Establishment and application of enzymological models for predicting quality of flue-cured tobacco

The enzyme activities of polyphenol oxidase (PPO), phenylalanine ammonia-lyase (PAL) and alpha-amylase and their relationships with the quality of the tobacco in their aging stages were conducted to establish an enzymological model to evaluate the quality of the tobacco. Sensory quality of tobacco and enzyme activities were analyzed by the way of chemometrics and statistics. The results showed that the activity of PPO and PAL decreased with the elongation of aging, but the activity of alpha-amylase increased initially and then decreased, reaching the highest level at the fifteenth month. The regression model was y = 87.49-1.08x(1) + 0.22x(1)(2) (y, sensory quality; x(1), alpha-amylase). The prediction showed that the average error was 0.45% and the accuracy was more than 99.5%. The application of enzymological model was effective to predict the quality of flue-cured tobacco.