Results are presented that were obtained on the geographic traceability of the white truffle Tuber magnatum Pico. Solid-phase microextraction coupled to gas chromatography/mass spectrometry (SPME-GC/MS) was employed to characterize the volatile profile of T. magnatum white truffle produced in seven geographical areas of Italy. The main components of the volatile fraction were identified using SPME-GC/MS. Significant differences in the proportion of volatile constituents from truffles of different geographical areas were detected. The results suggest that, besides genetic factors, environmental conditions influence the formation of volatile organic compounds. The mass spectra of the volatile fraction of the samples were used as fingerprints to characterize the geographical origin. Next, stepwise factorial discriminant analysis afforded a limited number of characteristic fragment ions that allowed a geographical classification of the truffles studied.

Mycorrhizal ascomycetous fungi are obligate ectosymbionts that colonize the roots of gymnosperms and angiosperms. In this paper we describe a straightforward approach in which a combination of morphological and molecular methods was used to survey the presence of potentially endo-and epiphytic bacteria associated with the ascomycetous ectomycorrhizal fungus Tuber borchii Vittad. Universal eubacterial primers specific for the 5 and 3 ends of the 16S rRNA gene (16S rDNA) were used for PCR amplification, direct sequencing, and phylogenetic analyses. The 16S rDNA was amplified directly from four pure cultures of T. borchii Vittad. mycelium. A nearly full-length sequence of the gene coding for the prokaryotic small-subunit rRNA was obtained from each T. borchii mycelium studied. The 16S rDNA sequences were almost identical (98 to 99% similarity), and phylogenetic analysis placed them in a single unique rRNA branch belonging to the CytophagaFlexibacter-Bacteroides (CFB) phylogroup which had not been described previously. In situ detection of the CFB bacterium in the hyphal tissue of the fungus T. borchii was carried out by using 16S rRNA-targeted oligonucleotide probes for the eubacterial domain and the Cytophaga-Flexibacter phylum, as well as a probe specifically designed for the detection of this mycelium-associated bacterium. Fluorescent in situ hybridization showed that all three of the probes used bound to the mycelium tissue. This study provides the first direct visual evidence of a not-yet-cultured CFB bacterium associated with a mycorrhizal fungus of the genus Tuber.The mycorrhizal ascomycetous fungi belonging to the genus Tuber, commonly called truffles, are obligate ectosymbionts that colonize the roots of gymnosperms and angiosperms (23,39,45). Ectomycorrhizal fungi are present in natural and agricultural ecosystems, provide health benefits to plants, and contribute to soil nutrient cycling. The symbiotic development of mycorrhizal fungi on plant roots has been reported to be influenced by bacteria present in the mycorrhizosphere (10,16,35,47). Although various bacterial populations, such as fluorescent Pseudomonas strains and the spore-forming bacteria Micrococcus spp., Moraxella spp., Corynebacterium spp., and Staphylococcus spp., have been isolated from truffles (3,14,20), no molecular evidence has been found concerning the relationship between these organisms and their specific locations in the Tuber host tissue. There is also no information concerning the endo-and epiphytic bacteria which throughout life or during part of the life cycle may invade the tissues of the living fungus and cause unapparent and asymptomatic infections throughout the fungal life cycle and thus during production of the mycelium, contact with the host root, and development of the ectomycorrhizae and fruit bodies.Since at least 95% of all soil bacteria have not been cultured (2, 25, 36), bacteria isolated from truffles could represent only a fraction of the entire natural bacterial community associated with truffles. For this rea...

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BackgroundApples are an important source of polyphenols in the human diet and the consumption of this fruit has been linked to the prevention of degenerative diseases.ResultsCatechins, procyanidins, hydroxycinnamic acids, flavonol glycosides, dihydrochalcone glycosides and one anthocyanin: cyanidin-3-O-galactoside, were identified both in the peel and pulp. Procyanidins, catechins and flavonols represent the main constituents of peel. Concerning the antioxidant activity, in the reduction of the stable DPPH radical and in the inhibition of lipid peroxidation, the ethanolic extracts of red peel and red pulp showed a good similar activity comparable to ascorbic acid in the DPPH test and about ten times more active than BHT in the lipoxygenase test, and were much more active than aqueous extracts. The ORAC value of red pulp aqueous extract resulted comparable to that of red berries: vaccinium, rubus and ribes, foods appreciated for their health value.ConclusionThis apple contains an appreciable amount of polyphenols also in the flesh; this variety with red flesh can also be useful for researchers engaged in apples varietal innovation in addition to being used as food apple.

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