Penicillium salamii strain ITEM 15302: A new promising fungal starter for salami production.

Traditional sausages are often considered of superior quality to sausages inoculated with commercial starter cultures and this is partially due to the action of the typical house microflora. Penicillium nalgiovense is the species commonly used as starter culture for dry-cured meat production. Recently a new species, Penicillium salamii, was described as typical colonizer during salami seasoning. In order to understand its contribution to the seasoning process, two different experiments on curing of fresh pork sausages were conducted using P. salamii ITEM 15302 in comparison with P. nalgiovense ITEM 15292 at small and industrial scale, and the dry-cured sausages were subjected to sensory analyses. Additionally, proteolytic and lipolytic in vitro assays were performed on both strains. P. salamii ITEM 15302 proved to be a fast growing mould on dry-cured sausage casings, well adapted to the seasoning process, with high lipolytic and proteolytic enzymatic activity that confers typical sensory characteristics to meat products. Therefore, P. salamii ITEM 15302 was shown to be a good candidate as new starter for meat industry.

Ready-to-cook fresh meal: study for shelf life prolongation.

In this study, to preserve the quality of a fresh meal based on a mix of meatballs and semi-dry vegetables, two main strategies were combined: during process the meat before grinding was dipped in sodium lactate and during packaging different modified atmospheres were applied (30:70 CO2:N2, 70:30 CO2:O2, 5:5:90 O2:CO2:N2). The parameters monitored during the storage at 4 °C were the headspace gas composition, the microbial loads (Total viable count, Pseudomonas spp., lactic acid bacteria and Enterobacteriaceae), the pH and the sensory quality. Overall, the results indicate that the sodium lactate acted in synergy with MAP improving above all the microbial quality. A significant shelf life prolongation was obtained with 30 % CO2 in the package, corresponding to a 168 % shelf life increase compared to the control sample in air.

Bio-based nanocomposite coating to preserve quality of Fior di latte cheese.

The aim of this study was to evaluate the effects of a bio-based coating containing silver-montmorillonite nanoparticles combined with modified-atmosphere packaging (MAP) on microbial and sensory quality decay of Fior di latte cheese. Different concentrations of silver nanoparticles (0.25, 0.50, and 1.00 mg/mL) were dispersed in a sodium alginic acid solution (8% wt/vol) before coating the cheese. Modified-atmosphere packaging was made up of 30% CO(2), 5% O(2), and 65% N(2). The combination of silver-based nanocomposite coating and MAP enhanced Fior di latte cheese shelf life. In particular, product stored in the traditional packaging showed a shelf life of about 3 d, whereas coated cheese stored under MAP reached a shelf life of more than 5 d, regardless of the concentration of silver nanoparticles. The synergistic effects between antimicrobial nanoparticles and initial headspace conditions in the package could allow diffusion of dairy products beyond the local area.

Fat microstructure of yogurt as assessed by x-ray microtomography.

In this work, the x-ray microtomography (µCT) technique was used for the analysis of fat microstructure and quantification of fat in 7 types of yogurts. The dynamic mechanical properties of the yogurt samples also were studied using a controlled-strain rotational rheometer and correlated to the fat microstructure. Five types of commercially produced and 2 homemade yogurts, chosen to exhibit variability in terms of visible structure of fat, were used for this experiment. Appropriate quantitative 3-dimensional parameters describing the fat structure were calculated. With regard to the microstructural and rheological relationship, results from the correlation carried out show that a correlation exists among some microstructural and rheological parameters of the yogurt samples. The results from this study also show that µCT is a suitable technique for the microstructural analysis of fat as it not only quantifies the fat deposits present, but also determines the deposits' spatial distribution.

Active coating and modified-atmosphere packaging to extend the shelf life of Fior di Latte cheese.

In this work the combination of active coating and modified-atmosphere packaging (MAP) was used to prolong the shelf life of Fior di Latte cheese. The active coating was based on sodium alginate (8% wt/vol) containing lysozyme (0.25 mg/mL) and EDTA, disodium salt (Na(2)-EDTA, 50 mM). The MAP was made up of 30% CO(2), 5% O(2), and 65% N(2). The speed of quality loss for the Fior di Latte cheese, stored at 10 degrees C, was assessed by monitoring pH and weight loss, as well as microbiological and sensorial changes. Results showed that the combination of active coating and MAP improved Fior di Latte cheese preservation, increasing the shelf life to more than 3 d. In addition, the substitution of brine with coating could allow us to gain a double advantage: both preserving the product quality and reducing the cost of its distribution, due to the lower weight of the package.

Shelf life of Stracciatella cheese under modified-atmosphere packaging.

The aim of this work is to evaluate the shelf life of Stracciatella cheese packaged in a protective atmosphere, using 4 different CO(2):N(2):O(2) gas mixtures [50:50:0 (M1), 95:5:0 (M2), 75:25:0 (M3), and 30:65:5 (M4) vol/vol] and stored at 8 degrees C. Cheese in traditional tubs and under vacuum were used as the controls. Results showed that the modified-atmosphere packaging, in particular M1 and M2, delayed microbial growth of spoilage bacteria, without affecting the dairy microflora, and prolonged the sensorial acceptability limit.

Effects of natural compounds on microbial safety and sensory quality of Fior di Latte cheese, a typical Italian cheese.

This work presents a preliminary study to assess the efficiency of plant essential oils as natural food preservatives in Fior di Latte cheese. Selected compounds were directly dissolved into Fior di Latte brine. Packaged Fior di Latte samples were stored at 10 degrees C for about 6 d. The cell loads of spoilage and useful microorganisms were monitored to calculate the microbial acceptability limit. Results show that some tested compounds were not acceptable by the panel from a sensorial point of view. Most compounds did not affect the microbial acceptability limit value to a great extent, and only a few such as lemon, sage, and thyme markedly prolonged the microbial acceptability limit of the investigated fresh cheese. Moreover, the above active agents exerted an inhibitory effect on the microorganisms responsible for spoilage without affecting the dairy microflora.

Effect of chitosan on the rheological and sensorial characteristics of Apulia spreadable cheese.

The effect of chitosan on the rheological and sensorial properties of Apulia spreadable cheese during storage time was evaluated. The investigated spreadable cheese samples were stored at 4 degrees C. Storage modulus (G'), loss modulus (G''), tandelta, and the overall sensorial quality of the spreadable cheese were monitored for 24 d. Moreover, moisture content, pH, color, and lactic acid bacteria during storage time were evaluated. Results indicate that statistically significant differences in G', G'', and tandelta values and in the sensorial scores exist between the control sample and the spreadable cheese samples with chitosan. In particular, chitosan improved the rheological and sensorial properties of the spreadable cheese, particularly its softness. Moreover, its addition influenced the physicochemical properties of the investigated spreadable cheese during storage time, without affecting the dairy microflora.