Immobilized-cell carrageenan bead production and a brewing process utilizing carrageenan bead immobilized yeast cells

摘要

A process for immobilizing viable cells in gelled carrageenan beads comprises preparing an aqueous phase that is a mixture of a gellable concentration of un-gelled carrageenan, in an aqueous suspension of viable cells, in which the mixture's potassium concentration is low enough that the thermogellation temperature of the carrageenan in the suspension is below a temperature to which the viable cells are substantially thermosensitive. This is done at a first processing temperature that exceeds the thermogellation temperature of the carrageenan in that aqueous suspension, but which is below the temperature to which the cells are substantially thermosensitive. A mixture of the aqueous phase and a non-reactive food-grade oil phase is then prepared, and subjected to shear by passing it through a static mixer under flow-rate conditions selected to disperse the aqueous phase in the oil phase, such that a resulting emulsion has a selected droplet size distribution. Thereafter, the temperature of the resulting emulsion is decreased from the first processing temperature, to a second processing temperature which is below the thermogellation temperature of the carrageenan in the suspension. This results in the formation of polymer gel beads having the immobilized viable cells entrapped therein.