提前采收对清甜香型烤烟上部叶质量及风格特征的影响
Effects of earlier harvesting on the quality and style characteristic of fresh-sweetness flavor type flue-cured tobacco upper leaves
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摘要: 【目的】 探索提前采收对清甜香型上部烟叶质量及风格特征的影响,为贵州清甜香型上部烟叶质量提升和风格特征彰显提供参考依据。【方法】 以云烟87上部叶为材料,研究不同采收时间与成熟度(CK,正常采收/成熟;T1,提前4 d采收/尚熟;T2,提前8 d采收/欠熟)对烤后烟叶外观质量、致香物质含量和感官质量的影响,并解析贵州清甜香型上部烟叶风格特征彰显的物质基础。【结果】 随采收时间的提前和成熟度的降低,烤后上部烟叶外观质量变差,主要表现在颜色、成熟度和叶片结构等方面;相较于CK,T1和T2处理烤后烟叶外观质量评价总分分别下降8.33%和22.92%。T1处理能显著提高烤后烟叶类胡萝卜素降解产物、美拉德反应产物、芳香族氨基酸降解产物、类西柏烷类降解产物、脂肪酸类物质、未分类致香物质、总致香物质(除新植二烯)及总致香物质含量(P<0.05,下同),其中总致香物质含量增幅7.54%,且有利于清甜香烟叶风格特征的彰显(评价分值增幅3.64%)。T2处理烤后烟叶总致香物质含量增幅为4.27%,但不利于烟叶风格特征的彰显。筛选出6种质体色素降解产物(藏红花醛、β-大马酮和巨豆三烯酮Ⅰ~Ⅳ)、3种芳香族氨基酸降解产物(苯乙醇、苯乙醛和2-甲氧基-4-乙烯基苯酚)和2种未分类致香物质[(E)-3-已烯-1-醇和壬醛]以彰显烟叶清甜香风格特征为主;2种美拉德反应产物[癸醛和1-(1H-吡咯-2-基)-乙酮]和1种类西柏烷类降解产物(茄酮)以彰显烟叶青香风格特征为主;2种脂肪酸类物质(棕榈酸和亚麻酸甲酯)以彰显烟叶甜香风格特征为主。CK和T1处理的感官质量评价总分显著高于T2处理,增幅分别为7.57%和7.41%,工业可用性和配方适配性均高于T2处理1个档次/水平。【结论】 提前4 d采收有利于提高上部烟叶香气物质含量及风格特征彰显度,并筛选了16种风格特征彰显的标志物质,但提前4 d采收烤后烟叶外观质量变差;提前8 d采收烤后上部烟叶质量整体较差。因此,贵州清甜香型上部烟叶提前采收须根据烟叶质量调整相应烘烤工艺参数。Abstract: 【Objective】 The effects of earlier harvesting on the quality and style characteristics of fresh-sweetness flavor type flue-cured tobacco upper leaves were explored to provide reference for improving the quality and highlighting the style characteristics of fresh-sweetness flavor type of flue-cured tobacco upper leaves in Guizhou. 【Method】 Yunyan 87 upper tobacco leaves used as experimental material,the effects of different harvesting times and maturities(CK,normal harvesting/mature;T1,4 d earlier harvesting/ just mature;T2,8 d earlier harvesting/immature)on the appearance quality,fragrance substance content and sensory quality were studied,and the substance basis of the style characteristics manifestation of fresh-sweetness flavor type flue-cured tobacco upper leaves in Guizhou was analyzed. 【Result】 With the earlier of harvesting time and the decrease of maturity,the appearance quality of flue-cured tobacco upper leaves became worse,mainly showing in the aspects of color,maturity and leaf structure. Compared with CK,the total scores of fluecured tobacco leaf appearance quality evaluation of T1 and T2 treatments decreased by 8.33% and 22.92% respectively. T1 treatment could significantly increase the content of carotenoid degradation products,Maillard reaction products,aromatic amino acid degradation products,cemdrenoids degradation products,fatty acid substances,unclassified fragrance substances,total fragrance substances(except neophytadiene)and total fragrance substances(P<0.05,the same below), among them,total fragrance substances increased by 7.54%. In addition,it was beneficial to highlight the style characteristics of fresh-sweetness flavor type flue-cured upper tobacco leaves with the evaluation score increased by 3.64%. However,T2 treatment was not conducive to highlight the style characteristics of tobacco leaves,with the total fragrance substances content of flue-cured tobacco leaves increased by 4.27%. Six kinds of plastid pigment degradation products(safranal,β-damascenone and megastigmatrienone Ⅰ-Ⅳ),three kinds of aromatic amino acid degradation products(phenylethyl acohol,phenyl acetaldehyde and 2-methoxy-4-vinylphenol)and two kinds of unclassified aroma substances(trans- 3-hexen-1-ol and nonanal)were screened and mainly characterized by the fresh-sweetness flavor type of tobacco leaves. Moreover,2 kinds of Maillard reaction products(decanal and 1-(1H-pyrrol-2-yl)-ethanone),and 1 kind of cemdrenoids degradation product(solanone)were mainly characterized by the grass flavor type of tobacco leaves. In addition,2 kinds of fatty acid substances(palmitic acid and methyl linolenate)were mainly characterized by the sweetness flavor type of tobacco leaves. The total scores of sensory quality evaluation of CK and T1 treatment were significantly higher than that of T2 treatment,with an increase of 7.57% and 7.41% respectively. Industrial availability and formula suitability of CK and T1 treatment were one grade/level higher than that of T2 treatment. 【Conclusion】 It is beneficial to improve the fragrance content and manifestation of the style characteristics of tobacco leaves with 4 d earlier harvesting. Moreover,a total of 16 kinds of marker substances that highlighting style characteristic of fresh-sweetness flavor type are screened. However,4 d earlier harvesting is not conducive to the improvement of appearance quality of flue-cured tobacco upper leaves. In addition,8 d earlier harvesting has the poor overall quality of flue-cured tobacco upper leaves. Therefore,earlier harvesting of upper tobacco leaves of fresh-sweetness flavor type in Guizhou should adjust the corresponding curing parameters according to the tobacco leaves.