microbiological testing of seal oil

Milton milton_pace at my-deja.com
Wed Aug 30 17:07:35 EST 2000

In article <01C0128C.94A90480.mdesbien at agr.gouv.qc.ca>,
  mdesbien at agr.gouv.qc.ca (Michel Desbiens) wrote:
> A processor of seal oil (these adult mammalian are very abundant in
> wants to export his product to Asia as a food supplement. He was
asked by
> the Asian custom authorities to perform routine microbiological
> (coliforms, Salmonella). The processor asked to our lab to help him
> perform these analyses.
> As the process includes centrifugation to remove residual solid
> and all the water content (less than 0,2 % in the final product), we
> see the use of such microbiological testing, but the requirements
have to
> be met anyway. So, we wonder what kind of method to use to test the
> Most of the methods are adequate for aqueous phase, and we strongly
> that official methods using plating or MPN cannot give satisfactory
> due to the immiscibility of fat with water. Can somebody suggest a
> methodology ?
> Thank you very much,
> M. Desbiens

It is possible that the pathogens you mentioned could be encapsulated
in oil phase you describe. Very probably any pathogens will be present
in low numbers and may be extremely damaged

Clearly you will require some form of  homogenisation process to
reintroduce  an aqueous phase ( ie your primary enrichment media for
each pathogen). A Gilson Blending device would do the trick.

Addtionally emulsifying agents tween 80 or lecithin might assist in
solubilising the oil phase suffciently to permit acess to nutrients in
the aqeous phase.

Good hunting. I suggest you do some spike tests to validate any
candidate recovery proceedure.

Yours Milton Pace
> ---

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