A factory-scale application of secondary adjunct cultures selected from lactic acid bacteria during Puzzone di Moena cheese ripening

The lactic acid populations of 2 seasonal Puzzone di Moena cheeses made from winter and summer raw cow's milk were characterized at different ripening times. Lactic acid bacteria (LAB) were isolated on selective media and subjected to genetic typing and identification. The species most frequently found during ripening were Lactobacillus paracasei ssp. paracasei, Lactobacillus plantarum, and Pediococcus pentosaceus. The different strains recognized by random amplification of polymorphic DNA-PCR were characterized for their acidifying and proteolytic activities to select nonstarter LAB to be used as secondary adjunct cultures (SAC). For each of the 3 above species, a strain showing weak acidification and high proteolytic capacity was selected. The 3 strains (Lb. paracasei ssp. paracasei P397, Lb. plantarum P399, and P. pentosaceus P41) constituted a mixed SAC used at 2 levels of concentration (10³ and 10⁴ cfu/mL) in experimental cheese making at dairy factory-scale. The analysis of volatile organic compounds as well as sensory analyses showed that the preferred level of SAC inoculation was 10³ cfu/mL.