Apple Browning

Questions

• How many different types of apples do you know?

• Did you ever have you apple go brown before you finished eating it?

• Do you know why apples are good for you?

An apple a day keeps the doctor away?

• Apples contain antioxidants which may help lower the chances of developing diabetes and asthma.

• Research has shown that eating food high in fiber such as apples can lower the build up of cholesterol in arteries and lower your risk for pancreatic cancer and Parkinson’s disease.

• Eating an apple helps stimulate the production of saliva in your mouth which helps reduce tooth decay by lowering the amount of bacteria.

An apple a day keeps the doctor away?

• A medium sized apple has about 80 calories! This makes it a healthier alternative to other snacks!

• Apples don’t have any fat, sodium or cholesterol!

Why do apples brown?

• Apples contain an enzyme that reacts with oxygen when the apple is cut.– Enzymes are made up of proteins that can either

break things down or connect molecules together. • When the apple is cut or dropped, these enzymes

are exposed to the air and react causing the brown spots.

• Different apples brown at different rates because they have varying concentrations of the enzymes.

Why do apples brown?

• There are ways to stop the browning of apples!• Certain solutions can stop or kill the enzyme

which will prevent the browning. The browning usually occurs if the pH of the fruit is between 5.0 and 7.0, so adding an acidic solution will help prevent the browning.

• Heating the apple slices will kill the enzymes, which will prevent browning. They can’t react if they are dead!

Materials• Apples (1 can be divided between 2-3 groups)• Knife• Plates (1 per group)• Vinegar• Lemon juice• Lime juice• Sugar solution• Baking soda solution• Salt water solution • worksheets

The Activity!

• Get the campers into small groups• Hand each group a plate and a worksheet to

record their observations.• Get each group to put a few drops of the

solutions on the apple slice. Each different solution gets its own apple slice.

• Make sure they mark down which apple has which solution on it.

The Activity!

• Set the apple trays off to the side. It takes awhile for the slices to go brown so have the campers check them through out the day and record their observations

• This can take awhile! In the lab they were left over night, but there should be noticeable changes after a few hours.

The Activity!

• The control, baking soda and sugar slices were all noticably brown.

• The part of the apple submerged under water hardly browned, while the part above was brown.

• The lemon and lime slices were only just starting to brown after being left over night! The vinegar slice was slightly browner but not as much as the control

Did you know?

• An apple’s flavour comes from cells found on the skin? So for the best flavour, don’t peel your apple! The vitamins also are just below the peeling and they are pretty important for you too!

• Apples soften/ripen up to 10 times faster at room temperature than if they are in the refrigerator

Did you know?

• The world’s largest apple peel was 172 feet, 4 inches long! It was peeled by Kathy Madison in 1976.

• The science of apple growing is called pomology

• Did you ever wonder why apples float? It is because 25% of their volume is air!