Web grading is the first and one of the most important steps in onion peeling. The onions are separated into different size categories using a vibrating grading system with interchangeable web screens. This ensures that only onions of uniform size continue together in the line. Consistent sizing is crucial because the following machines, such as peelers and top-and-tailers, are adjusted to handle specific size ranges (e.g., small, medium, or large onions). Without this step, the efficiency of peeling and trimming would drop significantly, leading to higher waste and lower yield.

Once graded, onions enter the peeling stage. Modern onion peeling machines use high-pressure air, rollers, or mechanical knives to gently remove the dry outer skin layers. The machine can be calibrated to match the onion size category determined during grading, allowing for optimal peeling results with minimal waste. Proper peeling is essential not only for appearance but also for food safety and hygiene, as the outer layers may carry dirt or contaminants. By automating this stage, processors reduce labor while achieving a consistent and clean finish.

After peeling, the onions undergo top and tail removal, where the root end and the stem end are precisely trimmed. This step gives the onions a uniform shape and prepares them for downstream processing such as slicing, dicing, or packaging whole. These operations can be performed either manually or fully automatically using specialized machinery, ensuring consistent results and high efficiency. Precision trimming also minimizes unnecessary product loss, which is especially important when working with high-volume production.

Despite the efficiency of automated systems, human inspection remains a critical quality control measure. Trained operators visually check onions for any remaining defects, blemishes, or incomplete peeling. Manual inspection allows processors to catch irregularities that machines may occasionally miss, ensuring that only high-quality onions reach the consumer. This stage is especially important for fresh-market onions, where visual appearance directly affects consumer preference.

As an alternative to manual inspection, optical sorting technology offers a faster and more accurate solution. Equipped with high-resolution cameras and advanced sensors, these machines can detect imperfections such as discoloration, damage, or incomplete peeling. Optical sorters automatically remove defective onions from the line, guaranteeing consistent quality while significantly reducing labor requirements. This technology is particularly valuable in large-scale operations where speed and accuracy are critical.

The final step is weighing and packaging. Onions are portioned into fixed weights using precise weighing systems, ensuring compliance with retail and wholesale requirements. They can then be packed into consumer bags, bulk boxes, or net packaging depending on the end market. Automated weighing and bagging lines minimize product giveaway and increase efficiency, while also providing attractive, uniform packs that are ready for distribution.

Once onions are packed, the filled bags, cartons, or crates are stacked onto pallets for easier handling, storage, and transportation. Automated palletizing systems arrange the packages in stable layers, maximizing load efficiency and reducing manual labor. This step ensures that onions are safely prepared for logistics, whether for local delivery or export, while improving warehouse organization and supply chain efficiency.