低场核磁共振方法下热泵干燥过程中蚕蛹的品质变化  

Quality changes of silkworm pupa during heat pump drying based on low-field nuclear magnetic resonance

作　　者：吴钊龙 黄纪民[1,2,3] 林芳 李秉正 陈振林[4] 黄志民 WU Zhaolong;HUANG Jimin;LIN Fang;LI Bingzheng;CHEN Zhenlin;HUANG Zhimin(State Key Laboratory of Non-Food Biomass and Enzyme Technology,Guangxi Academy of Sciences,Nanning 530007,China;Guangxi Key Laboratory of Biorefinery,Guangxi Academy of Sciences,Nanning 530007,China;Nanning Zhongke Microwave Institute of Advanced Manufacturing Industrial Technology,Nanning 530007,China;Research Institute of Food Science and Engineering Technology,Hezhou University,Hezhou 542899,China)

机构地区：[1]广西科学院非粮生物质酶解国家重点实验室,广西南宁530007 [2]广西科学院广西生物炼制重点实验室,广西南宁530007 [3]南宁市中科微波先进制造产业技术研究院,广西南宁530007 [4]贺州学院食品科学与工程技术研究院,广西贺州542899

出　　处：《食品与发酵工业》2022年第15期267-272,共6页Food and Fermentation Industries

基　　金：广西科技计划项目(桂科AB18294028);贺州市创新驱动发展专项(贺科创ZX0710001;贺科创CX2009009)。

摘　　要：在65℃条件下对蚕蛹进行热泵干燥,测定不同干燥时间蚕蛹的含水量、脆度、硬度和亮度(L^(*)),并采用低场核磁共振(low-field nuclear magnetic resonance,L^(*)F-NMR)技术检测氢质子成像图、横向弛豫时间(T_(2))和T_(2)反演谱的总峰面积(A_(2))的变化。结果表明,新鲜蚕蛹中存在结合水T_(21)(0~2 ms)、不易流动水T_(22)(2~100 ms)、自由水T_(23)(100~1000 ms)3种水分状态,其中含量最少的是结合水,其次是不易流动水,最多的是自由水。随着干燥时间增加,整个T_(2)反演谱呈现出所有峰逐渐向左移动、总峰面积减少和峰融合的现象。蚕蛹的含水量和硬度显著降低(P<0.05),脆度显著增加(P<0.05),L^(*)没有显著变化(P>0.05)。当干燥240 min时,含水量、脆度、硬度和L^(*)值分别为7.79%、12.67个、57.38 g和68.02。分别建立A_(2)与含水量、脆度和硬度之间的关系方程,发现均有较高的拟合度(R^(2)>0.9)。其中,A_(2)与含水量和硬度之间的关系方程R 2分别为0.988和0.986。结果表明,通过热泵干燥可以制备品质较高的蚕蛹干制品,采用L^(*)F-NMR技术可实现热泵干燥过程中蚕蛹含水量和硬度的快速、准确、无损检测。The changes of silkworm pupa quality index during heat pump heating were studied.Silkworm pupas were dried in a heat pump drier at 65℃.At different drying times,the moisture content,brittleness,hardness and brightness(L^(*))of silkworm pupas were measured,and their hydrogen proton images,transverse relaxation time(T_(2))and total peak areas of the T_(2)inversion spectrum(A_(2))were also investigated by low-field nuclear magnetic resonance(L^(*)F-NMR)technology.The results showed that there were three kinds of water states,bound water T_(21)(0-2 ms),immobilized water T_(22)(2-100 ms)and free water T_(23)(100-1000 ms)in fresh silkworm pupa.In which the content bound water was the least.The second were non-flowing water and the freest water.As the drying time increased,the entire T_(2)inversion spectrum showed that all peaks gradually moved to the left,the total peak area decreased,and the peaks merge.The moisture content and hardness decreased significantly(P<0.05),the brittleness increased significantly(P<0.05),but L values changed insignificantly(P>0.05)as drying time increase.After drying for 240 min,the moisture content,brittleness,hardness and L^(*) values were 7.79%、12.67 units、57.38 g and 68.02,respectively.The relation equations of A_(2)and moisture content,brittleness or hardness were established,respectively.High correlation coefficients(R 2>0.9)were found for all three equations,and the R^(2)values were 0.988 and 0.986 for relation equations of A_(2)-moisture content and A_(2)-hardness,respectively.It suggested that high quality dried silkworm pupas could be prepared by heat pump drying,and their moisture content and hardness during heat pump drying could be measured rapidly,accurately and non-destructively by LF-NMR technology.

关 键 词：蚕蛹 热泵干燥 水分 低场核磁共振 

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]