What is Food?
According to Encyclopedia Britannica, food is any substance consumed to provide nutritional support for an organism. Food is usually made of plant, animal or fungal origin, and contains essential nutrients needed by the body of an organism (human or animal).
Food in real sense is any substance that is or can be consumed by living organisms, especially by eating, in order to sustain life. Food is normally eaten or drunk by living things. The term food also includes liquid drinks. It is the main source of energy and of nutrition for animals, and is usually of animal or plant origin. Food makes your body work, grow and repair itself. The kind of food you eat can affect the efficiency of these processes. Body function and the food that sustains it is infinitely complex. Food is in fact one of the most complicated sets of chemicals imaginable. The substance is ingested by an organism (human or animal) and assimilated by the organism’s cells to provide energy, maintain life, or stimulate growth.
Food sources
Most food has its origin in plants. Some food is obtained directly from plants; but even animals that are used as food sources are raised by feeding them food derived from plants. Cereal grain is a staple food that provides more food energy worldwide than any other type of crop. Corn (maize), wheat, and rice – in all of their varieties – account for 87% of all grain production worldwide. Most of the grain that is produced worldwide is fed to livestock.
However, it is also important to remember that numerous edible fungi, especially mushrooms, contain many foods that are not from animal or plant sources. In the preparation of fermented and pickled foods, fungi and aquatic bacteria are used, such as leavened bread, alcoholic beverages, cheese, pickles, kombucha, and yogurt. Blue-green algae such as Spirulina are another example. To retain or chemically change an ingredient, inorganic compounds such as salt, baking soda, and tartar cream are used.
Plants as food source
Many plants and parts of plants are consumed as food and nearly 2,000 plant species are grown for food. There are many distinct cultivars of each of these plant species. For animals, including humans, plant seeds are a good source of food since they provide the nutrients required for the plant’s initial development, including many healthy fats, such as omega fats. In fact, seed-based foods are the majority of the food eaten by humans. Cereals (corn, wheat, rice, et cetera), legumes (beans, peas, lentils, et cetera), and nuts are among the edible plants. Oilseeds – sunflower, flaxseed, rapeseed (including canola oil), sesame, etc. – are also pressed to produce rich oils. Seeds are usually rich in unsaturated fats and are considered a balanced meal in moderation. Not all plants, though, are edible. Large seeds, such as those from a lemon, face a danger of choking, whereas seeds from cherries and apples contain cyanide that can only be harmful if eaten in large amounts.
Animals as food source
Animals are used as food either directly or indirectly by the products they produce. Meat is an example of a direct commodity that comes from muscle systems or organs taken from an animal (offal).
Animal-based food products include milk produced by mammary glands that is drunk or refined into dairy products in many cultures (cheese, butter, etc.). In addition, eggs, which are sometimes consumed, are laid by birds and other species, and bees produce honey, a reduced nectar from flowers that is a common sweetener in many cultures. In periods of food shortages, some cultures eat blood, sometimes in the form of blood sausage, as a thickener for sauces, or in a cured, salted form, and some use blood in stews, such as jugged hare.
Classification of foods
Foods are categorized based on their roles in the body. The basic classifications of food are:
- Energy giving foods
- Body building foods
- Protective foods
Energy giving foods
This group consists of foods rich in carbohydrates, fat and protein. They may be broadly divided into two groups.
- Cereals, pulses, roots and tubers: In addition to energy, cereal contains significant quantities of proteins, minerals and vitamins in the diet. In addition to providing energy to the body, the pulses often give protein and B vitamins.
- Fats, Oils and pure carbohydrates like sugars: Sugars provide only energy and fats provide concentrated source of energy.
Body Building Foods
Protein rich foods are referred to as body building foods. They can be meaningfully categorized into two groups.
- Milk, egg, meat and fish: They are rich in proteins of high biological value. These proteins have all the essential amino acids in correct proportion for the synthesis of body tissues.
- Pulses, nuts and oilseeds: They are rich in protein but may not contain all the essential amino acids required by the human body.
Protective Foods
Foods rich in protein, vitamins and minerals have regulatory functions in the body like maintaining the heartbeat, water balance, temperature, etc.
Protective foods are broadly classified into two groups.
- Foods rich in vitamins and minerals and proteins of high biological value, For example, milk, egg, and fish.
- Foods rich in certain vitamins and minerals only. For example, green leafy vegetables and fruits