Knowledge is knowing that a tomato is a fruit. Wisdom is not putting it in a fruit salad.

Tomatoes (or ‘apples of love’, as they were once known by the French), are native to South America and were originally grown for decorative purposes. The historical tomato was thought to have been small and yellow in appearance. Spanish settlers in South America were reluctant to eat them, initially believing them to be poisonous due to the bright shiny fruit. They weren’t far wrong – the tomato belongs to the deadly nightshade family.

Today, consumption of fresh and processed tomatoes is second only to potatoes. All New Zealand tomatoes are ripened on the vine which makes them tastier than some imported varieties. There is a large range of specialty and pre-packed tomatoes available. Most tomato varieties are of Dutch origin and are selected for flavour, quality, colour and size.

Tomatoes on the vine, or on the truss, are popular. Small, medium and large tomatoes are sold on the truss. There are many different vine varieties; as a rule, vine varieties have a very intense flavour.

Cherry tomatoes have a sweet, intense flavour and are very popular with children. Several different varieties are on the market. Coloured red or yellow, the shape varies from round to oval to pear-shaped. Small plum tomatoes are particularly sweet and higher in acid.

Plum, low acid and Roma tomatoes are oval or plum shaped, have firmer flesh, fewer seeds and less juice than standard varieties, making them ideal for cooking. They come in differing shapes and sizes. Levels of acid vary with variety, and no tomato is entirely acid-free. Large plum varieties are often known as Roma.

Outdoor tomatoes make up a very small percentage (around 1 percent) of the total tomato crop and tend to be less firm than greenhouse-grown tomatoes. They have a lumpier and flatter shape and tend to be available from January to April.

When purchasing tomatoes, choose smooth, firm and plump tomatoes with an even colour and no blemishes. For best flavour make sure the fruits are fully red. Tomatoes should be stored at room temperature out of direct sunlight. Tomatoes will ripen in these conditions. Do not refrigerate unless they are over ripe. Refrigerated tomatoes do not have the full flavour of tomatoes stored at room temperature.

Tomatoes are a good source of vitamin C and a source of vitamin A (from beta-carotene) and contain potassium. Tomatoes contain many different phytonutrients; the most well-known being the carotenoid lycopene, responsible for the red colour. It is of interest as it is found in few other foods and is being studied for a range of potential health benefits. Other carotenoids, particularly beta-carotene, are also found together with phenolic acids and flavonoids.

Mark Southon, executive chef at Auckland’s O’Connell St Bistro, uses tomatoes with seared tuna, capers and buffalo mozzarella (pictured above).