低場核磁共振法測定烘烤過程中煙葉水分
發(fā)布時(shí)間:2019-08-25 來源: 歷史回眸 點(diǎn)擊:
摘要:為全面了解烘烤過程煙葉不同位置水分變化,提高烘烤過程中煙葉水分檢測效率,以秦?zé)?6品種上部葉為材料,利用低場核磁共振技術(shù)分別對(duì)烘烤過程煙葉葉片、主脈水分含量進(jìn)行檢測,并與烘箱法進(jìn)行對(duì)比分析。結(jié)果表明:(1)煙葉不同位置弛豫圖譜顯示,煙葉葉片含有3種狀態(tài)水分,分別為T21(0.1~1 ms)結(jié)合水、T22(1~10 ms)半結(jié)合水、T23(100~1000 ms)自由水,煙葉主脈含有2種狀態(tài)水分,分別為T21(1~10 ms)結(jié)合水,T22(100~1000 ms)自由水。(2)煙葉葉片、主脈總信號(hào)幅值與其水分質(zhì)量、干基含水率呈極顯著正相關(guān)(決定系數(shù)R2依次為0.9847、0.9929、0.9952,P<0.01)。(3)與烘箱法相比,低場核磁共振法檢測穩(wěn)定性較好,適用于烘烤過程中煙葉葉片和主脈水分的快速、精確檢測分析。
關(guān)鍵詞:低場核磁;烘烤;煙葉;水分
中圖分類號(hào):TS44+1文章編號(hào):1007-5119(2017)03-0056-05DOI:10.13496/j.issn.1007-5119.2017.03.010
Determination of Moisture in Tobacco Leaves during Curing Process by Low-field NMR
SONG Zhaopeng1, LI Shengdong1,WEI Shuo1, TAN Fangli2, WU Wenxin2,
XU Qingxiao2, LI Hongguang2, FANG Ming2
。1. College of Tobacco Science,Henan Agricultural University,Zhengzhou 450002, China; 2. Chenzhou Company of Hunan Tobacco Company,Chenzhou,Hunan 423000, China)
Abstract:In order to fully understand the change of moisture content in different positions of tobacco leaves during curing process, and to improve the moisture detection efficiency of tobacco leaf during curing, using the upper leaf of Qinyan96 as test material, Low-field NMR was used to determine the moisture content in lamina and midrib. The results were compared with those determined by a conventional oven method. The results showed that: (1)The map of different positions of tobacco leaves showed that there were 3 states of water in lamina, bound water T21(0.1-1 ms), semi-bound water T22 (1-10 ms)and free water T23 (100-1000 ms). There were 2 states of water in midrib, bound water T21 (1-10 ms) and free water T22 (100-1000 ms). (2)The inversion spectrum oflamina and midrib has an extremely significant positive correlation with the water mass and moisture content of dry base (the coefficient of determination are in turn 0.9847, 0.9929, 0.9952, P<0.01). (3) Comparing with the conventional oven method, the stability of Low-field NMR was better, which is suitable for rapid and accurate detection of thelamina and midrib moisture content of tobacco leaves during curing.
Keywords: low-field NMR; flue-curing; tobacco leaves; moisture
烘烤過程煙葉水分變化影響其內(nèi)在生理化學(xué)反應(yīng),決定著煙葉的烘烤品質(zhì)[1-3],水分的快速檢測有利于及時(shí)掌握烘烤過程煙葉干燥狀況、調(diào)整烘烤參數(shù)。烘箱法是烘烤過程中煙葉水分測定的常用方法,但其檢測耗費(fèi)時(shí)間較長,無法得到即時(shí)的含水率信息,而且加熱會(huì)導(dǎo)致物質(zhì)揮發(fā)或性質(zhì)改變[4],影響檢測結(jié)果的準(zhǔn)確性;紅外水分檢測技術(shù)容易受到物料表觀性質(zhì)和檢測環(huán)境影響,檢測誤差略大[5];氣相色譜法[6]或卡爾費(fèi)休法[7]經(jīng)測定結(jié)果較為精確,但其操作復(fù)雜繁瑣;同時(shí)上述這些方法均不能提供物料水分的詳細(xì)情況。核磁共振(NMR)是一種精準(zhǔn)、快速、無損的檢測技術(shù),是目前較為理想的測量水分工具[8],在農(nóng)產(chǎn)品加工領(lǐng)域研究應(yīng)用較多[9-14],而在煙葉烘烤過程水分檢測研究尚不多見。本試驗(yàn)
基金項(xiàng)目:湖南省煙草公司郴州市公司項(xiàng)目“特殊煙葉烘烤技術(shù)研究”(201543100094001)
相關(guān)熱詞搜索:核磁共振 煙葉 烘烤 水分 過程中
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