Mechanical properties of aquaculture feed pellets using plant-based proteins

This study investigated the properties of fish pellets made with plant-based ingredients intended for rainbow trout (Oncorhynchus mykiss) or other Salmonids. Plant protein from camelina meal (CMM), canola meal (CM), and isolated soybean protein (ISP) were the variable portions constituting 70% (w/w) of the seven formulations. The other 30% of ingredients included binders (7% wheat gluten protein (WGP) and 3% guar gum (GG)), 7.5% vitamins, 5% fish oil and 7.5% fishmeal. The densified pellets were made one at a time using a compaction plunger and die apparatus at 14% moisture, a die temperature of 90 °C and a compaction pressure of 112 MPa. The feed properties studied were morphology of the starting pellet powders, pellet density, durability, disintegration in water (e.g. water stability) and transverse crushing load. Results indicated the mix containing 5% CMM/5% CM/60% ISP had better durability, water stability and transverse tensile strength. The CM contributed to poor pellet performance, while the ISP produced the most favorable results. Camelina meal performed moderately well and resulted in the highest density. This study may help aqua feed producers in the selection, composition and performance of feed containing agricultural products that are more economical than current meat-based fishmeal.