How lemon juice can prevent reddish-brown reaction on fresh fruit?

Lemon Juice inhibits the enzymatic browning of fruits by interfering with the oxidation process. The browning reaction, known as enzymatic browning, is caused by the enzyme polyphenol oxidase which converts phenolic compounds in the fruit to brown-coloured pigments called melanins.

Lemon juice contains a high concentration of ascorbic acid (Vitamin C), which is a natural antioxidant. When applied to the cut surface of a fruit, ascorbic acid reacts with the oxygen present to form dehydroascorbic acid.

Dehydroascorbic acid then acts as a reducing agent and donates electrons back to the oxidized phenolic compounds, converting them back to their original colorless form.

Additionally, the acidic nature of lemon juice helps to slow down enzyme activity by changing the pH of the fruit. The lower pH inhibits the enzymes responsible for browning, delaying the oxidation process and preserving the natural color of the fruits.

Therefore, spraying or brushing fresh fruit with lemon juice can effectively prevent the reddish-brown discoloration caused by enzymatic browning, allowing fruits to retain their appealing appearance for a longer period.