Continuous coupled jet-cooking/spray-drying process and novel pregelatinized high amylose starches prepared thereby

A continuous coupled jet-cooking/spray-drying process for processing inherently water-dispersible or water-soluble crystalline polymers, such as starches, polygalactomannan gums, and fully hydrolyzed polyvinyl alcohols, is disclosed. It involves the steps of: (a) forming a slurry or paste of the polymer and water, (b) jet-cooking the slurry or paste with steam at a temperature sufficient to fully disperse or solubilize the polymer, (c) immediately conveying and introducing under elevated temperature and pressure the jet-cooked dispersion or solution into a nozzle of a spray-dryer chamber, (d) atomizing the jet-cooked dispersion or solution through the nozzle, (e) drying the atomized mist within the spray-dryer chamber at a temperature sufficient to dry the polymer; and (f) recovering the dried polymer as a water-dispersible or water-soluble powder. High amylose starches (above about 40% amylose) prepared by this process are characterized in that the starch is substantially non-crystalline and substantially non-degraded. Starch mixtures, mixtures of high amylose starches and other starches, gums, or polyvinyl alcohols can be co-processed.