No abstract

No abstract

No abstract

Cork harvesting and stopper production represent a major forest industry in Sardinia (Italy). The target of the present investigation was to evaluate the ''classification tree'' as a tool to discover possible relationships between microsite characteristics and cork quality. Seven main cork oak (Quercus suber) producing areas have been identified in Sardinia, for a total of more than 122,000 ha. Sixty-three sample trees, distributed among different geographical locations and microsite conditions, were selected. A soil profile near each sample tree was described, soil samples were collected and analysed. After debarking, cork quality of each sample tree was graded by an independent panel of experts. Microsites where trees had more than 50% of the extracted cork graded in the best quality class, according to the official quality standard in Italy, were labelled as prime microsites, the others as nonprime microsites. Relationships between a binary dummy variable (0 for nonprime microsites, 1 for prime microsites) and site factors were investigated using classification tree analysis to select the relevant variables and to define the classification scheme. Prime quality microsites for cork production proved to be characterised by elevation, soil phosphorus content and sandiness. Results have been compared with those of the more conventional parametric approach by logistic regression. The work demonstrates the advantages of the classification tree method. The model may be appropriate for classifications at landscape and stand mapping levels, where it is possible to sample a number of microsites and to evaluate distributional characteristics of model output, while its precision is only indicative when estimating the prime quality of single microsites.

The chemical composition affects the sensory properties and quality of Extra Virgin Olive Oil (EVOO). In addition, its knowledge can supply valuable information about the cultivar and its geographical origin. The goal of this study is to obtain a protocol in order to be able to recognize the composition of various Sardinian oils and to consequently correlate them with their production areas. High‐resolution 1H NMR spectroscopy was used to analyze 100 (82 training + 18 test sets) samples of EVOO from the Bosana cultivar, collected from different growing areas in Sardinia (Italy). Growth areas were classified on the basis of FAO‐UNEP aridity index. NMR data were processed with multivariate statistical analysis. NMR profiling presents a connection between environmental factors of Sardinian cultivation areas and the chemical composition of EVOO. An NMR‐based metabolomic approach that uses six “one‐to‐one” OPLS‐DA models allowed us to discriminate the different influence of evapotranspiration, solar exposure, and altitude on the chemical composition of Bosana EVOO. Practical Applications: Detailed knowledge of NMR spectra pattern variations could have a potential impact on olive oil market. The application of the 1H NMR metabolomic, based on chemometric models, can be a useful tool in order to certificate the geographical origin of EVOO. An NMR‐based metabolomic approach,using “one‐to‐one” OPLS‐DA models, allows to identify biomarkers of different production zones in “Bosana” Sardinian EVOO.

Bacterial diversity of 15 extra virgin olive oils, obtained from different Italian varieties, including Frantoio, Coratina, Bosana, and Semidana, was analyzed in this study. All bacterial isolates were genotyped using RAPD and REP-PCR method and grouped by means of cluster analyses. Sequencing of 16S rDNA of 51 isolates, representative of 36 clusters, led to the identification of Bacillus spp., Brevibacillus spp., Micrococcus spp., Staphylococcus spp., Pantoea spp., Kocuria spp., Lysinbacillus spp., and Lactobacillus spp., most of which reported for first time in olive oils. Phenotypic characterization of the 51 isolates, some of which ascribed to potentially probiotic species, indicate that two of them have beta-glucosidase activity while 37% present lipolytic activity. Preliminary evaluation of probiotic potential indicates that 31% of the isolates show biofilm formation ability, 29% acidic pH resistance, and 25% bile salt resistance. Finally, 29% of the isolates were sensitive to antibiotics while the remaining 71%, that include bacterial species well-recognized for their ability to disseminate resistance genes in the environment, showed a variable pattern of antibiotic resistance. The results obtained underline that microbial diversity of extra virgin olive oils represents an unexpected sink of microbial diversity and poses safety issues on the possible biotechnological exploitation of this microbial biodiversity.

Protected Designation of Origin (PDO) labels are important tools to promote high quality virgin olive oils (VOO). To better valorize and differentiate among others these labeled products it is necessary to have a deep knowledge of characteristics and features of the monovarietal VOOs that are used. In Sardinia, only one PDO, named “Sardegna,” is registered. Drupes from several local varieties are mixed up before pressing. Four are the principal autochthonous Sardinian varieties: Bosana, Tonda di Cagliari, Tonda di Villacidro, Semidana, and respective synonyms. This study examines the chemical and nutritional characteristics of monovarietal VOOs of some of the varieties that comprise the label with the aim to establish the identity and natural variability of the registered product. Results are compared with those from some minor Sardinian and Italian cultivars, all grown under the same agronomic and environmental conditions. Data for the fatty acid and sterol composition together with those for some specific nutrient and non nutrient antioxidants are used to investigate whether the mixing up of many different varieties is favorable in the production of this particular product. PDO varieties achieve broadly minimum quality levels requested by the label regulation and express some specific characteristics in accordance to genetic similarities. Practical Applications: Knowledge of chemical composition of VOOs from minor local varieties is of great interest for the promotion of products typical of a specific territory and to improve quality and competitiveness of protected denominations labels. The characterization of VOO admitted to a PDO can help producers to optimize blends obtaining specific nutritional and sensorial features. Moreover, findings are important to highlight some distinctive features among genetic groups that might be useful for further supporting the integrity of the registered product in the near future. PDO “Sardegna” is the only quality label for EVOO registered in Sardinia (Italy). It must be characterized at least for the 80% by the four principal autochthonous Sardinian varieties: Bosana, Semidana, Tonda di Cagliari, Tonda di Villacidro, and their other names. VOO composition of 14 of the Sardinian varieties that can be used in the production of the registered product, with the aim to establish its identity and natural variability of this label are analyzed.

Wildland fires represent a major threat to Quercus suber L. ecosystems, which provide relevant socioeconomic and ecological services in the Mediterranean Basin. In this work, we analyzed recent wildland fire dynamics in cork oak woodlands along the fire-prone areas of Sardinia (Italy), Corsica (France) and Catalonia (Spain). We first characterized geographic extent and main characteristics of cork oak woodlands in these regions and analyzed how environmental (climate and elevation) and socioeconomic factors (population and land uses) vary in the areas covered by Quercus suber L. We then evaluated how wildfires affected cork oak stands and, by logistic regression analysis, to what extent wildfires in cork oak areas were related to the above set of environmental and anthropic explanatory variables. Results revealed specific variations across study areas in cork oak characteristics as well as in environmental and social factors. We highlighted the spatial and temporal patterns of wildfires on cork oak woodlands, in terms of extent, seasonality, frequency and main driving factors. In the period 2003-2015, the percentage of cork oak woodlands burned ranged from 3.42% in Corsica to 11.30% in Sardinia. A few large and severe wildfires accounted for most of the area burned in cork oak woodlands. The most significant predictive variable that explained the spatial variation in wildland fire ignitions inside or nearby cork oaks was summer precipitation, while the weight of other factors varied depending on the region. This study provides evidence on recent fire dynamics in cork oak woodlands and gives valuable information and insights for the implementation of forest management and planning strategies in the Mediterranean area. Keywords Cork oaks • Mediterranean Basin • Fire regime • Fire management • Land management Communicated by Lluís Coll.