ICAR-CIAE Automatic Fruit Grader

Background

After harvest, fruits and vegetables remain metabolically active and are vulnerable to stresses during handling, storage, and transport. These stresses accelerate quality loss, reduce nutritional value, and cause significant economic damage. Manual washing, grading, and sorting by unskilled labor often lead to inconsistent quality, reduced market appeal, and added drudgery-underscoring the need for improved, mechanized post-harvest solutions.

Technology Details

This ergonomically designed, single-operator machine measures 6.4 m in length, 1 m in width, and 1.6 m in height, and is constructed from durable SS-304 stainless steel. Operating on three-phase electric power, it produces noise levels below 80 dB, ensuring a safer and more comfortable working environment. The machine’s capacity varies with the product, delivering an output of approximately 1,700 fruits per hour. 

Fully automated, it performs key postharvest operations-including washing, vision-based sorting, and weight-based grading of citrus fruits-with minimal human effort while maintaining high accuracy. At its core is a custom lightweight CNN model, “SortNet,” specifically designed and tuned for vision-based classification, enabling reliable separation of fruits into “accept” and “reject” categories based on surface characteristics. With weight grading and color sorting efficiencies exceeding 90%, the machine achieves excellent performance across designated tasks. Importantly, it reduces operator drudgery by nearly 83%, while ensuring precision, consistency, and improved postharvest quality management.