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Water underwater? Alessandro Mario, Hydronix Fish feed has multiple forms and a wide variety of formulations with different ingredients. In the process, ingredients go through similar steps, including storage, milling, drying, conditioning and pelletizing. Imagine that it would be possible to improve the protein ratio and the profitability in your processes, while saving energy, reducing waste and carbon footprint. Sure, it would be a dream but is it possible? Let us analyze the processes to see where we can find a solution.
Storage The ingredients must be stored and preserved correctly to prevent mycotoxins, spoilage, or heat spots. These often give problems that are directly related to the moisture contents and so monitoring water content while transferring into storage is important to be able to react to problems. Drying Drying is a common practice to store materials safely, and it is a delicate process to reach the perfect moisture target. If you miss the target, the ingredients are prone to mycotoxins and spoilage. On the other hand, over-drying is not just an expensive waste of energy but can cause damage, shrinkage and loss of yield. The material entering the drier has variable water content, and this makes it challenging to regulate the amount of time the material needs to be exposed to the heat or to regulate the temperature. In this process, inline moisture control is used to automate the dryer to save money and improve quality. Conditioning After drying, depending on the material and system requirements, it may be necessary to reintroduce moisture into the product by conditioning. This can be done before milling or pelleting operations. Depending on the final application, the conditioning
Figure1. Moisture control affects the cost and quality of feed products.
can also heat the material to kill germs, cook ingredients and gelatinate starch. In the same way that moisture control enhances the drying phase, it also improves the conditioning process by reacting quickly to changes in the input material moisture.
Grinding Grinding is one of the most energy-consuming transformations in many food processes. Through mechanical action, it reduces the size of feed materials such as grain, seed, fruit and many more to achieve different chemical and microbiological stability. Results vary based on machines and methods used, as well as toughness and moisture of the material processed. The toughness is the ability of a material to resist breakage. Therefore, tougher material will need more mechanical energy to reduce size. The plasticity or ductility of a material determines the amount of energy absorbed before breaking down as well as the final size. More plastic or ductile material will need more energy to break, but it will maintain a more regular final shape. In contrast, less plastic or ductile material will shatter into finer and irregular shards like particles.
Aquafeed: Advances in Processing & Formulation Vol 13 Issue 1 2021
