Definition of Tomato
Is tomato a fruit or vegetable? To determine whether tomatoes are fruit or vegetables, the definitions of tomatoes and vegetables must be closely examined.
The tomato is an edible fleshy berry of the plant Solanum lycopersicum or Lycopersicon esculentum and is commonly called the tomato plant.
Tomatoes are tender perennials and were grown as such when its earlier ancestor was first used as food by the Aztecs (Mesoamerican Nahuatl speaking ethnic groups from central Mexico) and other people of Mesoamerica (a cultural region of North America that extends from central Mexico through Belize, Guatemala, El Salvador, Nicaragua, and northern Costa Rica) western South America. They were cultivated along with other vegetables.
However, tomatoes are now mainly cultivated and grown as annual crops. The most important physiological and botanical categorization of tomatoes to note regarding the debate on whether tomatoes are fruits or vegetables is that the tomato is botanically a berry which is technically a fruit. However, tomatoes are culinarily considered vegetables.
What is a Fruit?
The fleshy or dry ovary of flowering plants that encloses the seed or seeds is known as a fruit. However, the popular impression and perceived definition of fruit only include ripened ovaries that are sweet and succulent or pulpy. This perception further enhances the narrative that tomatoes are more like vegetables than fruit. This consideration is bolstered by the fact that it is derived from small plant vegetation, not trees.
Definition of Fruit; to determine if tomatoes are fruits or vegetables
Botanically speaking, a fruit is a seed-bearing structure that is formed from the ovary of angiosperms (flowering plants) after pollination. This criterion applies to the tomato among other fruits.
The primary purpose of the fruit is to safeguard the health and viability of the seeds and to aid in their successful propagation.
The fleshy tissue of the fruit protects the seeds and aids in providing nourishment after germination as it decays in instances that it is not consumed by another organism.
The fruit structure is comprised of two main parts the pericarp and the seed. The outer wall of the ovary from which the fruit developed is called the pericarp layer.
This pericarp layer is made up of three layers from the outermost to the inner layer surrounding the seed or seeds namely:
Exocarp or epicarp
The exocarp or epicarp is the outermost layer of the pericarp that constitutes the skin of the fruit and will typically be tougher than the rest of the fleshy parts of the fruit to protect the seeds from any exterior damage.
Mesocarp is the thick, fleshy, and the most voluminous part of the fruit and the second and middle layer of the pericarp. It is the part of the fruit that is most nutritious and most consumed. Much of this part is constituted of fibrous plant tissue.
The innermost layer of the pericarp of the fruit that usually develops into the pith or the medulla is called the endocarp. It is the final layer before the seed.
Types of fruits
Fruits are broadly classified into three types or categories and one less significant one based on the number of ovaries and flowers that were involved in their formation. They are further sub-divided based on various other criteria.
The main broadly grouped types of fruit and one additional category are:
- Simple fruits
- Aggregate fruits
- Multiple fruits
- Accessory fruits
Simple fruits are those that developed from a single ovary of one or more carpels in an individual flower.
Simple fruits are further sub-divided into dry or fleshy fruits depending on the pericarp.
Dry fruits have pericarps that are generally not succulent and become dry or shriveled as soon as the fruit begins to mature.
There are two types of dry fruits and they are termed:
- Dehiscent fruits
- Indehiscent fruits
Dehiscent fruits have a pre-determined and purposely evolved weakness in the pericarp along strategic areas, sutures, or seams that allows them to dehisce (split or burst open) when they mature to disperse the seeds.
Examples of some types of dehiscent fruits are:
- Follicle– A dry, uniocular dehiscent fruit that is formed from a single carpel and splits along a single suture on maturity. E.g. Consolida (some of the larkspurs), milkweed (Asclepias), peony fruit.
- Legumes-Dry dehiscent fruits that are formed from a single carpel and when mature splits along its pre-determined weak strips along their dorsal and ventral sutures. E.g. Peas, beans, lentils, chickpeas, soybeans, peanuts, vetches, clover.
- Capsule– Made up of several carpels and splits into four sections. Examples; Cotton (Gossypium), Eucalyptus (Eucalyptus), Witch Hazel (Hamamelis), Horse Chesnut (Aesculus hippocastanum).
- Silique-This is made up of two carpels that split when the fruit reaches maturity. Examples; Brassica Rappa (field mustard), stock (Matthiola), wallflower (Erysimum).
Indehiscent fruits are the seed-bearing structures of dry fruits that do not split on maturity to disperse the seeds. They do not have a pre-determined strip of weakened sutures so the whole fruit drops from the plant when it attains maturity.
- Akene or Achene – A monocarpellary (formed from one carpel) indehiscent plant that contains a seed that almost fills the pericarp but does not stick to it. The seed is attached to the fruit at one point by a funiculus (the stalk attaching the ovule and later seed to the ovary wall in angiosperms; it serves as an anchor and provides vascular supply to the ovule and seed).-Examples; buttercup, buckwheat, caraway, quinoa, cannabis, sunflower.
- Caryopsis– A monocarpellate (formed from a single carpel) simple dry indehiscent fruit that is very similar to the achene fruit but differs in having a pericarp that is fused to the thin seed coat. Examples; rice (Oryza), wheat (Triticum), corn, barley (Hordeum), oats (Avena), rye (Secale).
- Samara – An indehiscent fruit that is classified as being achene but has an additional evolutionary adaptation of wing-like protrusions or elongations. These wing-like structures are comprised of flattened extensions of fibrous papery tissue that develops from the ovary wall. The aerodynamics and shape of the samara enable the seed to be carried by wind further from the parent tree than average. Examples; vine maple (Acer circinatum), Combretum zeyheri, the Siberian elm (Ulmus pumila).
- Schizocarp – An indehiscent fruit that is made up of multiple carpels which separate when mature into several mericarps. Examples; parsnip (Pastinaca sativa), musk mallow (Malva moschata), cranesbill.
- Nut – A dry indehiscent one-seeded fruit that resembles an achene but develops from a compound ovary with more than one carpel, is often larger and has a tough woody wall. Examples; Chesnut, hazelnut, acorn.
- Cypsela – A dry monocarpellate indehiscent fruit formed from a double ovary in which one ovule develops into a seed. It is similar to achene and characteristic of members of the family Compositae (Asteraceae). Cypsela typically has a crown of hair-like processes known as a pappus. Examples; dandelion, Sonchus, sunflower.
A fruit whose pericarp (fruit wall) and accessory parts develop into succulent tissue when it reaches maturity. There are three main types of fleshy fruits namely:
A berry is a small pulpy and fleshy usually edible fruit. They do not have stones or pits but will usually have several small seeds. Berries are often rounded, brightly colored, juicy, and may either be sweet, tart, or sour. Tomatoes are typical examples of berries.
Raspberries, blackberries, and strawberries are not true berries but aggregate fruits (fruits that consist of several small fruits). True berries are fruits like; blueberries, grapes, cranberries, tomatoes, gooseberries, bananas, and peppers.
In common usage, the word berry is used to describe a wide range of different small fruits many of which are not true berries. As usual with botanical descriptions, that of the berry has specific physiological criteria that determine the categorization.
The botanical description of a berry states that it is a simple fruit that does not have a stone or pit, that contains seeds and pulp produced from a single ovary of an individual flower.
There is no distinction or demarcation between the middle and inner layers of the fruit wall.
Types of Berries
Tomatoes and other berries are categorized under the following types of berries:
A fruit that is formed from a single or compound ovary with only one pistil of an individual flower. The entire pericarp is fleshy, it usually has several seeds which constitute the only parts that are not fleshy and the skin may sometimes be taut.
Examples of simple fleshy berries are grape, tomatoes, papaya, banana, pomegranate, sapote guava, and avocado.
Hesperidium is a modified berry with a leathery rind studded with volatile oil glands in pits. It has parchment-like partitions between sections that contain flesh packed with small vesicles that are full of juice.
Examples are citrus fruits like oranges, lemon, tangelo, lime, grapefruit.
A type of berry that is indehiscent (not splitting open to release the seeds within), one-celled, and many-seeded with a hard thick rind from the gourd family.
Examples are cucumber, melons, squash, zucchini, and pumpkin.
Drupes or stone fruits are formed from a single carpel and differ from tomatoes by containing a single seed. The exocarp is made up of thin skin. The mesocarp is typically fleshy and succulent and the endocarp eventually becomes stony-hard.
Examples; mangoes, apricot, peaches, cherries, pecans.
A fibrous one-seeded drupe is also referred to as a dry drupe. It consists of a single seed encased in a hard fibrous membrane.
The pome fruit has a core or ovary that is surrounded by edible fleshy receptacle tissue that is not actually part of the pericarp that is separated from the seeds by tough tissue from the core. It is a typical fruit of the Rosaceae family.
Examples; apple, pear, quince, and loquat.
Aggregate fruits also called etaerio, develop from a single flower that sprouts multiple simple pistils (the innermost seed-bearing female part of a flower) with each pistil holding one carpel and together forming a fruitlet. Each fleshy lobe is actually an individual fruit attached at the end.
The aggregation of the pistils as fruitlets is termed an aggregate fruit or etaerio. Examples; blackberries, raspberries, dewberries, Fragaria ananassa (strawberry), Annona squamosa (sugar/custard apple).
Multiple fruits collective, false, or composite fruits are formed by the inflorescence (cluster of several) of flowers with each making up individual fruitlets that fuse into a single mass or one large fruit at maturity.
Examples; Pineapple, mulberry, breadfruit, soursop, jackfruit, Indian mulberry (noni fruit).
Some of the fibrous tissue of accessory fruits are derived from some nearby tissue that is exterior to the carpel rather than the floral ovary.
These fruits that contain tissue derived from plant parts other than the ovary are similar and sometimes include plants in the pome drupe category. Examples; apple, pear strawberry.
Is Tomato a Fruit?
Given the general antecedence and common usage of tomatoes, it and other similarly ambiguously defined foods are the subjects of some confusion in terms of categorization. Are tomatoes actual fruit? This question has been asked over the course of hundreds of years.
From the botanical definition of what constitutes a fruit above it can be concluded that:
- Since fruit is the fleshy or dry ovary structure of angiosperms (flowering plants) containing the seeds, tomatoes fitting these criteria are indeed fruits.
- The botanical categorization of the berry as a type of fruit automatically defines tomatoes as fruits since they (tomatoes) are definitively categorized as berries.
What are Vegetables?
Vegetables can be broadly defined as edible plants and their parts apart from the fruits and seeds, and particularly those used as food by humans and animals.
Vegetables are also said to be botanically non-existent as scientifically they are considered to be either roots, stems, bark, leaves, or flowers and that the term vegetable is a culinary creation of the last few centuries.
In a September 2015 BBC Earth forum, Henry Nicholls, a freelance science journalist, and teacher put some questions to the forum.
The topic of discussion and questions asked included what vegetables are, whether tomatoes can be considered vegetables, and whether there is scientifically such a thing as vegetables.
Among the many participating respondents was Wolfgang Stuppy, research leader in Comparative Plant and Fungal Biology at the U.K.’s world-renowned Royal Botanical Gardens at Kew & Wakehurst Place.
His response was as telling as it was surprising: “The term vegetable does not exist in botanical terminology” Tamara Kershner, a senior special field investigator, and biologist echoed this position stating: ” Vegetable is a general term that does not exist in the biological world.”
In the more modern specified classification especially in culinary considerations, vegetables are sometimes defined excluding certain plants, like cereals, herbs, spices, and parts of other plants like the fruits, seeds, leaves, stems, bark, roots, or forms of plant extract like pulp, sap, oil, resin, and other plant extracts.
With the information above taken into consideration, vegetables can be more descriptively defined as any parts of a plant, and in some instances fungi like edible mushrooms, and edible algae like seaweed, apart from the fruits and seeds that are consumed for food but may include mature fruits that can be used as part of the main meal.
Examples of regular botanically defined vegetables: Lettuce, asparagus, spring onions, celery, broccoli, cauliflower, cabbage, parsley, spinach, coriander leaves, etc.
Culinary vegetables are foods that mainly include but are not restricted to vegetables and other sources of food that can be used to cook or prepare a main meal but excluding meat, poultry, fish, other seafood, and dairy products.
Several foods are not botanically vegetables but are considered to be culinarily vegetables because of their suitability for use in main course recipes.
Another reason some foods that are not botanical vegetables are defined as culinary vegetables is the flawless way they can be prepared and used in the same way or together with true vegetables.
Examples of Botanical Fruits that are Culinary Vegetables
- String/green beans
Examples of non-Plant-based Foods that are not true Vegetables but like tomatoes are used and listed as Culinary Vegetables
- Edible mushrooms
- Edible seaweed
Edible mushrooms are the fleshy fruit bodies of many species of macrofungi (fungi with large fruiting structures that can be seen with the naked eye).
They are either epigeous (growing above the ground), or hypogeous (found beneath the ground). Some commercially cultivated mushroom types include;
- Tremella fuciformis-the snow ear, silver ear fungus, white jelly mushroom.
- Pleurotus-oyster mushroom.
- Flammulina velutipes- the enoki mushroom, golden needle mushroom, seafood mushroom.
- Lentilnula edodes-shiitake mushrooms
- Volvariella volvacea-the paddy straw or straw mushrooms.
- Stropharia rugosoannulata-the wine cap mushroom, burgundy mushroom, the garden giant mushroom.
Edible seaweed is a broad term for several species of some different forms of fibrous algae (photosynthetic eukaryotic organisms) that are similar to conventional plants and can be safely consumed or used for culinary purposes.
Edible seaweed may belong to several groups among which are:
- Multicellular algae
- Red algae
- Brown algae
- Green algae
Is the tomato a vegetable?
According to one of the widely accepted definitions of a vegetable, most of the parts of a plant are considered vegetables except for the fruit and the seeds. This definition would clearly exclude tomatoes from the group of vegetables.
However, in some instances, the roots, bark, pulp, or other plant extracts like the resin are also excluded.
Other generalized definitions include all plant matter to be part of vegetables, especially in terms of how they are used, which would classify the tomato as a vegetable.
Being that both definitions are generally correct, it would not be completely wrong to refer to the tomato as either a fruit or a vegetable depending on the context of usage.
Tomato Vegetable or Fruit?
After a brief analysis of what fruits and vegetables are and outlining the debate on the dichotomy of fruits and vegetables in regards to tomatoes, the reasons for the contentious perceptions should be outlined for clarity.
Why the tomato is sometimes thought to be a vegetable
The reasons why tomatoes are widely thought to be vegetables are as follows:
- The tomato has a much lower sugar content than most familiar fruits. This made earlier users think it must be a vegetable for that reason.
- Vegetables are used in the main course of a meal and tomato always used in the main course of a meal; therefore, it can be categorized as a vegetable just as other vegetables because of their additions to the main course of meals.
- It is not suited for and is not normally used in fruit salads along with other fruits but is suitable for, and used in vegetable salads alongside other vegetables.
- Tomatoes became the subject of legal litigation in 1887 when the Nix family when to court against federal officer Edward Hedden over the Tariff Act of 1883 imposed tax duties on vegetables but not on fruit. The Nix family who had a financial stake in the tomato trade argued along botanical lines that tomatoes were in fact fruits and should not be subject to tax. However, on May 10, 1893, the U.S. Supreme Court ruled that the tomato was a vegetable not based on botanical definition but on the popular definition that classifies vegetables by how they are used.
From all the above information it can be inferred that the tomato is culinarily a vegetable and botanically a fruit.
In view of determining the categorization of the tomato as either a fruit or vegetable, the overall function of its evolutionary purpose should also be examined.
The fundamental function of species, in general, is propagation. From an evolutionary standpoint, the success of any species is the ability to replicate itself not only a single time but to develop the ability to continually self-replicate as the parent species die off.
This is done for the species to continue to exist. Different types of organisms have evolved different ways of reproducing. Angiosperms (flowering plants) such as tomatoes have evolved to produce seeds as basic embryonic units of the parent plants carrying their genetic data.
The seeds are generated from a pollinated ripened ovule and are encased in the structure known as the fruit for protection, nourishment, and eventual dispersal and dissemination.
The fact that tomatoes are fleshy structures that contain seeds of the parent plant makes them a product of the parent plant and not necessarily an appendage or part of that plant itself.
The Merriam-Webster dictionary wrote:
“So fruits are not part of the plant itself but a reproductive part growing from the plant. The thing a tomato plant produces isn’t a part of the plant itself, any more than the egg a chicken lays is part of the chicken. When vegetables are eaten, on the other hand, either the plant itself or parts like the leaves, stems, or roots are consumed.”
A 100g medium-sized tomato contains 18 calories. 95% water and 0.9grams of protein.
Tomatoes are a generally very healthy and nutritious food. It is not accidental that the tomato is estimated to be the most consumed food second only to the potato.
Tomatoes are a major dietary source of the antioxidant lycopene which has been definitively linked to many health benefits including reduced risks of heart disease and cancer.
The main nutrients that are derived from tomatoes include:
Carbs in Tomatoes
Tomatoes contain about 3.9grams of carbohydrates which translates to about roughly 4% of raw tomatoes. A medium specimen of tomato weighing about 123grams may contain less than 5grams of carbohydrates.
Simple sugars like glucose and fructose make up 70% of the carb content in tomatoes.
Fiber in Tomato
Tomatoes are comprised of about 1.5grams of fiber per average fruit. About 87% of the fibers that are present in tomatoes are insoluble. They are in the form of hemicellulose, cellulose, and lignin.
Vitamins and Minerals
Vitamin C is one of the essential nutrients and antioxidants that can be derived from tomatoes. One medium-sized tomato can provide 28% of the Reference Daily Intake (RDI).
Potassium is another essential nutrient derived from tomatoes that is beneficial for normal blood pressure regulation and the prevention of heart disease.
Vitamin K1 also known as phylloquinone is important in aiding normal clotting of blood and bone health.
Folate Vitamin B9
Folate vitamin B9 is one of the B complex vitamins. It is essential for normal tissue growth and cell function. It is particularly important for pregnant women.
Compounds in Tomatoes
In addition to lycopene, other important compounds are contained in tomatoes such as:
Beta carotene is often responsible for giving foods that contain it a yellowish or orange hue. It is converted to vitamin A in the body.
Naringenin is a flavonoid that is found in the tomato skin and has been shown to decrease inflammation and protect against various diseases.
Chlorogenic acid is a powerful antioxidant compound that may lower abnormally high blood pressure.
Benefits of Tomatoes
Whether you are using tomatoes as fruits or vegetables, they all give you the same health benefits. Here are the benefits of eating tomatoes:
- Improved skin health.
- Lower risk of heart disease.
- Lower risk of cancer.
- Savory taste in cuisine.
- Relief from inflammation.
- General detoxication of the body.
- Enhanced visual aesthetics of food.
- Enhanced visual aesthetics of the garden.
- Enhances and compliments the taste of other foods it is combined with.
- Provision of healthy compounds, minerals, and nutrients.
Allergies or side effects from tomatoes are extremely low and very rare. However, in the unlikely event, allergic reactions and side effects do occur, the condition is called pollen-food allergy syndrome, or oral allergy syndrome.
The immune system attacks fruit and vegetable proteins that are similar to pollen leading to allergic reactions. These reactions may include itching in the mouth, scratchy throat, or swelling in either of those places.
People with latex allergies can also experience cross-reactivity (an individual’s allergic reaction to a substance that they are not directly allergic to but react to as the result of allergy to another substance) to tomatoes.