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Name: Alysha C.
Status: student
Age: 11
Location: N/A
Country: N/A
Date: 11/24/2003


Question:
I did an experiment with bread mold. I soaked one piece of bread in salt water and one in sugar water after 10 days no mold has grown on the bread with salt water. Why? The only thing I have found is salt reduces the Water Activity level.


Replies:
Alysha,

Salt is a powerful dehydrating agent -- in other words, salt pulls water out of cells. Mold spores cannot live and multiply easily in a dehydrated condition. In addition, salt water is an excellent conductor of electricity. As such, it interferes with the life processes that depend on electrical transmissions within and between cells.

Regards,
ProfHoff 751


High concentrations of salt creates an unfavorable osmotic environment essentially drawing out the water from the inside of most cells...

pf


Look up the words osmosis and diffusion. Salty or in some cases very sugary water actually causes water to leave cells. Water goes where there is less water. A salt solution has less water in it than a plain water solution. So water goes toward the salty solution. Mold and bacteria need a moist environment to grow. Salt solution takes water out of the cells of the mold.

Van Hoeck



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