Dietary fibre is present in different quantities throughout the different layers of the onion. Jaime et al. (2002) analysed the dietary fibre of the entire onion from the skin to the lavers in three different varieties of onion.they found that the highest levels of the total dietary fibre were present in the skin of the onion (68.3% DM ‘Grano de Oro’ cultivar), and the lowest levels were found in the inner part of the onion (11.6% DM). Also, the highest level of insoluble fibre was present in the skin of the onion (66.6% DM ‘Grano de Oro’ cultivar) with the lowest levels again located in the inner part of the onion. The authors suggested that this was due to the constituent and location of the layers. For example, each layer is made up of differing amounts of inner, outer and skin tissues, therefore the outer skin layer largely contains skin tissues compared to the inner layer, which mainly consists of inner tissues. This decreases as the layers build outward the skin layer. The soluble fibre content of the onion was found to considerably lower than the insoluble fibre content of the onion. No significant difference was found in the quantity or location of the soluble fibre (10.2% DM (‘Grano de Oro’ cultivar) in the bottom layer of the onion).