Post-Harvest Leafy Green Processing & Packaging
Post-harvest infeed and automated processing through case packing
Leafy vegetable washer with water recapture and recycling, plus kill step options
Multiple non-wilting dryer / de-watering options
Our leafy green washing and vibratory de-watering systems have been in market for some time. Over the last year or so, more have asked us to further remove post-harvest labor and reduce human touches to help efficiently scale operations and mWe have solutions for leafy greens from brassicas to lettuce to migrgreensitigate contamination and recalls. Also, automation helps in traceability measures.
In response, we’ve integrated additional technologies into our portfolio. Our lines reduce labor and physical interaction all the way from post-harvest through case packing. This includes infeed, washing, drying / de-watering, cutting, clamshell fillers, vertical baggers and flow wrappers, metal detectors and case packing, with some robotic functions.
Automated leafy greens packing line
We have added additional automation options to our leafy green line package. These lines and equipment include options for head lettuce, leafy greens and microgreens.
Line infeed and regulation for leafy greens
Part of this is due to requests from vertical and hydroponic leafy green growers, on top of traditional field growers. Plenty of controlled environment facilities automate growing operations, yet a significant amount still rely on manual harvesting and post-harvest processing. By applying our solutions, a crew of 25 or more can often be reduced to 2, depending on scale. Additionally, many of facilities realize that, regardless of the growing environment, there is still a need to properly wash and dry product. These customers stress the importance of reducing water consumption, not only during the growing process, but during post-harvest functions.
Today, traditional, vertical and hydroponic all have rapidly evolving needs, so we have added tumbling drums, water capture and recirculation options to several of our washers, including our leafy green models. This complete washing system, even though it is relatively compact, gently washes leafy products, filters out and removes waste and can cycle used water through particulate filters, dosing and/or additive enrichment processes in a closed system. All of these functions are tightly integrated and controlled as a holistic system.
De-watering shaker for fruits and vegetables after washing
In many traditional lines, vibratory de-watering shakers or centrifuge dryers are utilized. However, the ProEx Food R&D group has a new cooling and drying system in development. We recognize a need to help manage the effects of environmental temperature and humidity fluctuations on the end product. Some processors have also requested lines that further reduce moisture at this stage, beyond typical market offerings. Combined, our Cool Dry System addresses these needs and reduces wilting and spoilage – extending the shelf life for lettuce heads and bagged greens.
PACKING OF LEAFY GREENS FOR SUPERMARKETS: New look packaging for leafy greens grower
WP Rawl, a grower, processor and shipper of leafy greens based in South Carolina, will unveil a fresh new look to their leafy greens packaging at this year’s Southern Exposure in Orlando, Florida.
The complete line of conventional, triple-washed and ready to use leafy greens are “turning over a fresh new leaf” with a packaging refresh. The traditional Nature’s Greens brand’s colors and nutritional information call outs remain the core attributes on pack while also adding a fresh new twist, the company said.
The product line consisting of collard, kale, mustard, turnip and a greens blend will now include illustrations of each products leaf design. Each leaf is positioned vertically on the package to simulate how the produce grows up from the ground. The chopped and bagged leafy greens fill in the color of the leaves from inside the bag.
“As the leafy greens guide in the produce industry, we pride ourselves in continuing to invest in the leafy greens category by staying in tune with trends,” said Ashley Rawl, vice president of sales, marketing and product development. “With a fresh new look and creative modern design, we are excited to draw in new consumers to the leafy greens category.”
PACKING LEAFY GREENS: Keeping leafy greens fresh and healthy an exact science
It might not seem that impressive today, but the fact that fresh leafy greens are available all across America at any time of year is quite remarkable.
Considering that California and Arizona produce more than 90% of U.S. lettuce, if you live anywhere east of these two states, the leafy greens on your plate have traveled a long way to get there.
So how is it that they look as if they were harvested from a nearby garden just this morning? The short answer is cooperation and the right technology: Equilibrium Modified Atmosphere Packaging, or EMAP.
Equilibrium modified atmosphere packaging is technology that slows respiration and extends the shelf life of fresh produce. Unlike most food products, fresh fruits and vegetables continue to “breathe” or respire after they have been harvested. Through this process, produce consumes oxygen, creating carbon dioxide and water vapor in the process.
The primary purpose of EMAP is to keep packaged products fresh for as long as possible without harming product quality, including taste, texture and appearance, said David Bell, president of Witt Gas Controls. Witt Gas Controls manufactures equipment for gas mixing and analysis and leak detection.
“In general, the rate of respiration can be controlled by having lower levels of oxygen — usually less than 5% — in the packaging atmosphere, and increased levels of carbon dioxide, normally around 5-15%, with the balance gas being nitrogen,” said Bell.
This is not as simple as it sounds. To meet and continue to control the gas mix in the package, the process exchanges “air” made up of 79% nitrogen and 21% oxygen. If there’s too little oxygen in the packaging atmosphere, anaerobic respiration occurs. This process causes unwanted tastes and odors, and results in product deterioration. On the other hand, too much carbon dioxide can damage some products. Nitrogen itself has no effect on the food product.
EMAP works best when the right packaging material is used and properly sealed to prevent leaks. Permeability and breathability are important qualities in packaging, especially for leafy greens.
“If the products are sealed in an airtight package, oxygen will soon become depleted and undesirable anaerobic conditions could develop,” Bell explained. “On the other hand, if the material is too porous, the modified atmosphere will escape and no benefit will be derived.”
The target is to reach the desired range by verifying, controlling and monitoring the environment inside the package. Correct EMAP can extend shelf life up to 100%, Bell said.
Leak-Master Pro 2
Witt Gas showcased several new pieces of equipment suitable for modified atmosphere packaging at Fruit Logistica 2020. Packagers of leafy greens and other fresh produce may want to check out Oxybeam, a new non-destructive gas analyzer that uses laser technology to determine the residual oxygen in packaged food. The company also considers Leak-Master Pro 2 an essential component for quality assurance. The package leak detector is based on CO2 technology.
But, like Bell said, the success of the technology is also dependent on packaging. Companies like Coveris produce films suitable for products that require gas flushing, as well as products that don’t.
Work has been done to better understand optimal head space for leafy greens and how fast different leafy greens respire, said Eric Duncan, Head of Food Science, Coveris.
Leafy greens respire slower than other produce, which means they require assistance in reaching the optimum headspace. This includes a fine balance of proper packaging permeability and active gas flushing. In dark leafy greens like spinach, for instance, natural respiration leads to yellowing of the leaves, which leads to food waste. In pale-colored lettuces like iceberg and Romaine, too much oxygen can cause the greens to turn pink.
“What we do is we combine the correct permeability of film with a gas flush,” said Duncan. “And that will allow us to instantly reduce the oxygen to prevent yellowing and pinking, and instantly increase the carbon dioxide.”
“It’s still just the natural respiratory gases — oxygen and carbon dioxide — that we use in the gas flush, it’s just that the gas flush gets the head space to those optimal levels very quickly,” said Duncan.
While Coveris can be contacted individually for packaging solutions, when launching a new product Duncan said it’s best if equipment suppliers work together as a project management team. Ideally, that team would include the packaging supplier, the gas flushing equipment manufacturer and sealer equipment providers. For the latter, Duncan mentioned Proseal.
“It makes communication a lot better for us to have a team of technical service engineers that work closely with packaging suppliers, like Proseal, that understand what the sealing requirements are,” said Duncan, pointing to potential compatibility issues that can arise without cooperation.
Together, that team evaluates everything from line speed to temperature requirements for sealing to product respiration rates. For the latter, it helps to have the right equipment on site for testing, he said.
“The Witt mixers are really nice because they allow you to change the composition of O2 and CO2,” said Duncan.
Proseal manufactures machinery that seals films like those supplied by Coveris to a flexible tray. It also applies the pre-mixed gas necessary to modify the atmosphere within the package before sealing.
Tray sealing technology offers advantages to retailers, especially in the current crisis. Top seal packaging is secure, food-safe and tamper-evident, and it allows for modified atmosphere packaging.
“Current packaging for leafy greens is a rigid bottom with a rigid lid,” said Anna Leigh Prochaska, sales associate at Proseal. “You can’t modify the atmosphere with a rigid lid. You have to have that film seal.”
Using film seals allows customers to see if packaging has been tampered with prior to purchase as well, she said.
“We’ve seen a lot of interest from customers because they want that food safety element,” she added.
Prochaska reiterated Duncan’s comment on the importance of working together as a product management team.
“Once our customer has decided what they want, we work with their chosen film and tray suppliers to give them exactly what they want,” she said. “It’s important that all of those parties are brought together in the initial conversations. The customer has to be very involved in the process as well, because they know their product better than anyone else.”
PACKING OF LEAFY GREENS AND TENDER LEAFY GREENS
Industry researchers say traceability comes down to label codes
By News Desk on December 4, 2020
A new research report from the food industry shows investigations of leafy greens foodborne illness outbreaks could be streamlined if produce was labeled with traceable codes, something food safety experts have been urging for decades.
For four months food industry researchers reviewed supply chain partners including growers, distributors and both independent and chain retailers, “offering a detailed response to the request by the U.S. Food and Drug Administration for improved traceability in the food system,” according to a group announcement from the six industry groups that conducted the pilot projects.
“The three pilots, conducted July through October, also showed that investigations could be conducted more effectively if supply chain partners provided extended product information during tracebacks,” the announcement states.
“Additionally, the use of a standard template called the Produce Traceback Template to exchange pertinent product information was found to enhance the speed of tracing procedures.”
Participants told researchers they would adopt the template in the future. Also, the research sponsors said, the pilots revealed opportunities to refine the template and highlighted the need for a greater focus on education for future use of it, including additional industry training and modifications to maximize effectiveness and increase ease of use.
The three pilots tracked romaine lettuce through three separate supply chains, starting with actual consumer purchases made with loyalty cards or credit cards. Small teams of industry experts mimicked the FDA’s role in conducting the traceback, including determining the data to be requested and how to format the requests for such data.
Supply chain members, starting with the point-of-sale or point-of-service, used the template to provide key data elements that allowed an item to be traced back to its source. The expert groups conducting the traceback analyzed the information provided by each supply chain node to determine next steps.
“Notably, the data that enabled each of the teams to independently and successfully identify the finished product lot purchased by the consumer is not currently captured by the template,” the report states.
“These data included business intelligence such as sales data, stock rotation, inventory controls and delivery schedules. These were critical in bracketing the scope of the traceback.”
Bryan Hitchcock, executive director of IFT’s Global Food Traceability Center, said the pilots provided insight that will inform future outbreak responses and recall protocols, helping industry to work together to support the FDA’s focus on tech-enabled traceability.
The six organizations that led this industry activity were: FMI-The Food Industry Association; GS1 US; the International Foodservice Distributors Association (IFDA); the Institute of Food Technologists (IFT); Produce Marketing Association (PMA) and United Fresh Produce Association (United Fresh).