Product inspection and sorting of nuts, dried vegetables and dried fruit

Across the globe, the trend towards discerning customers who demand top-quality food is growing. For manufacturers of nuts, dried vegetables and dried fruit, it is essential to detect and eliminate contaminants, impurities and quality issues. Thanks to a wide range of different detection technologies, our systems can efficiently and reliably live up to this task.

For decades, Sesotec has specialised in systems for industrial materials sorting and contaminant detection. We provide a technologically perfected range of optical food-sorting systems, metal detectors and X-ray systems for the reliable detection and automatic removal of contaminants and products that do not meet strict quality standards. Our machines and systems of course comply with the special hygienic requirements of the food industry and meet the prescribed standards for audits.

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over 40 years of experience and reliability

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Long-term reliability for spare part supply

More detailed information

Why is product inspection and sorting important with regard to nuts, dried vegetables and dried fruit?

Rising incomes and changing eating habits are creating ever-higher demand for quality among consumers. Accordingly, the demands placed by increasingly globalised food brands and retailers on suppliers are growing as well. As a result, quality issues and contaminants – from discolouration to metal filings – pose an increasing risk to a company’s sales and reputation. The only way to counteract these concerns effectively and efficiently is with assistance from automatic product inspection and sorting systems.

What are the advantages of automatic systems?

Compared to sorting products by hand, machine-based systems are able to sort out and eliminate contaminants and impurities with much greater precision and consistency. Sesotec systems stand out here for their excellent quality. Thanks to their high capacity level, reliability and low operating costs (energy consumption, wear parts), they amortise quickly. In addition, they help optimise downstream processes, for example by protecting processing machines from damage caused by contaminants. Finally, our systems follow the plug-and-play principle. As a result, they are extremely user-friendly, which is a great benefit to operating staff.

What kinds of contaminants could appear?

The following are examples of contaminants that could enter the products during harvest, transport to storage, subsequent processing steps or through careless staff:

  • Stones
  • Metal
  • Glass
  • Husks/hulls
  • Pits
  • Wood
  • Pellets
  • Blades of grass
  • Septa (dividing walls of walnuts)


What other kinds of quality issues could occur?

Apart from contaminants, it is necessary to prevent other forms of contamination and flaws in appearance, such as the following:

  • Fungal toxins due to mouldy products (aflatoxins, mycotoxins)
  • Over-roasting
  • Rotten products
  • Discolouration
  • Chip and scratch (damage caused by processing)


What products are inspected and sorted?

Our sorting systems are used for a wide range of applications, such as for sorting the following:

  • Almonds
  • Hazelnuts
  • Walnuts
  • Ground nuts
  • Cashews
  • Peanuts
  • Macadamia nuts
  • Pecans
  • Pistachios
  • Apple chips
  • Banana chips
  • Apricots
  • Cranberries
  • Dates
  • Figs
  • Cherries
  • Plums
  • Raisins
  • Beans
  • Peas
  • Lentils
  • Corn

What kinds of technology are used?

Metal detection and X-ray inspection

Nuts, dried vegetables and dried fruit can be inspected loose as bulk goods. For this particular application, Sesotec offers what are known as free-fall metal detectors. Fed in through pipes, the products undergo inspection and the systems reliably separate out metal contaminants from the bulk goods through reject flaps. Metal detectors are also used with conveyor belts, in addition to X-ray inspection machines in particular for already packaged products. As part of the final check, products are inspected for metal and other contaminants to ensure optimum quality before being shipped out.

Sorting technologies

Colour, ultraviolet and infrared wavelengths, dimensions and thickness are key criteria used to distinguish nuts, dried vegetables and dried fruit from one another and from contaminants for safe sorting. Depending on the specific application, our systems can be equipped with the following detection technologies:

  • Colour analysis using grey tones (monochrome camera) or a means similar to the human eye (true-colour camera)
  • Shape recognition (analysis of geometrical shapes)
  • Multispectral technology (including the use of UV and IR radiation, which helps with the recognition of materials, such as glass and stones)

Thanks to our many years of experience with materials sorting and contaminant detection, we cover the entire range of technology with proficiency and professionalism. Based on our modular designs, we can find a tailored, economical solution for your particular need. Simply contact us − we would be happy to advise you!


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