Why Food Manufacturers Struggle with Yield
One Messer food processing team member remarks that “the first thing I look for when evaluating yield is liquid on the floor—or, if it’s a cooking plant, steam escaping to the ceiling.” In short, moisture loss or evaporation can reduce final output weight, affect quality, and result in inconsistent product quality. We should also mention products sticking to the belts that produce fines. Any potential product loss represents reduced yield.
Whatever the underlying issues, suboptimal yield directly impacts revenue and profit. Quality problems are also part of the yield equation. Scrap rates impact yield directly, while re-work represents added labor cost and additional processing time where more product can be lost.
What are common reasons for percent yield loss in food manufacturing?
- Raw Ingredient Processing: any yield loss during raw ingredient processing represents a lost product and requires larger inputs to be used to maintain weight.
- Unquenched Cooked Products: any time spent hot after cooking is completed represents potentially yield-threatening moisture loss via steam or drip loss.
- Lost Ingredients for Prepared Foods: for any prepared food with loose ingredients or toppings, the product can be lost by being shaken loose during processing or packaging.
- The “Chocolate Chip Problem”: many food processing scenarios involve different ingredients with varied properties that create processing challenges—a classic example is chocolate chip cookies, where excess heat can cause chips to melt into the dough during mixing, ruining the batch.
- Individually Quick Frozen (IQF) Foods: yield loss means less precise weight outcomes, forcing processors to use the extra product to create a buffer margin against underweight packages.
- Food Products Sticking to Conveyor Belts: many food products can leave products stuck to conveyor belts, which reduces yield while negatively affecting product quality and consistency.
Strategies and Procedures to Identify Yield Problems
Pinpointing a yield problem is the first step toward solving it. This article from Food Engineering is a great resource, identifying several approaches to identifying yield problems:
- Use SPC (Statistical Process Control) to identify yield issues in blending and batching processes, with a reported ROI ranging from 20 to 30 percent.
- Mass-balance reporting systems can help track and identify product loss across the entire production line.
- Track and analyze key metrics (e.g. protein content, weight fluctuation, water content) throughout processing. In-process adjustments can help account for variation in raw materials.
- Evaluate control system software to find an approach that can protect quality without sacrificing speed.
Solving Yield Problems Helps Support Continuous Improvement of Food Manufacturing
When solving yield issues, identifying the problem is a great starting place. Because yield is closely interrelated with efficiency, waste, and virtually every other aspect of manufacturing operations, it can be difficult to know where to begin tackling the problem.
Our experience suggests that improvements can be pursued along two related paths:
- Improving management procedures to ensure that best practices are followed and that the existing technical process is working as efficiently as possible.
- Looking for opportunities to apply new technologies that enhance the yield of the production process itself.
This article from Food Manufacturing offers several valuable examples from the first category. Tighter quality control, preventive maintenance, improved inventory tracking, employee training, and even facility cleaning can play an important role.
New technologies, meanwhile, can help solve the root causes behind yield issues. For example, Messer’s experience with cryogenics has shown a variety of use cases where our team can use cryogenic-based systems to improve yield.
How Messer Cryogenics Can Directly Address Food Processing Yield Problems
Backed by support from our experienced food industry team, Messer cryogenic solutions are a valuable resource even for processors with limited cryogenic experience.
In each of the applications outlined below, solutions can be tailored to unique cost parameters, equipment needs, efficiency targets, and more. Cryogenic food processing technologies are also highly scalable and can help improve yields for both large and small processing facilities.
Even if past experiences with related technologies like mechanical freezing have proved unsatisfactory, we recommend exploring the capabilities of new approaches like cryo-assisted impingement and tunnel freezers, which overcome key limitations of traditional techniques.
Example Yield-Enhancing Applications for Messer Cryogenics
- Chilling with bottom-injection nitrogen or CO2 system can ensure ingredients reach optimal temperatures during blending operations, enabling a consistently better-formed product. Chilling the product in the blender reduces rework, limits loss through sticking to the forming machine, and ultimately enhances yield. Improved farming operations can reduce rework and lost products while improving quality.
- Cryogenic freezers such as Messer’s Cross Flow Tunnel, Modular Tunnel, and Immersion systems can quench a cooked product much more quickly than a traditional mechanical cooling system, delivering better overall results in many contexts. Fast freezing helps retain moisture by quenching the product and reducing steam and drip loss as a cryo-assist to a current mechanical freezing system. Messer cryogenic systems can also perform a full freeze, allowing for the efficient reuse of gas within the freezing system.
Cryo-assisted food quenching and freezing can improve not only yield, but increase overall throughput. In mechanical freezers, moisture on refrigeration coils often requires production to be slowed (or freezer temperatures raised) in order to accommodate coil defrosting. In some cases, defrosting represents 1-2 hours per day of lost production. Cryogenic pre-treatment can reduce the need for coil defrosting.
- IQF quick-crusting cryogenic freezers improve the overall precision of IQF processing by reducing product marriages and clumping. Higher quality IQF product processing allows for minimal weight buffers in final packaging, improving yield while ensuring a reliable end product. Precise IQF freezing also helps reduce costly rework or scrappage further down the line.
Learning More: Other Suggestions to Improve Food Production
Yield is just one target for enhanced food processing efficiency. Reducing waste is another operational priority that can offer substantial ROI. If you are interested in learning more, we take a look at reducing food processing waste in our blog here.
If you’re interested in a more detailed discussion about your improving your food processing operation we encourage you to contact the Messer team for advice and/or a complimentary production process assessment. We have decades of industry-leading experience, and assessment of your facility and processes is a great way to start down the path to maximizing your product yield.