Potato is a living plant tuber (a modified stem specialized for storage of food). There is a lot of difference in the cellular structure and chemical nature of the potato peel and that of the flesh. The flesh is made up of parenchyma cells, specialized to store starch. The walls of these cells are made up of cellulose and they are joined together by a sort of glue called pectin. The peel or the skin of potato is made up of cork cells, the walls of which have a lot of lignin and suberin deposits. These substances give a greater mechanical and structural strength to the corky cells and hence are easy to remove as a continuous peel. In un-boiled potato the corky skin and the flesh of potato are sealed together by pectin. Hence peeling is difficult. During boiling, little change occurs in the corky peel, but the fleshy parenchyma becomes soft. Also the glue-like substances present between the cells, swell up and break down. As a result, the adhesion between the peel and the flesh is reduced and the effort required to separate the peel from the flesh is highly reduced. Hence it is easier to peel a boiled potato.
