摘 要：以烤煙K326品種上部葉為試驗(yàn)材料，分別選取返青煙、高溫逼熟煙、貪青晚熟煙3種類型難落黃煙葉進(jìn)行烘烤，測定烘烤過程中煙葉的水分含量、外觀顏色參數(shù)、葉綠素含量和多酚氧化酶活性等指標(biāo)。研究結(jié)果顯示：返青煙在變黃期和定色期失水較快，葉綠素降解量最高，多酚氧化酶活性波動(dòng)較大；高溫逼熟煙在變黃期失水最慢，葉綠素降解量中等，多酚氧化酶活性較低且變化較為平穩(wěn)；貪青晚熟煙在變黃期和定色期失水較慢，葉綠素降解量最低，多酚氧化酶活性波動(dòng)最大。研究得出：易烤性為返青煙>貪青晚熟煙>高溫逼熟煙；耐烤性為高溫逼熟煙>返青煙>貪青晚熟煙。
　　關(guān)鍵詞：難變黃；煙葉素質(zhì)；烘烤特性
　　中圖分類號：S572 文獻(xiàn)標(biāo)識(shí)碼：A DOI 編碼：10.3969/j.issn.1006-6500.2017.08.018
　　Abstract： The upper leaves of flue-cured tobacco variety K326 were used as experimental materials， three types of tobacco leaves including re-greening leaves，heat-forced maturity leaves，over-green and late-maturing leaves were selected to bake. The moisture content， appearance color parameters， chlorophyll content and polyphenol oxidase activity were measured. The results showed that during yellowing and color fixing stage， re-greening leaves dehydrate faster， the degradation of chlorophyll was the highest， polyphenol oxidase activity fluctuations. Heat-forced maturity leaves water losing speed was the slowest， the chlorophyll degradation was medium， the polyphenol oxidase activity was low and the change was relatively stable. Over-green and late-maturing leaves slowly dehydrate， the degradation of chlorophyll was the lowest， the polyphenol oxidase activity has maximum fluctuation. It was concluded that for the easy curing potential，re-greening leaves were the best，over-green and late-maturing leaves were medium，heat-forced maturity leaves were the worst. And for the endurable curing potential， heat-forced maturity leaves were the best， re-greening leaves were medium， over-green and late-maturing leaves wee the worst.
　　Key words： hard to turn yellow；tobacco quality；curing characteristics
　　目前我國煙草生產(chǎn)對自然條件依賴性較強(qiáng)[1]，南方的土壤和氣候更適于優(yōu)質(zhì)煙葉的種植。然而，近年來南方煙區(qū)在烤煙生長季節(jié)自然災(zāi)害頻發(fā)，干旱和降雨分布不均等多重因素嚴(yán)重影響了煙葉正常的生長發(fā)育[2]。因大田期降雨過多、光照不均、肥效利用供應(yīng)遲緩，造成部分煙葉出現(xiàn)返青、貪青晚熟、高溫逼熟的現(xiàn)象，這些煙葉在田間難以成熟落黃，且在烘烤過程中變黃較難，但其難變黃原因不同，從而增加了烘烤難度和煙葉損失。吳錫剛等[3]研究了多種非正常煙葉的形成原因和相應(yīng)烘烤技術(shù)，王貴等[4]以煙葉中水分含量為中心，研究了水分含量高煙葉和水分含量低煙葉的烘烤方法。但這些研究大都僅僅依據(jù)非正常煙葉的形成機(jī)理及鮮煙素質(zhì)判定其烘烤特性并在烘烤過程中調(diào)整溫濕度，通過探究非正常煙葉在烘烤過程中相關(guān)指標(biāo)的變化來反映煙葉烘烤特性的區(qū)別較少。本研究以烤煙品種K326上部葉為試驗(yàn)材料，分析3類難變黃煙葉在烘烤過程中水分、顏色值、葉綠素、多酚氧化酶這些指標(biāo)的變化，判定不同類型難變煙葉烘烤特性的區(qū)別，為難變黃煙葉烘烤可用性以及精準(zhǔn)烘烤提供理論支持。
　　1 材料和方法
　　1.1 試驗(yàn)材料
　　供試材料為烤煙品種K326出現(xiàn)返青、貪青晚熟、高溫逼熟現(xiàn)象的上部葉（第14～16位），煙株于2016年3月25號移栽，種植行距為120 cm，株距為50 cm，打頂后株高為110～120 cm。供試土壤為水稻土，前茬作物為水稻。在樣品采集試驗(yàn)田測定土壤肥力，差異不顯著（P>0.05）。
　　1.2 測定項(xiàng)目及方法
　　烘烤工藝采用常規(guī)三段式烘烤工藝[5]，煙葉水分測定采用 YC/T31—1996 法[6]，3種顏色參數(shù)采用霍開玲等的烤煙樣品顏色測定方法[7]，葉綠素含量測定采用95%乙醇提取法[8]，多酚氧化酶活性用愈創(chuàng)木酚比色法[9]，烘烤特性參照 YC/T311—2009進(jìn)行評價(jià)[10]。

相關(guān)熱詞搜索：煙葉 烘烤 不同類型 變黃 特性