Introduction
The eggplant is an important food crop that belongs to the same family (Solanaceae) and genus (Solanum) as the potato and tomato. It is a very popular vegetable in many parts of the world, particularly in the warm parts of southern Europe, the Middle East, and Asia. The eggplant has a number of different names in English speaking countries – the two most common are eggplant and aubergine. The plants were originally called eggplant because the fruit on the first plants that arrived in Northern Europe and America, which were grown as ornamentals in the 1600s, looked just like small white eggs. These plants are still available today but their fruits are not as tasty as the well-known dark purple variety.
Today, eggplants come in many shapes, sizes, and colours and are enjoyed around the world. Several different species of Solanum are commonly known as eggplant: Solanum melongena is the common eggplant or aubergine, Solanum aethiopicum is the Gilo eggplant, and Solanum macrocarpon is the Goma eggplant.
Wild eggplants
As with many of today’s kitchen vegetables, the wild varieties of eggplant look very different from the varieties that are commonly available in our food markets. The fruits on wild eggplants are small (ranging from pea-size to baseball-size), yellow in colour, and taste very bitter. The stem of the plant can also be very spiny. Wild varieties grow in India, Africa, and Southeast Asia and most botanists have believed that eggplant originated in India. However, some botanists think that the domesticated eggplant originated in Southeast Asia because there are more varieties of eggplant found there than anywhere else.
Wild eggplant varieties are very bitter – almost inedible – and, interestingly, nearly all wild eggplants seem to be resistant to the pests and diseases that commonly affect domesticated varieties. This may be because bugs and insects choose to stay well clear of something that contains so many bitter compounds.
Domestication of the eggplant
It is not known exactly where the eggplant was first domesticated, but most botanists think that ancient civilisations in Southeast Asia were the first to grow, and gradually improve, eggplants for eating. Over many years, they selected seeds to grow for the next season only from plants with preferred qualities. The favoured plants most likely had tastier (less bitter) and bigger fruit, and smoother stems.
Eggplants were grown in China as early as 59 BC and Chinese people used some of the techniques that are still used today, including hybridisation or cross breeding, to create their own varieties of different shaped and coloured fruits. The long and slender eggplant varieties are today referred to as Chinese eggplants. It is said that in China, as part of her “bride price” a woman used to be required to produce at least 12 eggplant recipes prior to her wedding day.
Eggplants grow well in hot temperatures and don’t like frosts so they grow very well in warmer parts of the world such as Southeast Asia, South America, and southern Europe. They are traditionally a summer vegetable although it is now possible to buy eggplant almost year round because many farmers use greenhouses. As our climate warms, eggplant may be set to spread in both cultivation and popularity. Asia accounts for 78% of world eggplant production; Turkey, the largest producer in the European Union, accounts for 19%. European eggplant harvests are often consumed locally, as well as exported to colder countries in northern Europe.
Use of the eggplant
Eggplant is cooked and eaten in a variety of ways; it can be marinated, stuffed, roasted, grilled, fried, or stewed. Well-known recipes include melanzane parmigiana in Italy, a delicious dip called Baba Ghanoush in the Middle East, and Bangan ka Bhurta (Indian Eggplant). In Japan, it is among the top five most important vegetables and is eaten in many different ways.
Eggplants have a unique flavour and because of their sponge-like flesh they tend to absorb many flavours of the ingredients they are cooked with. Some cooks believe that "salting" the eggplant prior to cooking helps to reduce the amount of oil it absorbs and removes any bitterness. Salting involves cutting the eggplant into slices, sprinkling them with salt, and leaving them for 20-30 minutes until beads of water form on the surface. The water is then wiped off and the eggplant is ready to be cooked. Many other cooks believe that salting is not necessary anymore because bitterness has been bred out of the fruit.
How the eggplant has changed
There is a big difference between modern eggplants and the wild varieties from India, Southeast Asia, and Africa. A large variety of eggplants are now available — from the dark purple teardrop ones to pink and white stripy Italian eggplant and long, skinny Chinese eggplants. The main changes to the fruit, which have resulted from many years of plant breeding, include a much better tasting fruit, often much bigger fruit, lots of different colours and sizes, and also a much higher yield (more fruit per plant). However, the changes to the eggplant have not been all been for the best. Plant breeders now realise that wild eggplant (so bitter it is almost inedible for humans) is rarely attacked by pests, yet the domesticated varieties are susceptible to attack from a variety of pests. Wild eggplants also tend to be more drought resistant than the commonly cultivated varieties. Plant breeders are looking closely at the qualities of the wild relatives of eggplant to try to enhance resistance to pests and disease in the domesticated varieties but, at the same time, maintain the delicious taste.
To find out more about the work of EU-SOL, a multi-million Euro research project funded by the European Commission focussed on improving the quality of potatoes and tomatoes, click here.
