Taking advantage of optical sorting machines for spices and dried chili with TORMA food Equipment

Although India leads the world in exporting spices and dried chili, producing these crops in great quantities can no longer guarantee international sales success. Great quality is also necessary, now more than ever before. To retain their leadership position, Indian businesses must maintain high quantities while also efficiently removing foreign materials to satisfy increasingly stringent global standards.

One reason for this is that increasing numbers of consumers around the world now expect food products to be perfect every time. If shoppers find serious fault with the food they buy and complain about it on social media platforms, their criticisms can reach enough people to damage brand reputations.

Another reason is food regulations defining maximum permissible levels of pesticide residues, mycotoxins, heavy metals, microbiological organisms, and additives. These rules are already so strict in some nations that products, including dried chili spices, sometimes get turned back from export destinations at the point of entry. Even where food regulations are not so strict, they are expected to get tougher in the future.

The good news is that other sectors of the food industry have faced such challenges and overcome them. One of the most effective solutions is to replace manual sorting methods with optical sorting machines. Whereas manual sorting is unavoidably subjective, imperfect, and especially vulnerable to error when laborers are tired or bored, automated sorters can work hour after hour with superior accuracy, consistent standards, and unflagging efficiency. Switching to automation requires investment, of course, but it pays back handsomely by delivering greater throughputs and consistently higher product quality.

This brings us to more good news: the industry leader in designing and manufacturing sorting and grading technologies, TOMRA Food, recently made new sorting applications available for spices and dried chili. What’s more, these applications were fine-tuned here in India, at TOMRA’s Test Center in Bangalore and on the premises of a small number of spice and chili producers in Kerala, Madhya Pradesh, Gujarat, and Andhra Pradesh.

These extensive validation tests led to impressive results. The two key objectives, ensuring food safety and consistently high product quality, were convincingly achieved. In the words of one of India’s earliest adopters of this technology, Mr. Amit Singhal of DKC Tradex Private Limited: “We had been using conventional sorting machines in our spices and herbs business for quite some time and had some challenges in pushing our limits. Now, with our new TOMRA machine, we see excellent results on our final product and our end customers are also very happy with these results.”

Another early adopter of TOMRA’s technologies is the leading coriander processor in India. The owner and Managing Director of P.C. Kannan & Co, Mr. P.C.K. Maheswaran explains: “The Indian spices industry is shifting from traditional manufacturing methods to global food safety and hygiene standards. With the right investments, we believe that we will be able to satisfy our end customer market requirements. Higher technology machines will help in improving the quality of the product at the same time as minimizing wastage. TOMRA sorting machines are high-quality equipment that helps in solving industry issues. We have seen the improvement in end products and are happy to partner with TOMRA.”  
   
And there’s more: in addition to acting as guardians of food safety and product quality, TOMRA’s state-of-the-art sorting machines can also grade to specification, reduce line downtime, cut food waste by minimizing false rejects, and enhance profitability by maximizing yields.

How sorters see
Even though TOMRA’s spices and chili application is relatively new, the company’s expertise is founded on decades of experience. To date, TOMRA has installed more than 12,800 units around the world to optimize capabilities and reduce waste in the processing of fruits, nuts, vegetables, potato products, dried fruit, meat, seafood, and some types of grains and seeds. 

When TOMRA’s sorting machines look for foreign materials and product defects, they inspect the processing line’s material stream with one or more detection technologies: high-resolution color cameras, lasers, near-infrared sensors, and biometric signature identification software. These are able to assess objects on the line according to their color, size, shape, and even their structure and internal characteristics. 

In the instant after the sorting machine inspects materials, air jets precisely separate unwanted and wanted products into ‘eject’ and ‘accept’ streams. Ejected materials are either discarded or sent along another line to be sorted again; accepted materials continue along the line toward packaging. Whether the product is sent through the sorting machine one, two, or three times, and what’s most likely to be removed by the sorter on each of these occasions depends on the type of food being processed. So, let’s take a brief look at the processes for dried chili and spices.

Finding foreign materials and product defects
The biggest nuisance crushed chili processors have to deal with is stems. If just one of these gets all the way down the line and packaged with the final product, it can spoil the consumer’s eating experience, tarnish their opinion of the brand that sold the product, and worse still, perhaps pose a choking hazard. Other threats to food safety include foreign materials that get mixed up with the crop during harvesting, such as stones and rat excreta, and materials that fall onto the processing line, such as fragments from workers’ glass bangles. It’s simply not possible for the human eye to see all of these unwanted materials when they’re mixed into the product stream, but that’s no excuse: for the sake of food safety, they must be removed.

At the same time that the sorting machine looks for foreign materials, it also detects and ejects defective product. With dried chili, this typically means removing product with discolorations. Another common defect is cross-contamination of one type of product with another. Again, these things are difficult to detect manually but essential to remove: export markets strictly require packets of food to contain only what’s named on the label listing ingredients.

When processing spices, the sorting machine is located some way down the line. Before the spices reach this point, they will have passed through a pre-cleaning machine to remove dust and heavier impurities such as sticks, stones, and plastic bags and threads; through a finer cleaning machine to remove smaller foreign materials; and through a gravity-separator which divides light and dense product. Then it’s the sorter’s job to detect and eject any remaining foreign materials (likely by this stage to be very small) and discolored products. After this, the rejected product is sent through a sorter once again - a two-step process that minimizes food waste by ensuring that no good materials get discarded.

Cameras, lasers, and seeing beyond the surface 
The optical sorting machine best suited to dried chili and spices is the TOMRA 3C, which is also very effective at sorting grains, beans, pulses, and nuts. This is an affordable and compact piece of equipment that doesn’t need much floor space and is loved by operators for its easy, intuitive user interface. It works by pouring infeed materials into a hopper, then sends the feed falling onto a vibration plate, where it is spread evenly on an infeed chute. Then the materials fall further into a detection area, where a dual laser and double-sided cameras inspect them. In a matter of milliseconds, the intelligent inspection system rejects all defects. The acceptable products continue through the accept chute, while the flaws are diverted via the reject chute.

The TOMRA 3C’s state-of-the-art technologies result in numerous advantages. The dual laser-induced scattering results in superior glass and foreign material removal; the double-sided RGB cameras, combined with high intensity LED lighting, remove the subtlest color and shape defects; the high-speed ejection valve, with direct nozzle connection, results in an exceptionally low rate of false rejects; intelligent auto-cleaning sustains the machine’s optimum performance; and the control interface, with a large touch screen showing application-specific tuning parameters, is easy for operators to use. A further potential benefit of TOMRA’s sorting technologies is their unique ability to detect and reject food products contaminated with aflatoxin. This capability is already being put to good use in the nut industry, by using a specialized Biometric Signature Identification (BSI) scanner with TOMRA’s Nimbus sorting platform, and is now under development for other applications, including dried chili and spices. This could open the door for more Indian businesses to the potentially lucrative European market, where the presence of mycotoxins (aflatoxins and ochratoxin A) is the main reason why dried chilies get refused market entry. When this technology is signed-off for spices and dried chili, we’ll let you know!  

Test and Demonstration Center
To ensure that operators extract the full potential of their machines, TOMRA provides on-site training for customers and makes technical experts accessible via a helpline. And with the recently-launched smartphone app TOMRA Visual Assist, TOMRA field service engineers and customers can work closely together even when they are thousands of miles apart. The engineer can provide detailed advice just as if standing right in front of the customer’s machine. Both the engineer and the customer can share documents or annotate images to clarify and explain directions.

Before getting to this stage, food producers are welcome to try out TOMRA’s machines with their own infeed materials at TOMRA’s Test and Demonstration Center in Yelahanka New Town, Bangalore. And since the advent of the COVID-19 pandemic, TOMRA has also offered an Online Demonstration Room facility. This shows tests via video link, with viewers encouraged to ask questions, make requests, and direct one of the cameras showing the proceedings. After the test’s conclusion, observers are provided with a report which quantifies results in precise detail.

This means that seed and chili processors can be certain of the machine’s capabilities without having to visit a Test Center in person and before deciding whether to invest in the technology. It’s an investment that pays back in many ways, not least by opening new doors to markets that demand high product standards and protecting that most valuable of all business assets, brand reputation.