almidones

Almidones are a group of polysaccharides that serve as the primary storage carbohydrates in plants. They are composed mainly of two glucose polymers: amylose, which is largely linear, and amylopectin, which is highly branched. These polymers form starch granules that accumulate in plastids such as amyloplasts in seeds, tubers, and endosperm. The relative amounts of amylose and amylopectin vary by species and cultivar, typically around 20–30% amylose and 70–80% amylopectin, with some varieties exhibiting higher amylose content.

Starches are extracted as a fine powder from crops such as maize (corn), potatoes, rice, wheat, cassava (manioc), and tapioca. In cooking and food processing, starch granules undergo gelatinization when heated in water: hydrogen bonds loosen, granules swell and absorb water, and the mixture thickens. Upon cooling, retrogradation can occur, leading to gel formation or staling in baked goods. The crystalline and amorphous regions within granules influence their functional properties and digestion.

Digestibility depends on enzyme action: amylases cleave α-1,4- and, to a lesser extent, α-1,6-glycosidic bonds, yielding maltose and glucose. A portion of starch is resistant starch, passing to the large intestine largely intact and acting as dietary fiber with potential prebiotic effects. Starch consumption influences glycemic response.

Applications include thickening and texturizing in foods, fermentation substrates for bioethanol production, and uses in paper, textiles, and biodegradable materials. High-amylose starches and modified starches are developed to tailor functionality. Analytical tests include the iodine-binding assay, which yields a characteristic color with amylose-containing starch.