Different Topping Period And Maturity Of Baking Conditions On The Quality Of Chuxiong K326 Middle Leaf

Tobacco is one of important economic crop in China.High quality development of tobacco leaf production is significant to the development of the tobacco industry.Chuxiong Prefecture is the second largest high-quality tobacco production area in Yunnan Province and an important high-quality tobacco production base,In recent years,climate change has reduced the compliance of tobacco leaves in Chuxiong Prefecture,it is urgent to upgrade the technology system suitable for Chuxiong tobacco to improve the comprehensive quality of Chuxiong tobacco.This study took K326 in Chuxiong as the research object.Optimization was carried out from different topping time,tobacco maturity and corresponding baking process.In view of the main problems in local tobacco production in Chuxiong,such as the influence of single curing conditions on the chemical composition of tobacco leaves in different topping periods and different maturity,Taking K326 central tobacco leaf as the research object,the tobacco leaves of three different topping periods(bud,first flower and full flower)and three different maturity(early ripe,proper ripe and overripe)were designed,constituting a three-factor test with three different baking conditions.By comparing the changes of agronomic characters of tobacco in different topping periods and the changes of chemical components of different curing processes in different topping periods combined with different maturity to explore the optimal treatment combination that adapts to the current production status,the main research results are as follows:(1)The result of agronomic characters of K326 in different topping periods showed that the agronomic characters of K326 in the first topping method were better.After the first flower topping treatment,compared with other treatments,the plant height increased by 5.28%,the maximum leaf length increased by 6.63%,the maximum leaf width increased by 10.63%,and the stem circumference increased by2.32%,which was consistent with the topping of buds and better than the topping of flowers.In terms of pitch,the changes of the three treatments are not obvious.(2)The results of chemical composition analysis of tobacco leaves before roasting showed that the contents of total sugar and reducing sugar under the treatments of the bud-early ripe were the best,which were 90.10 mg/g and 55.10 mg/g,respectively.They were 2.39% and 2.50% higher than those of the first flower-early ripe treatment,2.62% and 3.20% higher than those of the full flower-early ripe treatment,respectively.The highest nicotine content was 15.70 mg/g under the treatments of the bud-early ripe and the bud-proper ripe.The lowest chlorine content under the full flower-overripe treatment was 3.30mg/g.The best potassium was 2.17mg/g under the first flower-proper ripe treatment.The maximum total nitrogen content was 59.40 mg/g under the first flower-proper ripe treatment,which was found that the chemical quality of the bud-early ripe treatment was more advantageous.(3)The results of chemical composition analysis of tobacco leaves after curing showed that compared with the chemical composition before curing,total sugar and reducing sugar of tobacco leaves after curing under curing condition 2 increased the most.After baking condition 1,the contents of nicotine,chlorine,potassium and total nitrogen increased the most,and the contents of potassium and total nitrogen increased significantly.(4)Combined with different topping period,different maturity and different baking method results comprehensive analysis.In terms of total sugar,the highest total sugar under the first flower-proper ripe-baking condition 2 was 397 mg/g,which was 25.88% higher than that under the first flower-proper ripe-baking condition 1,and 3.12% higher than that under the full flower-proper ripe-baking condition 3.In terms of reducing sugar,the highest reducing sugar in the full flower-proper ripe-baking condition 2 treatment was 343 mg/g,17.87% higher than that in the first flower-proper ripe-baking condition 1 treatment and 1.48% higher than that in the full flower-proper ripe-baking condition 3 treatment.In terms of nicotine,the highest nicotine was 19.80 mg/g under the bud-proper ripe-baking condition 2,which was11.86% higher than the full flower-overripe-baking condition 1,which was 20.01%higher than the bud-early ripe-baking condition 3.In terms of chlorine,the highest chlorine was 4.80 mg/g under the full flower-proper ripe-baking condition 1,which was 41.18% higher than the bud-overripe-baking condition 2,and 17.07% higher than the full flower-overripe-baking condition 3.In terms of potassium,the highest potassium was 24.10 mg/g under the bud-overripe-baked condition 1,which was9.09% higher than the first flower-proper ripe-baking condition 2 and 16.43% higher than that under the full flower-overripe-baking condition 3.In terms of total nitrogen,the highest total nitrogen under the full flower-early ripe-baking condition 1 was23.30 mg/g,which was 17.09% higher than the bud-proper ripe-baking condition 2and the first flower-early ripe-baking condition 2.(5)Based on the analysis of sensory evaluation results and the comprehensive evaluation indexes of sensory quality,the highest score of baking condition 2 was75.1,which was superior to the other two baking conditions.Based on the preliminary topping and chemical composition data,it was concluded that the optimal three-factor treatment combination for tobacco K326 in this experiment was the first flower-early ripe-baking condition 2 treatment combination.