Pectin is a polysaccharide from the cell walls of plants that helps plant cells to grow and also to stick to their neighbors. Commercially, pectin is extracted mostly from citrus peels, but other plants are also used. Pectin is the gelling agent that helps jams and jellies to set, giving them a consistency that is useful for spreading on toast. It does this using a very similar mechanism as the one it uses to keep plant cells together. The chains of sugar molecules (polysaccharides) can form bond between strands, creating an elastic network known as a gel…or jelly.