What To Know
- This enzyme reacts with oxygen in the air to produce a compound called melanin, which gives the apple its characteristic brown color.
- Apples can still turn brown in the refrigerator, although at a slower rate.
- However, it is not a long-term solution as the apples will eventually turn brown once exposed to air again.
Apples, known for their crisp texture and sweet flavor, are a popular fruit enjoyed by people of all ages. However, some may have noticed that their apples often remain white or cream-colored, even after being cut or bruised. This raises the question: why is my apple not turning brown?
Understanding the Browning Process
To unveil the answer, we must first delve into the science behind the browning process. When an apple is cut or bruised, its cells release an enzyme called polyphenol oxidase (PPO). This enzyme reacts with oxygen in the air to produce a compound called melanin, which gives the apple its characteristic brown color.
Factors Inhibiting Browning
Several factors can inhibit or delay the browning process in apples:
1. Antioxidants
Apples contain antioxidants such as vitamin C and quercetin, which can neutralize free radicals and prevent the oxidation process that leads to browning.
2. pH Level
The pH level of an apple can also affect browning. Apples with a higher pH (less acidic) are more resistant to browning.
3. Storage Temperature
Storing apples in cold temperatures slows down the enzymatic reactions responsible for browning.
4. Modified Atmosphere Packaging (MAP)
MAP involves storing apples in a controlled atmosphere with reduced oxygen levels. This helps to minimize the availability of oxygen and slow down browning.
5. Genetic Variation
Some apple varieties, such as Granny Smith, are naturally resistant to browning due to genetic factors that reduce PPO activity.
Other Causes of Non-Browning
In addition to the factors mentioned above, certain other factors can also prevent apples from turning brown:
1. Chemical Treatments
Some apples are treated with chemicals such as ascorbic acid (vitamin C) or calcium chloride to inhibit browning.
2. Enzymatic Inhibitors
Certain substances, such as lemon juice or pineapple juice, contain enzymes that can inhibit PPO activity and prevent browning.
3. Air Exposure
Minimizing air exposure by storing apples in airtight containers can slow down browning.
Recommendations: Unraveling the Enigma
The mystery of the unbrowning apple is now unravelled. Various factors, including antioxidants, pH level, storage temperature, and genetic variation, can influence the browning process. By understanding these factors, we can appreciate the complexities of nature and enjoy the freshness of apples without the worry of discoloration.
Questions You May Have
1. Why does my apple turn brown even after storing it in the refrigerator?
Apples can still turn brown in the refrigerator, although at a slower rate. The cold temperature slows down but does not completely stop the enzymatic reactions.
2. Can I prevent apples from browning by soaking them in water?
Soaking apples in water can temporarily delay browning by displacing oxygen from the surface. However, it is not a long-term solution as the apples will eventually turn brown once exposed to air again.
3. How can I prevent apples from browning when making apple slices for lunch?
To prevent apple slices from browning, you can sprinkle them with lemon juice or pineapple juice. Alternatively, you can store them in an airtight container with a damp paper towel to minimize air exposure.
