Food Safety Issues/food safety


Hi, I just read your answer to question about black residue on inside of lid of canned tomatoes.  You said the acidity of the tomatoes produced that interacting with the aluminum.  Might that be what caused the black gooky in my can of chicken broth too?  I wouldn't have thought of chicken broth as being that acidic though, but I do believe the taste is affected as well.  My main concern is safety of course.


Hi Darlene,

I'm sorry to have taken so long in answering your question.

Chicken broth is not an acidic food like tomatoes but it can have a sulfide reaction between the broth and lid which can produce a dark deposit on the lid. This is not unsafe to consume.

Here is a research abstract on this very subject that you may enjoy reading:


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Carol Schlitt


I can answer questions on home food safety, sanitation and home food preservation.


I am a former Extension educator, nutrition, wellness and food safety, having retired August 1, 2010. I am a food safety instructor for the Illinois Department of Public Health, a ServSafe Instructor/Proctor and have my own company, Safe & Savory Solutions, Inc -

National Extension Association of Family and Consumer Sciences (Past President and current Historian), St. Louis Culinary Society.

BS - University of Illinois MS - Southern Illinois University at Edwardsville

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