Accelerated ripening of Caciocavallo Pugliese cheese with attenuated adjuncts of selected nonstarter lactobacilli.

The nonstarter lactic acid bacteria Lactobacillus plantarum CC3M8, Lactobacillus paracasei CC3M35, and Lactobacillus casei LC01, previously isolated from aged Caciocavallo Pugliese cheese or used in cheesemaking, were used as adjunct cultures (AC) or attenuated (by sonication treatment) adjunct cultures (AAC) for the manufacture of Caciocavallo Pugliese cheese on an industrial scale. Preliminary studies on the kinetics of growth and acidification and activities of several enzymes of AAC were characterized in vitro. As shown by the fluorescence determination of live versus dead or damaged cells and other phenotype features, attenuation resulted in a portion of the cells being damaged and a portion of the cells being capable of growing with time. Compared with the control cheese (without adjunct cultures) and the cheese with AAC, the addition of AC resulted in a lower pH after manufacture, which altered the gross composition of the cheese. As shown by plate count and confirmed by random amplification of polymorphic DNA-PCR, the 3 species of nonstarter lactobacilli persisted during ripening but the number of cultivable cells varied between AC and AAC. Slight differences were found between cheeses regarding primary proteolysis. The major differences between cheeses were the accumulation of free amino acids and the activity levels of several enzymes, which were highest in the Caciocavallo Pugliese cheeses made with the addition of AAC. As shown by triangle test, the sensory properties of the cheese made with AAC at 45 d did not differ from those of the control Caciocavallo Pugliese cheese at 60 d of ripening. In contrast, the cheese made with AC at 45 d differed from both the Caciocavallo Pugliese cheese without adjuncts and the cheese made with AAC. Attenuated adjunct cultures are suitable for accelerating the ripening of Caciocavallo Pugliese cheese without modifying the main features of the traditional cheese.