A phytase is sensitive to external stresses like heat and humidity during storage, and also to other aggressive feed compounds, for instance when mixed into a vitamin/mineral mix. Therefore, storage tests of phytases need to be conducted to assess their stability when stored as a product or when stored in a premix.
OptiPhos® Plus G, CT and L demonstrate long shelf life
Shelf life is determined by defining the time point when more than 20 % activity has been lost. The shelf life of OptiPhos® Plus granular (G), coated (CT) and liquid (L) were evaluated during incubation at a constant temperature of 25 ± 2 oC and 60 ± 5 % humidity.
The results indicated that OptiPhos® Plus G and CT have a shelf life of at least 24 months, showing recoveries which were above 90 % (Figure 1).
OptiPhos® Plus L was incubated and showed a recovery of 90 % after 12 months (Figure 1).
Figure 1. Recoveries over time of OptiPhos® Plus G, CT and L incubated at 25 oC
OptiPhos® Plus stability in a concentrated premix
OptiPhos® Plus G and CT were mixed into a very concentrated vitamin/mineral mix (0.1 % premix) containing 250 g/kg choline chloride (known as the most aggressive compound in premixes). Despite this very aggressive environment, OptiPhos® Plus G and CT demonstrated recoveries of 87 % and 92 %, respectively after 6 months incubation at 25 oC (Figure 2). This demonstrates that OptiPhos® Plus G, a mainstream choice of phytase form, is very stable in premix.
Figure 2. Recoveries of OptiPhos® Plus G and CT in a concentrated vitamin/mineral blend incubated at 25 oC for 3 and 6 months
Advantages of high stability of OptiPhos® Plus
This high stability of OptiPhos® Plus reduces the risk of substantial activity losses during storage, avoiding final feeds which are deficient in phosphorus. In particular, the fact that OptiPhos® Plus G and CT are very stable when blended into an aggressive and concentrated premix makes it the ideal phytase to be used for companies active in the export of concentrated premixes.