NIR assessment of soluble solids and firmness for pears of different cultivars

Development of nondestructive measurements of soluble solids and firmness, which are two important ripeness and quality attributes of fruits, benefits the producers, processors and packers. The objective of this research was to evaluate the use of near-infrared (NIR) spectroscopy in detecting soluble solid content (SSC) and firmness for pears of three cultivars 'Cuiguan', 'Xueqing' and 'Xizilv' (n=160 of each cultivar). Relationships between nondestructive NIR spectral measurements and firmness and SSC of pear fruits were established by partial least square regression (PLSR) method. Models were developed for each cultivar, every two cultivars, and for all three cultivars in the spectral range of 800-2500 nm. The results of the models for all three cultivars turned out the best. For SSC assessment: correlation coefficients of calibration (rcal), root mean standard errors of calibration (RMSEC) and root mean standard errors of prediction (RMSEP) were 0.93, 0.35 °Brix and 0.50 °Brix for all three cultivars, respectively. For firmness assessment: rcal, RMSEC and RMSEP were0.92, 2.29 N, 2.95 N for all three cultivars, respectively. The results indicate that NIR spectroscopy can be used for predicting SSC and firmness of pear fruit and are the basis for the development of NIR analyzer suitable for on line application.

[1]  Clifford J Studman,et al.  A multi-purpose firmness tester for fruits and vegetables , 1995 .

[2]  S. Kawano,et al.  Firmness, dry-matter and soluble-solids assessment of postharvest kiwifruit by NIR spectroscopy , 1998 .

[3]  G. Roeck,et al.  Determining the Firmness of a Pear using Finite Element Modal Analysis , 1999 .

[4]  V. A. McGlone,et al.  NON-CONTACT FRUIT FIRMNESS MEASUREMENT BY THE LASER AIR-PUFF METHOD , 1999 .

[5]  Kalman Peleg.  Development of a commercial fruit firmness sorter , 1999 .

[6]  Robert K. Prange,et al.  Comparison of a new apple firmness penetrometer with three standard instruments , 2000 .

[7]  P. Schaare,et al.  Comparison of reflectance, interactance and transmission modes of visible-near infrared spectroscopy for measuring internal properties of kiwifruit (Actinidia chinensis) , 2000 .

[8]  R. Lu.  PREDICTING FIRMNESS AND SUGAR CONTENT OF SWEET CHERRIES USING NEAR–INFRARED DIFFUSE REFLECTANCE SPECTROSCOPY , 2001 .

[9]  V. A. McGlone,et al.  Dry matter determination in ‘Hass’ avocado by NIR spectroscopy , 2003 .

[10]  M. Hubert,et al.  Robust PCR and Robust PLSR: a Comparative Study , 2004 .

[11]  C. Hsieh,et al.  Applied Visible/Near-Infrared Spectroscopy on Detecting the Sugar Content and Hardness of Pearl Guava , 2005 .

[12]  Y. Tao,et al.  Nondestructive quantification of the soluble-solids content and the available acidity of apples by fourier-transform near-infrared spectroscopy. , 2005, Applied optics.

[13]  Y. Ying,et al.  Optical system for measurement of internal pear quality using near-infrared spectroscopy , 2005 .

[14]  Philip K. Hopke,et al.  Application of PLS and Back-Propagation Neural Networks for the estimation of soil properties , 2005 .

[15]  J. Roger,et al.  Non-destructive tests on the prediction of apple fruit flesh firmness and soluble solids content on tree and in shelf life , 2006 .