Better processing to reduce food waste streams
Processors can uncover hidden value in recovering waste
The world faces a food waste epidemic. Approximately one-third of the food supply produced for human consumption worldwide is lost or wasted. With a world population expected to reach 9.7 billion in 2050, global food production will need to increase an estimated 60 percent to feed the planet. Food manufacturers can better manage food waste with smarter, more efficient processing. They may also find new profits.
How food is wasted in manufacturing
In food manufacturing, 32.4 percent of all food waste is due to production issues. A top concern for food manufacturers is always pathogen contamination. Production lines are under strict scrutiny to produce food-safe products, and any product that could be suspect has to be removed. This rejected product can add up to large amounts of waste.
A well-designed and -installed processing operation may be able to salvage product scrap by re-introducing it, but a poorly designed line might not. Product that is allowed to fall to the floor is instantly discarded, because it cannot be reworked into processing. In rice production, for instance, maintaining the whole kernel is most desirable and profitable. Full kernels are sorted based on quality, and broken kernels are rejected. In cereal manufacturing, broken kernels will not process well, and this can lead to the final cereal product being out of spec.
Mislabeled product also contributes to food waste. In 2015, there were 193 recalls, withdrawals and safety alerts due to undeclared ingredients in the US. Recalls can put a financial strain on a company, and the only upside is potentially to salvage the product by finding a way to rework it. If rework is not possible because of process line restrictions, then this food becomes waste. Sometimes product can be used in animal nutrition. The guidelines for food consumed by animals are strict but not as strict as that for human nutrition.
Key challenges and areas for improvement
Transportation is one of the biggest challenges when it comes to food waste, because a lot of product can be lost due to spillage. This product cannot be recovered. If proper restraints are put in place, lost product can be minimized. Time in transit plays a substantial role in the life of a product, especially fruits and vegetables. Having a climate-controlled mode of transit is beneficial for products that already have a very limited shelf life. If the transportation system is not controlled, there is a possibility of infestation, spoilage and reduced shelf life.
Having employees who are knowledgeable of the production process is essential to managing food waste. It is often easier to dump product when in doubt than to go through the proper parameters to keep it in spec. If product must be removed from the production process, employees should be aware of what can be done with the discarded product to reduce the amount of waste. This could make the difference between product being reworked, used for animal feed, or sent to the landfill.
The flexibility of a production line is important when it comes to rework. If product is deemed out of spec, there should be a re-introduction area if rework is possible. Unfortunately, many lines are not designed with this in mind. Typically, reworked product is hand fed, and this is labor intensive. Typical rework and recall history should be considered when re-introducing product. A production line is product specific and so are the methods for rework. If an out-of-spec product is high in moisture, then a particular drying process may be needed. If a consequence of production is dust accumulation, then an extrusion process may be a better option. If a product needs to be remade, then a mill could potentially be used. As we said, a production line is product specific, and so will be the re-introduction of product and from whence it came.
Running multiple products on the same production line can also pose challenges during changeovers. There is typically a lot of out-of-spec product during this time due to adjusting parameters for the next recipe. Recipe presets and equipment instrumentation help take the guessing out of the changeover of products. The ability to have one-button, change-all parameters is faster than guessing what temperatures, bed depths, or fan speeds were run previously. This type of automation reduces time and loss of product during recipe changeover.
Solutions that can help reduce food waste
The challenge for the food industry is to tap its immense creative capacity to reengineer waste in food production, in both the developing and the industrialized world. Re-engineering food processes can minimize losses, turn waste by-products into profit and introduce a new dimension of product value.
Extrusion is a process where mixed ingredients are forced through a die to form a certain shape, using heat and pressure. Products that create dust or fines as a byproduct have the opportunity to be extruded to form additional products or be reintroduced to the original process. Many food manufacturers already use an extruder in their process. An example would be the extrusion of inferior quality wheat flour—not suitable for bakery applications—which could be extruded and converted to pre-gelatinized wheat flour, a high demand and higher value product. Other industries that use extrusion for rework include: pasta, snack foods and RTE cereals in human nutrition, and petfood and aqua feed in animal nutrition.
Drying is the use of time and temperature to reduce moisture, increase shelf life and potentially combat pathogens. Studies have shown that under certain time/temperature conditions, certain pathogens can be reduced. Products that have tested positive for microbial contamination have limited options for rework. A product may not be acceptable for human nutrition, but it may be acceptable for animal nutrition. Typically, contaminated products are sent to the landfill. But if contaminated products are processed to remove pathogens and validated, they could potentially be used for animal nutrition. Drying is a process that uses heat and mass transferred between the air and the product. A validated dryer has been shown to reduce pathogen numbers by five logs. Depending on the initial contamination number, this reduction can be reused for animal nutrition or feed.
Broken rice kernels, as a whole, are aesthetically undesirable, but can be converted into a high value product. Rice flour is one example. It can be used to make many Asian products such as rice noodles, Indian flat bread, and desserts. The most endearing trait of rice flour is that it is gluten free, making it a substitute for wheat flour. The process for making rice flour involves milling the broken kernels. If rice noodles are the desired product, the flour can be extruded to form the noodles. Another example: 10 percent of all long goods pasta is unpackaged due to trimmings made from its manufacture. This pasta can be used in a regrinding process where it is introduced in the processing line as an ingredient. Having the ability to use what was once thought of as waste is essential in reducing food waste.
Reconstituted rice can be made from broken rice kernels and rice dust, both of which are a consequence of rice milling. Through extrusion, reconstituted rice can be fortified with vitamins and minerals to increase nutritional value. This adds value to the final product. The processing of reconstituted rice uses milling, extruding, and drying, but due to high demand, can be worth the investment if you have access to rice dust or broken rice kernels.
Reversing the trend, creative capacity of the food industry
If there is anything positive about the trending scale of global food waste, it is that the food industry has a tremendous opportunity to make sustainable improvements that will also generate new profits. Capturing this potential will go a long way toward addressing the growing concerns about feeding the world’s populations. Food manufacturers must first identify where food waste and food loss occurs; then, combine the creativity of the food industry with emerging processing solutions to convert waste into value-added products.
About the author:
Dvijal Patel is a field engineer and food technologist at Bühler Aeroglide, where he works with customers to research and develop new products, design the most efficient thermal processes that can be scaled for volume production, and maximize existing processes through system evaluations and staff training.
Use big data analytics to improve the process, reduce waste
Earlier this year Bühler Aeroglide introduced a new customer-partnership approach that uses big data flows to reach improved levels of efficiency, and at the same time, lowering the amount of scrap that a process produces. The company’s new Digital Services Group is using IIoT connectivity to give operators and managers the ability to make process decisions with confidence.
“Bühler’s Digital Services Group brings another dimension to our partnerships with customers,” says Paul McKeithan, head of Digital Services. “We’re going one step further, after engineering a pilot process, scaling it for mass production, and manufacturing and commissioning a technology solution. Access to data analytics from full time, real-time process monitoring means we can help customers make better decisions. We can help them act on information quickly and effectively, in ways that impact every aspect of business.”
With data analytics that track and measure operational success, processors can make real-time business decisions that have an impact on the bottom line. Required changes to the process can be immediate, saving valuable time needed for manual testing, while increasing, for example, a dryer’s yield. Even the smallest percentage gain can increase profitability. A real-time management that achieves a net increase of just one percent in finished moisture can result in a ROI increase of $300,000. This translates into an energy savings valued at $20,000 per year, says McKeithan.
—By Wayne Labs
For more information: www.buhlergroup.com/drying.