Response Of Tobacco Yield To Fertilizers And The Regulation And Forecast Of Aging Quality

The quality of cigarette products is directly determined by the quality of flue-cured tobacco (FCT), and thus, to improve and to estimate the quality of FCT in the aging process is the main work of tobacco researchers. In this paper, a series of experiments, such as 3414 field fertilizer experiment, FCT aging experiment, and lab batch experiment, were carried out to understand the relationship between the FCT quality and nutrient application, and the changing of FCT quality during the aging. The main results were as follows:1. The relationship between fertilizer and the value, yield of FCT was studied by a 3414 field experiment.The results showed that the response curve of N fertilizer on FCT yield was a quadric parabola, with the maximum yield at N 75kg/hm2. Based on the response quadric quations between FCT yield and N, P, K fertilizers, the calculated maximum amount of fertilizer application for maximum FCT yield were 125kg/hm2,102kg/hm2,385kg/hm2 for N, P, K fertilizer respectively; the calculated economic amount of fertilizer application for maximum yield values of FCT were 105kg/hm2,91kg/hm2,352kg/hm2 for N, P, K fertilizer respectively.2. The relationship between fertilizer and nutrient accumulation in FCT was studied, and the results showed that N application increased N accumulation in FCT leaves,with the highest content of N of 1.84% which was 1.32 fold of the control without N fertilizer. Similarly, the highest content of P and K in FCT leaves when application of P or K fertilizer was 0.72% and 1.94%, which was 1.13-fold and 1.2-fold of the control, respectively.3. Study on the relationship between fertilizer and the content of chemical components showed that both P and K application increased the content of carbohydrate. The content of total water-soluble sugar and reducing sugar was 1.2 and 1.12 times of the control without P respectively, and was 1.20 times and 1.15 times of the control without K respectively. 4. The aging conditions of FCT influenced the sensory quality significantly.The results indicated that aging process could be shorten and the sensory quality of FCT was better when raising the leaf moisture to 13±0.5% and storehouse temperature to 45±3℃, and reducing packing density to 180kg/Box and using packaging materials (3 mm).5. The activity of enzyme varied with the aging time and the production area of FCT. The activity of polyphenol oxidase (PPO) and phenylalnine ammonialyase (PAL) decreased in the aging process. The activity of a-amylase increased at first and then decreased, reaching the maximum in the 15th month of aging. PPO activity in Yunnan FCT was 14.4 units g-1min-1 which was 89% higher than Fujian FCT of 7.6 units g-1min-1, when aging time reached 6 months. PAL activity of Yunnan FCT was 1.64 units g-1Wn-1, the highest among the samples in the early aging time, and was 0.4 units g-1min-1 which was only 24% of the initial value 21 months later. The maximum of the a-amylase activity,4.32 mg (glucose) min-1g-1 was obtained in the 15th month of aging.6. The relationship between the activity of enzyme and the sensory quality of FCT was studied. The regression equation:y=87.49-1.08x1+0.0.22x12(y:sensory quality; clamps its x1:α-amylase) was established based on the changes of activity of enzyme in the aging process in using multiple regression analysis.The predictie accuracy was above 97% in using the equation to predict the sensory quality of FCT.7. The aging time was clustered into three groups:i.e., (1) 0-6 months of the initial stage. (2) 9-12 months of the intermediate stage. And (3) 15-21 months of the mature stage. The discriminant formulation was established by using Bayesian analysis. They were Y1=-12.40+4.58x1+2.27x2-0.45x3, Y2=-8.94+0.48x1+ 1.89x2-1.13x3, Y3=-3.29-0.64x1+0.97x2+1.32x3 (Y1, Y2, Y3 stage of aging process; x1, x2, x3 represent the activity of PAL,PPO and a-amylase respectively)8. The procedure of fingerprint fugures for FCT was had been established firstly by using HPLC, which included mobile phase A:0.1% of phosphoric acid and B: acetonitrile; the sample size 10μL; the flow rate 0.8 mL/min; the temperature of Column 25℃. The detector was VWD and the wavelength used 250nm. The Gradient elution was used as the quantity of acetonitrile was from 5% to 20% during 0-30min, from 20% to 30% during 30-45min, from 30% to 55% during 45-55min and maintain 5min; then reduced to 5% at running for 63min and maintain 2min; and at end run 3 min after operation.9. The difference of fingerprint figures of FCT from different areas and aging for different times was studied. The results showed that the methanol extracts of leaves from Fujian and Sichuan decreased along the aging time; a parabolic curve trend occurred for leaves from Yunnan, Guizhou and Hubei. The methanol extracts of Yunnan leaves had the greatest amount, and Dongbei was the least. The characteristic peaks were studied using Principal Component Analysis, and the accumulation contribution rate was 85.01% for the first four principal components. The regression model for the sensory quality and the area of peak was established by regression analysis, and it was:Y=79.34+0.00105 clamps its x1-0.00690 x2+0.00316 x3+ 0.00053 x7+0.00051 x8+0.00356 x9-0.00113 x10(F=26.6). The predictie accuracy for the sensory quality of unknown samples was above 95%.10. The changes of aroma composition of FCT was studied.The result showed that the contents of the metabolites of aromatic amino acids, Maillard reaction products, Siebel alkane degradation substances and Carotenoid Blends were increasing along the aging time; but the changes of aromatic substances showed a slight decline with the aging time. The greatest contents were from the samples of Hubei, which were 739 -800μg g-1, while the lowest was from Dongbei, being about 536μg g-1—594μg g-1 during the stage. Sichuan and Yunnan had basically the same content of total aromatic substances.