Amido

Amido is the term used in Portuguese and some other Romance languages for starch, a carbohydrate storage polymer in plants. Starch serves as an energy reserve in seeds, roots, and tubers, and is a major component of many staple foods. It is made primarily from two glucose polymers: amylose, which is largely linear with α-1,4 glycosidic bonds, and amylopectin, which is highly branched with α-1,6 linkages. The relative amounts of amylose and amylopectin vary by plant source, influencing properties such as gelatinization, viscosity, and digestibility.

Starch occurs as microscopic granules with a semi-crystalline structure. When heated in water, starch undergoes gelatinization: granules swell, absorb water, and form a viscous paste. Cooling can lead to retrogradation, wherein the paste becomes firmer over time. Enzymes such as amylases can hydrolyze starch to simpler sugars like maltose and glucose, a reaction exploited in baking and brewing.

Natural sources include cereals (such as maize, wheat, and rice), tubers (potatoes and cassava), and legumes. In the food industry, starch is widely used as a thickener, binder, and texture modifier, and it can be processed into glucose syrups, maltose, or bioethanol. Starch resistance varies with processing and structure; resistant starch behaves similarly to dietary fiber and can influence glycemic response.

In summary, amido refers to starch in everyday language within certain languages, describing a versatile plant carbohydrate central to nutrition and industry.