ABSTRACT

Most fermented products must be further processed after biotransformation and before packaging; these are called downstream operations. These may range from simple sedimentation to sophisticated drying of frozen products at low pressures. One useful scheme for looking at downstream operations of fermented products is the RIPP scheme (removal of insolubles, isolation of the product, purication, and polishing; Table 9.1) (Belter 1988). Removal of insolubles is usually necessary for fermented beverages, such as wine and beer, where biomass and protein precipitates may add cloudiness; also, if the product is the biomass itself, as in starter cultures, the solid-removal step is essential. Isolation of the product stands for the concentration, which may be done by distillation in fermented beverages or membrane separations in some dairy products.