The direct consumption of algae as human food is widely practiced around the world. A list of more than hundred species can be made which provide direct food to the human beings, especially to the coastal people of the world.
With the beginning of civilisations and human settlements, the need to preserve excess foods became essential for survival. Since then, many traditional and household practices have evolved to limit food spoilage. Such as cooking, the addition of spices and fermentation. In modern commercial food production, spoilage and contamination are preserved by a variety of methods such as Filtration, Lyophilisation, Refrigeration, Pasteurisation, Canned Food, Vaccum packing, Irradiation, Food preservatives etc.