• Clostridium botulinum, pH >4.5 toxin • 65% fatality after ingest • Minimum process :2.45 min/121℃ • Higher thermal resistance of nonpathogenic spores cause spoilage. • pH<3.7 spore-forming bacteria, yeasts, and molds are responsible for food spoilage • Conduction, mixed, convection
• Clostridium botulinum, pH >4.5 toxin • 65% fatality after ingest • Minimum process :2.45 min/121℃ • Higher thermal resistance of nonpathogenic spores cause spoilage. • pH<3.7 spore-forming bacteria, yeasts, and molds are responsible for food spoilage • Conduction, mixed, convection
Typical foods and the processes required for the various pH levels
Typical foods and the processes required for the various pH levels
A minimum thermal process • All foods with pH greater than 4.5 must receive a minimum thermal process. This minimum process is indicated by the thermal death time versus temperature relationship, the typical reference process is 2.45 minutes at 121℃, and the thermal resistance constant (Z) is 10℃ to eliminate Clostridium botulinum
A minimum thermal process • All foods with pH greater than 4.5 must receive a minimum thermal process. This minimum process is indicated by the thermal death time versus temperature relationship, the typical reference process is 2.45 minutes at 121℃, and the thermal resistance constant (Z) is 10℃ to eliminate Clostridium botulinum
Thermal death time curve for C. B
Thermal death time curve for C. B
• With the growth and toxin production, Clostridium botulinum produce gas. the gas produced is sufficient to cause visible swelling of the container. This chara. represents the basis for an important quality control step used to eliminate the possibility of a canned food containing botulinum toxin from reaching a consumer
• With the growth and toxin production, Clostridium botulinum produce gas. the gas produced is sufficient to cause visible swelling of the container. This chara. represents the basis for an important quality control step used to eliminate the possibility of a canned food containing botulinum toxin from reaching a consumer