Several factors affect pellet quality, such as the size of pellets, raw material, Steam, state of the pellet machine, the granulation process, and fat content. Pay attention to these factors when making fish feed pellets.
The size of the particle is another factor that affects quality. As a rule, the finer the particle is ground, the higher the quality of the pellet obtained. This is because the particles are more exposed to the conditioning process and the pellet obtained is more compact
Since the goal temperatures required to accomplish gelatinization will vary depending on the origin of the starch, the type of cereal grain utilized (corn versus wheat) and its inclusion % will have an impact on quality. No matter the source (animal or vegetable), the inclusion of lipids (more than 1%) can significantly degrade the quality of the pellets.
The effective management of steam quality, moisture content, and retention time in the conditioner is essential to the granulation process. In addition to lubricating the feed through the matrix and extracting the essential oils from the cereal grains, steam also lowers friction and wear on the equipment while enhancing pelletizer production rates (kg/hour).
The condition of the manufacturing machinery affects the pellet’s quality as well. This is so evident that it is frequently not given the attention it deserves in the factory’s everyday operations. Damage to the hammers, dies, rollers, etc., as well as improper positioning or orientation of the blades or steam injection valves, all have an adverse effect on the pellet’s quality.
Because it directly affects the durability, amount of particles, and effectiveness of the pelletizing process, good granulation is crucial (amount produced and energy consumption). The ideal temperature for conditioning to cause starch to gelatinize is above 80–85°C. After leaving the boiler and before entering the conditioner, the steam must be controlled to ensure that the quantity, quality, and energy are sufficient to produce the desired results.
Less durable pellets could be the result of a high dietary fat intake. Fat facilitates feed movement through the die and lessens feed compaction inside the die holes by minimizing the contact of the meal with the die-hole walls. Fat is added prior to conditioning, which partially encapsulates feed particles and prevents steam from penetrating, reducing starch gelatinization and weakening capillary adhesion forces. If a high percentage of undamaged pellets is needed, the extra fat should be kept to 5–10 g per kilogram of feed.