In the field of agricultural product processing and export, the grading of carrots is a key link to ensure product quality and enhance market value. Scientific grading can not only meet the needs of different customers, but also optimize logistics efficiency and reduce losses. The following is a standard operation method for carrot grading, which is suitable for large-scale planting bases or processing plants.
1. Preliminary preparation
Before grading, the carrots need to be preliminarily screened to remove individuals with obvious deformities, rot or mechanical damage. The washed carrots should have no soil residue on the surface and the root cut should be flat for subsequent measurement. Operators need to wear gloves to avoid hand grease or stains from contaminating the product.
2. Grading standards
Carrot grading is usually based on three core indicators: length, diameter and appearance quality:
Length grading: Common specifications include 15-20 cm (small), 20-25 cm (medium) and more than 25 cm (large). Use customized conveyor belts or sorting tables with length measuring tools for quick sorting.
Diameter grading: Divided by cross-sectional diameter, such as 1-2 cm (mini), 2-3 cm (standard) and 3 cm or more (extra large). This can be done by a drum sorter or manual comparison ruler.
Appearance quality: Grade 1 products require smooth skin, uniform color (orange-red is preferred), no cracks or spots; Grade 2 products allow slight defects, and Grade 3 products are used for processing raw materials (such as carrot juice or canned food).
3. Combination of mechanization and manual labor
Modern processing plants mostly use photoelectric sorting machines, which use cameras to identify colors and shapes, combined with airflow or robotic arm sorting, and can achieve an efficiency of several tons per hour. However, for high-end market orders, manual re-inspection is still required, especially for the control of details such as curvature and top neatness.
4. Packaging and storage
Graded carrots need to be packed into breathable mesh bags or plastic trays according to specifications, and marked with grade codes (such as "L" for large size and "A" for grade 1). For short-term storage, it is recommended to control the temperature at 0-5℃ and the humidity at 90%-95% to extend the shelf life.
Mastering scientific grading methods can not only increase product added value, but also enhance competitiveness in the international market. With the popularization of automation technology, carrot grading is moving towards a more efficient and accurate direction.
