At 08:02 AM 4/3/00 -0700, you wrote:
>My last conversation regarding this effect (termed "iridescence") with the
>meat science people at Iowa State University yielded the following
>information: 1. This does not indicate spoilage or any health hazard. 2.
>No one has determined why this happens. 3. Efforts to reproduce it in a
>lab environment have been unsuccessful. 4. It usually occurs in roasted
>meats. 5. The only way to positively prevent it is to use a dull knife!
>
>If anyone else has more information, I would appreciate hearing it.
>
>Paul
The cause of this problem is the refraction via small water droplets on the
surface. Erratic surfaces will reduce the problem by involving random
action of scattering instead of optical refraction.
Chemicals added to the fish can aggravate the problem by increasing the
refractive index. This includes salt, phosphate and sugar.
A dry surface will not iridesce either.
================================================================
Robert A. LaBudde, PhD, PAS, Dpl. ACAFS e-mail: ral@lcfltd.com
Least Cost Formulations, Ltd. URL: http://lcfltd.com/
824 Timberlake Drive Tel: 757-467-0954
Virginia Beach, VA 23464-3239 Fax: 757-467-2947
"Vere scire est per causae scire"
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