Behavior of Brevibacterium linens and Debaryomyces hansenii as ripening flora in controlled production of smear soft cheese from reconstituted milk: Growth and substrate consumption

Experimental cheeses inoculated with Debaryomyces hansenii and Brevibacteri um linens were ripened for 76 d under aseptic conditions. Triplicate cheese -making trials were similar as a result of efficient control of the atmosph ere. In all trials, D. hansenii grew rapidly during the first 2 d and then slowed, but growth remained exponential until d 10 (generation time around 70 h). Total cell counts were higher than the number of viable cells, and a fter 10 d they remained around 3 x 10(9) yeast/g of DM. This difference res ulted from the nonviability of a fraction of D. hansenii. After d 15, the p H of the rind was close to 7, and B. linens grew exponentially until d 25 ( generation time around 70 h). The growth rate subsequently decreased but re mained exponential (generation time around 21 d). Cell counts of D. hanseni i and B. linens were correlated with the environmental technical conditions . Total D. hansenii counts were also correlated with total B. linens counts . Viable B. linens counts were related to rind lactate, and total counts de pended on rind pH, internal lactate, and D. hansenii viable counts. The int ernal pH of the cheese depended on lactate concentrations, whereas surface pH was related to internal lactose, temperature, and relative humidity. The se results suggest a determining role of the diffusion of the carbon source s in the ripening of smear soft cheese.