Growers, processors and packers of fresh, fresh-cut, canned, frozen and dried vegetables face many challenges including: guaranteeing food safety, protecting brand reputations, complying with product specifications, minimizing food waste and maximizing yields while protecting profitability.
“These challenges are intensifying because the market is changing. Increasing demand for both fresh and frozen vegetables - a trend accelerated by the COVID-19 pandemic - puts processors under more pressure to handle greater volumes at higher throughputs,” said Pieter Minner Sales Manager at TOMRA Food.
“Demand for organic foods - expected to rise by 50% in the next five years - means that more vegetables grown without pesticides or herbicides are arriving at processors mixed up with toxic weeds, vermin, and insects.”
Technical developments and innovations by TOMRA Food, mean their optical sorting machines have highly effective sorting solutions for all types of vegetable products: IQF, fresh pack and fresh-cut, canned, dehydrated, and freeze-dried.
“Our sorters also deliver a multitude of other benefits. They grade to specification, increase removal efficiency, minimize false rejects, reduce or eliminate the need for manual intervention, help solve labour problems (scarcity, cost, effectiveness, knowledge and training), reduce line downtime, and - through the TOMRA Insight cloud-based data platform - provide valuable data about the product sorted. Through all of these capabilities, sorters improve sustainability by cutting food waste while enhancing yields and profits.”
Pre-sorting for foreign materials and critical defects
TOMRA offers four different optical sorters for vegetable pre-sorting: the Sentinel II, Halo, TOMRA 3A, and TOMRA 5A. The TOMRA 3A is used mostly for unwashed potatoes and unpeeled onions.
“The Sentinel II combines TOMRA’s pulsed LED/sensor arrays with a simple user interface to remove a broad range of foreign materials, rodents, defects, discoloration, damage, and undersize product. The Sentinel II’s technical specification enables it to outperform competitors in sorting efficiency and sorting capacity. With three different sizes giving a wide capacity range, it’s ideal for seasonal and year-round processors.
“Also popular for pre-sorting many types of whole vegetables is the Halo, a high-performance machine that sorts according to size, shape and quality. The Halo uses top and bottom sensor banks to view each individual object in flight using a combination of LED, CCD camera, and near-infrared. This performs targeted spectroscopy to 1mm precision. The Halo is suitable for carrots, beets, and onions, as well as fresh pack carrots, parsnips, cucumbers, and gherkins. Depending on the application, the Halo increases yield by up to 4%, increases throughput by up to 25%, and reduces labour requirements by up to 80%.
“Another machine often used for pre-sorting, and even more efficient than the Sentinel II and Halo at removing foreign material, is the TOMRA 5A. This belt machine employs top and bottom sensor banks to view each individual object in flight using a combination of pulsed LED, camera and near-infrared. As with the Halo, targeted spectroscopy is precise to 1mm - achieving a superior foreign object removal rate of more than 98%. These high efficiencies, combined with low false reject rates, are often a key requirement to protect the cutters in the processing line.”
Sorting next for foreign materials and quality
The Genius, a belt sorter that is low-maintenance and easy to use, offers different technologies for different inspection zones: high-resolution cameras and lasers can be combined with fluorescent lighting or LED in one area and ultraviolet or infrared in another. This machine is typically used for sorting fresh-cut, blanched, or dried/dehydrated vegetables.
More sophisticated still is the TOMRA 5B. Also, a belt machine, this combines 360-degree surround view camera technology with advanced shape algorithms for object processing and laser technology. Capable of sorting according to colour, shape, structure, and biological elements such as chlorophyll and solanine, this sorter is ideal for the targeted identification of individual defects in high-volume production flows the TOMRA 5B is typically used for peas, carrots, green beans and spinach, as well as corn, and bell peppers; is capable of detecting and ejecting toxic weeds such as Datura and Nightshade from peas and green beans; and has an unrivalled ability to remove core from Iceberg lettuce
End-of-line quality checks
“When processing IQF vegetables, there is a final quality check to be made, either immediately after the freezing tunnel, on the mixing line, or just before the product is packed. This is an additional opportunity to find and remove unwanted materials that were just not visible or were missed when sorting before the product was frozen.
“For example, there might be remaining carrot slices or dices in the product stream with colour or shape defects. Or there might still be some Datura or Nightshade mixed in with frozen peas because these weeds are so similar in appearance to the acceptable product and sometimes only possible to detect with our BSI+ technology. Another example is that there can be small embedded stones present inside of soft diced vegetables like eggplant or zucchini.”
Three machines are typically assigned to handle these checks: the Ixus Bulk, Blizzard, and Nimbus BSI+.
On-the-ground and remote support
TOMRA’s sorting technologies are easy to operate and the company has built it’s success on a solid foundation of local-level customer support. This includes operational advice, machine operator training, machine maintenance, and emergency technical support.
“The advent of the COVID-19 pandemic, with its travel limitations and social distancing, has highlighted the value of TOMRA’s ability to complement on-the-ground support with remote assistance. One recently launched technology, TOMRA Visual Assist, is a good example of this. By using a smartphone app, a TOMRA field service engineer can provide detailed advice to a customer thousands of miles away, just as if they were standing right in front of the customer’s machine. TOMRA Visual Assist also allows customers and engineers to share documents or annotate images to explain and clarify directions.”
Another initiative proving helpful during these unusual times is TOMRA’s Online Demonstration Room. This makes it possible for processors to test-run TOMRA’s sorting (and peeling) machines - using their own infeed materials, or materials very similar to what they have to deal with - even if they are unable to visit a TOMRA Test and Demonstration Center in person. Tests are shown via a live video link, with the customer encouraged to ask questions and make requests, and all results are precisely quantified. Despite travel restrictions, customers can be certain of a machine’s capabilities before making a significant investment decision.