Sulfur dioxide is employed to bleach wood pulp during paper manufacture. It is also used as an additive in making jam and marmalade, often in the form of sulfite compounds. If it is present in amounts greater than $10\ \text{mg kg}^{-1}$, it must be listed as an ingredient of the jam. What is the purpose of adding sulfur dioxide to jam?
- AIt is a bleaching agent and removes the undesirable colours from the fruit used in the jam.
- BIt is a preservative that destroys unwanted bacteria and enzymes.
- CIt is a reducing agent and removes the acids that give the jam a sharp taste.
- DIt is an acidic gas and maintains the pH of the jam at a suitable value to give it a sharp taste.