Effects of Curing with Stem on Main Aroma Precursor Substances Contents and Quality of Upper Leaves of Flue-Cured Tobacco

Yang Tengxu; Xu Hanxiao; Guo Lizhen; Gao Xinhan; Fan Guoqiang; Zhang Hong; Deng Bao'an; Zhao mingqin

doi:10.14083/j.issn.1001-4942.2026.03.010

Abstract：To elucidate the dynamic variations of major aroma precursor substances in upper tobacco leaves during curing with stem and their effects on post-curing leaf quality,this study was conducted with Yun-yan 97 upper leaves as experimental materials and four curing patterns as conventional leaf-by-leaf curing of six leaves(CK),six leaves with stem(T1),three leaves with stem(T2),and single leaf with stem(T3).The variation of contents of pigment,polyphenols,organic acids and alkaloid in tobacco leaves during curing process were analyzed,and the appearance quality,total volatile aroma compounds and sensory quality of cured leaves were subsequently assessed.The results were as follows.① All the curing treatments with stem reduced the chlorophyll a,chlorophyll b and carotenoid contents,and most reached significant level,which was benefit to promoting the formation of degradation products of chlorophyll and carotenoid.② The contents of chlorogenic acid,rutin and scopoletin increased progressively during curing,and they were higher in the cu-ring treatments with stem,suggesting curing with stem enhanced polyphenols accumulation conducive to im-prove flavor profile and visual quality.③ Compared to CK,curing with stem elevated malic acid and oxalic acid contents,while decreased malonic acid and citric acid contents.④ The nicotine content exhibited a con-tinuous upward trend,the nornicotine and anabasine followed an increasing-decreasing-increasing trend,and the neonicotine increased first and then decreased.But all the alkaloid concentrations in leaves were lower in curing treatment with stem compared to CK.⑤ Curing with stem significantly increased total volatile aroma compounds and improved the sensory quality.Through comprehensive comparison,the treatment of six-leaf cu-ring with stem(T1)demonstrated the most pronounced improvement in overall leaf quality and industrial ap-plicability.