The Perigo effect in pork

Abstract
Summary: Perigo, Whiting & Bashford (1967) showed that nitrite heated in a laboratory medium was more inhibitory to clostridia than was explicable by the nitrite level itself. They suggested that this effect may be involved in the safety of canned cured meats.A suitable experimental procedure has been developed to enable the inhibitory effect of nitrite heated in meat to be investigated. Using this procedure a Perigo type effect has been shown with minced pork. The roles of physical conditions, and of chemical additives, in the formation of this inhibition, have been examined.In most of the work described in this report Clostridium sporogenes NCTC 8594 was used as the test organism. Spores of this organism, and also vegetative and sporing cultures of Cl. botulinum (types A, B and E), together with some other strains of Cl. sporogenes, have also been tested in the meat/nitrite system.Finally, the work described in this report is considered in the light of the still unexplained stability and safety of canned cured meat products which have only received a mild heat process.