Production of Instant Rice Protein Concentrate by Rotating Pulsed Fluidized Bed Agglomeration Using Hydrolyzed Collagen Solution as Binder

Abstract

The rice protein has raised interest due to its unique nutritional and nutraceutical properties. Rice protein concentrate (RPC) is often used as a food or pharmaceutical ingredient in powder form, however, it presents fine particles and poor instant properties. This work aims to produce an instant and nutritional powder through agglomeration of RPC using a rotating pulsed fluidized bed (RPFB). Aqueous solution of hydrolyzed collagen HC (10 % and 30 % w/w) was used as a binder at flow rate of 1.5 mL/min and pressure of 80 kPa. The air temperature was at 65 °C. The influence of the binder concentration on the particle size and quality of the product was investigated. The agglomeration was stopped when 120 mL of binder was atomized, after that, the product was dried. The atomization of HC solutions provides the agglomeration, suggesting that HC can be a powerful binder for RPC agglomeration. The evolution of the particle growth was detected by Parsum probe. The binder concentration presented strong influence on the increase of the particle size. Higher binder concentration resulted in granules with median diameter 6 times larger than those of raw RPC, while a 4 time increase was achieved using lower binder concentration. Agglomerated particles had higher protein content, presenting free-flow improvement and lower wetting time. The RPFB was useful to fluidize the RPC particles and to perform the agglomeration, resulting in an instant powder with desirable moisture content. The powder produced presented a high potential to be used as an ingredient in food or pharmaceutical formulations.