Pectic substances of plant cell walls, polysaccharides built from uronic acid monomers that cement cells together and give structure to fruits and vegetables. They give jams their set, stabilize fruit preparations, thicken juices, and serve as soluble fiber in the diet. In processing, their breakdown by pectin-degrading enzymes softens fruit, so controlling that enzyme activity is key to texture in juices, preserves, canned produce, and fresh-cut fruit. Ripening, heat treatment, and enzyme preparations all act on polyuronides, and understanding their chemistry lets processors tune firmness, clarity, and mouthfeel across a wide range of fruit and vegetable products.