| 摘要 |
A continuous coupled jet-cooking/spray-drying process for processing or co-processing inherently water-dispersible or water-soluble crystalline polymers, such as starches, starch mixtures, gums (e.g., locust bean gum, carrageenan, agar), viscosifying proteins (e.g., gelatin), starch-gum mixtures, and fully hydrolyzed polyvinyl alcohols, is disclosed. The process 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. Non-high amylose prepared by this process are characterized in that they are substantially non-crystalline and have bulk densities higher than the bulk densities of the same base starches pregelatinized by jet-cooking and spray-drying in two separate steps.
|
