ABSTRACT
To evaluate the sodium chloride content effect on microbiological, biochemical, physicochemical and sensorial characteristics, Munster cheeses were prepared from pasteurized milk seeded with 3 yeasts (Kluyveromyces marxianus, Debaryomyces hansenii, Geotrichum candidum) and 5 ripening bacteria (Arthrobacter arilaitensis, Brevibacterium aurantiacum, Corynebacterium casei, Hafnia alvei, and Staphylococcus equorum). Experiments were performed under 1.0%, 1.7% and 2.4% NaCl levels in cheese in triplicate. Ripening (d2 - d27) was carried under 12°C and 96% RH. These kinetics were both reproducible and repeatable at 99% confidence level. For each microbial, biochemical and physicochemical parameter, 2 kinetic descriptors (maximal or minimal rate and its occurrence time) were defined. On d2 the physicochemical variables (water activity, dry matter, water content) were strongly dependent on the salting level. From d2 to d27 K. lactis was insensitive to salt while D. hansenii was stimulated. G. candidum growth appeared very sensitive to salt in cheese: at 1.0% NaCl G. candidum exhibited overgrowth, negatively impacting rind appearance, underrind consistency and thickness and off-flavor flaws. Salt concentration of 2.4% induced death of G. candidum. Four bacteria (A. arilaitensis, B. aurantiacum, C. casei, and H. alvei) were moderately sensitive to salt while S. equorum was insensitive to it. Salt level in cheese had a significant effect on carbon substrate consumption rates. Lactate consumption rate in 1.0% salted cheeses was approximately twice higher than under 2.4% NaCl. Data analysis of microorganism, biochemical, and physicochemical kinetics and sensory analysis showed that the best salt level in Munster-type cheeses to achieve an optimum balance between cheese characteristics, sensory qualities and marketability was 1.7% NaCl.