What causes the browning of fruits and how can I prevent it?

The browning of fruits is a fascinating topic, and it's great that you're interested in understanding the science behind it. The browning of fruits is caused by an enzymatic reaction that occurs when the inside of the fruit is exposed to oxygen. This reaction is called oxidation, and it's facilitated by an enzyme called polyphenol oxidase (PPO). When the fruit is cut or bruised, the cells are damaged, and the PPO enzyme is released, triggering the oxidation reaction.

The oxidation reaction involves the conversion of phenolic compounds in the fruit into brown pigments. This is why you'll often notice that the browning starts at the cut surface of the fruit and then spreads to the rest of the fruit. The rate of browning can vary depending on the type of fruit, the amount of oxygen present, and the temperature. Some fruits, like apples and bananas, are more prone to browning than others because they contain higher levels of PPO enzyme and phenolic compounds.

Now, let's talk about how to prevent browning. You've already tried using lemon juice, which is a great approach. The acidity in the lemon juice helps to inhibit the PPO enzyme and slow down the oxidation reaction. However, as you've noticed, it's not always 100% effective. Another method you can try is to use ascorbic acid (Vitamin C) to prevent browning. You can sprinkle some ascorbic acid powder on the cut fruit, or use a commercial product that contains ascorbic acid. Other methods include using honey or maple syrup to coat the fruit, as these have natural antioxidant properties that can help prevent browning.

Some other tips to help prevent browning include: storing the fruit in an airtight container to reduce oxygen exposure, keeping the