Vegetable comprises different types of plants. Some species of this plant can grow and die within just one or two years while others may grow from year to year. Some vegetable plants are very hardy and can withstand different climatic conditions while some are succulent or tender as they require specific conditions like temperature, water, light or photo-periods for growth. Other species can be grown only at a certain time of the year. Vegetable can be propagated sexually (seeds) and asexually (Vegetative parts). Its water content contributes greatly to its perishable nature.
Vegetables are of great importance to human health in terms of bioactive nutrient molecules such as vitamins, minerals, dietary fiber and phytochemicals such as bioactive peptides, flavonoids, phenolic compounds. These nutrient and non-nutrient molecules reduce the risk of chronic diseases such as diabetes, cardiovascular diseases, certain cancers etc.
Vegetables are rich sources of beta-carotene, thiamine, riboflavin, niacin, pantothenic acid, pyridoxine, folic acid, ascorbic acid, fiber, vitamin E, vitamin K, minerals (such as iron, zinc, calcium, magnesium, selenium), antioxidants (such as carotenoids, polyphenols, and glucosinolates).
Roles of vegetable in nutrition
Vitamins and Antioxidants
Vegetables are high in nutrient content and loaded with vitamins and minerals that contribute to the growth and maintenance of good health. For instance, vegetables are high in potassium which is essential for healthy blood pressure. Vegetables are rich in antioxidants which fight cellular damage and help prevent disease.
Fiber is an important nutrient found only in plant foods. Fiber helps to scour bad cholesterol out of the arteries, thus lowering the risk of heart disease. It also helps the digestive system to run smoothly and control blood sugar levels
Vegetables are also a boon to dieters because they are low in fat and calories. Large quantities can be eaten without gaining weight. The fiber in vegetables also helps in managing body weight because a diet rich in fiber makes one fuller for a longer period, which helps eat less and aid in weight loss and maintenance.
In order to make optimum use of the rich nutritional content of vegetables, choosing the right methods of preparation and cooking is as important as the consumption of adequate amounts of vegetables. To minimize nutritional losses, each vegetable should be cooked using the method and time that is most appropriate for it and consumed as soon as possible.