Stable starch-lipid compositions prepared by steam jet cooking

摘要

Starch is isolated from plant sources as discrete granules that are insoluble in water at room temperature due to hydrogen bonding and areas of crystallinity within the granule. Although true solutions of starch in water are difficult to prepare using conventional cooking procedures, starch solutions are easily obtained by passing starch-water slurries through a continuous steam jet cooker (Winfrey & Black, 1964; Klein & Brogly, 1981). This technique has been used commercially for decades to prepare starch solutions for non-food applications and involves pumping an aqueous starch slurry through an orifice where it is mixed with steam at high temperature and pressure. The intense turbulence that results from the condensation of high pressure steam and the passage of excess steam through the cooker not only promotes rupture and dissolution of starch granules but also leads to mechanical shearing of starch macromolecules and a lowering of solution viscosity (Klein & Brogly, 1981).