Onions are vegetables that are harvested from the plant Allium cepa. In many countries, small onions are used to make pickled onions. Pickled onions can be stored for a long time because the growth of microorganisms is prevented. Pickled onions are made using this method. • Remove the dry outer layer from small onions. • Place the onions in a sodium chloride solution for several hours. • Remove the sodium chloride solution and place the onions in a solution of ethanoic acid (vinegar). Fig. 1.1 shows a container of pickled onions and some fresh onions that have not been pickled. dry outer layer of onion container of pickled onions fresh onion [Figure 1.1]