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Food Microbiology Lab

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Food Microbiology Lab
Determining pH Using a Red Cabbage

Farnoosh Mazarei

Food Microbiology

April 22, 2011

Purpose: To test the pH level of many common household object by use of the juice from a red cabbage.

Background: pH is the measure of the acidity or basicity of a solution. The pH scale ranges from 1 to 14 with 1 through 6 being acidic and 8 through 14 being basic; 7 is considered neutral. The use of the red cabbage, or red cabbage juice is because red cabbage can be used as an acid/base indicator. The pH level of foods is important to food microbiology because having proper pH levels can prevent food borne illness. This is of extreme importance when it comes to canning of foods in particular. Many home canned foods can be a breading ground
…show more content…
To make an acid-base indicator, extract juice from red cabbage. First, cut up some red cabbage and place it in a large pot. Add enough water so that the pot is half full. Then bring the mixture to a boil. Let it cool, and pour off the cabbage juice. Save the solution. 2. Assemble food, beverages, and cleaning products to be tested. 3. If the substance being tested is a liquid, pour about 5 mL into a small beaker. If it is a solid, place a small amount into a beaker and moisten it with about 5 mL of water. 4. Add a drop or two of the red cabbage juice to the solution being tested, and note the color. The solution will turn red if it is acidic and green if it is basic.

Data:

|Solution |Result |
|Dishwashing Liquid |Basic |
|Dishwashing Detergent |N/A

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