Is there any definitive proof that a 4 log reduction is not adequate for air roasted seeds or beans?
Is there any definitive proof that a 4 log reduction is not adequate for air roasted seeds or beans?
Basing off the Peanut Tree Nut Processor Association data, for almonds and walnuts a 4 log reduction is adequate for processing. To meet our customers quality parameter, like moisture and crunch, our oven can only achieve a 4.6 log reduction on a Salmonella and E.coli surrogate strain.
Any information would be helpful. Thanks
Not sure you would ever find "definitive proof". The link below concerning almonds and the almond board testing should provide some further help and insight.
Is there any definitive proof that a 4 log reduction is not adequate for air roasted seeds or beans?
Basing off the Peanut Tree Nut Processor Association data, for almonds and walnuts a 4 log reduction is adequate for processing. To meet our customers quality parameter, like moisture and crunch, our oven can only achieve a 4.6 log reduction on a Salmonella and E.coli surrogate strain.
Any information would be helpful. Thanks
Hi krhaiar,
I don't quite understand yr post.
You state you can only achieve a 4.6 log reduction. This is better than the minimum requirement of 4 log. Or does yr customer want 5 log ?
the official decision involving 4 or 5 log was apparently originally made as per this logic -
The Board initially supported a 5-log reduction, which is FDA’s performance standard. However, the Board subsequently funded research with the University of California, Davis, in conjunction with Rutgers University, whereby a risk assessment model was developed using data from the two Salmonella outbreaks, as well as data from an industry pathogen survey. The risk assessment model demonstrated that a minimum 4-log reduction provides an appropriate level of consumer protection. Thus, the Board concluded that a 4-log reduction was an appropriate standard for almonds.
(Federal Register / Vol. 72, No. 61 / Friday, March 30, 2007 / Rules and Regulations)
The mathematical basis for the decision/validation that 4 log is adequate (ie the opposite to yr OP request) is detailed in various publications ranging from 2006 - 2012 (eg Danyluk et al). These are accessible on the net. The chronological pathway is summarised below -
Almonds reduction microbial load.pdf 528.62KB 11 downloads
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PS - This extract is slightly OT process-wise but seemed of some potential interest -
Blanching is a thermal process that is used by almond processors to remove almond skins. Dr. Linda
Harris of University of California at Davis (UCD) studied the efficacy of hot water on the reduction of
Salmonella on almonds in a hot water bath (ABC Supporting Document DOC002). Based upon the
information from that study, the ABC Technical Expert Review Panel (TERP) determined that a minimum
process of 2.0 minutes or more of exposure to hot water at 190°F or above will provide a 5-log or greater
reduction of Salmonella on almonds.
Subsequently, the US Food and Drug Administration (FDA) reviewed this information and issued a Letter
of Determination to acknowledge this process as a pasteurization process. Almond products processed
utilizing those conditions may be labeled as pasteurized
Since the mandatory treatment criterion is a minimum 4-log reduction of Salmonella on almonds (Federal
Register/Vol. 72, No. 61/Friday, March 30, 2007/Rules and Regulations, Pages 15021-15036), a handler
or Direct Verifiable (DV) user may choose to have their process validated to achieve a minimum 4-log
reduction. Please note that while this will satisfy the mandatory treatment criterion, the products
processed under such conditions may not be labeled as “pasteurized”. The purpose of this document is to
provide guidance for process authorities to validate lethality of almond blanching processes in terms of 4-
log reduction and 5-log reduction criteria.
California,Almond Board,2007,blanching-validation-guidelines.pdf 101.42KB 10 downloads
I know this is much too late but could you steam pasteurize the seeds or beans prior to roasting? this would allow flexibility in roast levels for various targets.