because of polyphenol oxidase which reacts on pear for sometime.
Polyphenol oxidase (PPO) enzymes, also known as polyphenoloxidases, are able to catalyze the transformation of an array of aromatic compounds that have two adjacent phenolic groups on them. This includes a number of polyphenols in plants that act as antioxidants. These copper-containing enzymes oxidize the phenolic groups to reactive oxygen molecules known as quinones, which continue reacting with each other and other cellular factors to form brown spots known as melanin. This browning causes the deterioration of fruits and vegetables, resulting in large economic losses. Examples include the pear
Enzymatic browningis not unique to pear. PPO - a mixture of monophenol oxidase and catechol oxidase enzymes - is present in nearly all plant tissues, and can also be found in bacteria, animals, and fungi. In fact, browning by PPO is not always an undesirable reaction; the familiar brown color of tea, coffee and cocoa is developed by PPO enzymatic browning during product processing.Tentoxin has also been used in recent research to eliminate the polyphenol oxidase activity from seedlings of higher plants. Enzymatic browning is not unique to apples. PPO - a mixture of monophenol oxidase and catechol oxidase enzymes - is present in nearly all plant tissues, and can also be found in bacteria, animals, and fungi.
Because they get rotten by not being used.
http://www.articlesbase.com/food-and-beverage-articles/keep-apple-slices-from-turning-brown-naturally-1238490.html
If you put lemon juice in the water it will prevent the browning.
sprinkle with lemon juice
To keep them from drying out and turning brown
cause it gets pooped on
you don't
Yes it should. Potatoes turn brown when exposed to air. Covering them with any liquid should keep them from turning brown.
Oxygen. Dip apple slices in lemon juice to keep them from turning brown.
A hypothesis doesn't have to be a correct statement. Just pick a chemical and say this one will or will not keep the fruit from turning brown. Then give a brief statement about why you think this way.
keep it in the frige
will covering peeled potatoes in olive oil keep them from turning brown
Use lemon juice.