Shun NagaiThe pet food industry continues to evolve in order to meet consumer expectations, and behind that progress is a precise and consistent manufacturing process. Producing high-quality dog food requires more than simply using good ingredients. Understanding and optimizing each stage of production leads directly to better pet food quality.
In this article, we explain the key points in the manufacturing process that pet food manufacturers should understand. How do grinding, mixing, heating and forming, drying, coating, and cooling each affect product quality?
Manufacturing Process
Grinding Process
In dry dog food production, the grinding process is a crucial step in which raw materials are broken down into fine, uniform particles.
During this stage, ingredients such as grains, meat meal, and legumes are ground into powder so that the subsequent mixing, forming, and heat-processing steps can proceed smoothly. Finer particles also improve digestibility for dogs and help promote nutrient absorption.
Main Purposes of Grinding
The primary purpose of the grinding process is to make the particle size of the raw materials uniform. Consistent particle size not only allows for more even mixing in the next stage, but also improves processing efficiency in forming equipment such as extruders.
In addition, finely ground ingredients allow heat to penetrate more evenly, increasing the effectiveness of cooking during the heating stage. As a result, manufacturers can produce products that are easier for dogs to digest and offer higher nutritional value.
Grinding also helps remove foreign matter and large lumps, which reduces the risk of mechanical strain, clogging, and other troubles in later stages of production.
Main Grinding Equipment Used
The following are some of the representative machines used in the grinding process.
Hammer Mill
- A structure in which rotating hammers crush the raw material.
- Particle size is adjusted as material passes through a screen.
- The most commonly used machine in dry food production.
- High processing capacity and suitable for a wide range of raw materials.
Roller Mill
- Raw material is crushed by applying pressure as it passes between two or more rollers.
- Capable of producing more uniform particle size.
- Generates less heat, helping reduce nutrient loss.
- More often adopted for specific applications or premium pet food products.
Importance and Control of Particle Size
If the particle size after grinding is not appropriate, various problems can arise. If the particles are too coarse, poor mixing and extrusion problems may occur, and digestibility for dogs may also be negatively affected.
On the other hand, if the particles are too fine, dust is more likely to be generated, worsening the working environment and accelerating machine wear. Excessive fineness can also make nutrients more vulnerable to heat-related loss.
Mixing Process
In dog food production, the mixing process is essential for uniformly blending various raw materials, ensuring consistency and maintaining nutritional value. These machines play a critical role in combining dry and wet ingredients in the right balance to create an optimal product.
When baking bread or cake, the way ingredients are mixed affects the final result. The same is true in dog food manufacturing. Mixers are like kitchen tools, but on a much larger industrial scale. They evenly blend ingredients such as meat, grains, vitamins, and minerals so that every kibble piece contains balanced nutrition.
Mixing Technologies Used
| Item | Batch Mixing | Continuous Mixing |
|---|---|---|
| Processing method | A fixed amount of raw material is mixed at one time | Raw materials are mixed continuously without interruption |
| Production scale | Ideal for small- to medium-scale production | Suitable for large-scale production |
| Quality control | Easy to fine-tune each batch | Stable uniformity and high production efficiency |
| Suitable products | Specialty formulas and small-lot products | Standard dog food for mass production |
There are two main mixing methods: batch mixing and continuous mixing.
Batch Mixing
- A method in which a fixed quantity of ingredients is mixed at one time.
- Because adjustments can be made for each batch, quality control is easier.
- Best suited for small-scale production or special formula products.
Continuous Mixing
- A method designed for large-scale plants producing high volumes of dog food.
- Because ingredients are mixed continuously without interruption, efficiency is extremely high.
- Commonly used by major manufacturers to meet high demand.
Extrusion Process
The mixed ingredients are then sent to an extruder, one of the core technologies in dry dog food production. Here, the material is cooked under high temperature and high pressure (100–180°C). When you break down an extruder, each component has a specific role.
| Component | Function |
|---|---|
| Inlet (Hopper) | Feeds raw materials into the machine |
| Barrel | Mixes and heats the material |
| Screw | Generates friction and heat and pushes the material forward |
Benefits of Using an Extruder
Quality Control in the Extruder
Quality control is carried out as carefully as a chef checking a dish. Moisture level, density, cooking time, and other factors are monitored to ensure that safety standards are met. Advanced sensors and monitoring systems are commonly used to enable consistent production.
The extrusion process is an essential technology for producing safe, nutritious, and palatable dog food. By understanding this process, manufacturers can achieve high-quality dry dog food production.
Forming and Cutting Process
In dry dog food production, the forming and cutting stages take place immediately after extrusion and are important parts of the process.
These stages determine the shape and size of the dog food. They affect not only appearance, but also palatability, ease of eating, and digestibility, making them highly important.
Common Examples of Shapes
Round
Square
Star-shaped
Bone-shaped
Disc-shaped
Donut-shaped
These shapes are selected according to the dog’s size (small, medium, or large breed) and age (puppy, adult, or senior). In general, smaller kibble that is easy to chew is used for small dogs, while larger, more substantial shapes are chosen for large dogs.
Temperature and Moisture Content
In the cutting process, the temperature and moisture content of the extruded material are extremely important. If the temperature is too high or the moisture content is too great, the material becomes too soft during cutting and is more likely to lose its shape.
Conversely, if the moisture content is too low, the dough becomes too hard and difficult to cut, which can also cause irregularities in shape. For this reason, the condition of the material must be monitored constantly, and processing conditions must be adjusted to maintain the proper balance of temperature and moisture.
Cutter Rotation Speed
The cutter’s rotation speed is another factor that greatly affects the cutting result. When the cutter speed is set high, the dough is cut quickly into shorter lengths, producing shorter kibble pieces.
When the cutter speed is set lower, the extruded dough remains longer, resulting in a somewhat stick-like shape. By making this adjustment, manufacturers can optimize product size and shape for target markets such as small-breed or large-breed dogs.
Blade Angle and Number of Blades
The angle and number of cutter blades are also important parameters. If the blade angle is not appropriate, the cut surface may not be smooth, which can negatively affect the kibble’s appearance and texture.
In addition, adjusting the number of blades can change how many pieces are cut at the same time and at what speed, which in turn affects production efficiency and product uniformity.
Drying Process
Because formed kibble still contains a high level of moisture, it is dried in a large dryer (oven) at a temperature range of 70–100°C. In this stage, the moisture content of the kibble is reduced to around 10% or less, which extends shelf life and prevents spoilage, thereby ensuring the safety and quality of the pet food.
At first glance, it may seem harmless if some moisture remains, but excess moisture can lead to bacterial growth and mold in the dog food. For this reason, precise temperature control is essential during this stage so that the product is dried sufficiently without causing unnecessary nutrient loss.
Retaining Nutritional Value and Flavor
Have you ever opened a bag of dog food and noticed the rich, savory aroma that immediately captures your dog’s attention? That is one of the benefits of proper drying technology. By removing moisture appropriately, flavor can be enhanced.
Properly dried kibble also helps maintain an optimal balance of protein, carbohydrates, and fats.
Extending Shelf Life
Thanks to the drying process, pet owners can store dog food for long periods without worrying about spoilage. By removing moisture, the shelf life of the dog food is significantly extended, helping it stay fresh over time.
Coating and Cooling Process
The coating and cooling stages are important steps that determine the final quality of dog food. In these stages, coating is applied to enhance flavor and nutritional value, and cooling is carried out to improve product stability and shelf life.
By applying coating and cooling properly, manufacturers can maximize palatability and nutritional value while also producing a product suitable for long-term storage.
Once drying is complete, the kibble may still be somewhat lacking in flavor or nutritional value on its own. That is why the coating stage is carried out. In this stage, ingredients such as fats, flavors, vitamins, minerals, and probiotics are added to the surface of the kibble to improve nutritional value and palatability.
A rotating drum coater is generally used, and while the kibble is turning, liquid or powdered additives are sprayed evenly through nozzles. This forms a thin layer of fat on the surface of the kibble, enhancing aroma and dramatically improving palatability.
In addition, heat-sensitive nutrients such as vitamins and enzymes can be added at this stage as nutritional fortification, making it possible to replenish components that may have been lost during extrusion and drying. This helps create a well-balanced final product and contributes significantly to maintaining pet health.
After coating, the kibble still retains heat, and a small amount of moisture and oil may remain on the surface. If it is packaged in this state, steam may build up inside the bag, causing condensation, mold growth, and deterioration. That is why the cooling stage is indispensable.
Cooling is mainly carried out using cold-air cooling tunnels or cooling conveyors. By bringing the coated kibble down to room temperature, the process helps the oil adhere properly, removes excess moisture, and improves product stability.
When this stage is performed correctly, it prevents condensation inside the package, preserves quality, and improves long-term shelf stability.