Rapid and nondestructive detection of watercore and sugar content in Asian pear by near infrared spectroscopy for commercial trade

Abstract

Watercore and sugar content are internal qualities which are impossible for exterior determination. Therefore the aims of this study were to develop models for nondestructive detection of watercore and predicting sugar content in pear using Near Infrared Spectroscopy (NIR) technique. A total of 93 samples of Asian pear variety \SH-078" were used. For sugar content, spectrum of each fruit was measured in the short wavelength region (700-1100 nm) in the re°ection mode and the¯rst derivative of spectra were then correlated with the sugar content in juice determined by digital refractometer. Prediction equation was performed by multiple linear regression. The result showed Standard Error of Prediction ðSEPÞ ¼ 0:58 Bx, and Bias ¼ 0:11. The result from t-test showed that sugar content predicted by NIR was not signi¯cantly di®erent from the value analyzed by refractometer at 95% con¯dence. For watercore disorder, NIR measurement was performed over the short wavelength range (700-850 nm) in the transmission mode. The¯rst derivative spectra were correlated with internal qualities. Then principle component analysis (PCA) and partial least squares discriminant analysis (PLSDA) were used to perform discrimination models. The accuracy of the PCA model was greater than the PLSDA one. The scores from PC1 were separated into two boundaries, one predicted rejected pears with 100% classi¯cation accuracy, and the other was accepted pears with 92% accuracy. The high accuracy of sugar content determining and watercore detecting by NIR reveal the high e±ciency of NIR technique for detecting other internal qualities of fruit in the future.

Non-Destructive Identification and Estimation of Granulation in Honey Pomelo Using Visible and Near-Infrared Transmittance Spectroscopy Combined with Machine Vision Technology

“…As shown in Figure 7a,b, within the visible spectral region (400-780 nm), no obvious absorption peaks were detected in the raw spectra and mean spectra. In the near-infrared spectral region, typical overlapping absorption peaks correspond to C-H, O-H, and N-H chemical bonds of water and carbohydrates in fruits [48]. In the short-wave near-infrared (SW-NIR) spectral region (780-1100 nm), an overlapping peak was detected at approximately 813 nm.…”

Nondestructive Testing of Pear Based on Fourier Near-Infrared Spectroscopy

“…Different types of pears have distinct flavors and textures. China produces more than 60 percent of the world's pears [2]. Consumers consider the outer quality of the pear, such as size, color and shape, as well as the inner quality of the pear, such as sugar content, acidity and taste.…”

Nondestructive Analysis of Internal Quality in Pears with a Self-Made Near-Infrared Spectrum Detector Combined with Multivariate Data Processing

“…The tastes and textures of different kinds of pears are different. More than 60% of the world's pears are produced in China [1]. Consumers pay attention to the external quality of pears, including size, color, and shape, as well as to the internal quality of pears, including the sugar content, acidity, and taste.…”

“…Xu et al [12] developed an application for the online determination of sugar content in pears based on variable selection in vis-and NIR spectra, with Rv = 0.880 and RMSEP = 0.459% for the validation set. Rittiron et al [1] used NIR spectroscopy in the short wavelength region (700-1100 nm) for rapid and nondestructive detection of watercore and sugar content in Asian pears for commercial trade. Travers et al [13] predicted and compared preharvest pear dry matter (DM) and SSC, based on two near-spectral ranges (680-1000 nm and 1100-2350 nm).…”