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Marina di Ragusa, Italy

Licitra G.,University of Catania | Carpino S.,CoRFiLaC
Microbiology Spectrum

Approximately 39 Italian cheeses carry protected designation of origin (PDO) status. These cheeses differ in their manufacturing technology and the microbial flora which comprise the finished products. The evolution of lactic microflora in cheeses with PDO status is of particular interest because the biochemical activities of these organisms participate in cheesemaking and may play an acknowledged role in the development of organoleptic characteristics during ripening. Nonstarter lactic acid bacteria (NSLAB) constitute complex microbial associations that are characterized by the occurrence of various species and many biotypes as a result of a number of selective conditions persisting during the manufacturing process and different ecological niches. The evolution of different species during ripening of Fiore Sardo showed that, when present, Lactobacillus paracasei persists and dominates the microflora of the cheese in the last period of ripening, suggesting that this species, more resistant to the constraints of the mature cheese, could be involved in proteolysis and in other enzymatic processes occurring during cheese ripening. In contrast, the stretching step typical of pasta filata cheese, such as Ragusano, induced a simplification of the raw milk profiles, allowing the persistence only of some predominant species, such as Streptococcus thermophilus, Lactobacillus delbrueckii subsp. lactis, Lactococcus lactis, and Streptococcus macedonicus, after the stretching step. Lactobacillus plantarum and L. paracasei were isolated from ripened Castelmagno PDO cheese samples with the highest frequencies. These species, generally absent in the milk, occur in dairy ecosystems and dominate the bacterial flora of many ripened semihard cheeses. In PDO long-ripened Italian cheese such as Parmigiano Reggiano, the NSLAB population is mainly formed by L. paracasei, Lactobacillus rhamnosus, and Pediococcus acidilactici. Lactobacillus helveticus, L. delbrueckii subsp. lactis, and L. delbrueckii subsp. © 2014 American Society for Microbiology. Source

Licitra G.,CoRFiLaC | Licitra G.,University of Catania
Dairy Science and Technology

Traditional cheeses are characterized by strong links to their territory of origin and are testimonial of the history and the culture of the community that produces them. Every traditional cheese originates from a complex system which results in unique organoleptic characteristics. The development of these unique characteristics is linked to several biodiverse factors: the environment, the climate, the natural pasture, the breed of the animals, the use of raw milk and its natural microflora, the cheesemaking technology with the unique role of human beings rather than automated technology, historical tools as well as the natural aging conditions. In many countries traditional products are almost banned, even in Europe, despite Article 8 of the Directive 92/46 of the EEC, which grants derogations for the manufacture of cheese with a period of aging or ripening of at least 60 days. Issues relating to "food safety" are frequently given as a "false" argument to explain the banning of traditional products. Reviews of food safety outbreaks have demonstrated that raw-milk cheeses do not pose any greater risk than industrial cheeses made from pasteurized milk. Improper pasteurization, post-processing contamination, storage and cross-contamination are the main contributing factors that are responsible for these outbreaks. Traditional cheeses cannot be identified simply by the use of "raw milk"; there are a "multiplicity of practices" that have the potential to make safe products. The challenge for the research community is to demonstrate the role and the importance of those practices to deliver the maximum safety benefits to the consumer. Eliminating the production of traditional cheeses would make it much easier to market industrial products. However, consumers would lose the opportunity to compare the natural aroma, the health benefits, the cultural background as well as the biodiversity of traditional products. © INRA, EDP Sciences, 2010. Source

Settanni L.,University of Palermo | Gaglio R.,University of Palermo | Guarcello R.,University of Palermo | Francesca N.,University of Palermo | And 3 more authors.
International Dairy Journal

To evaluate the efficacy of lactic acid bacteria (LAB) to improve the hygienic safety of a traditional raw milk cheese, the raw ewes' milk protected denomination of origin (PDO) Pecorino Siciliano cheese was used as a model system. Different Pecorino Siciliano curds and cheeses were used as sources of autochthonous LAB subsequently used as starter and non-starter LAB. These were screened for their acidification capacity and autolysis. Starter LAB showing the best performance were genotypically differentiated and identified: two strains of Lactococcus lactis subsp. lactis were selected. From the non-starter LAB, Enterococcus faecalis, Lactococcus garvi e ae and Streptococcus macedonicus strains were selected. The five cultures were used in individual or dual inocula to produce experimental cheeses in a dairy factory for which production was characterised by high numbers of undesirable bacteria. At 5-month of ripening, the experimental cheeses produced with LAB were characterised by undetectable levels of enterobacteria and pseudomonads and the typical sensory attributes. © 2013 Elsevier Ltd. Source

Marino V.M.,CoRFiLaC | Schadt I.,CoRFiLaC | La Terra S.,CoRFiLaC | Manenti M.,CoRFiLaC | And 4 more authors.
Dairy Science and Technology

It has been shown that several factors such as feed source and breed might influence milk fat-soluble antioxidants (AOs). This study investigated pasture feeding effects and dairy cattle breed on the content of α-tocopherol and β-carotene in cows' milk by monitoring two grazing seasons (spring and fall) as well as a summer nopasture season. Four dairy farms located in Sicily were selected: two with both Holstein and Brown Swiss cows and two with only a Modicana (M) local breed cows. Bulk milk samples of each breed per farm were collected. Milk α-tocopherol and β-carotene were highest during spring (16.2 and 9.7 μg.g-1 of fat, respectively), lowest during fall (11.2 and 0.8 μg.g-1 of fat, respectively) and intermediate during summer (13.3 and 2.5 μg.g-1 of fat, respectively). These results indicate that grazing pasture season has an important impact on milk fat-soluble antioxidant content. In particular, higher milk AO levels in spring compared to fall might be attributed to several factors such as differences in the quality and composition of pasture, differences in pasture intake and even the climate. Breed effect on milk AO contents was not so pronounced. Milk β-carotene levels did not differ significantly among breeds. Saturation of milk β-carotene may explain similar vitamin levels among breeds in spring despite different pasture intakes. It was interesting that significant levels of α-tocopherol were detected in milk from M cows during summer. The latter effect could be masked by the considerably higher pasture intake of M in spring compared to the other two breeds. © INRA and Springer-Verlag, France 2012. Source

Schadt I.,CoRFiLaC | Ferguson J.D.,University of Pennsylvania | Azzaro G.,CoRFiLaC | Petriglieri R.,CoRFiLaC | And 4 more authors.
Journal of Dairy Science

Not only feed but also respective bolus particle size could alter diet efficiency and cow performance. The objective of this project was to characterize particle size of selected feeds and respective swallowed boli. Feed samples included 6 different particle length rye grass hay samples, 1 grass silage, 1 corn silage, and 1 total mixed ration (TMR). Rye grass hay samples consisted of long hay and chopped hay particles retained on the 19- (19_PSPS hay), 8- (8_PSPS hay), and 1.18-mm (1.18_PSPS hay) Penn State Particle Separator (PSPS) screens and those collected on the pan (PSPS_pan hay). A sixth hay treatment was rye grass forage cut at 50-mm lengths and dried to hay (50-mm hay). Treatments were offered to 4 nonlactating and 4 lactating cows following rumen evacuation. Swallowed boli were collected and the number of chews per gram of ingested feed dry matter was determined. Feed and bolus particles of lengths ≥5. mm were collected on a 1.6-mm screen using a horizontal wet sieving technique. This cut point was chosen, as the literature suggests that most fecal particles are shorter than 5. mm. Dry matter proportions on this screen (PROP_1.6) were determined and particle lengths of retained particles were measured by image analysis. Mean particle lengths (ML) were calculated considering particles ≥5. mm in length. Boli of long hay, of 19_PSPS hay, of 8_PSPS hay, and of 50-mm hay had similar ML of 10 to 11. mm. Bolus PROP_1.6 were also similar between these treatments, ranging from 0.54 to 0.69. Bolus particle lengths and distributions of these treatments were not related to respective hay particles. Bolus of 1.18_PSPS hay had PROP_1.6 of 0.51 and a smaller ML of 8. mm. The PSPS_pan hay had PROP_1.6 of only 0.33, but was still chewed intensely. Apparently, little particle size reduction occurred when cows ate the TMR or the silages. Feed and respective bolus PROP_1.6 were as follows: 0.66 and 0.59 in grass silage, 0.52 and 0.55 in corn silage, and 0.44 and 0.38 in the TMR. Feed and respective bolus ML were as follows: 13.8 and 11.6. mm in grass silage, 12.0 and 11.2. mm in corn silage, and 13.1 and 12.5. mm in the TMR. Rye grass hay particles retained on PSPS screens ≥8. mm, with ML of at least 25. mm were longer compared with TMR particles, but respective bolus particles were shorter. Bolus particle size is not associated with the size of large feed particles chewed to a constant size that is appropriate for deglutition. This size may be related to feed chemical composition. © 2012 American Dairy Science Association. Source

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