An investigation of operational parameters of jet cutting method on the size of Ca-alginate beads

摘要

A rarely used option for reduction the size of Ca-alginate beads is the jet cutter, a rotating disk coupled to the output of the nozzle, and responsible for cutting the jet in smaller sizes. There are few systematic studies in the literature about this apparatus and its operational effects on the bead size. Therefore, this work aimed to investigate some operational parameters on the size of Ca-alginate beads produced by dripping and jet cutting methods. First, physicochemical properties of different concentrations of sodium alginate solutions were determined, and the viscosity of 0.92Pas, corresponding to 2% (wt/wt), was found to be optimum for bead formation. For the dripping process, the highest flow rate of the alginate solution (49mL/min) caused a limited reduction of bead size to 2mm. This study on drop formation demonstrated that models developed for size prediction cannot be used as a tool for determination of size, due to the possible influences of the viscous forces. The jet cutter, adapted to a continuous jet regime, allowed to reduce from 5.2 mm to less than 1mm in size with the increase of the rotation speed from 200 to 900rpm. However, this increase resulted in higher tangential velocity of the beads, requiring larger collect recipients. This study developed the basis for broadening the application of the jet cutter to different biopolymers and ensures a better performance of this system.