No abstract

This investigation is based on the gas chromatographic analysis of the volatile fraction of Sicilian goat cheese. Volatile analytes were extracted through static headspace solid phase microextraction (HS-SPME) with the support of a modern automatic instrument designed specifically for this sampling procedure. Component identification was carried out by GC-MS and the employment of internal standard compounds. In the preliminary part of this research, different fibres and capillary columns were tested and their effectiveness compared in order to optimize solute extraction and separation. Furthermore, the HS-SPME sampling conditions were properly tuned in order to maximize solute absorption. Evaluations were also made on the SPME instrumentation and its capability to supply reproducible data. The optimized method was applied to the investigation of six goat cheese samples and their aroma profiles were evaluated, leading to the identification of 44 components.

The use of agro-industrial by-products for ruminant feed represents both an economical and environmental convenient way for reducing waste discharge and waste management costs for food industries. Large amounts of waste from citrus processing industries are available in Sicily, Italy. In the present study, the effect of dried citrus pulp as sheep dietary supplementation was evaluated on physico-chemical, microbiological and fatty acid composition of resulting milk and cheese. Pelleted feed integrated with molasses and blond orange pulp, replacing cane molasses, beet pulp and part of the maize and sunflower in ration, were administrated to ewes as an experimental treatment The experiment involved sixty Comisana breed sheep divided into two groups and two feeding trials (experimental and control). Ewe's milk and cheese samples were collected from January to April and analyzed for physico-chemical, microbiological and fatty acid profile composition. Results suggested that both the experimental milk and cheese were different from the controls. In particular, an increase of experimental milk yield and fat content were registered whilst the cheese samples exhibited a significant decrease of pH values and an increase in fat and protein contents. In addition, an increase of conjugated linoleic acids as well as of the oxidative stability were observed indicating the beneficial effect of dietary supplementation. Furthermore, among the main microbial groups, the experimental and control samples, no differences were detected. However, with the exception of streptococci, which was found higher in experimental cheeses, and staphylococci, which was significantly reduced by experimental feed. Moreover, the application of culture-independent methods highlighted the dominance of Lactobacillus rhamnosus/casei group in the experimental cheese, suggesting a driving role of the dietary supplementation in the cheese microbiota composition. The present study demonstrated that the inclusion of citrus by-products in the diet of small dairy ruminants is a promising feeding, which could positively affect milk composition and cheese manufacture.

No abstract

Nero Siciliano (NS; Sicilian Black) is a local pig breed reared on the island of Sicily mainly under extensive management.
The breed is well adapted to marginal conditions and is appreciated for its reproductive performance, disease resistance
and production of tasty meat. For a genetic characterization of this breed we analyzed the allele frequencies of single
nucleotide polymorphisms (SNPs) in eight major or candidate genes (ryanodine receptor 1, RYR1; Na+, K+ ATPase subunit
α 2, ATP1A2; myosin heavy chain 2B, MYH4; sarcolipin, SLN; cathepsin B, CTSB; cystatin B, CSTB; estrogen receptor,
ESR; melanocortin receptor 1, MC1R) for performance and phenotypic traits. The animals that were sampled and
analyzed represent about 6-8% of the total NS pig population. PCR-RFLP or PCR-SSCP techniques were used to type the
DNA markers in the selected loci. Exact test of Hardy-Weinberg equilibrium was computed for each locus, Fis statistics
and heterozygosity were calculated for each locus and over all loci. Allele frequencies obtained in NS breed were compared
to the frequencies already available in literature for the Large White, Landrace, Duroc, Belgian Landrace, Piétrain,
Hampshire and Meishan breeds. For the ESR locus, as no information on the distribution of the two alleles were available,
we typed a sample of unrelated pigs from the considered breeds.
Even if only eight loci were studied in NS breed, important elements were obtained from the data. The 1843T (n) allele
at the RYR1 locus is present in NS breed, thus the molecular test to identify the carriers of this allele should be adopted
to avoid its spreading in the population. Moreover, other studies are needed to clarify the allelic structure of the MC1R
gene, which affects coat color, in order to evaluate if this gene could be used in genetic tests for the traceability of the
meat products of this breed. Finally, the present work represents an attempt to evaluate data on mutations within major
and candidate genes with the final aim to provide information that could be useful for the conservation and valorization
of local farm animal genetic resources