1
Singulation
Incoming sesame seeds are fed via precision vibratory channels, forcing the bulk material to spread uniformly and accelerate into a continuous, single-layer curtain, ensuring individual kernels are isolated for accurate scanning.
Premium Processing Stage
Optical Colour Sorting (Sortex) for Sesame Seeds
Optical colour sorting—commonly referred to in the industry by the proprietary name Sortex—is an advanced electronic process that utilizes high-resolution cameras and sensor arrays to evaluate individual sesame seeds in real-time free-fall. By identifying and ejecting visually non-conforming seeds via precision bursts of compressed air, this technology elevates the aesthetic uniformity of the final product.
This highly selective separation stage is reserved for our premium Natural Sortex and high-grade hulled sesame products. It is the definitive processing step for applications where the seed's visual presentation is critical to the end-consumer experience, ensuring a consistent, homogeneous appearance free from visually distinct foreign matter or discoloured kernels.
Admin Note:
Please verify exact throughput capacities (e.g., MT/hour) and specific camera technologies (e.g., InGaAs, exact RGB resolutions) used in your facility to ensure precise technical accuracy.
How Optical Sorting Works
A highly calibrated, split-second electronic evaluation of millions of individual seeds.
2
Illumination & Scanning
As seeds enter the viewing zone in free-fall, multidirectional LED lighting illuminates them. High-speed RGB and NIR cameras capture images of every seed from multiple angles at rates exceeding 5,000 frames per second.
3
Algorithmic Analysis
Onboard FPGA processors instantly analyze the optical data, comparing the shape, shade, and spectral signature of each seed against a pre-programmed acceptable colour profile, identifying microscopic deviations in milliseconds.
4
Targeting
When a seed falls outside the established optical tolerance—whether due to discolouration, spot defects, or foreign material—the system calculates its exact trajectory and velocity to coordinate precise ejection timing.
5
Pneumatic Ejection
A high-speed pneumatics manifold fires a targeted, 0.2-millisecond blast of compressed air, deflecting the defective seed out of the primary product stream and into a reject chute before it reaches the accepted batch.
What Sortex Detects and Removes
Targeting specific visual anomalies that traditional mechanical cleaning cannot separate.
| Defect Type | Why Removed | Effect on Final Product |
|---|---|---|
| Discoloured Seeds | Dark or black spots on natural sesame caused by weather or physiological stress. | Prevents visually jarring dark specks on light-coloured bakery items like burger buns. |
| Faded / Chalky Seeds | Immature or poorly developed kernels lacking typical pigment and oil content. | Improves overall batch colour vibrancy and ensures consistent roasting characteristics. |
| Hull Fragments | Residual darker seed coats remaining after the mechanical hulling process. | Guarantees a stark, bright white appearance essential for premium hulled applications. |
| Black/Dark Weed Seeds | Foreign botanical seeds that share identical size and weight to sesame. | Eliminates foreign matter that bypasses sieves and gravity separators. |
| Fungal Staining | Surface discolouration indicative of field mold or improper drying conditions. | Enhances overall aesthetic quality and removes visually degraded material. |
Sortex Grade vs Standard Grade
Understanding the distinct specifications between processing tiers to select the right product for your manufacturing needs.
Standard Natural Grade
- Colour Uniformity Commercial / Uniform
- Defect Seeds Typically 2-3%
- Visual Rejection Rate N/A (Mechanical Clean Only)
- Best Application Oil Mills, Bulk Seasoning
Premium
Natural Sortex Grade
- Colour Uniformity Premium / Consistent
- Defect Seeds < 0.1%
- Visual Rejection Rate Camera Verified
- Best Application Bakery Toppings, Confectionery
Critical Limitations of Optical Sorting
While optical sorting provides unparalleled visual improvement, it is vital for food manufacturers to understand what the process cannot accomplish regarding food safety and chemical compliance.
Cannot Detect Microbiology
Optical cameras rely on visual light and near-infrared spectra. Microbial pathogens such as Salmonella, E.coli, or Listeria are microscopic and entirely invisible to Sortex machines. Validated laboratory testing remains mandatory for microbiological safety.
Cannot Detect Pesticides
Agrochemical residues, heavy metals, and mycotoxins present no visual cues on the seed surface. Compliance with Maximum Residue Limits (MRLs) requires stringent agricultural sourcing controls and accredited chemical laboratory analysis.
Cannot Sterilize Seeds
The Sortex process is a physical segregation method utilizing ambient compressed air. No heat, steam, UV radiation, or chemical treatments are applied. It does not pasteurize or reduce the inherent biological load of the agricultural product.
When Buyers Should Request Sortex
Aligning your raw material specification with your finished product application to optimize cost and quality.
Where Sortex is Essential
-
Visible Bakery Applications
Burger buns, bagels, and bread rolls where the seed forms a prominent, visual crust.
-
Confectionery Decoration
Cookies, pastries, and snack bars where aesthetic perfection directly influences consumer appeal.
-
Premium Retail Seasoning Blends
Clear glass jar packaging where visual inconsistencies could be perceived as low quality by the end-user.
Where Standard Grade Suffices
-
Oil Extraction
Industrial crushing for sesame oil where the visual appearance of the seed is irrelevant to the liquid output.
-
Tahini Production
Milling operations where the seed is ground into a uniform paste (though hulled grades are typically required).
-
Industrial Seasoning Incorporation
Bulk formulations where the seed is heavily coated, dyed, or into opaque matrices.
Frequently Asked Questions
What is the cost premium for Sortex grade versus standard grade sesame seeds?
Because optical sorting results in a yield loss (as non-conforming seeds are ejected) and requires significant capital investment in high-speed machinery, Sortex grades typically carry a pricing premium. The exact premium depends on the raw material quality and specific colour tolerance requested.
Does the Sortex process guarantee food safety for my application?
No. Optical sorting is strictly a visual and physical segregation process. It does not provide microbial reduction, heat treatment, or pesticide removal. Food safety guarantees require separate interventions such as laboratory testing, heat treatment, and controlled supply chain management.
Can buyers specify custom colour tolerances for optical sorting?
For volume contract buyers, we can adjust the sorting profile to accommodate specific requirements. However, standard commercial production runs on optimized profiles that balance maximum defect removal with sustainable product yields.
What is the throughput of your optical sorting lines?
Modern high-capacity optical sorters process multiple metric tons per hour, ensuring we can fulfill bulk container contracts efficiently while maintaining stringent visual quality standards.
Do you perform optical sorting on hulled sesame seeds as well as natural?
Yes, optical sorting is frequently applied to hulled sesame seeds as a final polishing step to remove any remaining unhulled seeds, hull fragments, or discoloured kernels, resulting in a pristine white product for premium applications.
Require Premium Visual Consistency?
Secure your supply of rigorously sorted, aesthetically superior sesame seeds for your manufacturing lines.