Freeze drying for the production of dried starter cultures

Modified according to Pnpp and Hartmann (1991) Oetjen and Haseley (2004). 

Modified according to Roos (1995), copyright 1995, with permission from Elsevier. 

More recently, it was even hypothesized that a structural collapse would not lead to a deleterious product quality as— unUke for pharmaceutical applications—optical appearance of the product is not a quality criterion for starter cultures (see Section 11.1). First investigations even show that the storage stability of collapsed products may be higher, probably due to the lower porosity and also drying time may be shorter (Schersch et al., 2010, 2012). This aspect including all the consequences on product quality has to be investigated further. 

In general, freeze drying leads to high survival rates, high metabolic activity, and good rehydratability and therefore to a high product quality (Kivihaiju, Leisola, Eerikainen, 2005 Oetjen Haseley, 2004). However, investment costs and energy 

Drying technology Rel. investment costs at same throughput (%) Spec, energy costs (kWh/kg water) 

---

Freeze drying for the production of dried starter cultures... 

---