No abstract

The main hypothesis of this work was that Sicilian forestry resources are suitable for the production of equipment to be used in cheese making and indigenous milk lactic acid bacteria (LAB) are able to develop stable biofilms providing starter and nonstarter cultures necessary for curd fermentation and cheese ripening, respectively. Hence, the present work was carried out with deproteinized whey to evaluate LAB biofilm formation on different woods derived from tree species grown in Sicily. Microbiological and scanning electron microscopy analyses showed minimal differences in microbial levels and compositions for the neoformed biofilms. The specific investigation of spp.,, , coagulase-positive staphylococci (CPS), and sulfite-reducing anaerobes did not generate any colony for all vats before and after bacterial adhesion. LAB populations dominated all vat surfaces. The highest levels (7.63 log CFU/cm) were registered for thermophilic cocci. Different colonies were characterized physiologically, biochemically, and genetically (at strain and species levels). Six species within the genera ,, , and were identified. The species most frequently present were and LAB found on the surfaces of the wooden vats in this study showed interesting characteristics important for dairy manufacture. To thoroughly investigate the safety of the wooden vat, a test of artificial contamination on new Calabrian chestnut (control wood) vats was carried out. The results showed that LAB represent efficient barriers to the adhesion of the main dairy pathogens, probably due to their acidity and bacteriocin generation. This study highlights the importance of using wooden vats for traditional cheese production and provides evidence for the valorization of the Sicilian forest wood resources via the production of dairy equipment.

bThree Lactococcus lactis subsp. cremoris strains were used to develop ad hoc biofilms on the surfaces of virgin wooden vats used for cheese production. Two vats (TZ) were tested under controlled conditions (pilot plant), and two vats (TA) were tested under uncontrolled conditions (industrial plant). In each plant, one vat (TA1 and TZ1) was used for the control, traditional production of PDO Vastedda della Valle del Belìce (Vastedda) cheese, and one (TA2 and TZ2) was used for experimental production performed after lactococcal biofilm activation and the daily addition of a natural whey starter culture (NWSC). Microbiological and scanning electron microscopy analyses showed differences in terms of microbial levels and composition of the neoformed biofilms. The levels of the microbial groups investigated during cheese production showed significant differences between the control trials and between the control and experimental trials, but the differences were not particularly marked between the TA2 and TZ2 productions, which showed the largest numbers of mesophilic lactic acid bacterium (LAB) cocci. LAB populations were characterized phenotypically and genotypically, and 44 dominant strains belonging to 10 species were identified. Direct comparison of the polymorphic profiles of the LAB collected during cheese making showed that the addition of the NWSC reduced their biodiversity. Sensory evaluation showed that the microbial activation of the wooden vats with the multistrain Lactococcus culture generated cheeses with sensory attributes comparable to those of commercial cheese. Thus, neoformed biofilms enable a reduction of microbial variability and stabilize the sensorial attributes of Vastedda cheese.

No abstract

The interpretation of the several variables that contribute to defining milk quality is difficult due to the high degree of 

correlation among them. In this case, one of the best methods of statistical processing is factor analysis, which belongs 

to the multivariate groups; for our study this particular statistical approach was employed. 

A total of 1485 individual goat milk samples from 117 Girgentana goats, were collected fortnightly from January to July, 

and analysed for physical and chemical composition, and clotting properties. Milk pH and tritable acidity were within the 

normal range for fresh goat milk. Morning milk yield resulted 704 ± 323 g with 3.93 ± 1.23% and 3.48±0.38% for fat 

and protein percentages, respectively. The milk urea content was 43.70 ± 8.28 mg/dl. The clotting ability of Girgentana 

milk was quite good, with a renneting time equal to 16.96 ± 3.08 minutes, a rate of curd formation of 2.01 ± 1.63 min- 

utes and a curd firmness of 25.08 ± 7.67 millimetres. 

Factor analysis was performed by applying axis orthogonal rotation (rotation type VARIMAX); the analysis grouped the 

milk components into three latent or common factors. The first, which explained 51.2% of the total covariance, was 

defined as “slow milks”, because it was linked to r and pH. The second latent factor, which explained 36.2% of the total 

covariance, was defined as “milk yield”, because it is positively correlated to the morning milk yield and to the urea con-show abstract