Simulation And Application Of Moisture Change Model Of Tobacco Leaves During Bulk Curing Process

In order to promote and improve the development of tobacco curing lean management,flue-cured tobacco “K326,Yunyan87,Yunyan85” were set as samples,and based on the moisture change characteristics,the moisture change model,model parameter matching and model application effect were studied in three stages bulk curing technology.The results are as follows.(1)Moisture change characteristics.Moisture ratio and dry basis moisture content were all declined with the increasing of bulk curing cumulative time.The drying rate decreases with the decrease of dry basis moisture content during bulk curing process in different varieties,the average drying rate was highest when the dry basis moisture content was greater than 4.0g/g,and the average drying rate between 4.0 and 1.0g/g was second,and the average drying rate lower 1.0g/g was the lowest.The drying rate decreases with the decrease of dry basis moisture content during bulk curing process in lower leaf,The drying rate was the highest between 3.5~1.5 g/g of dry base moisture content,and there was a significant drying rate peak between 1.5~0.5 g/g.The average drying rate was highest when the dry basis moisture content between 1.5 and 0.5g/g,and the average drying rate between 3.0 and 1.5g/g was second,and the average drying rate lower 0.5g/g was the lowest in middle and upper leaf during bulk curing process.(2)Moisture change model simulation.The best fitness drying model of moisture ratio change during bulk curing process is ‘Wang and Singh'.The model fitting determination coefficient of K326,Yunyan 87,Yunyan 85 middle leaf were 0.995 9,0.987 8,0.989 2,respectively;Yunyan 85 lower leaf,middle leaf,upper leaf were 0.992 8,0.973 3,0.965 3,respectively.The linear regression method was used to verify the model and the predicted value of the model were set as x,and the measured value were set as y;The linear fitting results showed that the R2 of K326,Yunyan 87,Yunyan 85 middle leaf were 0.969 4,0.971 5,0.965 8,respectively;Yunyan 85 lower leaf,middle leaf,upper leaf were 0.991 5?0.987 9?0.977 0,respectively.It showed that the Wang and Singh model has good validation results and can provide good description and prediction for the moisture ratio change in tobacco leaves during ordinary bulk curing process.(3)Parameters of moisture change model.The determination coefficient(R2)of Wang and Singh model were all bigger than 0.95 in different in different varieties,leaf positions and production areas,besides,parameters adjustment coefficient and model parameter a had a positive correlation relationship,but had a negatively correlated relationship with model parameter b.The linear regression result showed that parameters adjustment coefficient and model parameters a,b were significantly correlated(P<0.05),and linear fitting determination coefficient(R2)were greater than 0.95.It can be used to estimate the model parameters accurately and accelerate the accurate prediction of moisture ratio changes during the bulk curing process,and improve the practical usability of the moisture change model.(4)The application of moisture change model.Compared with conventional method the economic efficiency showed that moisture change model curing method is slightly higher in yield,output value and average price than conventional method.Compared with the conventional method flue-cured tobacco leaves appearance quality,the moisture change model curing method can improve the proportion of orange and first class to 5.55% and 4.52%,and cut the proportion of low class by 0.41%.Chemical composition analysis results showed that the moisture change model curing method flue-cured tobacco leaves have higher total sugar,reducing sugar and reducing sugar/nicotine ratio than conventional method,and improved the coordination of chemical components in flue-cured tobacco leaves.The sensory quality of flue-cured tobacco showed that moisture change model curing method can significantly improve the score of quantity and quality of aroma,concentration,strength in lower leaf,and significantly improved the score of middle leaf's concentration,irritation,aftertaste and upper leaf's quantity of aroma.Compared with the conventional method moisture change model curing method can improve the sensory quality total score of lower,middle,upper leaf by 1.62,2.25 and 0.59 points.