利用低场核磁共振分析蓝莓贮藏过程中水分含量及迁移变化  

Analysis of the moisture content and migration changes of blueberries during storage by low-field nuclear magnetic resonance

作　　者：陈毅 顾莹 宋平[1] 杨磊 杜明波 姜凤利[1] Chen Yi;Gu Ying;Song Ping;Yang Lei;Du Mingbo;Jiang Fengli(School of Information and Electrical Engineering,Shenyang Agricultural University,Shenyang 110866,China)

机构地区：[1]沈阳农业大学信息与电气工程学院,沈阳110866

出　　处：《农业工程学报》2022年第17期321-328,共8页Transactions of the Chinese Society of Agricultural Engineering

基　　金：辽宁省科技厅揭榜挂帅科技攻关专项(2021JH1/10400035);辽宁省教育厅项目(LSNJC201906)。

摘　　要：为了探究蓝莓在不同贮藏温度下,其内部水分含量及迁移状况随贮藏时间的变化规律,利用低场核磁共振(Low Field Nuclear Magnetic Resonance,LF-NMR)及其成像技术(Magnetic Resonance Imaging,MRI)采集0、8、23℃贮藏0、3、6、9、12d的蓝莓波谱信息以及质子密度图像信息,并分析其规律变化。试验结果表明:采后蓝莓内部水分极易受到贮藏温度与贮藏时间的影响;同时,弛豫谱峰面积和弛豫时间可以有效判定蓝莓贮藏过程中水分含量及迁移变化。随着贮藏时间的延长,其液泡水含量A23与总水分含量A2呈现出整体显著下降(P<0.05)的趋势;在蓝莓贮藏至12 d过程中,弛豫时间随贮藏时间的延长而不断右移,细胞壁水含量A21变化不明显,细胞质水含量A22呈现小幅增加趋势;但23℃贮藏至9 d后,蓝莓发生腐烂,细胞壁水和细胞质水迅速增加,贮藏至12 d时液泡水急剧减少,转化为细胞质水和细胞壁水,试验发现23℃贮藏的蓝莓货架期为1周左右;与前者相比,蓝莓低温贮藏至12d时,液泡水含量仍占总水分含量的89%以上,说明蓝莓在低温贮藏下,其内部水分迁移缓慢、流失量较少,其贮藏时间更长、保鲜效果更佳。研究结果为蓝莓在不同温度下贮藏保鲜提供了理论支撑和数据参考。Water content can directly dominate the edible quality of blueberries during the storage process.This study aims to explore the changes in water content and migration in the internal blueberry with the storage time at different temperatures.The Low-Field Nuclear Magnetic Resonance(LF-NMR)and imaging technology were used to collect the relaxation spectrum and proton density image of blueberries stored at 0℃,8℃,and 23℃for 0,3,6,9,and 12 days.Then,the changes and migration of water content in the blueberries were analyzed under different storage conditions.The experimental results showed that the relaxation time and the peak area of the relaxation spectrum were used to effectively estimate the moisture content and migration changes of blueberries during storage.Among them,the temperature was sensitive to the moisture content.Both the vacuolar water content(A23)and the total water content(A2)showed an overall downward trend,as the storage time increased.The relaxation time was shifted to the right with the increase of storage time during the storage of blueberries at 0℃and 8℃for 12 days.Specifically,there was no significant change in the water content of the cell wall(A21),whereas,a slightly increasing trend was observed in the cytoplasmic water content(A22).Once the blueberries were stored at 23℃for 9 days,the cell wall and cytoplasmic water increased rapidly.Especially,the vacuolar water decreased sharply after being stored for 12 days,and then transformed into cytoplasmic and cell wall water.There was a slower migration of internal water in the low-temperature storage,where the loss was less,compared with the storage at 23℃.In addition to the moisture,an analysis was made on the variations in the gray value,pseudo-color value,shape,and water loss rate of blueberries during storage.It was found that the blueberries at low temperature were stored for at least 12 days,and the shelf life of blueberries was about one week at room temperature.The gray value of blueberries decreased slowly at 0℃and 8℃un

关 键 词：温度 贮藏 水分 蓝莓 低场核磁共振 

分 类 号：S24[农业科学—农业电气化与自动化]