Making a machine that is technologically up to date isn’t always an easy task, and the amount of labor that goes into studying and designing each component may often be rather substantial. However, manufacturers’ expectations continue to rise, and as a result, technology suppliers are required to come up with novel solutions daily. This transforms what was previously a selling feature into an essential prerequisite.
When selecting a sorting machine for a frozen food processing plant, the first consideration is what unwanted materials or product defects you need the machine to detect and eject. Some of these might be difficult to detect, and sorting machines differ greatly in their ‘seeing’ ability, according to Jacob Hobbel, TOMRA Food’s global category director for vegetables and fruit. Another consideration is the sorter’s ability to minimize food waste and maximize yields, he explains. “Will the machine work with a low level of false rejects, removing unwanted materials without also removing too much that’s saleable? Machine performance also differs in this respect. Yet another consideration is downtime. The sorter needs to be easy to operate, easy to set-up when switching from one type of food to another, easy to clean, and reliable. It must work well in the tough conditions found in IQF environments, in temperatures can be as cold as -30°C and as hot as 50°C. If a problem should occur, the machine user needs to know the manufacturer will quickly provide technical back-up, whether that’s remotely or by getting a technician on site.” One more factor to consider is futureproofing, Hobbel explains.
“Selecting a sorting machine is not only about current needs, but also what it will take to stay competitive in the future. As we move into an era of digital transformation, sorting machines with Artificial Intelligence will deliver advantages, as will machines which produce usable data.” For example, connectivity to the TOMRA Insight customer portal and cloud-based data platform can show operators live data which enables them to make line efficiencies almost instantly. This data can also ensure that when frozen vegetable products are mixed, each bag is packed with exactly the right mix. And by accessing data retrospectively it’s possible to quantify the standards of raw materials from suppliers and to make better-informed business decisions. Sorting plays a vital role in ensuring the quality and consistency of frozen produce, he points out, as sorters are essential for ensuring the product consistently meets the required quality specifications. This is achieved by removing foreign materials and defective product according to shape, color, and structure.
Still, sorting frozen produce is particularly challenging, compared to fresh produce, because the production process requires multiple sorting interventions. Specifically: presorting to remove foreign materials when raw materials are accepted; sorting just before or after the freezing tunnel on color and shape; and sorting again at the packaging stage to remove any remaining foreign material. “Because profit margins with frozen produce are low, sorting must be very efficient and effective, to maximize yield and minimize food loss and downtime. Sorting solutions also need to be flexible and easy to set up for different types of product, because the same production and packing line will typically process multiple applications,” Jacob Hobbel says. “To meet these challenges more effectively than any other solution available, last year we launched the TOMRA 5C premium sorting machine for frozen vegetables (mono and mixed). By using TOMRA Food’s unique biometric signature identification (BSI) technology, this assesses every object passing down the line not only for its color and shape, but also biological characteristics. The TOMRA 5C is located on the processing line between the IQF tunnel and the packing station, to make final checks for food safety and product quality with unrivalled accuracy. The sorter recognizes and removes any remaining foreign material, extraneous vegetable matter (EVM), and hard-to-detect product defects such as stems and stalks with green beans and nightshade with peas.”
Recent trends on the frozen vegetables and fruit market
“Consumers all over the world are getting fussier about the quality of food they buy,” according to TOMRA Food’s Global Category Director for Vegetables and Fruit. “They want food that’s healthy, safe, tasty, and conveniently easy to prepare. This means that the customers of food processors are getting more demanding about their product specifications. Consumers are also becoming increasingly conscious of our planet’s fragile environment and the need for sustainability. This, too, is changing the expectations of the retailers who buy from producers. There’s increasing pressure to grow and produce frozen vegetables and fruit with the smallest possible ecological footprint by reducing food waste and energy consumption.”
One consequence of environmental awareness is the increasing popularity of organic foods and the reduction in the use of chemicals for growing, he goes on to say. But organically-grown fruit and vegetables typically get delivered to processing lines containing more unwanted materials including the poisonous datura and nightshade weeds. Another advantage of the TOMRA 5C is that’s best-in-class at sorting out these weeds, even the hard-to-see datura without spikes. Regarding food waste, the best sorters minimize false rejects, so less good-in-bad gets taken off the line. “Two-way and three-way sorting also allows reject streams to be reused for other purposes, such as animal feed or pastes. This is good for food processors’ profits and for the planet,” Jacob Hobbel concludes.
Identifying the Challenges is Paramount
When considering a sorter, it’s important to identify the challenges you want to solve and the quality you want to achieve. Generally, for frozen food, the sorter needs to have sufficient technology to increase your yield and your quality, explains Stephen Jacobs, Bühler’s head of segment fruit & veg. “Beyond this, I also think it is important to look at the wider company, the customer experience, the history, and the locations when deciding upon a sorter.” The sorter can look at every individual piece of produce, and depending on set parameters, examine whether this individual piece is acceptable or unacceptable. In early stages, batches of produce can contain different types of defects and foreign material, this can include EVM, stones, wood, plastic, mold, color defects or even misshapen produce. Simply, the sorter will eliminate all produce that isn’t of acceptable standard, providing uniformity and safety to frozen food.”
But what are some of the challenges involved in sorting frozen produce, and how can they be addressed? The challenges can be logistical, for example, ensuring the machine is in the right location with the right space, and making sure that the product is brought to the machine in a way that can feed it efficiently, Stephen Jacobs. Other challenges can involve problems in the process line such as blocked ice chunks and clumped product etc. Sorters with high levels of connectivity, for example, the new SORTEX range, can alert processors of any blockages in the process line, ensuring that the problem is solved without much waste. “For sorting, the trend is towards zero tolerance for foreign material, as well as uniformity in shape and size,” Bühler’s Head of Segment Fruit & Veg says. “Customer expectation for high-quality produce (not just in freshness but also in how it looks) is at an all-time high. Even buying lower-cost produce, customers still want the quality to be as high as if from a premium marketplace. For this reason, sorting is essential to meet market needs.”
In terms of reducing food waste, due to the sorter looking at every individual piece of produce, “we can remove only the individual defect, instead of throwing away the whole batch. On top of this, with the latest technology in connectivity, processors are immediately alerted to issues in the process line, allowing them to fix problems before too much wastage has occurred,” Stephen Jacobs adds.
To read the entire article, please access your complimentary e-copy of Frozen Food Europe March-April, 2023 issue here.