2 replies to this topic

[Garnet-kun]

Hi, I am Garnet.

My company makes Red Bean Paste.

but I don't know how to calculate The Least Sterilizing Value.

Please help me.

 

Product's container type is Flexible Pouch.

Volume : 176.4 FL OZ (5kg)

 

finished equilibrium pH of the product after processing is 6.8

Maximum water activity : 0.9

 

heating medium : steam

process mode : Steam Jacketed Kettle

 

temperature of the product in the container at the end of the hold time : 176.0 Fahrenheit

 

Start Temp (when putting the product to container) 194 °F

Process Time (Hold time) : 30 min

Process Temp : 176 ~ 212 °F

 

Temp of Process Sterilization

: above 176°F 

(for 30 minutes)

 

Well. somebody help me.

Can Anybody calculate the least sterilizing value?

('The Least Sterilizing value' and 'F0 value' are same thing?) 

 

Please tell me.

 

If you ask more information. I will reply.

I need the value. 

[Charles.C]

Hi Garnet,

 

Not too sure about the Title.  Water activity ?   (But see PS below!)

As I understand, the “least sterilizing value (LSV)”, is typically determined by a so-called “Expert Authority” for the purposes of processors registering their process, eg with FDA.

The EA apparently makes this decision based on heat penetration data as supplied by the processor and knowledge / experience of the product/system to be used.

 

Unfortunately I have found specific definitions for LSV elusive. The only one I could find was –

 

Fo (LEAST STERILIZING VALUE) The number of minutes at a reference temperature of 250 degrees Fahrenheit required to kill a known population of microorganisms with a z value of 18 degrees Fahrenheit. This value must be obtained from a scientifically qualified process authority

 

 

afaik sterilization processes for Low-acid products usually involve 2 contributory factors to the overall required lethality value – (a) a safety contribution based on a 12D reduction of any existing C.botulinum (typically set at F0 =3) and (b) a non-safety component to ensure commercial sterility.

 

It is unclear to me if the LSV includes (a+b) or only refers to (a).

 

The data for LSV in the attached example  below rather implies (a,b) but is not definitive. If it does include (b) the determination looks non-simple.

 

Maybe you, or any canning/pouching people here, can clarify ?

 

 Principles-of-Thermal-Processing,2005.pdf   95.18KB   94 downloads

 

PS - Just realized the possible significance of yr titling water activity ! -

http://www.fda.gov/F...F/ucm222618.htm

Edited by Charles.C, 03 November 2015 - 08:56 PM.
amended

[Garnet-kun]

Thank you!!

I appreciate to your prompt reply.

seems like I should study more. :)

 

Thank you for your help again.