Development of macrocapsules containing bioflavors generated in situ by immobilized cells

Abstract

An alternative approach to microbial production of bioflavors, eliminating the need for lengthy product purification, is presented. It is based on co-immobilization of precursors for bioflavor generation by microbial cells, traditionally employed for food and beverage processing, within beads made of food-grade gel matrix. Following incubation under controlled conditions the bioflavor — or bioflavor mixture — is generated and accumulated within the beads. The flavor-retaining bead may then be employed as a food additive. A feasibility study demonstrated this approach with ethanol production by baker's yeast co-immobilized with glucose medium. Means and conditions for bead preparation and control of ethanol levels and production rate are presented. Complex bioflavor generation was also demonstrated by baker's yeast co-immobilized with apple juice, generating cider flavors. Beads providing beer taste were also readily made via co-immobilization of commercial brewing yeast with malt. Furthermore, the potential inherent in bioflavor generation by co-immobilization of filamentous fungi with an emulsion of oily precursor was demonstrated by γ-decalactone production from castor oil.