Pectins are the gel-forming polysaccharides extracted chiefly from citrus peel and apple pomace, the cell-wall components that set jams and jellies. Citrus peel ranks among the principal commercial sources: the outer coloured flavedo supplies essential oils while the white albedo is rich in pectin, which is extracted with hot acid and precipitated with alcohol. Their gelling depends on degree of esterification, with high-methoxyl pectins setting in high-sugar, acidic systems and low-methoxyl types gelling with calcium. Beyond preserves they stabilise yoghurts, confectionery, and pharmaceutical preparations, and they count as soluble dietary fibre. Standardised grades let manufacturers achieve consistent texture across products.