基于低场核磁共振及成像技术的油莎豆远红外干燥过程中水分变化规律  

Rule of water changes in the far-infrared drying of tiger nut based on low-field NMR and imaging technology

作　　者：余政毫 朱文学[1,2] 白喜婷 罗磊[1,2] 卫志娇 YU Zhenghao;ZHU Wenxue;BAI Xiting;LUO Lei;WEI Zhijiao(College of Food and Bioengineering,Henan University of Science and Technology,Luoyang 471023,China;Agricultural Product Drying Technology and Equipment of Henan Engineering Technology Research Center,Luoyang 471023,China)

机构地区：[1]河南科技大学食品与生物工程学院,河南洛阳471023 [2]农产品干燥技术与装备河南省工程技术研究中心,河南洛阳471023

出　　处：《食品与发酵工业》2022年第16期131-137,共7页Food and Fermentation Industries

基　　金：国家重点研发计划项目(SQ2019YFD100114)。

摘　　要：为研究油莎豆远红外干燥过程中水分分布状态与迁移变化规律,利用低场核磁共振技术和成像技术检测不同温度(50、60、70℃)下远红外干燥过程中的横向驰豫时间,分析峰面积A_(2x)的变化、磁共振成像(magnetic resonance imaging,MRI)图像的变化以及干燥前后微观结构变化。结果表明,在红外干燥过程中,温度为50、60、70℃时干燥至终点分别用时为450、360、260 min,随着温度的升高能够显著提高干燥速率,促进其内部的自由水、不易流动水和结合水的迁移。干燥过程中自由水逐渐减少外观发生收缩形变表皮皱缩,自由度高的水分向自由度低的迁移导致弛豫图向左迁移。水分总峰面积与干基含水率进行回归分析,得到R2分别为0.98903、0.99134、0.99046,回归线性方程具有较高的拟合度。通过MRI图像可以清晰地看到红色面积逐渐缩小,油莎豆内部水分分布状态不断变化。干燥前后油莎豆微观结构变化明显,轮廓模糊、淀粉堆积。该研究可以为油莎豆的远红外干燥工艺设计、水分分布情况及水分状态变化提供参考。To study the law of water distribution and migration changes of tiger nut in the far-infrared drying process,low-field nucle-ar magnetic resonance technology(nuclear magnetic resonance,NMR)and imaging techniques were used to detect transverse relaxation time and T2 time in far-infrared drying at different temperatures(50,60,70℃).The changes of peak area A_(2x),MRI images and micro structural changed before and after drying were also been analyzed.It was shown that during infrared drying,when the temperature were 50,60,and 70℃,the corresponding drying time were 450,360,and 260 minutes.With the increase of temperature,the drying rate could be significantly increased and can promote the migration of free water,bound water and combined water.During drying,free water gradually reduced the appearance,and the migration of water with high degrees of freedom to low degrees of freedom leads to the relaxation diagram migration to the left.The total water peak area and dry base moisture content were analyzed,and R2 was 0.98903,0.99134 and 0.99046 respectively.The red area gradually shrinked in the MRI image,and the water distribution state of the tiger nut was constantly changed.Moreover,the microstructure of the oil bean was obvious which with a fuzzy outline and starch accumulation.This study can provide a reference for the far-infrared drying process design,water distribution and water status of the tiger nut.

关 键 词：油莎豆 水分迁移 横向弛豫时间 低场核磁共振成像技术 低场核磁共振技术 微观结构 

分 类 号：TS207.3[轻工技术与工程—食品科学] O657.2[轻工技术与工程—食品科学与工程]