Firmness is one of the most important characteristics to estimate fruit maturity and quality.The potential of near-infrared(NIR)diffuse reflectance spectroscopy as a nondestructive way for pear firmness evaluation of ...Firmness is one of the most important characteristics to estimate fruit maturity and quality.The potential of near-infrared(NIR)diffuse reflectance spectroscopy as a nondestructive way for pear firmness evaluation of three varieties(‘Cuiguan’,‘Xueqing’and‘Xizilv’)was studied,both quantitatively and qualitatively.NIR models were established using partial least square(PLS)methods in the spectral range of 800 to 2500 nm.For quantitative analysis,the correlation coefficient r increased with more varieties involved in the model.Best results were obtained in the model for all three varieties:rcalwas 0.934,root mean square error of calibration(RMSEC)and root mean square error of prediction(RMSEP)were 2.06 N and 3.14 N,respectively.For qualitative analysis,the overall accuracies of discriminant PLS models for classifying pears into three firmness levels:low,medium and high firmness level were not so good,percentage of samples correctly classified ranged from 70.63%to 81.25%for calibration and from 56.25%to 74.38%for validation.The results indicate that NIR spectroscopy together with PLS chemometrics method is feasible for quantitative analysis of pear firmness,however,the classification accuracy is too low to put into practical application.展开更多
基金The authors gratefully acknowledge the financial support provided by National Natural Science Foundation of China(No.30671197)the Program for New Century Excellent Talents in University(No.NCET-04-0524).
文摘Firmness is one of the most important characteristics to estimate fruit maturity and quality.The potential of near-infrared(NIR)diffuse reflectance spectroscopy as a nondestructive way for pear firmness evaluation of three varieties(‘Cuiguan’,‘Xueqing’and‘Xizilv’)was studied,both quantitatively and qualitatively.NIR models were established using partial least square(PLS)methods in the spectral range of 800 to 2500 nm.For quantitative analysis,the correlation coefficient r increased with more varieties involved in the model.Best results were obtained in the model for all three varieties:rcalwas 0.934,root mean square error of calibration(RMSEC)and root mean square error of prediction(RMSEP)were 2.06 N and 3.14 N,respectively.For qualitative analysis,the overall accuracies of discriminant PLS models for classifying pears into three firmness levels:low,medium and high firmness level were not so good,percentage of samples correctly classified ranged from 70.63%to 81.25%for calibration and from 56.25%to 74.38%for validation.The results indicate that NIR spectroscopy together with PLS chemometrics method is feasible for quantitative analysis of pear firmness,however,the classification accuracy is too low to put into practical application.
