4 replies to this topic

[Antonia]

Dear all,

 

I would kindly like to ask for your help.

 

I am trying to find a time / temperature combination to pasteurize ready to eat products with a pH value > 4.3, that will effectively kill Clostridium botulinum spores, but will be lower than 121oC. For example if I choose a temperature of 105oC, what wouyld be the duration of the pasteurization?

 

Thank you very much in advance.

 

[Scampi]

you will not kill the spores, but render them inactive in your example

 

if you want to kill them, you need a retort

 

We need a lot more product information to be of assistance

[MOHAMMED ZAMEERUDDIN]

Higher the temperature less organoleptic quality depending on the product ingredients.

[Tony-C]

Hi Antonia,

 

 

Welcome to the IFSQN forums.

 

Your product formulation and exact pH will be important, you will need to achieve a minimum temperature of 115°C (240°F) for a defined time that may make your product completely unsatisfactory. It may be that you want to use Ultra-high temperature processing (UHT) - a food processing technology that sterilizes liquid food by heating it above 140 °C (284 °F) the temperature required to kill bacterial endospores - typically for one to five seconds.

 

Some suggested reading for processing at lower than UHT temperatures that will help:

 

PREVENTING FOODBORNE ILLNESS: CLOSTRIDIUM BOTULINUM

WHAT CAN BE DONE TO PREVENT ILLNESS?

Primary growth-limiting factors for C. botulinum include environmental temperature above 250°F (121°C) or below 39°F (4°C); high acidity (pH <4.6); low water activity (lack of available moisture); food preservatives such as nitrite, sorbic acid, phenolic antioxidants, polyphosphates, and ascorbates; a low redox potential (absence of oxygen); and competing microorganisms (Sobel et al. 2004).

As is evident in Table 1, most outbreaks of foodborne botulism are the result of improper canning at home. The heat-resistant spores produced by C. botulinum can only be destroyed under proper temperature and pressure for sufficient time. Temperatures in the range of 240°F to 250°F (115°C to 121°C) are needed in order to kill spores (USDA 2015).

 

USDA Complete Guide to Home Canning Guide 1 Principles of Home Canning

Botulinum spores are very hard to destroy at boiling-water temperatures; the higher the canner temperature, the more easily they are destroyed. Therefore, all low-acid foods should be sterilized at temperatures of 240° to 250°F, attainable with pressure canners operated at 10 to 15 PSIG. PSIG means pounds per square inch of pressure as measured by gauge. The more familiar “PSI” designation is used hereafter in this publication. At temperatures of 240° to 250°F, the time needed to destroy bacteria in low-acid canned food ranges from 20 to 100 minutes. The exact time depends on the kind of food being canned, the way it is packed into jars, and the size of jars. The time needed to safely process low-acid foods in a boiling-water canner ranges from 7 to 11 hours; the time needed to process acid foods in boiling water varies from 5 to 85 minutes.

 

Kind regards,

 

Tony

[Antonia]

Thank you all for your responses. Let's say that my product is grilled mushrooms in tomato sauce.Is it necessary to reach a temperature of 115°C to have a safe product? If I heat the product at 110°C for 30 minutes will I achieve the same result as heating the product at 121°C for 3 minutes? (12D reduction)