Effect of Different Stem-included Harvesting and Curing Methods on Cell Activity and Quality of Upper Tobacco Leaves

LI Songyan; ZHANG Yulin; ZHAO Yongwei; WANG Lifang; ZHANG Mingjin; WANG Jian'an

doi:10.15933/j.cnki.1004-3268.2026.02.018

Abstract：To optimize the stem-included harvesting and curing method of upper tobacco leaves and enhance its usability,three treatments were set up:Upper 6 tobacco leaves with stems(partial stem retention,CK),upper 3 and lower 3 tobacco leaves with stems(segmented stem retention,T1)and single leaves with 2-3 cm stems(single-leaf stem retention,T2).By measuring malondialdehyde(MDA)content and antioxidant enzyme[superoxide dismutase(SOD),catalase(CAT),peroxidase(POD),and polyphenol oxidase(PPO)]activities,along with flue-cured conventional chemical composition,appearance quality and sensory quality,the effects of different stem-included treatments on cell activity and quality of tobacco leaves were systematically analyzed.The results showed that the MDA content of the three treatments reached the peak at 144 h,and the MDA content of T1 and T2 treatments was 13.54%and 3.81%lower than that of CK treatment,respectively.During 24-36 h,the SOD activity of each treatment decreased the most,which was 18.18%in CK treatment,14.64%in T1 group and 20.50%in T2 treatment,respectively.The peak values of CAT and POD activities in T1 treatment increased most significantly,which were 13.46%and 32.66%higher than those in CK treatment,respectively,while those in T2 treatment were 4.91%and 12.19%,respectively.The decrease rate of PPO activity was T1>T2>CK.Comprehensive evaluation of the quality of flue-cured tobacco leaves showed that the coordination of chemical composition and sensory quality in T1 and T2 treatments were better than CK treatment,and the total scores of appearance quality were 6.35%and 1.47%higher than CK treatment,respectively.Correlation analysis showed that the correlation coefficient between MDA content and key enzyme activity in T2 and CK treatments was lower.Principal component analysis further showed that routine chemical components of T1 treatment had the highest score.In summary,T1 could effectively maintain the stability of enzyme activity,reduce MDA content,maintain the coordination of chemical composition,improve the color of flue-cured tobacco leaves,and thus comprehensively improve the quality of tobacco leaves.