ABSTRACT
When viewed in cross section, moving from the outside inwards, a citrus fruit has the following layers (Figure 8.1):
• a thick cuticle belonging to the epidermal cells, containing the stomata; • the epicarp or flavedo, made up of parenchymatous tissue which is rich in pigments
(chloroplasts and chromoplasts); • the albedo, parenchymatous tissue composed of irregular-shaped spongy cells which
are white in colour and separated by large air pockets;
• the endocarp, which is the edible portion of the fruit, made up of segments containing the juice vesicles which have ultra-thin walls. The segments are covered by a thin carpellary membrane and are distributed around a central axis which has the same composition as the albedo;
• the seeds, found around the central axis embedded in the endocarp.
