Influence of processing and ripening parameters on starter, non-starter and propionic acid bacteria and on the ripening characteristics of semi-hard cheeses

The influence of varying process (curd washing, drain pH, dry or brine salting) and ripening (at 9 or 12°C without a hot room step) parameters on manufacture and on biochemical changes during ripening of semi-hard cheeses with propionic acid bacteria (PAB) was studied. Levels of secondary proteolysis were significantly higher and viable thermophilic culture counts decreased at a faster rate in the dry-salted cheeses compared with the brine-salted cheeses. Increased ripening time and temperature resulted in increased PAB counts, levels of acetate, propionate, primary and secondary proteolysis. Increased cheese pH was significantly correlated with increased PAB counts during ripening. The washed-curd, dry-salted cheeses at 182 d of ripening at 12°C resulted in counts of PAB and levels of acetate and propionate similar to those of Swiss-type control cheeses ripened with a hot room temperature. The approach described may be used to manufacture Swiss-type cheese using technologies associated with Cheddar-type manufacture.