OK, I found this on phosphates... 450 and 414 may be what is described below.... don't know which is which.... Someone may want to drop a note to BP.... and ask them... or figure it out from the product description...
Phosphates
http://www.fao.org/docrep/010/ai407e/AI407E06.htm
Levels used: 0.05 – 0.5%
Phosphates have a wide application in the meat processing industry and improve binding and texture in processed meat products. They directly
increase the water-holding capacity by raising the pH as their own pH is alkaline (above 7.0). Phosphates also stabilize the texture of meat products by
increasing protein solubility in connection with salt and
reduce lipid oxidation/rancidity and hence the occurrence of negative flavours. Phosphates have also shown the ability to
reduce microbial growth. The most common phosphates used in meat processing are:
Sodium tripoly-phosphate STPP (pH 9.8)
Sodium di-phosphate SDP (pH 7.3)
For meat preparations such as sausage mixes, where phosphates are added as dry powder, phosphates with moderate alkaline effect are preferred, in particular
di-phosphates. The usual dose is 0.03 % (see page 134). Di-phosphates are the most effective form of increasing water binding. However, di-phosphates have a low water solubility. Thus, for meat curing brines containing phosphates (see page 179), the more soluble
poly-phosphates can be used.