Contamination Challenges for Fruit and Vegetable Processors

Processors of fresh fruits and vegetables face some unique contamination challenges and understanding these difficulties can guide product inspection system selection. First let’s look at the fruit and vegetable market in general.

A Healthy Option for Consumers and Businesses

As folks read the many studies that have been published showing clear links between consumption of fresh foods and health, one can expect fruit and vegetable consumption to grow (no pun intended). The World Health Organization promotes an increase in fruit and vegetable consumption, a message echoed by many governments in campaigns such as the UK’s ‘5-a-day’ promotion which encourages people to eat a recommended amount of a variety of fruit and vegetables each day. One Food Business News article noted that consumers under the age of 40 have increased their annual intake of fresh vegetables by 52% over the last decade. (It’s also notable that despite these advisories there is still a low proportion of the global population eating the recommended amounts.)

One can conclude that healthy eating is a big market driver. According to Fitch Solutions – Global Food & Drink Report 2021, the fruit market is worth US $640 billion each year and is growing at 9.4% per year, the fastest growth rate of any food sub-segment. A growing global middle class that has been linked to high fruit consumption is also leading to an increase in the proportion of fruit consumed.

The global vegetable market is larger, worth US $900 billion, and growing more steadily but still above the average for the food market. Vegetables are seen as essentials — staple foods that form the bulk of many meals — but there is also an increase in non-meat and reduced meat diets. Vegetables, especially those high in protein, are becoming more important both in their natural state and in processed products, as a replacement for meat-based proteins. (Read Plant-Based Protein Suppliers Face Some of the Same Challenges as Meat Processors.)

Fruit and Vegetable Product Challenges

A booming market is good news for the food processors but there are systemic challenges that those in the fruit and vegetable supply chain must deal with:

Harvested crops need to be kept fresh and brought to market in good condition.
The products can be stressed (damaged or starting to break down) by a wide variety of factors such as temperature, the atmosphere around them, light, processing activities, microbial infestation.
There are many regulations that must be adhered to in transporting and storing fresh produce, and if not adhered to, products can be rejected by buyers.
There are labor shortages in the supply chain, certainly at picking but at later points all the way through to retail or food service.
Fruit and vegetable production is impacted by weather and climate change; extremes of heat, droughts, flooding can all change the viability of production in both the short and long term.
Contamination. Contamination events can be caused by:
- pathogens (such as ecoli or salmonella), or
- chemicals (such as cleaning chemicals or high concentrations of fertilizers), or
- foreign objects (metal or glass for example).

Let’s take a look more closely at this last item: physical contaminants.

Containing Physical Contaminants

Natural products present challenges in downstream handling. Farmed goods can have inherent contaminant risks, for example stones or small rocks can be picked up during harvesting and these can present a damage risk to processing equipment and, unless detected and removed, a safety risk to consumers.

As the food moves into the processing and packaging facility, there is potential for more foreign physical contaminants. Fruit & vegetable processing machinery can break down and wear out over time. As a result, sometimes small pieces of that machinery can end up in a product or package. Metal and plastic contaminants can be accidentally introduced in the form of nuts, bolts and washers, or pieces that have broken off from mesh screens and filters. Other contaminants are glass shards resulting from broken or damaged jars and even wood from the pallets used to move goods around the factory.

Manufacturers can protect against such risk by inspecting incoming materials and auditing suppliers to ensure quality at the beginning of the process, and then inspecting products after each major processing step and at the end of production before products are shipped.

As well as accidental contamination, through processing steps or from harvesting, there exists the need to protect against deliberate, malicious contamination. The most famous recent example of this was in Australia in 2018 where a disgruntled farm worker placed sewing needles in strawberries, risking serious harm to consumers that whilst bad was thankfully was not worse than hospitalization.

The sheer variety of the different fruits and vegetables grown is another challenge that processors must be aware. But even within a single product type there can be a large amount of variability in size or shape that will affect the capabilities of food inspection equipment.

Finally, the package design must match the attributes of the food and be suitable to get it to its end destination in the best condition possible. For example, some products are delicate and require protection from damage in handling and shipping. Inspection after packaging offers the final chance to inspect finished products for safety and quality before they leave the control of the processor.

Food Safety Processes and Technologies

Food Safety processes need to be robust to respond to such potential challenges. Food manufacturers must remember that these events can happen anywhere from the growing phase through processing to retail sale. Prevention can help in some cases, e.g. tamper proof seals on packaged products. And detection can be implemented to detect the contaminant before it reaches the consumer.

There are food X-ray detection and inspection systems that are utilized to help find glass, rocks, bones or plastic pieces. X-ray inspection systems are based on the density of the product and the contaminant. As an X-ray penetrates a food product, it loses some of its energy. A dense area, such as a contaminant, will reduce the energy even further. As the X-ray exits the product, it reaches a sensor. The sensor then converts the energy signal into an image of the interior of the food product. Foreign matter appears as a darker shade of grey and helps identify foreign contaminants.

If your main concern is metal, wires, or mesh screen contamination in small, dry products, then you should choose a metal detector. Metal detectors use high frequency radio signals to detect the presence of metal in food or other products. The newest multiscan metal detectors are capable of scanning up to five user-selectable frequencies running at a time, offering one of the highest probability of finding ferrous, non-ferrous, and stainless steel metal contaminants.

A food checkweigher is equipment used for reliable weight control to check and confirm that the weight of food goods inline or after packaging during final inspection against a predefined weight limit specified on the package. They can also count and reject for a seamless quality control solution even in rugged plant environments. This can help minimize waste, prevent errors, and reduce the risk of regulatory non-compliance — guarding against incorrect labelling.

Summary

Fruit and vegetable processors face significant challenges in getting their fresh products into consumer hands. From inspection of foods received from farms to monitoring for broken pieces of equipment during production, to verifying packages before they are shipped out the door, food weighing and inspection technologies can help fruit and vegetable processors meet consumer expectations as well as the growing global demand.

And in case you were wondering, bananas and potatoes are the best-selling fruits and vegetables respectively. And another strong seller, tomatoes, are botanically a fruit but politically and culinarily are classed as a vegetable!