Reading Bakery Systems
https://www.readingbakery.com/About
Your trusted partner for innovative bakery and snack solutions
At RBS, we’re more than just a snack food equipment manufacturer. We make it our business to build strong and lasting relationships with our customers. As your working partner, collaboration and trust enable us to identify challenges and offer personalized solutions to help you create successful bakery and snack products.
The Reading Bakery Systems Brands - Thomas L. Green, Reading Pretzel, Exact Mixing and Reading Thermal - offer production lines capable of producing a wide range of snack products, continuous mixing solutions and oven profiling and consulting services.
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Drying
5+ MIN
02/12/2025
Ensuring Food Safety: Kill Step and Validation in Pet Food Baking
Growth of the Pet Food Market and Rising Safety Concerns
Growing pet ownership and greater nutritional awareness have fueled strong demand for commercial pet food in recent years. More consumers now prefer 'complete and balanced' foods, prompting a wave of manufacturers entering this dynamic market. While product variety is at an all-time high, the race for novelty sometimes overshadows food safety considerations.
For example, raw diets, once regarded as the most 'natural' choice, have faced heavy scrutiny following avian influenza outbreaks linked to pet deaths (Goodman, 2025). But contamination risks extend well beyond raw products. A review of recalls from 2003-2022 found that up to 35% of pet food recalls were caused by biological contamination, most often Salmonella (DeBeer, J. et al., 2024). This presents a particular risk to young children and older adults exposed during handling (PetfoodIndustry, 2024).
Even baked products, which undergo high temperatures during the baking process, are not immune if processes are inconsistent. A single safety lapse can erase years of brand trust, underscoring the importance of robust food safety controls. This paper explores the design and validation practices required to ensure an effective kill step in baked pet foods.
Challenges in Achieving the Kill Step in Pet Food Baking
Baked kibble is valued as a healthier, 'humanized' alternative to extruded products, yet ensuring every piece reaches a validated kill step is not guaranteed. Common risks include:
Cold or dead spots in ovens: Inconsistent airflow or temperature distribution can leave small kibble (5-6 mm) under-processed. Extending bake times to compensate often results in over-browning or burnt products.
Figure 1: Customer expectation of consistently baked kibble.
Excessive product piling: Loading too much product onto the belt impedes heat penetration into the inner layers as the kibbles pile up, especially in single-pass systems where the oven is the bottleneck in line throughput.
Post-baking contamination: Poor line layout or hard-to-sanitize conveyors can re-introduce pathogens after baking.
These risks highlight why oven design and process validation are critical for consistently achieving a verifiable kill step.
The RBS Approach to Safe and Efficient Baking
RBS addresses these challenges with a two-stage baking and drying process designed for both safety and throughput.
Step 1: Baking
RBS convection ovens feature a centralized penthouse system with independently controlled top and bottom airflow delivered through perforated plenums (Figure 2). Operation is simple—operators only need to set the penthouse air temperature, balance the airflow, adjust the exhaust fan speed, and control bake time. This is all done on the control screen, and recipes can be stored for easy and repeatable production.
Figure 2: RBS Convection Oven with centralized penthouse. Perforated plenums for consistent airflow.
This oven design delivers uniform airflow and precise temperature control, ensuring consistently baked products every time. The oven functionality can be validated with the Scorpion® 2 Profiling System. The Oven Air Velocity Graph (Figure 3) generated using data collected by Scorpion 2 shows different color lines to represent the sensors' position from left side to right side of oven belt. Overlapping lines indicate that air velocity from left to right side of oven belt is highly uniform. As the sensor travels along the tunnel oven from zone 1 to zone 5, velocities are largely uniform within each zone, where each peak represents the airflow surge from perforations on the plenum surface.
Figure 3: Scorpion 2 Air Velocity Graph.
Products are loaded in mono- or bi-layers, maximizing heat penetration and ensuring each piece receives sufficient heat. Over-stacking is avoided to prevent uneven baking between outer and inner layers. This high-temperature, short-time bake achieves the kill step while maintaining color uniformity and maximizing throughput (Figure 4).
Figure 4: Baked kibble entering the oven in one layer to ensure efficient baking.
Step 2: Drying
Once the kill step is secured, products move into a low-temperature, long-time drying phase to gently reduce residual moisture. Dryers use the same oven airflow design principles to maintain uniformity. Depending on space and capacity needs, customers may choose:
Single-pass oven with separate 3-pass dryer, or
2-pass oven/kiln system that integrates baking (top pass) and drying (bottom pass) into one zone. This set-up allows for a smaller footprint.
This separation allows shorter bake times with mono/bi-layer product loading for effective kill steps, followed by multi-layer drying (typically 4-5 product layers) for efficiency (Figure 5).
Figure 5: Multi-Pass Dryer for slower drying to gently reduce residual moisture.
Validating the Kill Step
Kill Step Validation requires direct measurement of the product's internal temperature during baking. The Reading Thermal Scorpion 2 Data Logger uses temperature probes for measurement of product internal temperature during the baking process (Figure 6). By combining this data with specific thermal tolerance coefficients (Tref, Dref, z), lethality can be calculated using the Kill Step Calculator developed by AIB International, in cooperation with Kansas State University, the American Bakers Association (ABA), and the University of Georgia, to determine if kill step is complete (Kill Step Calculator | Bakery Process | BAKERpedia, 2016). Our SV8 software can then be used to generate the kill step report. Bake time and baking temperature can be further optimized by analyzing the lethality curve generated by SV8 software.
Figure 6: Scorpion 2 R&D Kit with product probes. Product probes for measuring internal product temperature.
Figure 7: Internal temperature vs time and cumulative lethality vs time graphs as part of kill step report generated by SV8 software.
Beyond kill step validation, the Scorpion 2 can be equipped with air velocity, temperature, humidity, and heat flux sensors to better understand oven performance. The air velocity sensor and air temperature sensor arrays can be used to validate the convection oven design to ensure that air flow and temperature distribution is uniform both across and along the oven belt (Figure 8).
Figure 8: Temperature and air velocity sensor arrays for oven profiling, temperature and airflow distribution data within tunnel oven can be collected and displayed as 2D or 3D graph in SV8 software to identify cold/ hot spots in oven chamber.
Conclusion
RBS mitigates these risks with proven baking and drying solutions, paired with the Scorpion® 2 profiling system, giving manufacturers confidence that every batch meets FDA FSMA kill step requirements. With RBS, you can achieve both safety and efficiency—ensuring your products earn consumer trust and stand out in a crowded market.
By Readin Bakery Systems
Source: All Pet Food Magazine
References
DeBeer, J., Finke, M., Maxfield, A., Osgood, A.-M., Mona Baumgartel, D. and Blickem, E.R. (2024). A Review of Pet Food Recalls from 2003 Through 2022. Journal of Food Protection, [online] 87(1), p.100199. doi:https://doi.org/10.1016/j.jfp.2023.100199.
Goodman, B. (2025). With bird flu cases rising, certain kinds of pet food may be risky for animals – and people. [online] CNN. Available at: https://edition.cnn.com/2025/01/18/health/bird-flu-pet-food-cat-deaths/index.html [Accessed 12 Feb. 2025].
Kill Step Calculator | Bakery Process | BAKERpedia (2016) BAKERpedia. Available at: https://bakerpedia.com/processes/kill-step-calculator/ (Accessed: 25 February 2025).
PetfoodIndustry. (2024). US pet food recalls: More than 40% due to Salmonella. [online] Available at: https://www.petfoodindustry.com/blogs-columns/adventures-in-pet-food/blog/15678178/us-pet-food-recalls-more-than-40-due-to-salmonella [Accessed 13 Feb. 2025].
Manufacturing Process
3+ MIN
21/02/2025
RBS Baked Pet Food Systems: Optimized, Automated Solutions for Baked Pet Treats and Baked Kibble (Part 2)
RBS BAKING AND DRYING PICTURED: An RBS single pass convection oven for baked kibble and treats. Unlike cookie baking, which involves a mix of sugars and butters that need time to develop, pet food baking uses meat-based fats that require a faster, even bake. This is why pet kibble and treats are typically baked in a convection oven on an open mesh belt. Precise and uniform heat and airflow controls are essential, since too much heat in the first zones of the oven will cause case hardening of the product that keeps it from reaching proper moisture removal targets. The Prism convection oven addresses all of these concerns and more. This RBS oven system features automated airflow and conveyor speed controls that support an even bake for higher product quality and consistency. For baked kibble and small treats, RBS offers a proprietary oven over kiln for the most efficient space usage. While the final oven zone can be used as a dryer for lower throughput lines, most baked pet food products, particularly treats, require more drying. To ensure optimal product quality and shelf life, final baked pet food moisture targets should fall within the 8 – 10% range. The RBS Multi-Pass Dryer will help you meet these targets more effectively. Our Multi-Pass Dryer features three mesh tiers that allow the product to tumble from level to level to promote more even drying. Hot air is forced through the product pile from above and below each conveyor belt, and each conveyor tier can be set at different speeds for greater production flexibility. The Multi-Pass Dryer also features full-length doors on each side that open both ways for easy access and cleaning. PICTURED: The RBS MultiPass Dryer on a pet treat production line. As part of our sustainability initiatives to manage oven emissions and energy usage, we build our ovens with better insulation to minimize the conductive heat paths from the interior of the oven to the exterior. RBS also uses lighter-weight oven belting to help conserve energy, and we offer items like high-efficiency motors and heat reclamation systems that can assist by reheating the oven makeup air. Alternative heat sources and electric oven options are available for all RBS oven configurations. ADVANCED BAKING MEASUREMENT AND MONITORING To further support product quality, our proprietary SCORPION® 2 Data Logging Measurement System provides essential data during product development, system installation and commissioning and daily operation. The system features sensing bars and product probes that measure product temperatures as well as surrounding oven temperatures, air velocity, humidity and heat flux. During product development and oven set up, the SCORPION ® 2 can eliminate guesswork and save time in taking a product formula from pilot scale to production. During production, the SCORPION® 2 detects cold spots that can interfere with the kill step, and hot spots that can overheat the product and destroy nutrients. Measurements can also be saved as part of an overall safety log to validate the kill step. The SCORPION® 2 is a single user-friendly platform for data collection, analysis and problem-solving. HEALTHIER PET FOOD STARTS WITH RBS If you're ready to capitalize on the expanding and profitable baked pet food market, look to RBS. Our automated, energyefficient systems leverage many decades of cookie, pretzel and pet food production expertise, while our Science & Innovation Center provides system and product development support that other manufacturers can't match. For more information about RBS Baked Pet Food Systems, please visit www.readingbakery.com. Source: Reading Bakery Systems
Manufacturing Process
3+ MIN
20/02/2025
RBS Baked Pet Food Systems: Optimized, Automated Solutions for Baked Pet Treats and Baked Kibble (Part 1)
While baking pet food is a costlier, lower throughput process than high pressure extrusion, it promises much higher profit margins. Pet food owners perceive baked pet foods to be healthier and more humanized, so they are willing to spend more on them. Baked pet food production lines can produce kibble and treats, making them more flexible than high pressure extruded systems. That flexibility also enables innovation in new product development.
Baked kibble and treats share the same five production steps: mixing, feeding, forming, baking and drying. With baked kibble, outputs are higher and involve fewer shapes and ingredients than treats, so production is geared for greater throughput. With baked treats, outputs are lower but involve more shapes and ingredients, so production is geared toward greater flexibility.
Accordingly, your system and production processes will depend on your product portfolio. As the only OEM that offers a dedicated pet
food system from mixing through baking, RBS can help you select and optimize a baked pet food system for your current and future
product mix.
AUTOMATED, BAKED SYSTEM SOLUTIONS
Backed by 130 years of baking industry experience, RBS has been developing baked pet food systems and solutions for over 20 years. Our move into the baked pet food market was a natural evolution, as cookie and pretzel production are very similar to baked pet food production. And just like our cookie and pretzel systems, RBS baked pet food systems are engineered for sustainability, energy-efficiency and cost-effectiveness.
For most RBS customers, the introduction to our baked pet food systems and solutions begins at our state-of-the-art Science & Innovation Center. This unique research and development facility allows our customers to test products and processes on RBS equipment before purchasing. Our engineers will work with you to demonstrate our process machinery, validate product ingredients, produce market samples and more. It's a key part of the RBS system selection and optimization process, and it allows us to educate our customers on the many equipment considerations at each production stage.
RBS MIXING OPTIONS
PICTURED: A batch mixer, dough feeder and kibbler feeding a rotary moulder.
All RBS automated baked pet food systems start with either a batch or a continuous mixer. Depending on your products, each has its pros and cons. Batch mixers are generally best for low-to medium-capacity production lines, especially those with multiple recipe changeovers. In contrast, continuous mixers enable a much higher throughput and are usually the preferred choice for high-capacity lines. Continuous mixing offers several important benefits over batch mixing, including a fully automated system that reduces labor, saves energy, improves consistency and simplifies your mixing process.
RBS DOUGH HANDLING OPTIONS
The selection of a batch or continuous mixer will affect your dough handling equipment choices. With a batch mixing system, the larger batch sizes need to be broken down and metered into the forming equipment, a process that requires larger and more feeding equipment. With a continuous mixing system, the dough stream is discharged in smaller sizes, which enables smaller and less equipment. RBS has a portfolio of dough handling equipment for batch or continuous systems.
RBS DOUGH FORMING OPTIONS
PICTURED: Co-extruded pet treats produced on an RBS pet food line outfitted with a Low-Pressure Extrusion System.
RBS baked pet food systems are available with a variety of forming equipment options. Representing the industry standard, our rotary moulders can handle higher fat doughs and are flexible enough to produce kibble and treats. RBS wirecut machines are great for softer cookie-like products and bars.
Our low-pressure extruders can produce unique shapes and are ideal for rugged-looking kibble or kibble with a 60% or higher fresh meat content. Co-extrusion and sheeting systems are available for filled and cracker- type products.
PICTURED: An RBS rotary moulder producing baked pet kibble.
Source: Reading Bakery Systems
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