Which of the following is a white, crystalline organic acid often used as an acidulant in grape and lime-flavoured drinks, gelatine desserts, jams, jellies, and hard sour confectionery?

Tartaric acid

The correct answer is option 2. Tartaric acid.

Tartaric acid is a white, crystalline organic acid naturally found in fruits like grapes, bananas, and tamarinds.

It is commonly used as an acidulant in various food and beverage items, including:

Grape- and lime-flavored drinks:  Add tartness similar to the natural flavor of these fruits.

Gelatin desserts, jams, and jellies:  Enhances flavor and helps with the setting.

Hard sour confectionery:  Contributes to the sour taste.

While the other listed options are also organic acids, they have different properties and applications:

Malic acid: Found in fruits like apples and cherries, used as an acidulant and flavoring agent.

Oxalic acid: Toxic and not used in food, found in some plants and vegetables.

Ascorbic acid: Also known as Vitamin C, not commonly used as an acidulant.