The effect of pH on the thermal resistance of Clostridium sporogenes (PA 3679) in asparagus purée acidified with citric acid and glucono-delta-lactone.
The influence of type of acid, pH and temperature on heat resistance of Clostridium sporogenes (PA 3679) spores were investigated in white asparagus pureé acidified with citric acid and glucono-delta-lactone (GDL). The pH values studied were: 4.5, 4.8, 5.1 and 5.4 at temperatures of 110, 115, 118 and 121 degrees C. The addition of citric acid and GDL to reduce pH significantly diminished heat resistance of the spores. The two acids investigated differed in their effect on heat resistance at the various pH-levels. The most pronounced effect was observed at the lower heat treatment temperatures investigated. The z values ranged from 10.24 to 13.09 degrees C in the asparagus purée with acids added and with significant differences between the two acids and the various pH levels.
Silla Santos
M H
MH
Instituto de Agroquimica y Tecnologia de Alimentos (C.S.I.C.), Valencia, Spain.
Nuñez Kalasic
H
H
Casado Goti
A
A
Rodrigo Enguidanos
M
M
D002951:Citrates / Q000494:pharmacology; D019343:Citric Acid; D003013:Clostridium / Q000254:growth & development*; D005511:Food Handling; D005942:Gluconates / Q000494:pharmacology; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D007783:Lactones; D014675:Vegetables / Q000382:microbiology*
D002951:Citrates; D005942:Gluconates; D007783:Lactones; D019343:Citric Acid; C010730:beta-glucono-1,5-lactone