN Zhenhua1,2,*, LIU Yan1, DUAN Qiuxia1, YE Shoulin3, ZHU Xianghao1,2, YANG Yuxia1,2   

  1. 1. School of Food and Bioengineering, Hezhou University, Hezhou 542899, China;2. School of Food Science and Technology, Dalian Polytechnic University, Dalian 116034, China;3. Agricultural Product Quality and Safety Inspection Center of Cangwu County, Wuzhou 543100, China
  • Online:2019-03-15 Published:2019-04-02

摘要: 为研究调味山药片真空微波干燥过程中内部水分含量、分布及状态变化情况,采用低场核磁共振技术,测定不同微波功率下微波真空干燥过程中的横向弛豫时间T2反演谱,进而分析调味山药片内部的水分状态及其变化规律。结果表明:微波功率越高,自由水和不易流动水被除去所需的时间越短,其中对自由水作用尤为明显,但过高的微波功率会导致物料出现焦化现象;调味山药片干基含水率与核磁共振总峰面积之间呈线性关系,可以预测调味山药片真空微波干燥达到干燥终点所需的时间。核磁共振图像显示调味山药片干燥过程中水分含量的增加和减少均是由外而内,干燥结束时,剩余水主要存在于调味山药内层。水分含量的变化对调味山药片干燥后的品质有显著影响,低场核磁共振及成像技术为调味山药片干燥过程中水分的变化提供了直观的参考依据,本研究可以为调味山药片的真空微波脆化工艺设计、优化干燥参数、控制干燥过程及提高产品质量提供参考。

关键词: 调味山药片, 真空微波干燥, 低场核磁共振, 横向弛豫时间T2, 峰面积

Abstract: In order to gain an understanding of variations in moisture content, distribution and states during the vacuum microwave drying of flavored yam chips, inverted spectra of transverse relaxation time T2 of flavored yam chips dried at different microwave powers were measured using low-field nuclear magnetic resonance (LF-NMR). The results showed that the higher microwave power, the shorter the time it took to remove free water and immobilized water; a greater effect was noted on free water. But excessively high microwave power caused coking of the materials. A linear relationship was seen between the moisture content of flavored yam chips and the total peak area of NMR, which could predict the drying time. NMR images showed that the moisture increased or decreased from the exterior to the interior during the drying process. At the end of drying, the remaining moisture was mainly present in the inner layer of flavored yam chips. Changes in moisture content had a significant effect on the quality of flavored yam chips after drying. LF-NMR imaging can provide visual information of moisture changes during the drying process of flavored yam chips, and this study can provide a basis for designing and optimizing a vacuum microwave drying process for flavored yam chips and for improving the product quality.

Key words: flavored yam chips, vacuum microwave drying, low-field nuclear magnetic resonance, transverse relaxation time T2, peak area

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