In this episode of MeatsPad, we sat down with Dr. Jonathan Campbell, Meat Scientist, to explore one of the most important—and often misunderstood—topics in meat science: curing.

From Tradition to Science

Curing is one of the oldest methods of meat preservation. Salt containing naturally occurring sodium nitrate and sodium nitrite has helped extend shelf life of meat products and ensure food safety.

“Curing was really the original preservation method.”

What began as a practical technique evolved into a precise science that today ensures both product quality and food safety.

Currently, meat processors use sodium salt and sodium nitrite not only to preserve meat, but also to develop the flavor, aroma, and the characteristic pink color consumers expect from cured products like cured ham and bacon.

Nitrate vs. Nitrite: What’s the Difference?

Dr. Campbell explained that while the terms are often used together, nitrates and nitrites behave very differently.

“Sodium nitrite is really the compound that does the work in a meat system.”

• Sodium nitrite is the active compound responsible for cured color, flavor development, and key safety functions.

• Sodium nitrate is more stable and acts as a long-term reservoir. In products that cure for weeks or months—such as dry-cured meats—it gradually converts into nitrite over time.

“Sodium nitrate doesn’t do much initially, except serve as a pool that feeds nitrite during long curing processes.”

This distinction is essential for processors choosing the right ingredient for each product type.

A Critical Role in Food Safety

One of nitrite’s most important functions is pathogen control. In combination with salt, it is highly effective at inhibiting dangerous bacteria.

“Nitrite inhibits Clostridium botulinum almost 100% of the time.”

This bacterium is responsible for botulism, one of the most serious foodborne illnesses. Sodium nitrite also helps control other pathogens of concern in ready-to-eat meat products.

This protective effect is a major reason curing remains essential in modern meat processing.

Labeling, Regulations, and Precision

Curing ingredients are strictly regulated, and accuracy is non-negotiable.

Dr. Campbell cautioned processors against relying on informal terms commonly used in culinary spaces.

“I don’t like terms like Cure #1 or Cure #2. Those are culinary terms and can be confusing.”

Because commercial blends vary, processors must verify exact percentages on labels and use standardized calculations to stay within USDA limits.

“It’s important to justify that you’re within restricted limits set by regulation.”

Natural Alternatives: Vegetable Sources of Nitrite

As consumer demand for “natural” and “uncured” products grows, the industry has adopted plant-based curing alternatives.

“There are numerous sources of both sodium nitrate and sodium nitrite. Most of them come from plant sources grown in the ground.”

Vegetables such as celery and beets naturally contain high nitrate levels. Through fermentation, these nitrates are converted into nitrites and used for curing—providing similar safety and quality outcomes as purified sources.

“We get much more dietary nitrates from vegetables than from processed meats.”

Nitrates are a normal part of human diets and natural biological cycles, including water sources and soil minerals.

Consistency Matters

One challenge with natural sources is variability. Nitrate levels can fluctuate due to seasonality, growing conditions, and even groundwater composition.

“If you’re looking for consistency, groundwater may not be a great ingredient.”

For processors focused on uniform results, standardized inputs and purified water systems can help maintain control.

Supporting Processors Through Education

Beyond the science, the conversation highlighted Dr. Campbell’s dedication to supporting small and mid-sized processors through practical education and extension work.

His philosophy centers on respect, collaboration, and real-world application.

“I look at my students as equals. I’m training them to be scientists.”

“We can learn just as much from processors as they can from us.”

If you work with cured meats—or simply want to understand the science behind them—this episode delivers practical insights into one of meat processing’s most foundational techniques.

In a past episode of the podcast, we spoke with Dr. Kurt Vogel, an animal welfare scientist at the University of Wisconsin–River Falls, about one of the most important steps in meat processing: stunning animals before slaughter.

Stunning is essential because it ensures that animals lose consciousness before bleeding, preventing unnecessary suffering in the final moments of life. But its importance goes beyond ethics. As Dr. Vogel explains, effective stunning also improves worker safety, processing efficiency, and meat quality.

This principle is reflected in the Humane Slaughter Act, originally passed in 1958 in the United States. The law emphasizes four key goals of proper stunning:

• Preventing unnecessary animal suffering

• Improving the efficiency of slaughter operations

• Protecting workers

• Maintaining product quality

Main Stunning Methods

During the conversation, we discussed the three primary stunning methods used in meat processing today.

Mechanical stunning (such as captive bolt or gunshot) is commonly used in cattle. It is fast and effective, but it can cause strong involuntary muscle movements after the stun. These movements can make handling more difficult and may damage the carcass.

Electrical stunning works by passing an electrical current through the brain to immediately render the animal unconscious. In some systems, a second current is applied through the body to affect the heart as well. This approach can provide a longer window to properly bleed the animal before consciousness could return.

CO₂ stunning, often used in pigs and poultry, exposes animals to high concentrations of carbon dioxide gas. This method can improve meat quality by reducing carcass damage and blood splash, though researchers continue studying how animals experience the gas during the process.

A Practical Challenge in Small Plants

One of the research questions Dr. Vogel explored involved pigs regaining consciousness during bleeding in small slaughter plants that used electrical head-only stunning.

To address this, researchers tested a method called head-to-heart stunning. After the initial head stun renders the animal unconscious, a second electrical stun is applied near the heart. This disrupts the heart’s rhythm and gives workers more time to safely shackle and bleed the animal.

In their validation study, the method successfully disrupted the heartbeat in over 80% of pigs, helping reduce the risk of animals regaining consciousness during the process.

The Human Side of the Process

One point Dr. Vogel emphasized is that slaughter is not only about animals—it also affects the people doing the work.

When stunning systems fail or are poorly designed, it can be stressful for workers who care about doing the job correctly and humanely. Effective systems help ensure the process is predictable, humane, and easier for employees to perform consistently.

This episode highlighted an important reality: humane slaughter depends on good science, proper equipment, and well-trained people. When those pieces come together, the result is better animal welfare, safer workplaces, and higher-quality food production.

In an era where the word sustainability is applied to everything—from packaging to marketing campaigns—it’s worth pausing to return to a simpler, more grounded definition.

In a recent conversation on the Meats Pad podcast, Dr. Janet Helms, Senior Manager of Global Sustainable Food Strategy, Animal Health & Welfare at McDonald’s, offered a perspective that cuts through the noise:

“Sustainability is making sure you have a sustainable business that supports the environment you’re in, taking care of the land so you can pass it on to the next generation.”

That final phrase changes the conversation: pass it on to the next generation.

Sustainability, at its core, is about legacy.

Before Sustainability Was a Buzzword

Long before sustainability became a corporate priority, it was simply called good farming.

As a practicing dairy veterinarian for over a decade, Dr. Helms had to ensure:

• Cows were healthy.

• Reproduction was optimized.

• Nutrition was sound.

• Producers were profitable.

• The land could continue producing.

When a farmer once asked her, “What is sustainability?” her response was straightforward:

“Do you want to be able to leave your farm to your kids? That’s sustainability.”

Without profitability, there is no continuity.
Without animal health, there is no productivity.
Without soil stewardship, there is no future.

The Three Pillars That Must Work Together

True sustainability rests on three interconnected pillars:

1. Environmental – protecting soil, water, and ecosystems.

2. Social – maintaining public trust and producer well-being.

3. Economic – ensuring long-term profitability.

As renowned meat scientist Gary Smith once put it:

“Agriculture without profit is merely gardening.”

It’s a blunt reminder that financial viability is not optional—it is foundational.

What the Industry Is Doing Right

Despite public narratives that often focus on shortcomings, significant progress is happening across the meat value chain.

1. Data-Driven Animal Welfare

Within McDonald’s global chicken supply chain, broiler welfare commitments included:

• Environmental enrichments such as perches and platforms.

• Opportunities for natural behaviors like dust bathing.

• Measured welfare indicators, including footpad dermatitis.

• Large-scale benchmarking across suppliers.

This is not symbolic change—it is measurable, data-driven improvement.

Key welfare indicators allow benchmarking not to shame, but to elevate standards across the industry. Welfare becomes quantifiable rather than abstract.

2. Regenerative Practices Without Romanticism

Much of what is now called “regenerative agriculture” has long existed in cattle production:

• Pasture-based grazing.

• Natural manure incorporation.

• Soil structure improvement.

• Water infiltration enhancement.

• Crop rotations and cover crops.

Beef cows spend the vast majority of their lives on pasture. The interaction between ruminants and soil:

• Improves organic matter.

• Stimulates microbial activity.

• Reduces erosion.

• Enhances long-term soil resilience.

This is not ideology. It is biological systems functioning as designed.

3. The One Health Framework

The veterinarian’s oath emphasizes interconnected health: animal, human, and environmental.

You cannot isolate:

• Responsible antibiotic use.

• Manure management.

• Soil health.

• Food safety.

• Climate commitments.

These are integrated systems. Sustainable strategy must be holistic.

Defining Animal Welfare Clearly

Dr. Helms defines animal welfare as:

“The physical and mental state of the animal as it relates to how well it is coping with its living conditions.”

An animal with good welfare:

• Is physically healthy.

• Receives proper nutrition.

• Can express natural behaviors.

• Is free from unnecessary pain and distress.

An important truth often overlooked:

Animals with better welfare perform better.

• Dairy cows with reduced lameness produce more efficiently.

• Chickens with proper enrichment show improved health indicators.

• Pigs managed with lower stress exhibit stronger growth performance.

Welfare is not in conflict with productivity. It reinforces it.

Sustainability Also Includes the Consumer

One of the most overlooked dimensions of sustainability lies outside the farm.

Consumers influence outcomes through:

• Reducing food waste.

• Composting when feasible.

• Choosing recyclable or lower-waste packaging.

• Understanding regional limitations in recycling infrastructure.

Sustainability is systemic. It cannot rest solely on producers.

The Leverage of Supply Chain

Supply chain roles create scale.

Dr. Helms notes that more than 2.5 billion chickens are now reported annually in key welfare indicator databases. That represents structural transformation, not pilot projects.

When global buyers adjust policy:

• Suppliers adapt standards.

• Producers implement new practices.

• Entire systems evolve.

Change at scale is where measurable impact occurs.

The Core Idea: Leave It Better

Ultimately, sustainability returns to legacy.

If:

• The soil is healthier,

• Animals are treated with measurable care,

• Producers remain economically viable,

• Consumers receive safe, accessible food,

Then the system is sustainable.

Not perfect.

But sustainable.

In a sector as complex as meat production, that is significant progress.

Final Reflection

Sustainability is not a marketing slogan.

It is the alignment of:

Animal welfare + soil health + profitability + data transparency + open collaboration.

The question may not be whether meat production can be sustainable.

The more relevant question might be:

Are we willing to recognize and build upon the measurable progress already underway?