Apple’s In-Field Grading and Sorting Technology: A Review

Quality inspection is crucial to raise people’s living standards in the realm of processing fruits and vegetables. Since apples are one of the best-producing crops, post-harvest infield grading is advantageous for enhancing economic efficiency and lowering production costs. Apple infield grading and sorting equipment’s technology have advanced quickly in recent decades. This study overviews the quality inspection developments in infield grading and sorting equipment. We present typical visual quality variables, including color, size, flaws, and internal quality inspection, as supplemental data for detection parameters. Later, Optical imaging methods such as visible light, near-infrared, hyperspectral/multispectral, and structured light are surveyed for apple quality assessment. Finally, the difficulties in commercializing the existing apple infield grading and sorting equipment are offered, including the need to get information about the whole area, uneven lighting, and high prices. Further provides an overview of the pertinent hardware and computational solutions. This chapter makes a comprehensive summary of apple infield grading and sorting technology. It points out the problems that must be faced in the follow-up development, which can guide future work.