Infrared imaging technology for detection of bruising damages of 'Shingo' pear

Bruise damage on pears is one of the most crucial internal quality factors that needs to be detected in postharvest quality sorting processes. Development of sensitive detection methods for the defects including fruit bruise is necessary to ensure accurate quality assessment. Infra-red imaging techniques in the 1000 nm to 1700 nm has good potentials for identifying and detecting bruises since bruises result in the rupture of internal cell walls due to defects on agricultural materials. In this study, feasibility of hyperspectral infra-red (1000 - 1700 nm) imaging technique for the detection of bruise damages underneath the pear skin was investigated. Pear bruises, affecting the quality of fruits underneath the skin, are not easily discernable by using conventional imaging technique in the visible wavelength ranges. Simple image combination methods as well as multivariate image analyses were explored to develop optimal image analysis algorithm to detect bruise damages of pear. Results demonstrated good potential of the infra-red imaging techniques for detection of bruises damages on pears.